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1.1 |
=head1 NAME |
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IO::AIO - Asynchronous Input/Output |
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=head1 SYNOPSIS |
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use IO::AIO; |
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aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
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my $fh = shift |
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or die "/etc/passwd: $!"; |
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... |
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}; |
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aio_unlink "/tmp/file", sub { }; |
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aio_read $fh, 30000, 1024, $buffer, 0, sub { |
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$_[0] > 0 or die "read error: $!"; |
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}; |
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# version 2+ has request and group objects |
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use IO::AIO 2; |
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|
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aioreq_pri 4; # give next request a very high priority |
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my $req = aio_unlink "/tmp/file", sub { }; |
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$req->cancel; # cancel request if still in queue |
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my $grp = aio_group sub { print "all stats done\n" }; |
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add $grp aio_stat "..." for ...; |
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1.1 |
=head1 DESCRIPTION |
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This module implements asynchronous I/O using whatever means your |
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operating system supports. It is implemented as an interface to C<libeio> |
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(L<http://software.schmorp.de/pkg/libeio.html>). |
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Asynchronous means that operations that can normally block your program |
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(e.g. reading from disk) will be done asynchronously: the operation |
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will still block, but you can do something else in the meantime. This |
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is extremely useful for programs that need to stay interactive even |
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when doing heavy I/O (GUI programs, high performance network servers |
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etc.), but can also be used to easily do operations in parallel that are |
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normally done sequentially, e.g. stat'ing many files, which is much faster |
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on a RAID volume or over NFS when you do a number of stat operations |
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concurrently. |
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While most of this works on all types of file descriptors (for |
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example sockets), using these functions on file descriptors that |
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support nonblocking operation (again, sockets, pipes etc.) is |
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very inefficient. Use an event loop for that (such as the L<EV> |
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module): IO::AIO will naturally fit into such an event loop itself. |
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|
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In this version, a number of threads are started that execute your |
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requests and signal their completion. You don't need thread support |
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in perl, and the threads created by this module will not be visible |
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to perl. In the future, this module might make use of the native aio |
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functions available on many operating systems. However, they are often |
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not well-supported or restricted (GNU/Linux doesn't allow them on normal |
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files currently, for example), and they would only support aio_read and |
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aio_write, so the remaining functionality would have to be implemented |
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using threads anyway. |
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Although the module will work in the presence of other (Perl-) threads, |
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it is currently not reentrant in any way, so use appropriate locking |
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yourself, always call C<poll_cb> from within the same thread, or never |
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call C<poll_cb> (or other C<aio_> functions) recursively. |
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|
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=head2 EXAMPLE |
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This is a simple example that uses the EV module and loads |
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F</etc/passwd> asynchronously: |
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use EV; |
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use IO::AIO; |
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# register the IO::AIO callback with EV |
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my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
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|
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# queue the request to open /etc/passwd |
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aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
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my $fh = shift |
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or die "error while opening: $!"; |
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# stat'ing filehandles is generally non-blocking |
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my $size = -s $fh; |
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# queue a request to read the file |
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my $contents; |
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aio_read $fh, 0, $size, $contents, 0, sub { |
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$_[0] == $size |
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or die "short read: $!"; |
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close $fh; |
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# file contents now in $contents |
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print $contents; |
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# exit event loop and program |
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EV::break; |
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}; |
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}; |
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# possibly queue up other requests, or open GUI windows, |
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# check for sockets etc. etc. |
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# process events as long as there are some: |
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EV::run; |
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|
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=head1 REQUEST ANATOMY AND LIFETIME |
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Every C<aio_*> function creates a request. which is a C data structure not |
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directly visible to Perl. |
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If called in non-void context, every request function returns a Perl |
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object representing the request. In void context, nothing is returned, |
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which saves a bit of memory. |
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The perl object is a fairly standard ref-to-hash object. The hash contents |
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are not used by IO::AIO so you are free to store anything you like in it. |
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During their existance, aio requests travel through the following states, |
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in order: |
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=over 4 |
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=item ready |
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Immediately after a request is created it is put into the ready state, |
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waiting for a thread to execute it. |
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=item execute |
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A thread has accepted the request for processing and is currently |
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executing it (e.g. blocking in read). |
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=item pending |
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The request has been executed and is waiting for result processing. |
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While request submission and execution is fully asynchronous, result |
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processing is not and relies on the perl interpreter calling C<poll_cb> |
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(or another function with the same effect). |
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=item result |
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The request results are processed synchronously by C<poll_cb>. |
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The C<poll_cb> function will process all outstanding aio requests by |
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calling their callbacks, freeing memory associated with them and managing |
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any groups they are contained in. |
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=item done |
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Request has reached the end of its lifetime and holds no resources anymore |
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(except possibly for the Perl object, but its connection to the actual |
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aio request is severed and calling its methods will either do nothing or |
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result in a runtime error). |
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1.1 |
|
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1.88 |
=back |
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1.1 |
=cut |
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package IO::AIO; |
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1.117 |
use Carp (); |
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1.161 |
use common::sense; |
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1.23 |
|
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1.1 |
use base 'Exporter'; |
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BEGIN { |
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our $VERSION = 4.34; |
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1.1 |
|
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our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close |
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1.148 |
aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
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1.259 |
aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl |
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aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range |
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aio_pathsync aio_readahead aio_fiemap aio_allocate |
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1.120 |
aio_rename aio_link aio_move aio_copy aio_group |
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aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
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1.170 |
aio_chmod aio_utime aio_truncate |
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1.182 |
aio_msync aio_mtouch aio_mlock aio_mlockall |
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1.208 |
aio_statvfs |
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aio_wd); |
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1.120 |
|
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1.123 |
our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
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1.67 |
our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
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1.188 |
min_parallel max_parallel max_idle idle_timeout |
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1.86 |
nreqs nready npending nthreads |
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1.157 |
max_poll_time max_poll_reqs |
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1.182 |
sendfile fadvise madvise |
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mmap munmap munlock munlockall); |
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1.1 |
|
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1.143 |
push @AIO_REQ, qw(aio_busy); # not exported |
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1.54 |
@IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
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1.1 |
require XSLoader; |
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1.51 |
XSLoader::load ("IO::AIO", $VERSION); |
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1.1 |
} |
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1.5 |
=head1 FUNCTIONS |
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1.1 |
|
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1.175 |
=head2 QUICK OVERVIEW |
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This section simply lists the prototypes most of the functions for |
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quick reference. See the following sections for function-by-function |
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documentation. |
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aio_wd $pathname, $callback->($wd) |
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1.175 |
aio_open $pathname, $flags, $mode, $callback->($fh) |
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aio_close $fh, $callback->($status) |
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1.220 |
aio_seek $fh,$offset,$whence, $callback->($offs) |
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1.175 |
aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
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aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
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aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
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aio_readahead $fh,$offset,$length, $callback->($retval) |
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aio_stat $fh_or_path, $callback->($status) |
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aio_lstat $fh, $callback->($status) |
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aio_statvfs $fh_or_path, $callback->($statvfs) |
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aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
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aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
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1.220 |
aio_chmod $fh_or_path, $mode, $callback->($status) |
224 |
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1.175 |
aio_truncate $fh_or_path, $offset, $callback->($status) |
225 |
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1.229 |
aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
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1.230 |
aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
227 |
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1.175 |
aio_unlink $pathname, $callback->($status) |
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1.209 |
aio_mknod $pathname, $mode, $dev, $callback->($status) |
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1.175 |
aio_link $srcpath, $dstpath, $callback->($status) |
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aio_symlink $srcpath, $dstpath, $callback->($status) |
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1.209 |
aio_readlink $pathname, $callback->($link) |
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1.249 |
aio_realpath $pathname, $callback->($path) |
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1.175 |
aio_rename $srcpath, $dstpath, $callback->($status) |
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aio_mkdir $pathname, $mode, $callback->($status) |
235 |
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aio_rmdir $pathname, $callback->($status) |
236 |
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aio_readdir $pathname, $callback->($entries) |
237 |
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aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
238 |
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IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
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IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
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1.215 |
aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
241 |
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1.209 |
aio_load $pathname, $data, $callback->($status) |
242 |
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1.175 |
aio_copy $srcpath, $dstpath, $callback->($status) |
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aio_move $srcpath, $dstpath, $callback->($status) |
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1.209 |
aio_rmtree $pathname, $callback->($status) |
245 |
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1.259 |
aio_fcntl $fh, $cmd, $arg, $callback->($status) |
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aio_ioctl $fh, $request, $buf, $callback->($status) |
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1.175 |
aio_sync $callback->($status) |
248 |
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1.206 |
aio_syncfs $fh, $callback->($status) |
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1.175 |
aio_fsync $fh, $callback->($status) |
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aio_fdatasync $fh, $callback->($status) |
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aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
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1.209 |
aio_pathsync $pathname, $callback->($status) |
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1.175 |
aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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1.182 |
aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
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aio_mlockall $flags, $callback->($status) |
257 |
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1.175 |
aio_group $callback->(...) |
258 |
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aio_nop $callback->() |
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$prev_pri = aioreq_pri [$pri] |
261 |
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aioreq_nice $pri_adjust |
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IO::AIO::poll_wait |
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IO::AIO::poll_cb |
265 |
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IO::AIO::poll |
266 |
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IO::AIO::flush |
267 |
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IO::AIO::max_poll_reqs $nreqs |
268 |
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IO::AIO::max_poll_time $seconds |
269 |
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IO::AIO::min_parallel $nthreads |
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IO::AIO::max_parallel $nthreads |
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IO::AIO::max_idle $nthreads |
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1.188 |
IO::AIO::idle_timeout $seconds |
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1.175 |
IO::AIO::max_outstanding $maxreqs |
274 |
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IO::AIO::nreqs |
275 |
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IO::AIO::nready |
276 |
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IO::AIO::npending |
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IO::AIO::sendfile $ofh, $ifh, $offset, $count |
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IO::AIO::fadvise $fh, $offset, $len, $advice |
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1.226 |
IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
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IO::AIO::munmap $scalar |
282 |
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1.184 |
IO::AIO::madvise $scalar, $offset, $length, $advice |
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IO::AIO::mprotect $scalar, $offset, $length, $protect |
284 |
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1.182 |
IO::AIO::munlock $scalar, $offset = 0, $length = undef |
285 |
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1.175 |
IO::AIO::munlockall |
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|
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1.219 |
=head2 API NOTES |
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1.1 |
|
289 |
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1.5 |
All the C<aio_*> calls are more or less thin wrappers around the syscall |
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with the same name (sans C<aio_>). The arguments are similar or identical, |
291 |
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1.14 |
and they all accept an additional (and optional) C<$callback> argument |
292 |
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1.212 |
which must be a code reference. This code reference will be called after |
293 |
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the syscall has been executed in an asynchronous fashion. The results |
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of the request will be passed as arguments to the callback (and, if an |
295 |
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error occured, in C<$!>) - for most requests the syscall return code (e.g. |
296 |
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most syscalls return C<-1> on error, unlike perl, which usually delivers |
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"false"). |
298 |
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299 |
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Some requests (such as C<aio_readdir>) pass the actual results and |
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communicate failures by passing C<undef>. |
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1.1 |
|
302 |
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1.23 |
All functions expecting a filehandle keep a copy of the filehandle |
303 |
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internally until the request has finished. |
304 |
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1.1 |
|
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1.87 |
All functions return request objects of type L<IO::AIO::REQ> that allow |
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further manipulation of those requests while they are in-flight. |
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1.52 |
|
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1.209 |
The pathnames you pass to these routines I<should> be absolute. The |
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reason for this is that at the time the request is being executed, the |
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1.212 |
current working directory could have changed. Alternatively, you can |
311 |
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make sure that you never change the current working directory anywhere |
312 |
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in the program and then use relative paths. You can also take advantage |
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of IO::AIOs working directory abstraction, that lets you specify paths |
314 |
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relative to some previously-opened "working directory object" - see the |
315 |
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description of the C<IO::AIO::WD> class later in this document. |
316 |
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1.28 |
|
317 |
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1.87 |
To encode pathnames as octets, either make sure you either: a) always pass |
318 |
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in filenames you got from outside (command line, readdir etc.) without |
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1.212 |
tinkering, b) are in your native filesystem encoding, c) use the Encode |
320 |
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module and encode your pathnames to the locale (or other) encoding in |
321 |
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effect in the user environment, d) use Glib::filename_from_unicode on |
322 |
|
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unicode filenames or e) use something else to ensure your scalar has the |
323 |
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correct contents. |
324 |
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1.87 |
|
325 |
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This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
326 |
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1.136 |
handles correctly whether it is set or not. |
327 |
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1.1 |
|
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1.219 |
=head2 AIO REQUEST FUNCTIONS |
329 |
|
|
|
330 |
root |
1.5 |
=over 4 |
331 |
root |
1.1 |
|
332 |
root |
1.80 |
=item $prev_pri = aioreq_pri [$pri] |
333 |
root |
1.68 |
|
334 |
root |
1.80 |
Returns the priority value that would be used for the next request and, if |
335 |
|
|
C<$pri> is given, sets the priority for the next aio request. |
336 |
root |
1.68 |
|
337 |
root |
1.80 |
The default priority is C<0>, the minimum and maximum priorities are C<-4> |
338 |
|
|
and C<4>, respectively. Requests with higher priority will be serviced |
339 |
|
|
first. |
340 |
|
|
|
341 |
|
|
The priority will be reset to C<0> after each call to one of the C<aio_*> |
342 |
root |
1.68 |
functions. |
343 |
|
|
|
344 |
root |
1.69 |
Example: open a file with low priority, then read something from it with |
345 |
|
|
higher priority so the read request is serviced before other low priority |
346 |
|
|
open requests (potentially spamming the cache): |
347 |
|
|
|
348 |
|
|
aioreq_pri -3; |
349 |
|
|
aio_open ..., sub { |
350 |
|
|
return unless $_[0]; |
351 |
|
|
|
352 |
|
|
aioreq_pri -2; |
353 |
|
|
aio_read $_[0], ..., sub { |
354 |
|
|
... |
355 |
|
|
}; |
356 |
|
|
}; |
357 |
|
|
|
358 |
root |
1.106 |
|
359 |
root |
1.69 |
=item aioreq_nice $pri_adjust |
360 |
|
|
|
361 |
|
|
Similar to C<aioreq_pri>, but subtracts the given value from the current |
362 |
root |
1.87 |
priority, so the effect is cumulative. |
363 |
root |
1.69 |
|
364 |
root |
1.106 |
|
365 |
root |
1.40 |
=item aio_open $pathname, $flags, $mode, $callback->($fh) |
366 |
root |
1.1 |
|
367 |
root |
1.2 |
Asynchronously open or create a file and call the callback with a newly |
368 |
root |
1.233 |
created filehandle for the file (or C<undef> in case of an error). |
369 |
root |
1.1 |
|
370 |
|
|
The pathname passed to C<aio_open> must be absolute. See API NOTES, above, |
371 |
|
|
for an explanation. |
372 |
|
|
|
373 |
root |
1.20 |
The C<$flags> argument is a bitmask. See the C<Fcntl> module for a |
374 |
|
|
list. They are the same as used by C<sysopen>. |
375 |
|
|
|
376 |
|
|
Likewise, C<$mode> specifies the mode of the newly created file, if it |
377 |
|
|
didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>, |
378 |
|
|
except that it is mandatory (i.e. use C<0> if you don't create new files, |
379 |
root |
1.101 |
and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified |
380 |
|
|
by the umask in effect then the request is being executed, so better never |
381 |
|
|
change the umask. |
382 |
root |
1.1 |
|
383 |
|
|
Example: |
384 |
|
|
|
385 |
root |
1.181 |
aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
386 |
root |
1.2 |
if ($_[0]) { |
387 |
|
|
print "open successful, fh is $_[0]\n"; |
388 |
root |
1.1 |
... |
389 |
|
|
} else { |
390 |
|
|
die "open failed: $!\n"; |
391 |
|
|
} |
392 |
|
|
}; |
393 |
|
|
|
394 |
root |
1.194 |
In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>, |
395 |
|
|
C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the |
396 |
|
|
following POSIX and non-POSIX constants are available (missing ones on |
397 |
|
|
your system are, as usual, C<0>): |
398 |
|
|
|
399 |
|
|
C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
400 |
|
|
C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
401 |
root |
1.255 |
C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>. |
402 |
root |
1.194 |
|
403 |
root |
1.106 |
|
404 |
root |
1.40 |
=item aio_close $fh, $callback->($status) |
405 |
root |
1.1 |
|
406 |
root |
1.2 |
Asynchronously close a file and call the callback with the result |
407 |
root |
1.116 |
code. |
408 |
|
|
|
409 |
root |
1.117 |
Unfortunately, you can't do this to perl. Perl I<insists> very strongly on |
410 |
root |
1.121 |
closing the file descriptor associated with the filehandle itself. |
411 |
root |
1.117 |
|
412 |
root |
1.121 |
Therefore, C<aio_close> will not close the filehandle - instead it will |
413 |
|
|
use dup2 to overwrite the file descriptor with the write-end of a pipe |
414 |
|
|
(the pipe fd will be created on demand and will be cached). |
415 |
root |
1.117 |
|
416 |
root |
1.121 |
Or in other words: the file descriptor will be closed, but it will not be |
417 |
|
|
free for reuse until the perl filehandle is closed. |
418 |
root |
1.117 |
|
419 |
|
|
=cut |
420 |
|
|
|
421 |
root |
1.220 |
=item aio_seek $fh, $offset, $whence, $callback->($offs) |
422 |
|
|
|
423 |
root |
1.221 |
Seeks the filehandle to the new C<$offset>, similarly to perl's |
424 |
root |
1.220 |
C<sysseek>. The C<$whence> can use the traditional values (C<0> for |
425 |
|
|
C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for |
426 |
|
|
C<IO::AIO::SEEK_END>). |
427 |
|
|
|
428 |
|
|
The resulting absolute offset will be passed to the callback, or C<-1> in |
429 |
|
|
case of an error. |
430 |
|
|
|
431 |
|
|
In theory, the C<$whence> constants could be different than the |
432 |
|
|
corresponding values from L<Fcntl>, but perl guarantees they are the same, |
433 |
|
|
so don't panic. |
434 |
|
|
|
435 |
root |
1.225 |
As a GNU/Linux (and maybe Solaris) extension, also the constants |
436 |
|
|
C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they |
437 |
|
|
could be found. No guarantees about suitability for use in C<aio_seek> or |
438 |
|
|
Perl's C<sysseek> can be made though, although I would naively assume they |
439 |
|
|
"just work". |
440 |
|
|
|
441 |
root |
1.40 |
=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
442 |
root |
1.1 |
|
443 |
root |
1.40 |
=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
444 |
root |
1.1 |
|
445 |
root |
1.145 |
Reads or writes C<$length> bytes from or to the specified C<$fh> and |
446 |
|
|
C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> |
447 |
|
|
and calls the callback without the actual number of bytes read (or -1 on |
448 |
|
|
error, just like the syscall). |
449 |
root |
1.109 |
|
450 |
root |
1.146 |
C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to |
451 |
|
|
offset plus the actual number of bytes read. |
452 |
|
|
|
453 |
root |
1.112 |
If C<$offset> is undefined, then the current file descriptor offset will |
454 |
|
|
be used (and updated), otherwise the file descriptor offset will not be |
455 |
|
|
changed by these calls. |
456 |
root |
1.109 |
|
457 |
root |
1.145 |
If C<$length> is undefined in C<aio_write>, use the remaining length of |
458 |
|
|
C<$data>. |
459 |
root |
1.109 |
|
460 |
|
|
If C<$dataoffset> is less than zero, it will be counted from the end of |
461 |
|
|
C<$data>. |
462 |
root |
1.1 |
|
463 |
root |
1.31 |
The C<$data> scalar I<MUST NOT> be modified in any way while the request |
464 |
root |
1.108 |
is outstanding. Modifying it can result in segfaults or World War III (if |
465 |
|
|
the necessary/optional hardware is installed). |
466 |
root |
1.31 |
|
467 |
root |
1.17 |
Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at |
468 |
root |
1.1 |
offset C<0> within the scalar: |
469 |
|
|
|
470 |
|
|
aio_read $fh, 7, 15, $buffer, 0, sub { |
471 |
root |
1.9 |
$_[0] > 0 or die "read error: $!"; |
472 |
|
|
print "read $_[0] bytes: <$buffer>\n"; |
473 |
root |
1.1 |
}; |
474 |
|
|
|
475 |
root |
1.106 |
|
476 |
root |
1.40 |
=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
477 |
root |
1.35 |
|
478 |
|
|
Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
479 |
|
|
reading at byte offset C<$in_offset>, and starts writing at the current |
480 |
|
|
file offset of C<$out_fh>. Because of that, it is not safe to issue more |
481 |
|
|
than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
482 |
root |
1.196 |
other. The same C<$in_fh> works fine though, as this function does not |
483 |
|
|
move or use the file offset of C<$in_fh>. |
484 |
root |
1.35 |
|
485 |
root |
1.185 |
Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than |
486 |
root |
1.196 |
are written, and there is no way to find out how many more bytes have been |
487 |
|
|
read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the |
488 |
|
|
number of bytes written to C<$out_fh>. Only if the result value equals |
489 |
|
|
C<$length> one can assume that C<$length> bytes have been read. |
490 |
root |
1.185 |
|
491 |
|
|
Unlike with other C<aio_> functions, it makes a lot of sense to use |
492 |
|
|
C<aio_sendfile> on non-blocking sockets, as long as one end (typically |
493 |
|
|
the C<$in_fh>) is a file - the file I/O will then be asynchronous, while |
494 |
root |
1.196 |
the socket I/O will be non-blocking. Note, however, that you can run |
495 |
|
|
into a trap where C<aio_sendfile> reads some data with readahead, then |
496 |
|
|
fails to write all data, and when the socket is ready the next time, the |
497 |
|
|
data in the cache is already lost, forcing C<aio_sendfile> to again hit |
498 |
|
|
the disk. Explicit C<aio_read> + C<aio_write> let's you better control |
499 |
|
|
resource usage. |
500 |
|
|
|
501 |
|
|
This call tries to make use of a native C<sendfile>-like syscall to |
502 |
|
|
provide zero-copy operation. For this to work, C<$out_fh> should refer to |
503 |
|
|
a socket, and C<$in_fh> should refer to an mmap'able file. |
504 |
root |
1.35 |
|
505 |
root |
1.170 |
If a native sendfile cannot be found or it fails with C<ENOSYS>, |
506 |
root |
1.196 |
C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or |
507 |
|
|
C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any |
508 |
|
|
type of filehandle regardless of the limitations of the operating system. |
509 |
|
|
|
510 |
|
|
As native sendfile syscalls (as practically any non-POSIX interface hacked |
511 |
|
|
together in a hurry to improve benchmark numbers) tend to be rather buggy |
512 |
|
|
on many systems, this implementation tries to work around some known bugs |
513 |
|
|
in Linux and FreeBSD kernels (probably others, too), but that might fail, |
514 |
|
|
so you really really should check the return value of C<aio_sendfile> - |
515 |
root |
1.262 |
fewer bytes than expected might have been transferred. |
516 |
root |
1.35 |
|
517 |
root |
1.106 |
|
518 |
root |
1.40 |
=item aio_readahead $fh,$offset,$length, $callback->($retval) |
519 |
root |
1.1 |
|
520 |
root |
1.20 |
C<aio_readahead> populates the page cache with data from a file so that |
521 |
root |
1.1 |
subsequent reads from that file will not block on disk I/O. The C<$offset> |
522 |
|
|
argument specifies the starting point from which data is to be read and |
523 |
|
|
C<$length> specifies the number of bytes to be read. I/O is performed in |
524 |
|
|
whole pages, so that offset is effectively rounded down to a page boundary |
525 |
|
|
and bytes are read up to the next page boundary greater than or equal to |
526 |
root |
1.20 |
(off-set+length). C<aio_readahead> does not read beyond the end of the |
527 |
root |
1.1 |
file. The current file offset of the file is left unchanged. |
528 |
|
|
|
529 |
root |
1.261 |
If that syscall doesn't exist (likely if your kernel isn't Linux) it will |
530 |
|
|
be emulated by simply reading the data, which would have a similar effect. |
531 |
root |
1.26 |
|
532 |
root |
1.106 |
|
533 |
root |
1.40 |
=item aio_stat $fh_or_path, $callback->($status) |
534 |
root |
1.1 |
|
535 |
root |
1.40 |
=item aio_lstat $fh, $callback->($status) |
536 |
root |
1.1 |
|
537 |
|
|
Works like perl's C<stat> or C<lstat> in void context. The callback will |
538 |
|
|
be called after the stat and the results will be available using C<stat _> |
539 |
|
|
or C<-s _> etc... |
540 |
|
|
|
541 |
|
|
The pathname passed to C<aio_stat> must be absolute. See API NOTES, above, |
542 |
|
|
for an explanation. |
543 |
|
|
|
544 |
|
|
Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
545 |
|
|
error when stat'ing a large file, the results will be silently truncated |
546 |
|
|
unless perl itself is compiled with large file support. |
547 |
|
|
|
548 |
root |
1.187 |
To help interpret the mode and dev/rdev stat values, IO::AIO offers the |
549 |
|
|
following constants and functions (if not implemented, the constants will |
550 |
|
|
be C<0> and the functions will either C<croak> or fall back on traditional |
551 |
|
|
behaviour). |
552 |
|
|
|
553 |
|
|
C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, |
554 |
|
|
C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, |
555 |
|
|
C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. |
556 |
|
|
|
557 |
root |
1.1 |
Example: Print the length of F</etc/passwd>: |
558 |
|
|
|
559 |
|
|
aio_stat "/etc/passwd", sub { |
560 |
|
|
$_[0] and die "stat failed: $!"; |
561 |
|
|
print "size is ", -s _, "\n"; |
562 |
|
|
}; |
563 |
|
|
|
564 |
root |
1.106 |
|
565 |
root |
1.175 |
=item aio_statvfs $fh_or_path, $callback->($statvfs) |
566 |
root |
1.172 |
|
567 |
|
|
Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on |
568 |
|
|
whether a file handle or path was passed. |
569 |
|
|
|
570 |
|
|
On success, the callback is passed a hash reference with the following |
571 |
|
|
members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>, |
572 |
|
|
C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef> |
573 |
|
|
is passed. |
574 |
|
|
|
575 |
|
|
The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and |
576 |
|
|
C<ST_NOSUID>. |
577 |
|
|
|
578 |
|
|
The following non-POSIX IO::AIO::ST_* flag masks are defined to |
579 |
|
|
their correct value when available, or to C<0> on systems that do |
580 |
|
|
not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>, |
581 |
|
|
C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>, |
582 |
|
|
C<ST_NODIRATIME> and C<ST_RELATIME>. |
583 |
|
|
|
584 |
|
|
Example: stat C</wd> and dump out the data if successful. |
585 |
|
|
|
586 |
|
|
aio_statvfs "/wd", sub { |
587 |
|
|
my $f = $_[0] |
588 |
|
|
or die "statvfs: $!"; |
589 |
|
|
|
590 |
|
|
use Data::Dumper; |
591 |
|
|
say Dumper $f; |
592 |
|
|
}; |
593 |
|
|
|
594 |
|
|
# result: |
595 |
|
|
{ |
596 |
|
|
bsize => 1024, |
597 |
|
|
bfree => 4333064312, |
598 |
|
|
blocks => 10253828096, |
599 |
|
|
files => 2050765568, |
600 |
|
|
flag => 4096, |
601 |
|
|
favail => 2042092649, |
602 |
|
|
bavail => 4333064312, |
603 |
|
|
ffree => 2042092649, |
604 |
|
|
namemax => 255, |
605 |
|
|
frsize => 1024, |
606 |
|
|
fsid => 1810 |
607 |
|
|
} |
608 |
|
|
|
609 |
root |
1.244 |
Here is a (likely partial - send me updates!) list of fsid values used by |
610 |
|
|
Linux - it is safe to hardcode these when C<$^O> is C<linux>: |
611 |
root |
1.235 |
|
612 |
|
|
0x0000adf5 adfs |
613 |
|
|
0x0000adff affs |
614 |
|
|
0x5346414f afs |
615 |
|
|
0x09041934 anon-inode filesystem |
616 |
|
|
0x00000187 autofs |
617 |
|
|
0x42465331 befs |
618 |
|
|
0x1badface bfs |
619 |
|
|
0x42494e4d binfmt_misc |
620 |
|
|
0x9123683e btrfs |
621 |
|
|
0x0027e0eb cgroupfs |
622 |
|
|
0xff534d42 cifs |
623 |
|
|
0x73757245 coda |
624 |
|
|
0x012ff7b7 coh |
625 |
|
|
0x28cd3d45 cramfs |
626 |
|
|
0x453dcd28 cramfs-wend (wrong endianness) |
627 |
|
|
0x64626720 debugfs |
628 |
|
|
0x00001373 devfs |
629 |
|
|
0x00001cd1 devpts |
630 |
|
|
0x0000f15f ecryptfs |
631 |
|
|
0x00414a53 efs |
632 |
|
|
0x0000137d ext |
633 |
root |
1.257 |
0x0000ef53 ext2/ext3/ext4 |
634 |
root |
1.235 |
0x0000ef51 ext2 |
635 |
root |
1.257 |
0xf2f52010 f2fs |
636 |
root |
1.235 |
0x00004006 fat |
637 |
|
|
0x65735546 fuseblk |
638 |
|
|
0x65735543 fusectl |
639 |
|
|
0x0bad1dea futexfs |
640 |
|
|
0x01161970 gfs2 |
641 |
|
|
0x47504653 gpfs |
642 |
|
|
0x00004244 hfs |
643 |
|
|
0xf995e849 hpfs |
644 |
root |
1.257 |
0x00c0ffee hostfs |
645 |
root |
1.235 |
0x958458f6 hugetlbfs |
646 |
|
|
0x2bad1dea inotifyfs |
647 |
|
|
0x00009660 isofs |
648 |
|
|
0x000072b6 jffs2 |
649 |
|
|
0x3153464a jfs |
650 |
|
|
0x6b414653 k-afs |
651 |
|
|
0x0bd00bd0 lustre |
652 |
|
|
0x0000137f minix |
653 |
|
|
0x0000138f minix 30 char names |
654 |
|
|
0x00002468 minix v2 |
655 |
|
|
0x00002478 minix v2 30 char names |
656 |
|
|
0x00004d5a minix v3 |
657 |
|
|
0x19800202 mqueue |
658 |
|
|
0x00004d44 msdos |
659 |
|
|
0x0000564c novell |
660 |
|
|
0x00006969 nfs |
661 |
|
|
0x6e667364 nfsd |
662 |
|
|
0x00003434 nilfs |
663 |
|
|
0x5346544e ntfs |
664 |
|
|
0x00009fa1 openprom |
665 |
|
|
0x7461636F ocfs2 |
666 |
|
|
0x00009fa0 proc |
667 |
|
|
0x6165676c pstorefs |
668 |
|
|
0x0000002f qnx4 |
669 |
root |
1.257 |
0x68191122 qnx6 |
670 |
root |
1.235 |
0x858458f6 ramfs |
671 |
|
|
0x52654973 reiserfs |
672 |
|
|
0x00007275 romfs |
673 |
|
|
0x67596969 rpc_pipefs |
674 |
|
|
0x73636673 securityfs |
675 |
|
|
0xf97cff8c selinux |
676 |
|
|
0x0000517b smb |
677 |
|
|
0x534f434b sockfs |
678 |
|
|
0x73717368 squashfs |
679 |
|
|
0x62656572 sysfs |
680 |
|
|
0x012ff7b6 sysv2 |
681 |
|
|
0x012ff7b5 sysv4 |
682 |
|
|
0x01021994 tmpfs |
683 |
|
|
0x15013346 udf |
684 |
|
|
0x00011954 ufs |
685 |
|
|
0x54190100 ufs byteswapped |
686 |
|
|
0x00009fa2 usbdevfs |
687 |
|
|
0x01021997 v9fs |
688 |
|
|
0xa501fcf5 vxfs |
689 |
|
|
0xabba1974 xenfs |
690 |
|
|
0x012ff7b4 xenix |
691 |
|
|
0x58465342 xfs |
692 |
|
|
0x012fd16d xia |
693 |
root |
1.172 |
|
694 |
root |
1.106 |
=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
695 |
|
|
|
696 |
|
|
Works like perl's C<utime> function (including the special case of $atime |
697 |
|
|
and $mtime being undef). Fractional times are supported if the underlying |
698 |
|
|
syscalls support them. |
699 |
|
|
|
700 |
|
|
When called with a pathname, uses utimes(2) if available, otherwise |
701 |
|
|
utime(2). If called on a file descriptor, uses futimes(2) if available, |
702 |
|
|
otherwise returns ENOSYS, so this is not portable. |
703 |
|
|
|
704 |
|
|
Examples: |
705 |
|
|
|
706 |
root |
1.107 |
# set atime and mtime to current time (basically touch(1)): |
707 |
root |
1.106 |
aio_utime "path", undef, undef; |
708 |
|
|
# set atime to current time and mtime to beginning of the epoch: |
709 |
|
|
aio_utime "path", time, undef; # undef==0 |
710 |
|
|
|
711 |
|
|
|
712 |
|
|
=item aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
713 |
|
|
|
714 |
|
|
Works like perl's C<chown> function, except that C<undef> for either $uid |
715 |
|
|
or $gid is being interpreted as "do not change" (but -1 can also be used). |
716 |
|
|
|
717 |
|
|
Examples: |
718 |
|
|
|
719 |
|
|
# same as "chown root path" in the shell: |
720 |
|
|
aio_chown "path", 0, -1; |
721 |
|
|
# same as above: |
722 |
|
|
aio_chown "path", 0, undef; |
723 |
|
|
|
724 |
|
|
|
725 |
root |
1.110 |
=item aio_truncate $fh_or_path, $offset, $callback->($status) |
726 |
|
|
|
727 |
|
|
Works like truncate(2) or ftruncate(2). |
728 |
|
|
|
729 |
|
|
|
730 |
root |
1.229 |
=item aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
731 |
|
|
|
732 |
root |
1.249 |
Allocates or frees disk space according to the C<$mode> argument. See the |
733 |
|
|
linux C<fallocate> documentation for details. |
734 |
root |
1.229 |
|
735 |
root |
1.252 |
C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate |
736 |
|
|
space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>, |
737 |
|
|
to deallocate a file range. |
738 |
|
|
|
739 |
|
|
IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range |
740 |
|
|
(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see |
741 |
|
|
your L<fallocate(2)> manpage). |
742 |
root |
1.229 |
|
743 |
|
|
The file system block size used by C<fallocate> is presumably the |
744 |
|
|
C<f_bsize> returned by C<statvfs>. |
745 |
|
|
|
746 |
|
|
If C<fallocate> isn't available or cannot be emulated (currently no |
747 |
|
|
emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>. |
748 |
|
|
|
749 |
|
|
|
750 |
root |
1.106 |
=item aio_chmod $fh_or_path, $mode, $callback->($status) |
751 |
|
|
|
752 |
|
|
Works like perl's C<chmod> function. |
753 |
|
|
|
754 |
|
|
|
755 |
root |
1.40 |
=item aio_unlink $pathname, $callback->($status) |
756 |
root |
1.1 |
|
757 |
|
|
Asynchronously unlink (delete) a file and call the callback with the |
758 |
|
|
result code. |
759 |
|
|
|
760 |
root |
1.106 |
|
761 |
root |
1.209 |
=item aio_mknod $pathname, $mode, $dev, $callback->($status) |
762 |
root |
1.82 |
|
763 |
root |
1.86 |
[EXPERIMENTAL] |
764 |
|
|
|
765 |
root |
1.83 |
Asynchronously create a device node (or fifo). See mknod(2). |
766 |
|
|
|
767 |
root |
1.86 |
The only (POSIX-) portable way of calling this function is: |
768 |
root |
1.83 |
|
769 |
root |
1.209 |
aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
770 |
root |
1.82 |
|
771 |
root |
1.187 |
See C<aio_stat> for info about some potentially helpful extra constants |
772 |
|
|
and functions. |
773 |
root |
1.106 |
|
774 |
root |
1.50 |
=item aio_link $srcpath, $dstpath, $callback->($status) |
775 |
|
|
|
776 |
|
|
Asynchronously create a new link to the existing object at C<$srcpath> at |
777 |
|
|
the path C<$dstpath> and call the callback with the result code. |
778 |
|
|
|
779 |
root |
1.106 |
|
780 |
root |
1.50 |
=item aio_symlink $srcpath, $dstpath, $callback->($status) |
781 |
|
|
|
782 |
|
|
Asynchronously create a new symbolic link to the existing object at C<$srcpath> at |
783 |
|
|
the path C<$dstpath> and call the callback with the result code. |
784 |
|
|
|
785 |
root |
1.106 |
|
786 |
root |
1.209 |
=item aio_readlink $pathname, $callback->($link) |
787 |
root |
1.90 |
|
788 |
|
|
Asynchronously read the symlink specified by C<$path> and pass it to |
789 |
|
|
the callback. If an error occurs, nothing or undef gets passed to the |
790 |
|
|
callback. |
791 |
|
|
|
792 |
root |
1.106 |
|
793 |
root |
1.209 |
=item aio_realpath $pathname, $callback->($path) |
794 |
root |
1.201 |
|
795 |
|
|
Asynchronously make the path absolute and resolve any symlinks in |
796 |
root |
1.239 |
C<$path>. The resulting path only consists of directories (same as |
797 |
root |
1.202 |
L<Cwd::realpath>). |
798 |
root |
1.201 |
|
799 |
|
|
This request can be used to get the absolute path of the current working |
800 |
|
|
directory by passing it a path of F<.> (a single dot). |
801 |
|
|
|
802 |
|
|
|
803 |
root |
1.50 |
=item aio_rename $srcpath, $dstpath, $callback->($status) |
804 |
|
|
|
805 |
|
|
Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
806 |
|
|
rename(2) and call the callback with the result code. |
807 |
|
|
|
808 |
root |
1.241 |
On systems that support the AIO::WD working directory abstraction |
809 |
|
|
natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead |
810 |
|
|
of failing, C<rename> is called on the absolute path of C<$wd>. |
811 |
|
|
|
812 |
root |
1.106 |
|
813 |
root |
1.101 |
=item aio_mkdir $pathname, $mode, $callback->($status) |
814 |
|
|
|
815 |
|
|
Asynchronously mkdir (create) a directory and call the callback with |
816 |
|
|
the result code. C<$mode> will be modified by the umask at the time the |
817 |
|
|
request is executed, so do not change your umask. |
818 |
|
|
|
819 |
root |
1.106 |
|
820 |
root |
1.40 |
=item aio_rmdir $pathname, $callback->($status) |
821 |
root |
1.27 |
|
822 |
|
|
Asynchronously rmdir (delete) a directory and call the callback with the |
823 |
|
|
result code. |
824 |
|
|
|
825 |
root |
1.241 |
On systems that support the AIO::WD working directory abstraction |
826 |
|
|
natively, the case C<[$wd, "."]> is specialcased - instead of failing, |
827 |
|
|
C<rmdir> is called on the absolute path of C<$wd>. |
828 |
|
|
|
829 |
root |
1.106 |
|
830 |
root |
1.46 |
=item aio_readdir $pathname, $callback->($entries) |
831 |
root |
1.37 |
|
832 |
|
|
Unlike the POSIX call of the same name, C<aio_readdir> reads an entire |
833 |
|
|
directory (i.e. opendir + readdir + closedir). The entries will not be |
834 |
|
|
sorted, and will B<NOT> include the C<.> and C<..> entries. |
835 |
|
|
|
836 |
root |
1.148 |
The callback is passed a single argument which is either C<undef> or an |
837 |
|
|
array-ref with the filenames. |
838 |
|
|
|
839 |
|
|
|
840 |
|
|
=item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
841 |
|
|
|
842 |
root |
1.207 |
Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to |
843 |
|
|
tune behaviour and output format. In case of an error, C<$entries> will be |
844 |
root |
1.148 |
C<undef>. |
845 |
|
|
|
846 |
|
|
The flags are a combination of the following constants, ORed together (the |
847 |
|
|
flags will also be passed to the callback, possibly modified): |
848 |
|
|
|
849 |
|
|
=over 4 |
850 |
|
|
|
851 |
root |
1.150 |
=item IO::AIO::READDIR_DENTS |
852 |
root |
1.148 |
|
853 |
root |
1.190 |
When this flag is off, then the callback gets an arrayref consisting of |
854 |
|
|
names only (as with C<aio_readdir>), otherwise it gets an arrayref with |
855 |
root |
1.150 |
C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
856 |
root |
1.148 |
entry in more detail. |
857 |
|
|
|
858 |
|
|
C<$name> is the name of the entry. |
859 |
|
|
|
860 |
root |
1.150 |
C<$type> is one of the C<IO::AIO::DT_xxx> constants: |
861 |
root |
1.148 |
|
862 |
root |
1.150 |
C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>, |
863 |
|
|
C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>, |
864 |
|
|
C<IO::AIO::DT_WHT>. |
865 |
root |
1.148 |
|
866 |
root |
1.150 |
C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to |
867 |
root |
1.148 |
know, you have to run stat yourself. Also, for speed reasons, the C<$type> |
868 |
|
|
scalars are read-only: you can not modify them. |
869 |
|
|
|
870 |
root |
1.150 |
C<$inode> is the inode number (which might not be exact on systems with 64 |
871 |
root |
1.155 |
bit inode numbers and 32 bit perls). This field has unspecified content on |
872 |
|
|
systems that do not deliver the inode information. |
873 |
root |
1.150 |
|
874 |
|
|
=item IO::AIO::READDIR_DIRS_FIRST |
875 |
root |
1.148 |
|
876 |
|
|
When this flag is set, then the names will be returned in an order where |
877 |
root |
1.193 |
likely directories come first, in optimal stat order. This is useful when |
878 |
|
|
you need to quickly find directories, or you want to find all directories |
879 |
|
|
while avoiding to stat() each entry. |
880 |
root |
1.148 |
|
881 |
root |
1.149 |
If the system returns type information in readdir, then this is used |
882 |
root |
1.193 |
to find directories directly. Otherwise, likely directories are names |
883 |
|
|
beginning with ".", or otherwise names with no dots, of which names with |
884 |
root |
1.149 |
short names are tried first. |
885 |
|
|
|
886 |
root |
1.150 |
=item IO::AIO::READDIR_STAT_ORDER |
887 |
root |
1.148 |
|
888 |
|
|
When this flag is set, then the names will be returned in an order |
889 |
|
|
suitable for stat()'ing each one. That is, when you plan to stat() |
890 |
|
|
all files in the given directory, then the returned order will likely |
891 |
|
|
be fastest. |
892 |
|
|
|
893 |
root |
1.150 |
If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then |
894 |
|
|
the likely dirs come first, resulting in a less optimal stat order. |
895 |
root |
1.148 |
|
896 |
root |
1.150 |
=item IO::AIO::READDIR_FOUND_UNKNOWN |
897 |
root |
1.148 |
|
898 |
|
|
This flag should not be set when calling C<aio_readdirx>. Instead, it |
899 |
|
|
is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
900 |
root |
1.207 |
C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all |
901 |
root |
1.148 |
C<$type>'s are known, which can be used to speed up some algorithms. |
902 |
|
|
|
903 |
|
|
=back |
904 |
root |
1.37 |
|
905 |
root |
1.106 |
|
906 |
root |
1.209 |
=item aio_load $pathname, $data, $callback->($status) |
907 |
root |
1.98 |
|
908 |
|
|
This is a composite request that tries to fully load the given file into |
909 |
|
|
memory. Status is the same as with aio_read. |
910 |
|
|
|
911 |
|
|
=cut |
912 |
|
|
|
913 |
|
|
sub aio_load($$;$) { |
914 |
root |
1.123 |
my ($path, undef, $cb) = @_; |
915 |
|
|
my $data = \$_[1]; |
916 |
root |
1.98 |
|
917 |
root |
1.123 |
my $pri = aioreq_pri; |
918 |
|
|
my $grp = aio_group $cb; |
919 |
|
|
|
920 |
|
|
aioreq_pri $pri; |
921 |
|
|
add $grp aio_open $path, O_RDONLY, 0, sub { |
922 |
|
|
my $fh = shift |
923 |
|
|
or return $grp->result (-1); |
924 |
root |
1.98 |
|
925 |
|
|
aioreq_pri $pri; |
926 |
root |
1.123 |
add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { |
927 |
|
|
$grp->result ($_[0]); |
928 |
root |
1.98 |
}; |
929 |
root |
1.123 |
}; |
930 |
root |
1.98 |
|
931 |
root |
1.123 |
$grp |
932 |
root |
1.98 |
} |
933 |
|
|
|
934 |
root |
1.82 |
=item aio_copy $srcpath, $dstpath, $callback->($status) |
935 |
|
|
|
936 |
|
|
Try to copy the I<file> (directories not supported as either source or |
937 |
|
|
destination) from C<$srcpath> to C<$dstpath> and call the callback with |
938 |
root |
1.165 |
a status of C<0> (ok) or C<-1> (error, see C<$!>). |
939 |
root |
1.82 |
|
940 |
root |
1.134 |
This is a composite request that creates the destination file with |
941 |
root |
1.82 |
mode 0200 and copies the contents of the source file into it using |
942 |
|
|
C<aio_sendfile>, followed by restoring atime, mtime, access mode and |
943 |
|
|
uid/gid, in that order. |
944 |
|
|
|
945 |
|
|
If an error occurs, the partial destination file will be unlinked, if |
946 |
|
|
possible, except when setting atime, mtime, access mode and uid/gid, where |
947 |
|
|
errors are being ignored. |
948 |
|
|
|
949 |
|
|
=cut |
950 |
|
|
|
951 |
|
|
sub aio_copy($$;$) { |
952 |
root |
1.123 |
my ($src, $dst, $cb) = @_; |
953 |
root |
1.82 |
|
954 |
root |
1.123 |
my $pri = aioreq_pri; |
955 |
|
|
my $grp = aio_group $cb; |
956 |
root |
1.82 |
|
957 |
root |
1.123 |
aioreq_pri $pri; |
958 |
|
|
add $grp aio_open $src, O_RDONLY, 0, sub { |
959 |
|
|
if (my $src_fh = $_[0]) { |
960 |
root |
1.166 |
my @stat = stat $src_fh; # hmm, might block over nfs? |
961 |
root |
1.95 |
|
962 |
root |
1.123 |
aioreq_pri $pri; |
963 |
|
|
add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { |
964 |
|
|
if (my $dst_fh = $_[0]) { |
965 |
|
|
aioreq_pri $pri; |
966 |
|
|
add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { |
967 |
|
|
if ($_[0] == $stat[7]) { |
968 |
|
|
$grp->result (0); |
969 |
|
|
close $src_fh; |
970 |
|
|
|
971 |
root |
1.147 |
my $ch = sub { |
972 |
|
|
aioreq_pri $pri; |
973 |
|
|
add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub { |
974 |
|
|
aioreq_pri $pri; |
975 |
|
|
add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub { |
976 |
|
|
aioreq_pri $pri; |
977 |
|
|
add $grp aio_close $dst_fh; |
978 |
|
|
} |
979 |
|
|
}; |
980 |
|
|
}; |
981 |
root |
1.123 |
|
982 |
|
|
aioreq_pri $pri; |
983 |
root |
1.147 |
add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub { |
984 |
|
|
if ($_[0] < 0 && $! == ENOSYS) { |
985 |
|
|
aioreq_pri $pri; |
986 |
|
|
add $grp aio_utime $dst, $stat[8], $stat[9], $ch; |
987 |
|
|
} else { |
988 |
|
|
$ch->(); |
989 |
|
|
} |
990 |
|
|
}; |
991 |
root |
1.123 |
} else { |
992 |
|
|
$grp->result (-1); |
993 |
|
|
close $src_fh; |
994 |
|
|
close $dst_fh; |
995 |
|
|
|
996 |
|
|
aioreq $pri; |
997 |
|
|
add $grp aio_unlink $dst; |
998 |
|
|
} |
999 |
|
|
}; |
1000 |
|
|
} else { |
1001 |
|
|
$grp->result (-1); |
1002 |
|
|
} |
1003 |
|
|
}, |
1004 |
root |
1.82 |
|
1005 |
root |
1.123 |
} else { |
1006 |
|
|
$grp->result (-1); |
1007 |
|
|
} |
1008 |
|
|
}; |
1009 |
root |
1.82 |
|
1010 |
root |
1.123 |
$grp |
1011 |
root |
1.82 |
} |
1012 |
|
|
|
1013 |
|
|
=item aio_move $srcpath, $dstpath, $callback->($status) |
1014 |
|
|
|
1015 |
|
|
Try to move the I<file> (directories not supported as either source or |
1016 |
|
|
destination) from C<$srcpath> to C<$dstpath> and call the callback with |
1017 |
root |
1.165 |
a status of C<0> (ok) or C<-1> (error, see C<$!>). |
1018 |
root |
1.82 |
|
1019 |
root |
1.137 |
This is a composite request that tries to rename(2) the file first; if |
1020 |
|
|
rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if |
1021 |
|
|
that is successful, unlinks the C<$srcpath>. |
1022 |
root |
1.82 |
|
1023 |
|
|
=cut |
1024 |
|
|
|
1025 |
|
|
sub aio_move($$;$) { |
1026 |
root |
1.123 |
my ($src, $dst, $cb) = @_; |
1027 |
root |
1.82 |
|
1028 |
root |
1.123 |
my $pri = aioreq_pri; |
1029 |
|
|
my $grp = aio_group $cb; |
1030 |
root |
1.82 |
|
1031 |
root |
1.123 |
aioreq_pri $pri; |
1032 |
|
|
add $grp aio_rename $src, $dst, sub { |
1033 |
|
|
if ($_[0] && $! == EXDEV) { |
1034 |
|
|
aioreq_pri $pri; |
1035 |
|
|
add $grp aio_copy $src, $dst, sub { |
1036 |
|
|
$grp->result ($_[0]); |
1037 |
root |
1.95 |
|
1038 |
root |
1.196 |
unless ($_[0]) { |
1039 |
root |
1.123 |
aioreq_pri $pri; |
1040 |
|
|
add $grp aio_unlink $src; |
1041 |
|
|
} |
1042 |
|
|
}; |
1043 |
|
|
} else { |
1044 |
|
|
$grp->result ($_[0]); |
1045 |
|
|
} |
1046 |
|
|
}; |
1047 |
root |
1.82 |
|
1048 |
root |
1.123 |
$grp |
1049 |
root |
1.82 |
} |
1050 |
|
|
|
1051 |
root |
1.209 |
=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
1052 |
root |
1.40 |
|
1053 |
root |
1.52 |
Scans a directory (similar to C<aio_readdir>) but additionally tries to |
1054 |
root |
1.76 |
efficiently separate the entries of directory C<$path> into two sets of |
1055 |
|
|
names, directories you can recurse into (directories), and ones you cannot |
1056 |
|
|
recurse into (everything else, including symlinks to directories). |
1057 |
root |
1.52 |
|
1058 |
root |
1.61 |
C<aio_scandir> is a composite request that creates of many sub requests_ |
1059 |
|
|
C<$maxreq> specifies the maximum number of outstanding aio requests that |
1060 |
|
|
this function generates. If it is C<< <= 0 >>, then a suitable default |
1061 |
root |
1.81 |
will be chosen (currently 4). |
1062 |
root |
1.40 |
|
1063 |
|
|
On error, the callback is called without arguments, otherwise it receives |
1064 |
|
|
two array-refs with path-relative entry names. |
1065 |
|
|
|
1066 |
|
|
Example: |
1067 |
|
|
|
1068 |
|
|
aio_scandir $dir, 0, sub { |
1069 |
|
|
my ($dirs, $nondirs) = @_; |
1070 |
|
|
print "real directories: @$dirs\n"; |
1071 |
|
|
print "everything else: @$nondirs\n"; |
1072 |
|
|
}; |
1073 |
|
|
|
1074 |
|
|
Implementation notes. |
1075 |
|
|
|
1076 |
|
|
The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. |
1077 |
|
|
|
1078 |
root |
1.149 |
If readdir returns file type information, then this is used directly to |
1079 |
|
|
find directories. |
1080 |
|
|
|
1081 |
|
|
Otherwise, after reading the directory, the modification time, size etc. |
1082 |
|
|
of the directory before and after the readdir is checked, and if they |
1083 |
|
|
match (and isn't the current time), the link count will be used to decide |
1084 |
|
|
how many entries are directories (if >= 2). Otherwise, no knowledge of the |
1085 |
|
|
number of subdirectories will be assumed. |
1086 |
|
|
|
1087 |
|
|
Then entries will be sorted into likely directories a non-initial dot |
1088 |
|
|
currently) and likely non-directories (see C<aio_readdirx>). Then every |
1089 |
|
|
entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
1090 |
|
|
in order of their inode numbers. If that succeeds, it assumes that the |
1091 |
|
|
entry is a directory or a symlink to directory (which will be checked |
1092 |
root |
1.207 |
separately). This is often faster than stat'ing the entry itself because |
1093 |
root |
1.52 |
filesystems might detect the type of the entry without reading the inode |
1094 |
root |
1.149 |
data (e.g. ext2fs filetype feature), even on systems that cannot return |
1095 |
|
|
the filetype information on readdir. |
1096 |
root |
1.52 |
|
1097 |
|
|
If the known number of directories (link count - 2) has been reached, the |
1098 |
|
|
rest of the entries is assumed to be non-directories. |
1099 |
|
|
|
1100 |
|
|
This only works with certainty on POSIX (= UNIX) filesystems, which |
1101 |
|
|
fortunately are the vast majority of filesystems around. |
1102 |
|
|
|
1103 |
|
|
It will also likely work on non-POSIX filesystems with reduced efficiency |
1104 |
|
|
as those tend to return 0 or 1 as link counts, which disables the |
1105 |
|
|
directory counting heuristic. |
1106 |
root |
1.40 |
|
1107 |
|
|
=cut |
1108 |
|
|
|
1109 |
root |
1.100 |
sub aio_scandir($$;$) { |
1110 |
root |
1.123 |
my ($path, $maxreq, $cb) = @_; |
1111 |
|
|
|
1112 |
|
|
my $pri = aioreq_pri; |
1113 |
root |
1.40 |
|
1114 |
root |
1.123 |
my $grp = aio_group $cb; |
1115 |
root |
1.80 |
|
1116 |
root |
1.123 |
$maxreq = 4 if $maxreq <= 0; |
1117 |
root |
1.55 |
|
1118 |
root |
1.210 |
# get a wd object |
1119 |
root |
1.123 |
aioreq_pri $pri; |
1120 |
root |
1.210 |
add $grp aio_wd $path, sub { |
1121 |
root |
1.212 |
$_[0] |
1122 |
|
|
or return $grp->result (); |
1123 |
|
|
|
1124 |
root |
1.210 |
my $wd = [shift, "."]; |
1125 |
root |
1.40 |
|
1126 |
root |
1.210 |
# stat once |
1127 |
root |
1.80 |
aioreq_pri $pri; |
1128 |
root |
1.210 |
add $grp aio_stat $wd, sub { |
1129 |
|
|
return $grp->result () if $_[0]; |
1130 |
|
|
my $now = time; |
1131 |
|
|
my $hash1 = join ":", (stat _)[0,1,3,7,9]; |
1132 |
root |
1.40 |
|
1133 |
root |
1.210 |
# read the directory entries |
1134 |
root |
1.80 |
aioreq_pri $pri; |
1135 |
root |
1.210 |
add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub { |
1136 |
|
|
my $entries = shift |
1137 |
|
|
or return $grp->result (); |
1138 |
|
|
|
1139 |
|
|
# stat the dir another time |
1140 |
|
|
aioreq_pri $pri; |
1141 |
|
|
add $grp aio_stat $wd, sub { |
1142 |
|
|
my $hash2 = join ":", (stat _)[0,1,3,7,9]; |
1143 |
root |
1.95 |
|
1144 |
root |
1.210 |
my $ndirs; |
1145 |
root |
1.95 |
|
1146 |
root |
1.210 |
# take the slow route if anything looks fishy |
1147 |
|
|
if ($hash1 ne $hash2 or (stat _)[9] == $now) { |
1148 |
|
|
$ndirs = -1; |
1149 |
|
|
} else { |
1150 |
|
|
# if nlink == 2, we are finished |
1151 |
|
|
# for non-posix-fs's, we rely on nlink < 2 |
1152 |
|
|
$ndirs = (stat _)[3] - 2 |
1153 |
|
|
or return $grp->result ([], $entries); |
1154 |
|
|
} |
1155 |
root |
1.123 |
|
1156 |
root |
1.210 |
my (@dirs, @nondirs); |
1157 |
root |
1.40 |
|
1158 |
root |
1.210 |
my $statgrp = add $grp aio_group sub { |
1159 |
|
|
$grp->result (\@dirs, \@nondirs); |
1160 |
|
|
}; |
1161 |
root |
1.40 |
|
1162 |
root |
1.210 |
limit $statgrp $maxreq; |
1163 |
|
|
feed $statgrp sub { |
1164 |
|
|
return unless @$entries; |
1165 |
|
|
my $entry = shift @$entries; |
1166 |
|
|
|
1167 |
|
|
aioreq_pri $pri; |
1168 |
|
|
$wd->[1] = "$entry/."; |
1169 |
|
|
add $statgrp aio_stat $wd, sub { |
1170 |
|
|
if ($_[0] < 0) { |
1171 |
|
|
push @nondirs, $entry; |
1172 |
|
|
} else { |
1173 |
|
|
# need to check for real directory |
1174 |
|
|
aioreq_pri $pri; |
1175 |
|
|
$wd->[1] = $entry; |
1176 |
|
|
add $statgrp aio_lstat $wd, sub { |
1177 |
|
|
if (-d _) { |
1178 |
|
|
push @dirs, $entry; |
1179 |
|
|
|
1180 |
|
|
unless (--$ndirs) { |
1181 |
|
|
push @nondirs, @$entries; |
1182 |
|
|
feed $statgrp; |
1183 |
|
|
} |
1184 |
|
|
} else { |
1185 |
|
|
push @nondirs, $entry; |
1186 |
root |
1.74 |
} |
1187 |
root |
1.40 |
} |
1188 |
|
|
} |
1189 |
root |
1.210 |
}; |
1190 |
root |
1.74 |
}; |
1191 |
root |
1.40 |
}; |
1192 |
|
|
}; |
1193 |
|
|
}; |
1194 |
root |
1.123 |
}; |
1195 |
root |
1.55 |
|
1196 |
root |
1.123 |
$grp |
1197 |
root |
1.40 |
} |
1198 |
|
|
|
1199 |
root |
1.209 |
=item aio_rmtree $pathname, $callback->($status) |
1200 |
root |
1.99 |
|
1201 |
root |
1.100 |
Delete a directory tree starting (and including) C<$path>, return the |
1202 |
root |
1.239 |
status of the final C<rmdir> only. This is a composite request that |
1203 |
root |
1.100 |
uses C<aio_scandir> to recurse into and rmdir directories, and unlink |
1204 |
|
|
everything else. |
1205 |
root |
1.99 |
|
1206 |
|
|
=cut |
1207 |
|
|
|
1208 |
|
|
sub aio_rmtree; |
1209 |
root |
1.100 |
sub aio_rmtree($;$) { |
1210 |
root |
1.123 |
my ($path, $cb) = @_; |
1211 |
root |
1.99 |
|
1212 |
root |
1.123 |
my $pri = aioreq_pri; |
1213 |
|
|
my $grp = aio_group $cb; |
1214 |
root |
1.99 |
|
1215 |
root |
1.123 |
aioreq_pri $pri; |
1216 |
|
|
add $grp aio_scandir $path, 0, sub { |
1217 |
|
|
my ($dirs, $nondirs) = @_; |
1218 |
root |
1.99 |
|
1219 |
root |
1.123 |
my $dirgrp = aio_group sub { |
1220 |
|
|
add $grp aio_rmdir $path, sub { |
1221 |
|
|
$grp->result ($_[0]); |
1222 |
root |
1.99 |
}; |
1223 |
root |
1.123 |
}; |
1224 |
root |
1.99 |
|
1225 |
root |
1.123 |
(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs; |
1226 |
|
|
(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs; |
1227 |
root |
1.99 |
|
1228 |
root |
1.123 |
add $grp $dirgrp; |
1229 |
|
|
}; |
1230 |
root |
1.99 |
|
1231 |
root |
1.123 |
$grp |
1232 |
root |
1.99 |
} |
1233 |
|
|
|
1234 |
root |
1.259 |
=item aio_fcntl $fh, $cmd, $arg, $callback->($status) |
1235 |
|
|
|
1236 |
|
|
=item aio_ioctl $fh, $request, $buf, $callback->($status) |
1237 |
|
|
|
1238 |
|
|
These work just like the C<fcntl> and C<ioctl> built-in functions, except |
1239 |
|
|
they execute asynchronously and pass the return value to the callback. |
1240 |
|
|
|
1241 |
|
|
Both calls can be used for a lot of things, some of which make more sense |
1242 |
|
|
to run asynchronously in their own thread, while some others make less |
1243 |
|
|
sense. For example, calls that block waiting for external events, such |
1244 |
|
|
as locking, will also lock down an I/O thread while it is waiting, which |
1245 |
|
|
can deadlock the whole I/O system. At the same time, there might be no |
1246 |
|
|
alternative to using a thread to wait. |
1247 |
|
|
|
1248 |
|
|
So in general, you should only use these calls for things that do |
1249 |
|
|
(filesystem) I/O, not for things that wait for other events (network, |
1250 |
|
|
other processes), although if you are careful and know what you are doing, |
1251 |
|
|
you still can. |
1252 |
|
|
|
1253 |
root |
1.264 |
The following constants are available (missing ones are, as usual C<0>): |
1254 |
|
|
|
1255 |
|
|
C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>. |
1256 |
|
|
|
1257 |
|
|
C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>, |
1258 |
|
|
C<FS_IOC_FIEMAP>. |
1259 |
|
|
|
1260 |
|
|
C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>, |
1261 |
|
|
C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>. |
1262 |
|
|
|
1263 |
|
|
C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>, |
1264 |
|
|
C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>, |
1265 |
|
|
C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>, |
1266 |
|
|
C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>, |
1267 |
|
|
C<FS_FL_USER_MODIFIABLE>. |
1268 |
|
|
|
1269 |
|
|
C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>, |
1270 |
|
|
C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>, |
1271 |
|
|
C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>, |
1272 |
|
|
C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>, |
1273 |
|
|
|
1274 |
root |
1.119 |
=item aio_sync $callback->($status) |
1275 |
|
|
|
1276 |
|
|
Asynchronously call sync and call the callback when finished. |
1277 |
|
|
|
1278 |
root |
1.40 |
=item aio_fsync $fh, $callback->($status) |
1279 |
root |
1.1 |
|
1280 |
|
|
Asynchronously call fsync on the given filehandle and call the callback |
1281 |
|
|
with the fsync result code. |
1282 |
|
|
|
1283 |
root |
1.40 |
=item aio_fdatasync $fh, $callback->($status) |
1284 |
root |
1.1 |
|
1285 |
|
|
Asynchronously call fdatasync on the given filehandle and call the |
1286 |
root |
1.26 |
callback with the fdatasync result code. |
1287 |
|
|
|
1288 |
|
|
If this call isn't available because your OS lacks it or it couldn't be |
1289 |
|
|
detected, it will be emulated by calling C<fsync> instead. |
1290 |
root |
1.1 |
|
1291 |
root |
1.206 |
=item aio_syncfs $fh, $callback->($status) |
1292 |
|
|
|
1293 |
|
|
Asynchronously call the syncfs syscall to sync the filesystem associated |
1294 |
|
|
to the given filehandle and call the callback with the syncfs result |
1295 |
|
|
code. If syncfs is not available, calls sync(), but returns C<-1> and sets |
1296 |
|
|
errno to C<ENOSYS> nevertheless. |
1297 |
|
|
|
1298 |
root |
1.142 |
=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1299 |
|
|
|
1300 |
|
|
Sync the data portion of the file specified by C<$offset> and C<$length> |
1301 |
|
|
to disk (but NOT the metadata), by calling the Linux-specific |
1302 |
|
|
sync_file_range call. If sync_file_range is not available or it returns |
1303 |
|
|
ENOSYS, then fdatasync or fsync is being substituted. |
1304 |
|
|
|
1305 |
|
|
C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, |
1306 |
|
|
C<IO::AIO::SYNC_FILE_RANGE_WRITE> and |
1307 |
|
|
C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range |
1308 |
|
|
manpage for details. |
1309 |
|
|
|
1310 |
root |
1.209 |
=item aio_pathsync $pathname, $callback->($status) |
1311 |
root |
1.120 |
|
1312 |
|
|
This request tries to open, fsync and close the given path. This is a |
1313 |
root |
1.135 |
composite request intended to sync directories after directory operations |
1314 |
root |
1.120 |
(E.g. rename). This might not work on all operating systems or have any |
1315 |
|
|
specific effect, but usually it makes sure that directory changes get |
1316 |
|
|
written to disc. It works for anything that can be opened for read-only, |
1317 |
|
|
not just directories. |
1318 |
|
|
|
1319 |
root |
1.162 |
Future versions of this function might fall back to other methods when |
1320 |
|
|
C<fsync> on the directory fails (such as calling C<sync>). |
1321 |
|
|
|
1322 |
root |
1.120 |
Passes C<0> when everything went ok, and C<-1> on error. |
1323 |
|
|
|
1324 |
|
|
=cut |
1325 |
|
|
|
1326 |
|
|
sub aio_pathsync($;$) { |
1327 |
root |
1.123 |
my ($path, $cb) = @_; |
1328 |
|
|
|
1329 |
|
|
my $pri = aioreq_pri; |
1330 |
|
|
my $grp = aio_group $cb; |
1331 |
root |
1.120 |
|
1332 |
root |
1.123 |
aioreq_pri $pri; |
1333 |
|
|
add $grp aio_open $path, O_RDONLY, 0, sub { |
1334 |
|
|
my ($fh) = @_; |
1335 |
|
|
if ($fh) { |
1336 |
|
|
aioreq_pri $pri; |
1337 |
|
|
add $grp aio_fsync $fh, sub { |
1338 |
|
|
$grp->result ($_[0]); |
1339 |
root |
1.120 |
|
1340 |
|
|
aioreq_pri $pri; |
1341 |
root |
1.123 |
add $grp aio_close $fh; |
1342 |
|
|
}; |
1343 |
|
|
} else { |
1344 |
|
|
$grp->result (-1); |
1345 |
|
|
} |
1346 |
|
|
}; |
1347 |
root |
1.120 |
|
1348 |
root |
1.123 |
$grp |
1349 |
root |
1.120 |
} |
1350 |
|
|
|
1351 |
root |
1.170 |
=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1352 |
|
|
|
1353 |
|
|
This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1354 |
root |
1.176 |
scalars (see the C<IO::AIO::mmap> function, although it also works on data |
1355 |
|
|
scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the |
1356 |
|
|
scalar must only be modified in-place while an aio operation is pending on |
1357 |
|
|
it). |
1358 |
root |
1.170 |
|
1359 |
|
|
It calls the C<msync> function of your OS, if available, with the memory |
1360 |
|
|
area starting at C<$offset> in the string and ending C<$length> bytes |
1361 |
|
|
later. If C<$length> is negative, counts from the end, and if C<$length> |
1362 |
|
|
is C<undef>, then it goes till the end of the string. The flags can be |
1363 |
|
|
a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and |
1364 |
|
|
C<IO::AIO::MS_SYNC>. |
1365 |
|
|
|
1366 |
|
|
=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1367 |
|
|
|
1368 |
|
|
This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
1369 |
|
|
scalars. |
1370 |
|
|
|
1371 |
|
|
It touches (reads or writes) all memory pages in the specified |
1372 |
root |
1.239 |
range inside the scalar. All caveats and parameters are the same |
1373 |
root |
1.170 |
as for C<aio_msync>, above, except for flags, which must be either |
1374 |
|
|
C<0> (which reads all pages and ensures they are instantiated) or |
1375 |
root |
1.239 |
C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and |
1376 |
root |
1.170 |
writing an octet from it, which dirties the page). |
1377 |
|
|
|
1378 |
root |
1.182 |
=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
1379 |
|
|
|
1380 |
|
|
This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
1381 |
|
|
scalars. |
1382 |
|
|
|
1383 |
|
|
It reads in all the pages of the underlying storage into memory (if any) |
1384 |
|
|
and locks them, so they are not getting swapped/paged out or removed. |
1385 |
|
|
|
1386 |
|
|
If C<$length> is undefined, then the scalar will be locked till the end. |
1387 |
|
|
|
1388 |
|
|
On systems that do not implement C<mlock>, this function returns C<-1> |
1389 |
|
|
and sets errno to C<ENOSYS>. |
1390 |
|
|
|
1391 |
|
|
Note that the corresponding C<munlock> is synchronous and is |
1392 |
|
|
documented under L<MISCELLANEOUS FUNCTIONS>. |
1393 |
|
|
|
1394 |
root |
1.183 |
Example: open a file, mmap and mlock it - both will be undone when |
1395 |
|
|
C<$data> gets destroyed. |
1396 |
|
|
|
1397 |
|
|
open my $fh, "<", $path or die "$path: $!"; |
1398 |
|
|
my $data; |
1399 |
|
|
IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
1400 |
|
|
aio_mlock $data; # mlock in background |
1401 |
|
|
|
1402 |
root |
1.182 |
=item aio_mlockall $flags, $callback->($status) |
1403 |
|
|
|
1404 |
|
|
Calls the C<mlockall> function with the given C<$flags> (a combination of |
1405 |
|
|
C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). |
1406 |
|
|
|
1407 |
|
|
On systems that do not implement C<mlockall>, this function returns C<-1> |
1408 |
|
|
and sets errno to C<ENOSYS>. |
1409 |
|
|
|
1410 |
|
|
Note that the corresponding C<munlockall> is synchronous and is |
1411 |
|
|
documented under L<MISCELLANEOUS FUNCTIONS>. |
1412 |
|
|
|
1413 |
root |
1.183 |
Example: asynchronously lock all current and future pages into memory. |
1414 |
|
|
|
1415 |
|
|
aio_mlockall IO::AIO::MCL_FUTURE; |
1416 |
|
|
|
1417 |
root |
1.223 |
=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
1418 |
|
|
|
1419 |
root |
1.234 |
Queries the extents of the given file (by calling the Linux C<FIEMAP> |
1420 |
|
|
ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If |
1421 |
|
|
the ioctl is not available on your OS, then this request will fail with |
1422 |
root |
1.223 |
C<ENOSYS>. |
1423 |
|
|
|
1424 |
|
|
C<$start> is the starting offset to query extents for, C<$length> is the |
1425 |
|
|
size of the range to query - if it is C<undef>, then the whole file will |
1426 |
|
|
be queried. |
1427 |
|
|
|
1428 |
|
|
C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or |
1429 |
|
|
C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also |
1430 |
|
|
exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query |
1431 |
|
|
the data portion. |
1432 |
|
|
|
1433 |
|
|
C<$count> is the maximum number of extent records to return. If it is |
1434 |
root |
1.232 |
C<undef>, then IO::AIO queries all extents of the range. As a very special |
1435 |
root |
1.223 |
case, if it is C<0>, then the callback receives the number of extents |
1436 |
root |
1.232 |
instead of the extents themselves (which is unreliable, see below). |
1437 |
root |
1.223 |
|
1438 |
|
|
If an error occurs, the callback receives no arguments. The special |
1439 |
|
|
C<errno> value C<IO::AIO::EBADR> is available to test for flag errors. |
1440 |
|
|
|
1441 |
|
|
Otherwise, the callback receives an array reference with extent |
1442 |
|
|
structures. Each extent structure is an array reference itself, with the |
1443 |
|
|
following members: |
1444 |
|
|
|
1445 |
|
|
[$logical, $physical, $length, $flags] |
1446 |
|
|
|
1447 |
|
|
Flags is any combination of the following flag values (typically either C<0> |
1448 |
root |
1.231 |
or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)): |
1449 |
root |
1.223 |
|
1450 |
|
|
C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>, |
1451 |
|
|
C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>, |
1452 |
|
|
C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, |
1453 |
|
|
C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, |
1454 |
|
|
C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or |
1455 |
|
|
C<IO::AIO::FIEMAP_EXTENT_SHARED>. |
1456 |
|
|
|
1457 |
root |
1.232 |
At the time of this writing (Linux 3.2), this requets is unreliable unless |
1458 |
|
|
C<$count> is C<undef>, as the kernel has all sorts of bugs preventing |
1459 |
|
|
it to return all extents of a range for files with large number of |
1460 |
|
|
extents. The code works around all these issues if C<$count> is undef. |
1461 |
|
|
|
1462 |
root |
1.58 |
=item aio_group $callback->(...) |
1463 |
root |
1.54 |
|
1464 |
root |
1.55 |
This is a very special aio request: Instead of doing something, it is a |
1465 |
|
|
container for other aio requests, which is useful if you want to bundle |
1466 |
root |
1.71 |
many requests into a single, composite, request with a definite callback |
1467 |
|
|
and the ability to cancel the whole request with its subrequests. |
1468 |
root |
1.55 |
|
1469 |
|
|
Returns an object of class L<IO::AIO::GRP>. See its documentation below |
1470 |
|
|
for more info. |
1471 |
|
|
|
1472 |
|
|
Example: |
1473 |
|
|
|
1474 |
|
|
my $grp = aio_group sub { |
1475 |
|
|
print "all stats done\n"; |
1476 |
|
|
}; |
1477 |
|
|
|
1478 |
|
|
add $grp |
1479 |
|
|
(aio_stat ...), |
1480 |
|
|
(aio_stat ...), |
1481 |
|
|
...; |
1482 |
|
|
|
1483 |
root |
1.63 |
=item aio_nop $callback->() |
1484 |
|
|
|
1485 |
|
|
This is a special request - it does nothing in itself and is only used for |
1486 |
|
|
side effects, such as when you want to add a dummy request to a group so |
1487 |
|
|
that finishing the requests in the group depends on executing the given |
1488 |
|
|
code. |
1489 |
|
|
|
1490 |
root |
1.64 |
While this request does nothing, it still goes through the execution |
1491 |
|
|
phase and still requires a worker thread. Thus, the callback will not |
1492 |
|
|
be executed immediately but only after other requests in the queue have |
1493 |
|
|
entered their execution phase. This can be used to measure request |
1494 |
|
|
latency. |
1495 |
|
|
|
1496 |
root |
1.71 |
=item IO::AIO::aio_busy $fractional_seconds, $callback->() *NOT EXPORTED* |
1497 |
root |
1.54 |
|
1498 |
|
|
Mainly used for debugging and benchmarking, this aio request puts one of |
1499 |
|
|
the request workers to sleep for the given time. |
1500 |
|
|
|
1501 |
root |
1.56 |
While it is theoretically handy to have simple I/O scheduling requests |
1502 |
root |
1.71 |
like sleep and file handle readable/writable, the overhead this creates is |
1503 |
|
|
immense (it blocks a thread for a long time) so do not use this function |
1504 |
|
|
except to put your application under artificial I/O pressure. |
1505 |
root |
1.56 |
|
1506 |
root |
1.5 |
=back |
1507 |
|
|
|
1508 |
root |
1.209 |
|
1509 |
|
|
=head2 IO::AIO::WD - multiple working directories |
1510 |
|
|
|
1511 |
|
|
Your process only has one current working directory, which is used by all |
1512 |
|
|
threads. This makes it hard to use relative paths (some other component |
1513 |
|
|
could call C<chdir> at any time, and it is hard to control when the path |
1514 |
|
|
will be used by IO::AIO). |
1515 |
|
|
|
1516 |
|
|
One solution for this is to always use absolute paths. This usually works, |
1517 |
|
|
but can be quite slow (the kernel has to walk the whole path on every |
1518 |
|
|
access), and can also be a hassle to implement. |
1519 |
|
|
|
1520 |
|
|
Newer POSIX systems have a number of functions (openat, fdopendir, |
1521 |
|
|
futimensat and so on) that make it possible to specify working directories |
1522 |
|
|
per operation. |
1523 |
|
|
|
1524 |
|
|
For portability, and because the clowns who "designed", or shall I write, |
1525 |
|
|
perpetrated this new interface were obviously half-drunk, this abstraction |
1526 |
|
|
cannot be perfect, though. |
1527 |
|
|
|
1528 |
|
|
IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD |
1529 |
|
|
object. This object stores the canonicalised, absolute version of the |
1530 |
|
|
path, and on systems that allow it, also a directory file descriptor. |
1531 |
|
|
|
1532 |
|
|
Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat> |
1533 |
|
|
or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD |
1534 |
root |
1.214 |
object and a pathname instead (or the IO::AIO::WD object alone, which |
1535 |
|
|
gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the |
1536 |
root |
1.213 |
IO::AIO::WD object is ignored, otherwise the pathname is resolved relative |
1537 |
root |
1.209 |
to that IO::AIO::WD object. |
1538 |
|
|
|
1539 |
|
|
For example, to get a wd object for F</etc> and then stat F<passwd> |
1540 |
|
|
inside, you would write: |
1541 |
|
|
|
1542 |
|
|
aio_wd "/etc", sub { |
1543 |
|
|
my $etcdir = shift; |
1544 |
|
|
|
1545 |
|
|
# although $etcdir can be undef on error, there is generally no reason |
1546 |
|
|
# to check for errors here, as aio_stat will fail with ENOENT |
1547 |
|
|
# when $etcdir is undef. |
1548 |
|
|
|
1549 |
|
|
aio_stat [$etcdir, "passwd"], sub { |
1550 |
|
|
# yay |
1551 |
|
|
}; |
1552 |
|
|
}; |
1553 |
|
|
|
1554 |
root |
1.250 |
The fact that C<aio_wd> is a request and not a normal function shows that |
1555 |
|
|
creating an IO::AIO::WD object is itself a potentially blocking operation, |
1556 |
|
|
which is why it is done asynchronously. |
1557 |
root |
1.214 |
|
1558 |
|
|
To stat the directory obtained with C<aio_wd> above, one could write |
1559 |
|
|
either of the following three request calls: |
1560 |
|
|
|
1561 |
|
|
aio_lstat "/etc" , sub { ... # pathname as normal string |
1562 |
|
|
aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
1563 |
|
|
aio_lstat $wd , sub { ... # shorthand for the previous |
1564 |
root |
1.209 |
|
1565 |
|
|
As with normal pathnames, IO::AIO keeps a copy of the working directory |
1566 |
|
|
object and the pathname string, so you could write the following without |
1567 |
|
|
causing any issues due to C<$path> getting reused: |
1568 |
|
|
|
1569 |
|
|
my $path = [$wd, undef]; |
1570 |
|
|
|
1571 |
|
|
for my $name (qw(abc def ghi)) { |
1572 |
|
|
$path->[1] = $name; |
1573 |
|
|
aio_stat $path, sub { |
1574 |
|
|
# ... |
1575 |
|
|
}; |
1576 |
|
|
} |
1577 |
|
|
|
1578 |
|
|
There are some caveats: when directories get renamed (or deleted), the |
1579 |
|
|
pathname string doesn't change, so will point to the new directory (or |
1580 |
|
|
nowhere at all), while the directory fd, if available on the system, |
1581 |
|
|
will still point to the original directory. Most functions accepting a |
1582 |
|
|
pathname will use the directory fd on newer systems, and the string on |
1583 |
|
|
older systems. Some functions (such as realpath) will always rely on the |
1584 |
|
|
string form of the pathname. |
1585 |
|
|
|
1586 |
root |
1.239 |
So this functionality is mainly useful to get some protection against |
1587 |
root |
1.209 |
C<chdir>, to easily get an absolute path out of a relative path for future |
1588 |
|
|
reference, and to speed up doing many operations in the same directory |
1589 |
|
|
(e.g. when stat'ing all files in a directory). |
1590 |
|
|
|
1591 |
|
|
The following functions implement this working directory abstraction: |
1592 |
|
|
|
1593 |
|
|
=over 4 |
1594 |
|
|
|
1595 |
|
|
=item aio_wd $pathname, $callback->($wd) |
1596 |
|
|
|
1597 |
|
|
Asynchonously canonicalise the given pathname and convert it to an |
1598 |
|
|
IO::AIO::WD object representing it. If possible and supported on the |
1599 |
|
|
system, also open a directory fd to speed up pathname resolution relative |
1600 |
|
|
to this working directory. |
1601 |
|
|
|
1602 |
|
|
If something goes wrong, then C<undef> is passwd to the callback instead |
1603 |
|
|
of a working directory object and C<$!> is set appropriately. Since |
1604 |
|
|
passing C<undef> as working directory component of a pathname fails the |
1605 |
|
|
request with C<ENOENT>, there is often no need for error checking in the |
1606 |
|
|
C<aio_wd> callback, as future requests using the value will fail in the |
1607 |
|
|
expected way. |
1608 |
|
|
|
1609 |
|
|
=item IO::AIO::CWD |
1610 |
|
|
|
1611 |
|
|
This is a compiletime constant (object) that represents the process |
1612 |
|
|
current working directory. |
1613 |
|
|
|
1614 |
root |
1.239 |
Specifying this object as working directory object for a pathname is as if |
1615 |
|
|
the pathname would be specified directly, without a directory object. For |
1616 |
|
|
example, these calls are functionally identical: |
1617 |
root |
1.209 |
|
1618 |
|
|
aio_stat "somefile", sub { ... }; |
1619 |
|
|
aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
1620 |
|
|
|
1621 |
|
|
=back |
1622 |
|
|
|
1623 |
root |
1.239 |
To recover the path associated with an IO::AIO::WD object, you can use |
1624 |
|
|
C<aio_realpath>: |
1625 |
|
|
|
1626 |
|
|
aio_realpath $wd, sub { |
1627 |
|
|
warn "path is $_[0]\n"; |
1628 |
|
|
}; |
1629 |
|
|
|
1630 |
root |
1.241 |
Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir> |
1631 |
|
|
sometimes, fall back to using an absolue path. |
1632 |
root |
1.209 |
|
1633 |
root |
1.53 |
=head2 IO::AIO::REQ CLASS |
1634 |
root |
1.52 |
|
1635 |
|
|
All non-aggregate C<aio_*> functions return an object of this class when |
1636 |
|
|
called in non-void context. |
1637 |
|
|
|
1638 |
|
|
=over 4 |
1639 |
|
|
|
1640 |
root |
1.65 |
=item cancel $req |
1641 |
root |
1.52 |
|
1642 |
|
|
Cancels the request, if possible. Has the effect of skipping execution |
1643 |
|
|
when entering the B<execute> state and skipping calling the callback when |
1644 |
|
|
entering the the B<result> state, but will leave the request otherwise |
1645 |
root |
1.151 |
untouched (with the exception of readdir). That means that requests that |
1646 |
|
|
currently execute will not be stopped and resources held by the request |
1647 |
|
|
will not be freed prematurely. |
1648 |
root |
1.52 |
|
1649 |
root |
1.65 |
=item cb $req $callback->(...) |
1650 |
|
|
|
1651 |
|
|
Replace (or simply set) the callback registered to the request. |
1652 |
|
|
|
1653 |
root |
1.52 |
=back |
1654 |
|
|
|
1655 |
root |
1.55 |
=head2 IO::AIO::GRP CLASS |
1656 |
|
|
|
1657 |
|
|
This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to |
1658 |
|
|
objects of this class, too. |
1659 |
|
|
|
1660 |
|
|
A IO::AIO::GRP object is a special request that can contain multiple other |
1661 |
|
|
aio requests. |
1662 |
|
|
|
1663 |
|
|
You create one by calling the C<aio_group> constructing function with a |
1664 |
|
|
callback that will be called when all contained requests have entered the |
1665 |
|
|
C<done> state: |
1666 |
|
|
|
1667 |
|
|
my $grp = aio_group sub { |
1668 |
|
|
print "all requests are done\n"; |
1669 |
|
|
}; |
1670 |
|
|
|
1671 |
|
|
You add requests by calling the C<add> method with one or more |
1672 |
|
|
C<IO::AIO::REQ> objects: |
1673 |
|
|
|
1674 |
|
|
$grp->add (aio_unlink "..."); |
1675 |
|
|
|
1676 |
root |
1.58 |
add $grp aio_stat "...", sub { |
1677 |
|
|
$_[0] or return $grp->result ("error"); |
1678 |
|
|
|
1679 |
|
|
# add another request dynamically, if first succeeded |
1680 |
|
|
add $grp aio_open "...", sub { |
1681 |
|
|
$grp->result ("ok"); |
1682 |
|
|
}; |
1683 |
|
|
}; |
1684 |
root |
1.55 |
|
1685 |
|
|
This makes it very easy to create composite requests (see the source of |
1686 |
|
|
C<aio_move> for an application) that work and feel like simple requests. |
1687 |
|
|
|
1688 |
root |
1.62 |
=over 4 |
1689 |
|
|
|
1690 |
|
|
=item * The IO::AIO::GRP objects will be cleaned up during calls to |
1691 |
root |
1.55 |
C<IO::AIO::poll_cb>, just like any other request. |
1692 |
|
|
|
1693 |
root |
1.62 |
=item * They can be canceled like any other request. Canceling will cancel not |
1694 |
root |
1.59 |
only the request itself, but also all requests it contains. |
1695 |
root |
1.55 |
|
1696 |
root |
1.62 |
=item * They can also can also be added to other IO::AIO::GRP objects. |
1697 |
root |
1.55 |
|
1698 |
root |
1.62 |
=item * You must not add requests to a group from within the group callback (or |
1699 |
root |
1.60 |
any later time). |
1700 |
|
|
|
1701 |
root |
1.62 |
=back |
1702 |
|
|
|
1703 |
root |
1.55 |
Their lifetime, simplified, looks like this: when they are empty, they |
1704 |
|
|
will finish very quickly. If they contain only requests that are in the |
1705 |
|
|
C<done> state, they will also finish. Otherwise they will continue to |
1706 |
|
|
exist. |
1707 |
|
|
|
1708 |
root |
1.133 |
That means after creating a group you have some time to add requests |
1709 |
|
|
(precisely before the callback has been invoked, which is only done within |
1710 |
|
|
the C<poll_cb>). And in the callbacks of those requests, you can add |
1711 |
|
|
further requests to the group. And only when all those requests have |
1712 |
|
|
finished will the the group itself finish. |
1713 |
root |
1.57 |
|
1714 |
root |
1.55 |
=over 4 |
1715 |
|
|
|
1716 |
root |
1.65 |
=item add $grp ... |
1717 |
|
|
|
1718 |
root |
1.55 |
=item $grp->add (...) |
1719 |
|
|
|
1720 |
root |
1.57 |
Add one or more requests to the group. Any type of L<IO::AIO::REQ> can |
1721 |
|
|
be added, including other groups, as long as you do not create circular |
1722 |
|
|
dependencies. |
1723 |
|
|
|
1724 |
|
|
Returns all its arguments. |
1725 |
root |
1.55 |
|
1726 |
root |
1.74 |
=item $grp->cancel_subs |
1727 |
|
|
|
1728 |
|
|
Cancel all subrequests and clears any feeder, but not the group request |
1729 |
|
|
itself. Useful when you queued a lot of events but got a result early. |
1730 |
|
|
|
1731 |
root |
1.168 |
The group request will finish normally (you cannot add requests to the |
1732 |
|
|
group). |
1733 |
|
|
|
1734 |
root |
1.58 |
=item $grp->result (...) |
1735 |
|
|
|
1736 |
|
|
Set the result value(s) that will be passed to the group callback when all |
1737 |
root |
1.120 |
subrequests have finished and set the groups errno to the current value |
1738 |
root |
1.80 |
of errno (just like calling C<errno> without an error number). By default, |
1739 |
|
|
no argument will be passed and errno is zero. |
1740 |
|
|
|
1741 |
|
|
=item $grp->errno ([$errno]) |
1742 |
|
|
|
1743 |
|
|
Sets the group errno value to C<$errno>, or the current value of errno |
1744 |
|
|
when the argument is missing. |
1745 |
|
|
|
1746 |
|
|
Every aio request has an associated errno value that is restored when |
1747 |
|
|
the callback is invoked. This method lets you change this value from its |
1748 |
|
|
default (0). |
1749 |
|
|
|
1750 |
|
|
Calling C<result> will also set errno, so make sure you either set C<$!> |
1751 |
|
|
before the call to C<result>, or call c<errno> after it. |
1752 |
root |
1.58 |
|
1753 |
root |
1.65 |
=item feed $grp $callback->($grp) |
1754 |
root |
1.60 |
|
1755 |
|
|
Sets a feeder/generator on this group: every group can have an attached |
1756 |
|
|
generator that generates requests if idle. The idea behind this is that, |
1757 |
|
|
although you could just queue as many requests as you want in a group, |
1758 |
root |
1.139 |
this might starve other requests for a potentially long time. For example, |
1759 |
root |
1.211 |
C<aio_scandir> might generate hundreds of thousands of C<aio_stat> |
1760 |
|
|
requests, delaying any later requests for a long time. |
1761 |
root |
1.60 |
|
1762 |
|
|
To avoid this, and allow incremental generation of requests, you can |
1763 |
|
|
instead a group and set a feeder on it that generates those requests. The |
1764 |
root |
1.68 |
feed callback will be called whenever there are few enough (see C<limit>, |
1765 |
root |
1.60 |
below) requests active in the group itself and is expected to queue more |
1766 |
|
|
requests. |
1767 |
|
|
|
1768 |
root |
1.68 |
The feed callback can queue as many requests as it likes (i.e. C<add> does |
1769 |
|
|
not impose any limits). |
1770 |
root |
1.60 |
|
1771 |
root |
1.65 |
If the feed does not queue more requests when called, it will be |
1772 |
root |
1.60 |
automatically removed from the group. |
1773 |
|
|
|
1774 |
root |
1.138 |
If the feed limit is C<0> when this method is called, it will be set to |
1775 |
|
|
C<2> automatically. |
1776 |
root |
1.60 |
|
1777 |
|
|
Example: |
1778 |
|
|
|
1779 |
|
|
# stat all files in @files, but only ever use four aio requests concurrently: |
1780 |
|
|
|
1781 |
|
|
my $grp = aio_group sub { print "finished\n" }; |
1782 |
root |
1.68 |
limit $grp 4; |
1783 |
root |
1.65 |
feed $grp sub { |
1784 |
root |
1.60 |
my $file = pop @files |
1785 |
|
|
or return; |
1786 |
|
|
|
1787 |
|
|
add $grp aio_stat $file, sub { ... }; |
1788 |
root |
1.65 |
}; |
1789 |
root |
1.60 |
|
1790 |
root |
1.68 |
=item limit $grp $num |
1791 |
root |
1.60 |
|
1792 |
|
|
Sets the feeder limit for the group: The feeder will be called whenever |
1793 |
|
|
the group contains less than this many requests. |
1794 |
|
|
|
1795 |
|
|
Setting the limit to C<0> will pause the feeding process. |
1796 |
|
|
|
1797 |
root |
1.138 |
The default value for the limit is C<0>, but note that setting a feeder |
1798 |
|
|
automatically bumps it up to C<2>. |
1799 |
|
|
|
1800 |
root |
1.55 |
=back |
1801 |
|
|
|
1802 |
root |
1.5 |
=head2 SUPPORT FUNCTIONS |
1803 |
|
|
|
1804 |
root |
1.86 |
=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION |
1805 |
|
|
|
1806 |
root |
1.5 |
=over 4 |
1807 |
|
|
|
1808 |
|
|
=item $fileno = IO::AIO::poll_fileno |
1809 |
|
|
|
1810 |
root |
1.20 |
Return the I<request result pipe file descriptor>. This filehandle must be |
1811 |
root |
1.156 |
polled for reading by some mechanism outside this module (e.g. EV, Glib, |
1812 |
|
|
select and so on, see below or the SYNOPSIS). If the pipe becomes readable |
1813 |
|
|
you have to call C<poll_cb> to check the results. |
1814 |
root |
1.5 |
|
1815 |
|
|
See C<poll_cb> for an example. |
1816 |
|
|
|
1817 |
|
|
=item IO::AIO::poll_cb |
1818 |
|
|
|
1819 |
root |
1.240 |
Process some requests that have reached the result phase (i.e. they have |
1820 |
|
|
been executed but the results are not yet reported). You have to call |
1821 |
|
|
this "regularly" to finish outstanding requests. |
1822 |
|
|
|
1823 |
|
|
Returns C<0> if all events could be processed (or there were no |
1824 |
|
|
events to process), or C<-1> if it returned earlier for whatever |
1825 |
|
|
reason. Returns immediately when no events are outstanding. The amount |
1826 |
|
|
of events processed depends on the settings of C<IO::AIO::max_poll_req>, |
1827 |
|
|
C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>. |
1828 |
|
|
|
1829 |
|
|
If not all requests were processed for whatever reason, the poll file |
1830 |
|
|
descriptor will still be ready when C<poll_cb> returns, so normally you |
1831 |
|
|
don't have to do anything special to have it called later. |
1832 |
root |
1.78 |
|
1833 |
root |
1.192 |
Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
1834 |
|
|
ready, it can be beneficial to call this function from loops which submit |
1835 |
|
|
a lot of requests, to make sure the results get processed when they become |
1836 |
|
|
available and not just when the loop is finished and the event loop takes |
1837 |
|
|
over again. This function returns very fast when there are no outstanding |
1838 |
|
|
requests. |
1839 |
|
|
|
1840 |
root |
1.20 |
Example: Install an Event watcher that automatically calls |
1841 |
root |
1.156 |
IO::AIO::poll_cb with high priority (more examples can be found in the |
1842 |
|
|
SYNOPSIS section, at the top of this document): |
1843 |
root |
1.5 |
|
1844 |
|
|
Event->io (fd => IO::AIO::poll_fileno, |
1845 |
|
|
poll => 'r', async => 1, |
1846 |
|
|
cb => \&IO::AIO::poll_cb); |
1847 |
|
|
|
1848 |
root |
1.175 |
=item IO::AIO::poll_wait |
1849 |
|
|
|
1850 |
root |
1.240 |
Wait until either at least one request is in the result phase or no |
1851 |
|
|
requests are outstanding anymore. |
1852 |
|
|
|
1853 |
|
|
This is useful if you want to synchronously wait for some requests to |
1854 |
|
|
become ready, without actually handling them. |
1855 |
root |
1.175 |
|
1856 |
|
|
See C<nreqs> for an example. |
1857 |
|
|
|
1858 |
|
|
=item IO::AIO::poll |
1859 |
|
|
|
1860 |
|
|
Waits until some requests have been handled. |
1861 |
|
|
|
1862 |
|
|
Returns the number of requests processed, but is otherwise strictly |
1863 |
|
|
equivalent to: |
1864 |
|
|
|
1865 |
|
|
IO::AIO::poll_wait, IO::AIO::poll_cb |
1866 |
|
|
|
1867 |
|
|
=item IO::AIO::flush |
1868 |
|
|
|
1869 |
|
|
Wait till all outstanding AIO requests have been handled. |
1870 |
|
|
|
1871 |
|
|
Strictly equivalent to: |
1872 |
|
|
|
1873 |
|
|
IO::AIO::poll_wait, IO::AIO::poll_cb |
1874 |
|
|
while IO::AIO::nreqs; |
1875 |
|
|
|
1876 |
root |
1.86 |
=item IO::AIO::max_poll_reqs $nreqs |
1877 |
|
|
|
1878 |
|
|
=item IO::AIO::max_poll_time $seconds |
1879 |
|
|
|
1880 |
|
|
These set the maximum number of requests (default C<0>, meaning infinity) |
1881 |
|
|
that are being processed by C<IO::AIO::poll_cb> in one call, respectively |
1882 |
|
|
the maximum amount of time (default C<0>, meaning infinity) spent in |
1883 |
|
|
C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount |
1884 |
|
|
of time C<poll_cb> is allowed to use). |
1885 |
root |
1.78 |
|
1886 |
root |
1.89 |
Setting C<max_poll_time> to a non-zero value creates an overhead of one |
1887 |
|
|
syscall per request processed, which is not normally a problem unless your |
1888 |
|
|
callbacks are really really fast or your OS is really really slow (I am |
1889 |
|
|
not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead. |
1890 |
|
|
|
1891 |
root |
1.86 |
Setting these is useful if you want to ensure some level of |
1892 |
|
|
interactiveness when perl is not fast enough to process all requests in |
1893 |
|
|
time. |
1894 |
root |
1.78 |
|
1895 |
root |
1.86 |
For interactive programs, values such as C<0.01> to C<0.1> should be fine. |
1896 |
root |
1.78 |
|
1897 |
|
|
Example: Install an Event watcher that automatically calls |
1898 |
root |
1.89 |
IO::AIO::poll_cb with low priority, to ensure that other parts of the |
1899 |
root |
1.78 |
program get the CPU sometimes even under high AIO load. |
1900 |
|
|
|
1901 |
root |
1.86 |
# try not to spend much more than 0.1s in poll_cb |
1902 |
|
|
IO::AIO::max_poll_time 0.1; |
1903 |
|
|
|
1904 |
|
|
# use a low priority so other tasks have priority |
1905 |
root |
1.78 |
Event->io (fd => IO::AIO::poll_fileno, |
1906 |
|
|
poll => 'r', nice => 1, |
1907 |
root |
1.86 |
cb => &IO::AIO::poll_cb); |
1908 |
root |
1.78 |
|
1909 |
root |
1.104 |
=back |
1910 |
|
|
|
1911 |
root |
1.86 |
=head3 CONTROLLING THE NUMBER OF THREADS |
1912 |
root |
1.13 |
|
1913 |
root |
1.105 |
=over |
1914 |
|
|
|
1915 |
root |
1.5 |
=item IO::AIO::min_parallel $nthreads |
1916 |
|
|
|
1917 |
root |
1.61 |
Set the minimum number of AIO threads to C<$nthreads>. The current |
1918 |
|
|
default is C<8>, which means eight asynchronous operations can execute |
1919 |
|
|
concurrently at any one time (the number of outstanding requests, |
1920 |
|
|
however, is unlimited). |
1921 |
root |
1.5 |
|
1922 |
root |
1.34 |
IO::AIO starts threads only on demand, when an AIO request is queued and |
1923 |
root |
1.86 |
no free thread exists. Please note that queueing up a hundred requests can |
1924 |
|
|
create demand for a hundred threads, even if it turns out that everything |
1925 |
|
|
is in the cache and could have been processed faster by a single thread. |
1926 |
root |
1.34 |
|
1927 |
root |
1.61 |
It is recommended to keep the number of threads relatively low, as some |
1928 |
|
|
Linux kernel versions will scale negatively with the number of threads |
1929 |
|
|
(higher parallelity => MUCH higher latency). With current Linux 2.6 |
1930 |
|
|
versions, 4-32 threads should be fine. |
1931 |
root |
1.5 |
|
1932 |
root |
1.34 |
Under most circumstances you don't need to call this function, as the |
1933 |
|
|
module selects a default that is suitable for low to moderate load. |
1934 |
root |
1.5 |
|
1935 |
|
|
=item IO::AIO::max_parallel $nthreads |
1936 |
|
|
|
1937 |
root |
1.34 |
Sets the maximum number of AIO threads to C<$nthreads>. If more than the |
1938 |
|
|
specified number of threads are currently running, this function kills |
1939 |
|
|
them. This function blocks until the limit is reached. |
1940 |
|
|
|
1941 |
|
|
While C<$nthreads> are zero, aio requests get queued but not executed |
1942 |
|
|
until the number of threads has been increased again. |
1943 |
root |
1.5 |
|
1944 |
|
|
This module automatically runs C<max_parallel 0> at program end, to ensure |
1945 |
|
|
that all threads are killed and that there are no outstanding requests. |
1946 |
|
|
|
1947 |
|
|
Under normal circumstances you don't need to call this function. |
1948 |
|
|
|
1949 |
root |
1.86 |
=item IO::AIO::max_idle $nthreads |
1950 |
|
|
|
1951 |
root |
1.188 |
Limit the number of threads (default: 4) that are allowed to idle |
1952 |
|
|
(i.e., threads that did not get a request to process within the idle |
1953 |
|
|
timeout (default: 10 seconds). That means if a thread becomes idle while |
1954 |
|
|
C<$nthreads> other threads are also idle, it will free its resources and |
1955 |
|
|
exit. |
1956 |
root |
1.86 |
|
1957 |
|
|
This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1958 |
|
|
to allow for extremely high load situations, but want to free resources |
1959 |
|
|
under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1960 |
|
|
|
1961 |
|
|
The default is probably ok in most situations, especially if thread |
1962 |
|
|
creation is fast. If thread creation is very slow on your system you might |
1963 |
|
|
want to use larger values. |
1964 |
|
|
|
1965 |
root |
1.188 |
=item IO::AIO::idle_timeout $seconds |
1966 |
|
|
|
1967 |
|
|
Sets the minimum idle timeout (default 10) after which worker threads are |
1968 |
|
|
allowed to exit. SEe C<IO::AIO::max_idle>. |
1969 |
|
|
|
1970 |
root |
1.123 |
=item IO::AIO::max_outstanding $maxreqs |
1971 |
root |
1.5 |
|
1972 |
root |
1.195 |
Sets the maximum number of outstanding requests to C<$nreqs>. If |
1973 |
|
|
you do queue up more than this number of requests, the next call to |
1974 |
|
|
C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as |
1975 |
|
|
C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no |
1976 |
|
|
longer exceeded. |
1977 |
|
|
|
1978 |
|
|
In other words, this setting does not enforce a queue limit, but can be |
1979 |
|
|
used to make poll functions block if the limit is exceeded. |
1980 |
|
|
|
1981 |
root |
1.79 |
This is a very bad function to use in interactive programs because it |
1982 |
|
|
blocks, and a bad way to reduce concurrency because it is inexact: Better |
1983 |
|
|
use an C<aio_group> together with a feed callback. |
1984 |
|
|
|
1985 |
root |
1.248 |
Its main use is in scripts without an event loop - when you want to stat |
1986 |
root |
1.195 |
a lot of files, you can write somehting like this: |
1987 |
|
|
|
1988 |
|
|
IO::AIO::max_outstanding 32; |
1989 |
|
|
|
1990 |
|
|
for my $path (...) { |
1991 |
|
|
aio_stat $path , ...; |
1992 |
|
|
IO::AIO::poll_cb; |
1993 |
|
|
} |
1994 |
|
|
|
1995 |
|
|
IO::AIO::flush; |
1996 |
|
|
|
1997 |
|
|
The call to C<poll_cb> inside the loop will normally return instantly, but |
1998 |
|
|
as soon as more thna C<32> reqeusts are in-flight, it will block until |
1999 |
|
|
some requests have been handled. This keeps the loop from pushing a large |
2000 |
|
|
number of C<aio_stat> requests onto the queue. |
2001 |
|
|
|
2002 |
|
|
The default value for C<max_outstanding> is very large, so there is no |
2003 |
|
|
practical limit on the number of outstanding requests. |
2004 |
root |
1.5 |
|
2005 |
root |
1.104 |
=back |
2006 |
|
|
|
2007 |
root |
1.86 |
=head3 STATISTICAL INFORMATION |
2008 |
|
|
|
2009 |
root |
1.104 |
=over |
2010 |
|
|
|
2011 |
root |
1.86 |
=item IO::AIO::nreqs |
2012 |
|
|
|
2013 |
|
|
Returns the number of requests currently in the ready, execute or pending |
2014 |
|
|
states (i.e. for which their callback has not been invoked yet). |
2015 |
|
|
|
2016 |
|
|
Example: wait till there are no outstanding requests anymore: |
2017 |
|
|
|
2018 |
|
|
IO::AIO::poll_wait, IO::AIO::poll_cb |
2019 |
|
|
while IO::AIO::nreqs; |
2020 |
|
|
|
2021 |
|
|
=item IO::AIO::nready |
2022 |
|
|
|
2023 |
|
|
Returns the number of requests currently in the ready state (not yet |
2024 |
|
|
executed). |
2025 |
|
|
|
2026 |
|
|
=item IO::AIO::npending |
2027 |
|
|
|
2028 |
|
|
Returns the number of requests currently in the pending state (executed, |
2029 |
|
|
but not yet processed by poll_cb). |
2030 |
|
|
|
2031 |
root |
1.5 |
=back |
2032 |
|
|
|
2033 |
root |
1.157 |
=head3 MISCELLANEOUS FUNCTIONS |
2034 |
|
|
|
2035 |
root |
1.248 |
IO::AIO implements some functions that are useful when you want to use |
2036 |
|
|
some "Advanced I/O" function not available to in Perl, without going the |
2037 |
|
|
"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*> |
2038 |
|
|
counterpart. |
2039 |
root |
1.157 |
|
2040 |
|
|
=over 4 |
2041 |
|
|
|
2042 |
|
|
=item IO::AIO::sendfile $ofh, $ifh, $offset, $count |
2043 |
|
|
|
2044 |
|
|
Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>, |
2045 |
|
|
but is blocking (this makes most sense if you know the input data is |
2046 |
|
|
likely cached already and the output filehandle is set to non-blocking |
2047 |
|
|
operations). |
2048 |
|
|
|
2049 |
|
|
Returns the number of bytes copied, or C<-1> on error. |
2050 |
|
|
|
2051 |
|
|
=item IO::AIO::fadvise $fh, $offset, $len, $advice |
2052 |
|
|
|
2053 |
root |
1.184 |
Simply calls the C<posix_fadvise> function (see its |
2054 |
root |
1.157 |
manpage for details). The following advice constants are |
2055 |
root |
1.207 |
available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
2056 |
root |
1.157 |
C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
2057 |
|
|
C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
2058 |
|
|
|
2059 |
|
|
On systems that do not implement C<posix_fadvise>, this function returns |
2060 |
|
|
ENOSYS, otherwise the return value of C<posix_fadvise>. |
2061 |
|
|
|
2062 |
root |
1.184 |
=item IO::AIO::madvise $scalar, $offset, $len, $advice |
2063 |
|
|
|
2064 |
|
|
Simply calls the C<posix_madvise> function (see its |
2065 |
|
|
manpage for details). The following advice constants are |
2066 |
root |
1.207 |
available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
2067 |
root |
1.263 |
C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>, |
2068 |
|
|
C<IO::AIO::MADV_FREE>. |
2069 |
root |
1.184 |
|
2070 |
|
|
On systems that do not implement C<posix_madvise>, this function returns |
2071 |
|
|
ENOSYS, otherwise the return value of C<posix_madvise>. |
2072 |
|
|
|
2073 |
|
|
=item IO::AIO::mprotect $scalar, $offset, $len, $protect |
2074 |
|
|
|
2075 |
|
|
Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
2076 |
|
|
$scalar (see its manpage for details). The following protect |
2077 |
root |
1.207 |
constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
2078 |
root |
1.184 |
C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
2079 |
|
|
|
2080 |
|
|
On systems that do not implement C<mprotect>, this function returns |
2081 |
|
|
ENOSYS, otherwise the return value of C<mprotect>. |
2082 |
|
|
|
2083 |
root |
1.176 |
=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
2084 |
|
|
|
2085 |
|
|
Memory-maps a file (or anonymous memory range) and attaches it to the |
2086 |
root |
1.228 |
given C<$scalar>, which will act like a string scalar. Returns true on |
2087 |
|
|
success, and false otherwise. |
2088 |
root |
1.176 |
|
2089 |
|
|
The only operations allowed on the scalar are C<substr>/C<vec> that don't |
2090 |
|
|
change the string length, and most read-only operations such as copying it |
2091 |
|
|
or searching it with regexes and so on. |
2092 |
|
|
|
2093 |
|
|
Anything else is unsafe and will, at best, result in memory leaks. |
2094 |
|
|
|
2095 |
|
|
The memory map associated with the C<$scalar> is automatically removed |
2096 |
|
|
when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or |
2097 |
|
|
C<IO::AIO::munmap> functions are called. |
2098 |
|
|
|
2099 |
|
|
This calls the C<mmap>(2) function internally. See your system's manual |
2100 |
|
|
page for details on the C<$length>, C<$prot> and C<$flags> parameters. |
2101 |
|
|
|
2102 |
|
|
The C<$length> must be larger than zero and smaller than the actual |
2103 |
|
|
filesize. |
2104 |
|
|
|
2105 |
|
|
C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
2106 |
|
|
C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
2107 |
|
|
|
2108 |
root |
1.256 |
C<$flags> can be a combination of |
2109 |
|
|
C<IO::AIO::MAP_SHARED> or |
2110 |
|
|
C<IO::AIO::MAP_PRIVATE>, |
2111 |
|
|
or a number of system-specific flags (when not available, the are C<0>): |
2112 |
|
|
C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant), |
2113 |
|
|
C<IO::AIO::MAP_LOCKED>, |
2114 |
|
|
C<IO::AIO::MAP_NORESERVE>, |
2115 |
|
|
C<IO::AIO::MAP_POPULATE>, |
2116 |
|
|
C<IO::AIO::MAP_NONBLOCK>, |
2117 |
|
|
C<IO::AIO::MAP_FIXED>, |
2118 |
|
|
C<IO::AIO::MAP_GROWSDOWN>, |
2119 |
|
|
C<IO::AIO::MAP_32BIT>, |
2120 |
|
|
C<IO::AIO::MAP_HUGETLB> or |
2121 |
|
|
C<IO::AIO::MAP_STACK>. |
2122 |
root |
1.176 |
|
2123 |
|
|
If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
2124 |
|
|
|
2125 |
root |
1.179 |
C<$offset> is the offset from the start of the file - it generally must be |
2126 |
|
|
a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
2127 |
|
|
|
2128 |
root |
1.177 |
Example: |
2129 |
|
|
|
2130 |
|
|
use Digest::MD5; |
2131 |
|
|
use IO::AIO; |
2132 |
|
|
|
2133 |
|
|
open my $fh, "<verybigfile" |
2134 |
|
|
or die "$!"; |
2135 |
|
|
|
2136 |
|
|
IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh |
2137 |
|
|
or die "verybigfile: $!"; |
2138 |
|
|
|
2139 |
|
|
my $fast_md5 = md5 $data; |
2140 |
|
|
|
2141 |
root |
1.176 |
=item IO::AIO::munmap $scalar |
2142 |
|
|
|
2143 |
|
|
Removes a previous mmap and undefines the C<$scalar>. |
2144 |
|
|
|
2145 |
root |
1.182 |
=item IO::AIO::munlock $scalar, $offset = 0, $length = undef |
2146 |
root |
1.174 |
|
2147 |
root |
1.182 |
Calls the C<munlock> function, undoing the effects of a previous |
2148 |
|
|
C<aio_mlock> call (see its description for details). |
2149 |
root |
1.174 |
|
2150 |
|
|
=item IO::AIO::munlockall |
2151 |
|
|
|
2152 |
|
|
Calls the C<munlockall> function. |
2153 |
|
|
|
2154 |
|
|
On systems that do not implement C<munlockall>, this function returns |
2155 |
|
|
ENOSYS, otherwise the return value of C<munlockall>. |
2156 |
|
|
|
2157 |
root |
1.225 |
=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
2158 |
|
|
|
2159 |
|
|
Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or |
2160 |
|
|
C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they |
2161 |
|
|
should be the file offset. |
2162 |
|
|
|
2163 |
root |
1.227 |
C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might |
2164 |
|
|
silently corrupt the data in this case. |
2165 |
|
|
|
2166 |
root |
1.225 |
The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>, |
2167 |
|
|
C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and |
2168 |
|
|
C<IO::AIO::SPLICE_F_GIFT>. |
2169 |
|
|
|
2170 |
|
|
See the C<splice(2)> manpage for details. |
2171 |
|
|
|
2172 |
|
|
=item IO::AIO::tee $r_fh, $w_fh, $length, $flags |
2173 |
|
|
|
2174 |
root |
1.248 |
Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the |
2175 |
root |
1.225 |
description for C<IO::AIO::splice> above for details. |
2176 |
|
|
|
2177 |
root |
1.243 |
=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
2178 |
|
|
|
2179 |
|
|
Attempts to query or change the pipe buffer size. Obviously works only |
2180 |
|
|
on pipes, and currently works only on GNU/Linux systems, and fails with |
2181 |
|
|
C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer |
2182 |
|
|
size on other systems, drop me a note. |
2183 |
|
|
|
2184 |
root |
1.253 |
=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
2185 |
|
|
|
2186 |
|
|
This is a direct interface to the Linux L<pipe2(2)> system call. If |
2187 |
|
|
C<$flags> is missing or C<0>, then this should be the same as a call to |
2188 |
root |
1.254 |
perl's built-in C<pipe> function and create a new pipe, and works on |
2189 |
|
|
systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe |
2190 |
|
|
(..., 4096, O_BINARY)>. |
2191 |
root |
1.253 |
|
2192 |
|
|
If C<$flags> is non-zero, it tries to invoke the pipe2 system call with |
2193 |
|
|
the given flags (Linux 2.6.27, glibc 2.9). |
2194 |
|
|
|
2195 |
|
|
On success, the read and write file handles are returned. |
2196 |
|
|
|
2197 |
|
|
On error, nothing will be returned. If the pipe2 syscall is missing and |
2198 |
|
|
C<$flags> is non-zero, fails with C<ENOSYS>. |
2199 |
|
|
|
2200 |
|
|
Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the |
2201 |
|
|
time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and |
2202 |
|
|
C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported. |
2203 |
|
|
|
2204 |
root |
1.157 |
=back |
2205 |
|
|
|
2206 |
root |
1.1 |
=cut |
2207 |
|
|
|
2208 |
root |
1.61 |
min_parallel 8; |
2209 |
root |
1.1 |
|
2210 |
root |
1.95 |
END { flush } |
2211 |
root |
1.82 |
|
2212 |
root |
1.1 |
1; |
2213 |
|
|
|
2214 |
root |
1.175 |
=head1 EVENT LOOP INTEGRATION |
2215 |
|
|
|
2216 |
|
|
It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO |
2217 |
|
|
automatically into many event loops: |
2218 |
|
|
|
2219 |
|
|
# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
2220 |
|
|
use AnyEvent::AIO; |
2221 |
|
|
|
2222 |
|
|
You can also integrate IO::AIO manually into many event loops, here are |
2223 |
|
|
some examples of how to do this: |
2224 |
|
|
|
2225 |
|
|
# EV integration |
2226 |
|
|
my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
2227 |
|
|
|
2228 |
|
|
# Event integration |
2229 |
|
|
Event->io (fd => IO::AIO::poll_fileno, |
2230 |
|
|
poll => 'r', |
2231 |
|
|
cb => \&IO::AIO::poll_cb); |
2232 |
|
|
|
2233 |
|
|
# Glib/Gtk2 integration |
2234 |
|
|
add_watch Glib::IO IO::AIO::poll_fileno, |
2235 |
|
|
in => sub { IO::AIO::poll_cb; 1 }; |
2236 |
|
|
|
2237 |
|
|
# Tk integration |
2238 |
|
|
Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
2239 |
|
|
readable => \&IO::AIO::poll_cb); |
2240 |
|
|
|
2241 |
|
|
# Danga::Socket integration |
2242 |
|
|
Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
2243 |
|
|
\&IO::AIO::poll_cb); |
2244 |
|
|
|
2245 |
root |
1.27 |
=head2 FORK BEHAVIOUR |
2246 |
|
|
|
2247 |
root |
1.197 |
Usage of pthreads in a program changes the semantics of fork |
2248 |
|
|
considerably. Specifically, only async-safe functions can be called after |
2249 |
|
|
fork. Perl doesn't know about this, so in general, you cannot call fork |
2250 |
root |
1.204 |
with defined behaviour in perl if pthreads are involved. IO::AIO uses |
2251 |
|
|
pthreads, so this applies, but many other extensions and (for inexplicable |
2252 |
|
|
reasons) perl itself often is linked against pthreads, so this limitation |
2253 |
|
|
applies to quite a lot of perls. |
2254 |
|
|
|
2255 |
|
|
This module no longer tries to fight your OS, or POSIX. That means IO::AIO |
2256 |
|
|
only works in the process that loaded it. Forking is fully supported, but |
2257 |
|
|
using IO::AIO in the child is not. |
2258 |
|
|
|
2259 |
|
|
You might get around by not I<using> IO::AIO before (or after) |
2260 |
|
|
forking. You could also try to call the L<IO::AIO::reinit> function in the |
2261 |
|
|
child: |
2262 |
|
|
|
2263 |
|
|
=over 4 |
2264 |
|
|
|
2265 |
|
|
=item IO::AIO::reinit |
2266 |
|
|
|
2267 |
root |
1.207 |
Abandons all current requests and I/O threads and simply reinitialises all |
2268 |
|
|
data structures. This is not an operation supported by any standards, but |
2269 |
root |
1.204 |
happens to work on GNU/Linux and some newer BSD systems. |
2270 |
|
|
|
2271 |
|
|
The only reasonable use for this function is to call it after forking, if |
2272 |
|
|
C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in |
2273 |
|
|
the process will result in undefined behaviour. Calling it at any time |
2274 |
|
|
will also result in any undefined (by POSIX) behaviour. |
2275 |
|
|
|
2276 |
|
|
=back |
2277 |
root |
1.52 |
|
2278 |
root |
1.60 |
=head2 MEMORY USAGE |
2279 |
|
|
|
2280 |
root |
1.72 |
Per-request usage: |
2281 |
|
|
|
2282 |
|
|
Each aio request uses - depending on your architecture - around 100-200 |
2283 |
|
|
bytes of memory. In addition, stat requests need a stat buffer (possibly |
2284 |
|
|
a few hundred bytes), readdir requires a result buffer and so on. Perl |
2285 |
|
|
scalars and other data passed into aio requests will also be locked and |
2286 |
|
|
will consume memory till the request has entered the done state. |
2287 |
root |
1.60 |
|
2288 |
root |
1.111 |
This is not awfully much, so queuing lots of requests is not usually a |
2289 |
root |
1.60 |
problem. |
2290 |
|
|
|
2291 |
root |
1.72 |
Per-thread usage: |
2292 |
|
|
|
2293 |
|
|
In the execution phase, some aio requests require more memory for |
2294 |
|
|
temporary buffers, and each thread requires a stack and other data |
2295 |
|
|
structures (usually around 16k-128k, depending on the OS). |
2296 |
|
|
|
2297 |
|
|
=head1 KNOWN BUGS |
2298 |
|
|
|
2299 |
root |
1.73 |
Known bugs will be fixed in the next release. |
2300 |
root |
1.60 |
|
2301 |
root |
1.1 |
=head1 SEE ALSO |
2302 |
|
|
|
2303 |
root |
1.125 |
L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a |
2304 |
|
|
more natural syntax. |
2305 |
root |
1.1 |
|
2306 |
|
|
=head1 AUTHOR |
2307 |
|
|
|
2308 |
|
|
Marc Lehmann <schmorp@schmorp.de> |
2309 |
|
|
http://home.schmorp.de/ |
2310 |
|
|
|
2311 |
|
|
=cut |
2312 |
|
|
|