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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.88 by root, Sun Oct 29 01:50:29 2006 UTC vs.
Revision 1.94 by root, Wed Nov 8 02:01:02 2006 UTC

5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use IO::AIO; 7 use IO::AIO;
8 8
9 aio_open "/etc/passwd", O_RDONLY, 0, sub { 9 aio_open "/etc/passwd", O_RDONLY, 0, sub {
10 my ($fh) = @_; 10 my $fh = shift
11 or die "/etc/passwd: $!";
11 ... 12 ...
12 }; 13 };
13 14
14 aio_unlink "/tmp/file", sub { }; 15 aio_unlink "/tmp/file", sub { };
15 16
61etc.), but can also be used to easily do operations in parallel that are 62etc.), but can also be used to easily do operations in parallel that are
62normally done sequentially, e.g. stat'ing many files, which is much faster 63normally done sequentially, e.g. stat'ing many files, which is much faster
63on a RAID volume or over NFS when you do a number of stat operations 64on a RAID volume or over NFS when you do a number of stat operations
64concurrently. 65concurrently.
65 66
66While this works on all types of file descriptors (for example sockets), 67While most of this works on all types of file descriptors (for example
67using these functions on file descriptors that support nonblocking 68sockets), using these functions on file descriptors that support
68operation (again, sockets, pipes etc.) is very inefficient. Use an event 69nonblocking operation (again, sockets, pipes etc.) is very inefficient or
70might not work (aio_read fails on sockets/pipes/fifos). Use an event loop
69loop for that (such as the L<Event|Event> module): IO::AIO will naturally 71for that (such as the L<Event|Event> module): IO::AIO will naturally fit
70fit into such an event loop itself. 72into such an event loop itself.
71 73
72In this version, a number of threads are started that execute your 74In this version, a number of threads are started that execute your
73requests and signal their completion. You don't need thread support 75requests and signal their completion. You don't need thread support
74in perl, and the threads created by this module will not be visible 76in perl, and the threads created by this module will not be visible
75to perl. In the future, this module might make use of the native aio 77to perl. In the future, this module might make use of the native aio
98 poll => 'r', 100 poll => 'r',
99 cb => \&IO::AIO::poll_cb); 101 cb => \&IO::AIO::poll_cb);
100 102
101 # queue the request to open /etc/passwd 103 # queue the request to open /etc/passwd
102 aio_open "/etc/passwd", O_RDONLY, 0, sub { 104 aio_open "/etc/passwd", O_RDONLY, 0, sub {
103 my $fh = $_[0] 105 my $fh = shift
104 or die "error while opening: $!"; 106 or die "error while opening: $!";
105 107
106 # stat'ing filehandles is generally non-blocking 108 # stat'ing filehandles is generally non-blocking
107 my $size = -s $fh; 109 my $size = -s $fh;
108 110
188use strict 'vars'; 190use strict 'vars';
189 191
190use base 'Exporter'; 192use base 'Exporter';
191 193
192BEGIN { 194BEGIN {
193 our $VERSION = '2.1'; 195 our $VERSION = '2.2';
194 196
195 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 197 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
196 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 198 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
197 aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move 199 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link
198 aio_copy aio_group aio_nop aio_mknod); 200 aio_move aio_copy aio_group aio_nop aio_mknod);
199 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
200 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
201 min_parallel max_parallel max_idle 203 min_parallel max_parallel max_idle
202 nreqs nready npending nthreads 204 nreqs nready npending nthreads
203 max_poll_time max_poll_reqs); 205 max_poll_time max_poll_reqs);
416 418
417=item aio_symlink $srcpath, $dstpath, $callback->($status) 419=item aio_symlink $srcpath, $dstpath, $callback->($status)
418 420
419Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 421Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
420the path C<$dstpath> and call the callback with the result code. 422the path C<$dstpath> and call the callback with the result code.
423
424=item aio_readlink $path, $callback->($link)
425
426Asynchronously read the symlink specified by C<$path> and pass it to
427the callback. If an error occurs, nothing or undef gets passed to the
428callback.
421 429
422=item aio_rename $srcpath, $dstpath, $callback->($status) 430=item aio_rename $srcpath, $dstpath, $callback->($status)
423 431
424Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 432Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
425rename(2) and call the callback with the result code. 433rename(2) and call the callback with the result code.
939that are being processed by C<IO::AIO::poll_cb> in one call, respectively 947that are being processed by C<IO::AIO::poll_cb> in one call, respectively
940the maximum amount of time (default C<0>, meaning infinity) spent in 948the maximum amount of time (default C<0>, meaning infinity) spent in
941C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount 949C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
942of time C<poll_cb> is allowed to use). 950of time C<poll_cb> is allowed to use).
943 951
952Setting C<max_poll_time> to a non-zero value creates an overhead of one
953syscall per request processed, which is not normally a problem unless your
954callbacks are really really fast or your OS is really really slow (I am
955not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
956
944Setting these is useful if you want to ensure some level of 957Setting these is useful if you want to ensure some level of
945interactiveness when perl is not fast enough to process all requests in 958interactiveness when perl is not fast enough to process all requests in
946time. 959time.
947 960
948For interactive programs, values such as C<0.01> to C<0.1> should be fine. 961For interactive programs, values such as C<0.01> to C<0.1> should be fine.
949 962
950Example: Install an Event watcher that automatically calls 963Example: Install an Event watcher that automatically calls
951IO::AIO::poll_some with low priority, to ensure that other parts of the 964IO::AIO::poll_cb with low priority, to ensure that other parts of the
952program get the CPU sometimes even under high AIO load. 965program get the CPU sometimes even under high AIO load.
953 966
954 # try not to spend much more than 0.1s in poll_cb 967 # try not to spend much more than 0.1s in poll_cb
955 IO::AIO::max_poll_time 0.1; 968 IO::AIO::max_poll_time 0.1;
956 969
959 poll => 'r', nice => 1, 972 poll => 'r', nice => 1,
960 cb => &IO::AIO::poll_cb); 973 cb => &IO::AIO::poll_cb);
961 974
962=item IO::AIO::poll_wait 975=item IO::AIO::poll_wait
963 976
977If there are any outstanding requests and none of them in the result
964Wait till the result filehandle becomes ready for reading (simply does a 978phase, wait till the result filehandle becomes ready for reading (simply
965C<select> on the filehandle. This is useful if you want to synchronously 979does a C<select> on the filehandle. This is useful if you want to
966wait for some requests to finish). 980synchronously wait for some requests to finish).
967 981
968See C<nreqs> for an example. 982See C<nreqs> for an example.
969 983
970=item IO::AIO::poll 984=item IO::AIO::poll
971 985
972Waits until some requests have been handled. 986Waits until some requests have been handled.
973 987
988Returns the number of requests processed, but is otherwise strictly
974Strictly equivalent to: 989equivalent to:
975 990
976 IO::AIO::poll_wait, IO::AIO::poll_cb 991 IO::AIO::poll_wait, IO::AIO::poll_cb
977 if IO::AIO::nreqs;
978 992
979=item IO::AIO::flush 993=item IO::AIO::flush
980 994
981Wait till all outstanding AIO requests have been handled. 995Wait till all outstanding AIO requests have been handled.
982 996

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