[ViewVC] Diff of: cvs/IO-AIO/AIO.pm

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.276 by root, Fri Sep 22 05:24:41 2017 UTC vs.
Revision 1.284 by root, Fri Mar 23 01:14:08 2018 UTC

 use common::sense;
 use base 'Exporter';
 BEGIN {
-   our $VERSION = 4.35;
+   our $VERSION = 4.4;
    our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
                      aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
                      aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
                      aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
                      aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
                      aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
                      aio_chmod aio_utime aio_truncate
                      aio_msync aio_mtouch aio_mlock aio_mlockall
                      aio_statvfs
+                     aio_slurp
                      aio_wd);
    our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
    our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
                        min_parallel max_parallel max_idle idle_timeout
    IO::AIO::idle_timeout $seconds
    IO::AIO::max_outstanding $maxreqs
    IO::AIO::nreqs
    IO::AIO::nready
    IO::AIO::npending
+   $nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
-   IO::AIO::min_fdlimit $nfd;
+   IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
    IO::AIO::sendfile $ofh, $ifh, $offset, $count
    IO::AIO::fadvise $fh, $offset, $len, $advice
    IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
    IO::AIO::munmap $scalar
       namemax => 255,
       frsize  => 1024,
       fsid    => 1810
    }
-Here is a (likely partial - send me updates!) list of fsid values used by
-Linux - it is safe to hardcode these when C<$^O> is C<linux>:
-   0x0000adf5 adfs
-   0x0000adff affs
-   0x5346414f afs
-   0x09041934 anon-inode filesystem
-   0x00000187 autofs
-   0x42465331 befs
-   0x1badface bfs
-   0x42494e4d binfmt_misc
-   0x9123683e btrfs
-   0x0027e0eb cgroupfs
-   0xff534d42 cifs
-   0x73757245 coda
-   0x012ff7b7 coh
-   0x28cd3d45 cramfs
-   0x453dcd28 cramfs-wend (wrong endianness)
-   0x64626720 debugfs
-   0x00001373 devfs
-   0x00001cd1 devpts
-   0x0000f15f ecryptfs
-   0x00414a53 efs
-   0x0000137d ext
-   0x0000ef53 ext2/ext3/ext4
-   0x0000ef51 ext2
-   0xf2f52010 f2fs
-   0x00004006 fat
-   0x65735546 fuseblk
-   0x65735543 fusectl
-   0x0bad1dea futexfs
-   0x01161970 gfs2
-   0x47504653 gpfs
-   0x00004244 hfs
-   0xf995e849 hpfs
-   0x00c0ffee hostfs
-   0x958458f6 hugetlbfs
-   0x2bad1dea inotifyfs
-   0x00009660 isofs
-   0x000072b6 jffs2
-   0x3153464a jfs
-   0x6b414653 k-afs
-   0x0bd00bd0 lustre
-   0x0000137f minix
-   0x0000138f minix 30 char names
-   0x00002468 minix v2
-   0x00002478 minix v2 30 char names
-   0x00004d5a minix v3
-   0x19800202 mqueue
-   0x00004d44 msdos
-   0x0000564c novell
-   0x00006969 nfs
-   0x6e667364 nfsd
-   0x00003434 nilfs
-   0x5346544e ntfs
-   0x00009fa1 openprom
-   0x7461636F ocfs2
-   0x00009fa0 proc
-   0x6165676c pstorefs
-   0x0000002f qnx4
-   0x68191122 qnx6
-   0x858458f6 ramfs
-   0x52654973 reiserfs
-   0x00007275 romfs
-   0x67596969 rpc_pipefs
-   0x73636673 securityfs
-   0xf97cff8c selinux
-   0x0000517b smb
-   0x534f434b sockfs
-   0x73717368 squashfs
-   0x62656572 sysfs
-   0x012ff7b6 sysv2
-   0x012ff7b5 sysv4
-   0x01021994 tmpfs
-   0x15013346 udf
-   0x00011954 ufs
-   0x54190100 ufs byteswapped
-   0x00009fa2 usbdevfs
-   0x01021997 v9fs
-   0xa501fcf5 vxfs
-   0xabba1974 xenfs
-   0x012ff7b4 xenix
-   0x58465342 xfs
-   0x012fd16d xia
 =item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
 Works like perl's C<utime> function (including the special case of $atime
 and $mtime being undef). Fractional times are supported if the underlying
 syscalls support them.
 =over 4
 =item IO::AIO::READDIR_DENTS
-When this flag is off, then the callback gets an arrayref consisting of
+Normally the callback gets an arrayref consisting of names only (as
-names only (as with C<aio_readdir>), otherwise it gets an arrayref with
+with C<aio_readdir>). If this flag is set, then the callback gets an
-C<[$name, $type, $inode]> arrayrefs, each describing a single directory
+arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
-entry in more detail.
+single directory entry in more detail:
 C<$name> is the name of the entry.
 C<$type> is one of the C<IO::AIO::DT_xxx> constants:
 C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
 C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
 C<IO::AIO::DT_WHT>.
-C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
+C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
-know, you have to run stat yourself. Also, for speed reasons, the C<$type>
+to know, you have to run stat yourself. Also, for speed/memory reasons,
-scalars are read-only: you can not modify them.
+the C<$type> scalars are read-only: you must not modify them.
 C<$inode> is the inode number (which might not be exact on systems with 64
 bit inode numbers and 32 bit perls). This field has unspecified content on
 systems that do not deliver the inode information.
 short names are tried first.
 =item IO::AIO::READDIR_STAT_ORDER
 When this flag is set, then the names will be returned in an order
-suitable for stat()'ing each one. That is, when you plan to stat()
+suitable for stat()'ing each one. That is, when you plan to stat() most or
-all files in the given directory, then the returned order will likely
+all files in the given directory, then the returned order will likely be
-be fastest.
+faster.
-If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
+If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
-the likely dirs come first, resulting in a less optimal stat order.
+then the likely dirs come first, resulting in a less optimal stat order
+for stat'ing all entries, but likely a more optimal order for finding
+subdirectories.
 =item IO::AIO::READDIR_FOUND_UNKNOWN
 This flag should not be set when calling C<aio_readdirx>. Instead, it
 is being set by C<aio_readdirx>, when any of the C<$type>'s found were
 C<$type>'s are known, which can be used to speed up some algorithms.
 =back
+=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
+Opens, reads and closes the given file. The data is put into C<$data>,
+which is resized as required.
+If C<$offset> is negative, then it is counted from the end of the file.
+If C<$length> is zero, then the remaining length of the file is
+used. Also, in this case, the same limitations to modifying C<$data> apply
+as when IO::AIO::mmap is used, i.e. it must only be modified in-place
+with C<substr>. If the size of the file is known, specifying a non-zero
+C<$length> results in a performance advantage.
+This request is similar to the older C<aio_load> request, but since it is
+a single request, it might be more efficient to use.
+Example: load F</etc/passwd> into C<$passwd>.
+   my $passwd;
+   aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
+      $_[0] >= 0
+         or die "/etc/passwd: $!\n";
+      printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
+      print $passwd;
+   };
+   IO::AIO::flush;
 =item aio_load $pathname, $data, $callback->($status)
 This is a composite request that tries to fully load the given file into
 memory. Status is the same as with aio_read.
+Using C<aio_slurp> might be more efficient, as it is a single request.
 =cut
 sub aio_load($$;$) {
    my ($path, undef, $cb) = @_;
 Scans a directory (similar to C<aio_readdir>) but additionally tries to
 efficiently separate the entries of directory C<$path> into two sets of
 names, directories you can recurse into (directories), and ones you cannot
 recurse into (everything else, including symlinks to directories).
-C<aio_scandir> is a composite request that creates of many sub requests_
+C<aio_scandir> is a composite request that generates many sub requests.
 C<$maxreq> specifies the maximum number of outstanding aio requests that
 this function generates. If it is C<< <= 0 >>, then a suitable default
 will be chosen (currently 4).
 On error, the callback is called without arguments, otherwise it receives
 C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
 C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
 C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
 C<IO::AIO::FIEMAP_EXTENT_SHARED>.
-At the time of this writing (Linux 3.2), this requets is unreliable unless
+At the time of this writing (Linux 3.2), this request is unreliable unless
 C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
-it to return all extents of a range for files with large number of
+it to return all extents of a range for files with a large number of
-extents. The code works around all these issues if C<$count> is undef.
+extents. The code (only) works around all these issues if C<$count> is
+C<undef>.
 =item aio_group $callback->(...)
 This is a very special aio request: Instead of doing something, it is a
 container for other aio requests, which is useful if you want to bundle
 There are some caveats: when directories get renamed (or deleted), the
 pathname string doesn't change, so will point to the new directory (or
 nowhere at all), while the directory fd, if available on the system,
 will still point to the original directory. Most functions accepting a
 pathname will use the directory fd on newer systems, and the string on
-older systems. Some functions (such as realpath) will always rely on the
+older systems. Some functions (such as C<aio_realpath>) will always rely on
-string form of the pathname.
+the string form of the pathname.
 So this functionality is mainly useful to get some protection against
 C<chdir>, to easily get an absolute path out of a relative path for future
 reference, and to speed up doing many operations in the same directory
 (e.g. when stat'ing all files in a directory).
 =over 4
 =item $numfd = IO::AIO::get_fdlimit
+This function is I<EXPERIMENTAL> and subject to change.
 Tries to find the current file descriptor limit and returns it, or
 C<undef> and sets C<$!> in case of an error. The limit is one larger than
 the highest valid file descriptor number.
 =item IO::AIO::min_fdlimit [$numfd]
+This function is I<EXPERIMENTAL> and subject to change.
 Try to increase the current file descriptor limit(s) to at least C<$numfd>
 by changing the soft or hard file descriptor resource limit. If C<$numfd>
 is missing, it will try to set a very high limit, although this is not
 recommended when you know the actual minimum that you require.
 Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
 time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
 C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
+Example: create a pipe race-free w.r.t. threads and fork:
+   my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
+      or die "pipe2: $!\n";
+=item $fh = IO::AIO::eventfd [$initval, [$flags]]
+This is a direct interface to the Linux L<eventfd(2)> system call. The
+(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
+On success, the new eventfd filehandle is returned, otherwise returns
+C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
+Please refer to L<eventfd(2)> for more info on this call.
+The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
+C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
+Example: create a new eventfd filehandle:
+   $fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC
+      or die "eventfd: $!\n";
+=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
+This is a direct interface to the Linux L<timerfd_create(2)> system call. The
+(unhelpful) default for C<$flags> is C<0>.
+On success, the new timerfd filehandle is returned, otherwise returns
+C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
+Please refer to L<timerfd_create(2)> for more info on this call.
+The following C<$clockid> values are
+available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
+C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
+C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
+C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
+The following C<$flags> values are available (Linux
+2.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
+Example: create a new timerfd and set it to one-second repeated alarms,
+then wait for two alarms:
+   my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
+      or die "timerfd_create: $!\n";
+   defined IO::AIO::timerfd_settime $fh, 0, 1, 1
+      or die "timerfd_settime: $!\n";
+   for (1..2) {
+      8 == sysread $fh, my $buf, 8
+         or die "timerfd read failure\n";
+      printf "number of expirations (likely 1): %d\n",
+         unpack "Q", $buf;
+   }
+=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
+This is a direct interface to the Linux L<timerfd_settime(2)> system
+call. Please refer to its manpage for more info on this call.
+The new itimerspec is specified using two (possibly fractional) second
+values, C<$new_interval> and C<$new_value>).
+On success, the current interval and value are returned (as per
+C<timerfd_gettime>). On failure, the empty list is returned.
+The following C<$flags> values are
+available: C<IO::AIO::TFD_TIMER_ABSTIME> and
+C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
+See C<IO::AIO::timerfd_create> for a full example.
+=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
+This is a direct interface to the Linux L<timerfd_gettime(2)> system
+call. Please refer to its manpage for more info on this call.
+On success, returns the current values of interval and value for the given
+timerfd (as potentially fractional second values). On failure, the empty
+list is returned.
 =back
 =cut
 min_parallel 8;
 the process will result in undefined behaviour. Calling it at any time
 will also result in any undefined (by POSIX) behaviour.
 =back
+=head2 LINUX-SPECIFIC CALLS
+When a call is documented as "linux-specific" then this means it
+originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
+availability and compatibility of such calls regardless of the platform
+it is compiled on, so platforms such as FreeBSD which often implement
+these calls will work. When in doubt, call them and see if they fail wth
+C<ENOSYS>.
 =head2 MEMORY USAGE
 Per-request usage:
 Each aio request uses - depending on your architecture - around 100-200
 temporary buffers, and each thread requires a stack and other data
 structures (usually around 16k-128k, depending on the OS).
 =head1 KNOWN BUGS
-Known bugs will be fixed in the next release.
+Known bugs will be fixed in the next release :)
+=head1 KNOWN ISSUES
+Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
+or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
+non-created hash slots or other scalars I didn't think of. It's best to
+avoid such and either use scalar variables or making sure that the scalar
+exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
+I am not sure anything can be done about this, so this is considered a
+known issue, rather than a bug.
 =head1 SEE ALSO
 L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
 more natural syntax.

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.276 by root, Fri Sep 22 05:24:41 2017 UTC vs. Revision 1.284 by root, Fri Mar 23 01:14:08 2018 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.276 by root, Fri Sep 22 05:24:41 2017 UTC vs.
Revision 1.284 by root, Fri Mar 23 01:14:08 2018 UTC