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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.191 by root, Thu May 19 23:57:12 2011 UTC vs.
Revision 1.195 by root, Fri May 27 19:56:31 2011 UTC

 use common::sense;
 use base 'Exporter';
 BEGIN {
-   our $VERSION = '3.8';
+   our $VERSION = '3.9';
    our @AIO_REQ = qw(aio_sendfile 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_sync aio_fsync
                      aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
       } else {
          die "open failed: $!\n";
       }
    };
+In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>,
+C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the
+following POSIX and non-POSIX constants are available (missing ones on
+your system are, as usual, C<0>):
+C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
+C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
+C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.
 =item aio_close $fh, $callback->($status)
 Asynchronously close a file and call the callback with the result
 code.
 systems that do not deliver the inode information.
 =item IO::AIO::READDIR_DIRS_FIRST
 When this flag is set, then the names will be returned in an order where
-likely directories come first. This is useful when you need to quickly
+likely directories come first, in optimal stat order. This is useful when
-find directories, or you want to find all directories while avoiding to
+you need to quickly find directories, or you want to find all directories
-stat() each entry.
+while avoiding to stat() each entry.
 If the system returns type information in readdir, then this is used
-to find directories directly.  Otherwise, likely directories are files
+to find directories directly. Otherwise, likely directories are names
-beginning with ".", or otherwise files with no dots, of which files with
+beginning with ".", or otherwise names with no dots, of which names with
 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
 If not all requests were processed for whatever reason, the filehandle
 will still be ready when C<poll_cb> returns, so normally you don't have to
 do anything special to have it called later.
+Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
+ready, it can be beneficial to call this function from loops which submit
+a lot of requests, to make sure the results get processed when they become
+available and not just when the loop is finished and the event loop takes
+over again. This function returns very fast when there are no outstanding
+requests.
 Example: Install an Event watcher that automatically calls
 IO::AIO::poll_cb with high priority (more examples can be found in the
 SYNOPSIS section, at the top of this document):
    Event->io (fd => IO::AIO::poll_fileno,
 Sets the minimum idle timeout (default 10) after which worker threads are
 allowed to exit. SEe C<IO::AIO::max_idle>.
 =item IO::AIO::max_outstanding $maxreqs
+Sets the maximum number of outstanding requests to C<$nreqs>. If
+you do queue up more than this number of requests, the next call to
+C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
+C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
+longer exceeded.
+In other words, this setting does not enforce a queue limit, but can be
+used to make poll functions block if the limit is exceeded.
 This is a very bad function to use in interactive programs because it
 blocks, and a bad way to reduce concurrency because it is inexact: Better
 use an C<aio_group> together with a feed callback.
-Sets the maximum number of outstanding requests to C<$nreqs>. If you
+It's main use is in scripts without an event loop - when you want to stat
-do queue up more than this number of requests, the next call to the
+a lot of files, you can write somehting like this:
-C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
-function will block until the limit is no longer exceeded.
-The default value is very large, so there is no practical limit on the
+   IO::AIO::max_outstanding 32;
-number of outstanding requests.
-You can still queue as many requests as you want. Therefore,
+   for my $path (...) {
-C<max_outstanding> is mainly useful in simple scripts (with low values) or
+      aio_stat $path , ...;
-as a stop gap to shield against fatal memory overflow (with large values).
+      IO::AIO::poll_cb;
+   }
+   IO::AIO::flush;
+The call to C<poll_cb> inside the loop will normally return instantly, but
+as soon as more thna C<32> reqeusts are in-flight, it will block until
+some requests have been handled. This keeps the loop from pushing a large
+number of C<aio_stat> requests onto the queue.
+The default value for C<max_outstanding> is very large, so there is no
+practical limit on the number of outstanding requests.
 =back
 =head3 STATISTICAL INFORMATION

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.191 by root, Thu May 19 23:57:12 2011 UTC vs. Revision 1.195 by root, Fri May 27 19:56:31 2011 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.191 by root, Thu May 19 23:57:12 2011 UTC vs.
Revision 1.195 by root, Fri May 27 19:56:31 2011 UTC