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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.78 by root, Thu Oct 26 12:38:04 2006 UTC vs.
Revision 1.81 by root, Fri Oct 27 19:17:23 2006 UTC

                      aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
                      aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move
                      aio_group aio_nop);
    our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
    our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
-                       min_parallel max_parallel nreqs);
+                       min_parallel max_parallel nreqs nready npending);
    @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
    require XSLoader;
    XSLoader::load ("IO::AIO", $VERSION);
 environment, d) use Glib::filename_from_unicode on unicode filenames or e)
 use something else.
 =over 4
-=item aioreq_pri $pri
+=item $prev_pri = aioreq_pri [$pri]
-Sets the priority for the next aio request. The default priority
+Returns the priority value that would be used for the next request and, if
+C<$pri> is given, sets the priority for the next aio request.
-is C<0>, the minimum and maximum priorities are C<-4> and C<4>,
+The default priority is C<0>, the minimum and maximum priorities are C<-4>
-respectively. Requests with higher priority will be serviced first.
+and C<4>, respectively. Requests with higher priority will be serviced
+first.
-The priority will be reset to C<0> after each call to one of the C<aio_>
+The priority will be reset to C<0> after each call to one of the C<aio_*>
 functions.
 Example: open a file with low priority, then read something from it with
 higher priority so the read request is serviced before other low priority
 open requests (potentially spamming the cache):
 =cut
 sub aio_move($$$) {
    my ($src, $dst, $cb) = @_;
+   my $pri = aioreq_pri;
    my $grp = aio_group $cb;
+   aioreq_pri $pri;
    add $grp aio_rename $src, $dst, sub {
       if ($_[0] && $! == EXDEV) {
+         aioreq_pri $pri;
          add $grp aio_open $src, O_RDONLY, 0, sub {
             if (my $src_fh = $_[0]) {
                my @stat = stat $src_fh;
+               aioreq_pri $pri;
                add $grp aio_open $dst, O_WRONLY, 0200, sub {
                   if (my $dst_fh = $_[0]) {
+                     aioreq_pri $pri;
                      add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
                         close $src_fh;
                         if ($_[0] == $stat[7]) {
                            utime $stat[8], $stat[9], $dst;
                            chmod $stat[2] & 07777, $dst_fh;
                            chown $stat[4], $stat[5], $dst_fh;
                            close $dst_fh;
+                           aioreq_pri $pri;
                            add $grp aio_unlink $src, sub {
                               $grp->result ($_[0]);
                            };
                         } else {
                            my $errno = $!;
+                           aioreq_pri $pri;
                            add $grp aio_unlink $dst, sub {
                               $! = $errno;
                               $grp->result (-1);
                            };
                         }
 recurse into (everything else, including symlinks to directories).
 C<aio_scandir> is a composite request that creates of many sub requests_
 C<$maxreq> specifies the maximum number of outstanding aio requests that
 this function generates. If it is C<< <= 0 >>, then a suitable default
-will be chosen (currently 6).
+will be chosen (currently 4).
 On error, the callback is called without arguments, otherwise it receives
 two array-refs with path-relative entry names.
 Example:
 =cut
 sub aio_scandir($$$) {
    my ($path, $maxreq, $cb) = @_;
+   my $pri = aioreq_pri;
    my $grp = aio_group $cb;
-   $maxreq = 6 if $maxreq <= 0;
+   $maxreq = 4 if $maxreq <= 0;
    # stat once
+   aioreq_pri $pri;
    add $grp aio_stat $path, sub {
       return $grp->result () if $_[0];
       my $now = time;
       my $hash1 = join ":", (stat _)[0,1,3,7,9];
       # read the directory entries
+      aioreq_pri $pri;
       add $grp aio_readdir $path, sub {
          my $entries = shift
             or return $grp->result ();
          # stat the dir another time
+         aioreq_pri $pri;
          add $grp aio_stat $path, sub {
             my $hash2 = join ":", (stat _)[0,1,3,7,9];
             my $ndirs;
             limit $statgrp $maxreq;
             feed $statgrp sub {
                return unless @$entries;
                my $entry = pop @$entries;
+               aioreq_pri $pri;
                add $statgrp aio_stat "$path/$entry/.", sub {
                   if ($_[0] < 0) {
                      push @nondirs, $entry;
                   } else {
                      # need to check for real directory
+                     aioreq_pri $pri;
                      add $statgrp aio_lstat "$path/$entry", sub {
                         if (-d _) {
                            push @dirs, $entry;
                            unless (--$ndirs) {
 itself. Useful when you queued a lot of events but got a result early.
 =item $grp->result (...)
 Set the result value(s) that will be passed to the group callback when all
-subrequests have finished. By default, no argument will be passed.
+subrequests have finished and set thre groups errno to the current value
+of errno (just like calling C<errno> without an error number). By default,
+no argument will be passed and errno is zero.
+=item $grp->errno ([$errno])
+Sets the group errno value to C<$errno>, or the current value of errno
+when the argument is missing.
+Every aio request has an associated errno value that is restored when
+the callback is invoked. This method lets you change this value from its
+default (0).
+Calling C<result> will also set errno, so make sure you either set C<$!>
+before the call to C<result>, or call c<errno> after it.
 =item feed $grp $callback->($grp)
 Sets a feeder/generator on this group: every group can have an attached
 generator that generates requests if idle. The idea behind this is that,
 See C<nreqs> for an example.
 =item IO::AIO::nreqs
-Returns the number of requests currently outstanding (i.e. for which their
+Returns the number of requests currently in the ready, execute or pending
-callback has not been invoked yet).
+states (i.e. for which their callback has not been invoked yet).
 Example: wait till there are no outstanding requests anymore:
    IO::AIO::poll_wait, IO::AIO::poll_cb
       while IO::AIO::nreqs;
+=item IO::AIO::nready
+Returns the number of requests currently in the ready state (not yet
+executed).
+=item IO::AIO::npending
+Returns the number of requests currently in the pending state (executed,
+but not yet processed by poll_cb).
 =item IO::AIO::flush
 Wait till all outstanding AIO requests have been handled.
 This module automatically runs C<max_parallel 0> at program end, to ensure
 that all threads are killed and that there are no outstanding requests.
 Under normal circumstances you don't need to call this function.
-=item $oldnreqs = IO::AIO::max_outstanding $nreqs
+=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
-[REMOVED]
+This is a very bad function to use in interactive programs because it
+blocks, and a bad way to reduce concurrency because it is inexact: Better
+use an C<aio_group> together with a feed callback.
-Pre-2.x versions used max_outstanding for a crude request queue length limit.
-In 2.x+ you are advised to use a group and a feeder to limit
-concurrency. The max_outstanding feature ran very unstable (endless
-recursions causing segfaults, bad interaction with groups etc.) and was
-removed.
-I am deeply sorry, but I am still on the hunt for a good limiting interface.
-Original description was as follows:
-Sets the maximum number of outstanding requests to C<$nreqs>. If you try
+Sets the maximum number of outstanding requests to C<$nreqs>. If you
-to queue up more than this number of requests, the caller will block until
+to queue up more than this number of requests, the next call to the
-some requests have been handled.
+C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
+function will block until the limit is no longer exceeded.
+The default value is very large, so there is no practical limit on the
+number of outstanding requests.
+You can still queue as many requests as you want. Therefore,
+C<max_oustsanding> is mainly useful in simple scripts (with low values) or
+as a stop gap to shield against fatal memory overflow (with large values).
 =back
 =cut
    *$sym
 }
 min_parallel 8;
-END {
-   max_parallel 0;
-}
 1;
 =head2 FORK BEHAVIOUR

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing IO-AIO/AIO.pm (file contents): Revision 1.78 by root, Thu Oct 26 12:38:04 2006 UTC vs. Revision 1.81 by root, Fri Oct 27 19:17:23 2006 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.78 by root, Thu Oct 26 12:38:04 2006 UTC vs.
Revision 1.81 by root, Fri Oct 27 19:17:23 2006 UTC