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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.60 by root, Sun Oct 22 13:33:28 2006 UTC vs.
Revision 1.61 by root, Sun Oct 22 13:52:11 2006 UTC

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352Scans a directory (similar to C<aio_readdir>) but additionally tries to 352Scans a directory (similar to C<aio_readdir>) but additionally tries to
353separate the entries of directory C<$path> into two sets of names, ones 353separate the entries of directory C<$path> into two sets of names, ones
354you can recurse into (directories or links to them), and ones you cannot 354you can recurse into (directories or links to them), and ones you cannot
355recurse into (everything else). 355recurse into (everything else).
356 356
357C<aio_scandir> is a composite request that consists of many sub 357C<aio_scandir> is a composite request that creates of many sub requests_
358requests. C<$maxreq> specifies the maximum number of outstanding aio 358C<$maxreq> specifies the maximum number of outstanding aio requests that
359requests that this function generates. If it is C<< <= 0 >>, then a 359this function generates. If it is C<< <= 0 >>, then a suitable default
360suitable default will be chosen (currently 8). 360will be chosen (currently 6).
361 361
362On error, the callback is called without arguments, otherwise it receives 362On error, the callback is called without arguments, otherwise it receives
363two array-refs with path-relative entry names. 363two array-refs with path-relative entry names.
364 364
365Example: 365Example:
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404sub aio_scandir($$$) { 404sub aio_scandir($$$) {
405 my ($path, $maxreq, $cb) = @_; 405 my ($path, $maxreq, $cb) = @_;
406 406
407 my $grp = aio_group $cb; 407 my $grp = aio_group $cb;
408 408
409 $maxreq = 8 if $maxreq <= 0; 409 $maxreq = 6 if $maxreq <= 0;
410 410
411 # stat once 411 # stat once
412 add $grp aio_stat $path, sub { 412 add $grp aio_stat $path, sub {
413 return $grp->result () if $_[0]; 413 return $grp->result () if $_[0];
414 my $now = time; 414 my $now = time;
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752 IO::AIO::poll_wait, IO::AIO::poll_cb 752 IO::AIO::poll_wait, IO::AIO::poll_cb
753 if IO::AIO::nreqs; 753 if IO::AIO::nreqs;
754 754
755=item IO::AIO::min_parallel $nthreads 755=item IO::AIO::min_parallel $nthreads
756 756
757Set the minimum number of AIO threads to C<$nthreads>. The current default 757Set the minimum number of AIO threads to C<$nthreads>. The current
758is C<4>, which means four asynchronous operations can be done at one time 758default is C<8>, which means eight asynchronous operations can execute
759(the number of outstanding operations, however, is unlimited). 759concurrently at any one time (the number of outstanding requests,
760however, is unlimited).
760 761
761IO::AIO starts threads only on demand, when an AIO request is queued and 762IO::AIO starts threads only on demand, when an AIO request is queued and
762no free thread exists. 763no free thread exists.
763 764
764It is recommended to keep the number of threads low, as some Linux 765It is recommended to keep the number of threads relatively low, as some
765kernel versions will scale negatively with the number of threads (higher 766Linux kernel versions will scale negatively with the number of threads
766parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32 767(higher parallelity => MUCH higher latency). With current Linux 2.6
767threads should be fine. 768versions, 4-32 threads should be fine.
768 769
769Under most circumstances you don't need to call this function, as the 770Under most circumstances you don't need to call this function, as the
770module selects a default that is suitable for low to moderate load. 771module selects a default that is suitable for low to moderate load.
771 772
772=item IO::AIO::max_parallel $nthreads 773=item IO::AIO::max_parallel $nthreads
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813 or return undef; 814 or return undef;
814 815
815 *$sym 816 *$sym
816} 817}
817 818
818min_parallel 4; 819min_parallel 8;
819 820
820END { 821END {
821 max_parallel 0; 822 max_parallel 0;
822} 823}
823 824

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