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Revision 1.38 by root, Sat Jun 27 03:19:27 2009 UTC vs.
Revision 1.43 by root, Sun Jan 10 23:44:02 2010 UTC

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23 my $req = aio_unlink "/tmp/file", sub { }; 23 my $req = aio_unlink "/tmp/file", sub { };
24 $req->cancel; # cancel request if still in queue 24 $req->cancel; # cancel request if still in queue
25 25
26 my $grp = aio_group sub { print "all stats done\n" }; 26 my $grp = aio_group sub { print "all stats done\n" };
27 add $grp aio_stat "..." for ...; 27 add $grp aio_stat "..." for ...;
28
29 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
30 use AnyEvent::AIO;
31
32 # EV integration
33 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
34
35 # Event integration
36 Event->io (fd => IO::AIO::poll_fileno,
37 poll => 'r',
38 cb => \&IO::AIO::poll_cb);
39
40 # Glib/Gtk2 integration
41 add_watch Glib::IO IO::AIO::poll_fileno,
42 in => sub { IO::AIO::poll_cb; 1 };
43
44 # Tk integration
45 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
46 readable => \&IO::AIO::poll_cb);
47
48 # Danga::Socket integration
49 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
50 \&IO::AIO::poll_cb);
51 28
52DESCRIPTION 29DESCRIPTION
53 This module implements asynchronous I/O using whatever means your 30 This module implements asynchronous I/O using whatever means your
54 operating system supports. It is implemented as an interface to "libeio" 31 operating system supports. It is implemented as an interface to "libeio"
55 (<http://software.schmorp.de/pkg/libeio.html>). 32 (<http://software.schmorp.de/pkg/libeio.html>).
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168 anymore (except possibly for the Perl object, but its connection to 145 anymore (except possibly for the Perl object, but its connection to
169 the actual aio request is severed and calling its methods will 146 the actual aio request is severed and calling its methods will
170 either do nothing or result in a runtime error). 147 either do nothing or result in a runtime error).
171 148
172FUNCTIONS 149FUNCTIONS
150 QUICK OVERVIEW
151 This section simply lists the prototypes of the most important functions
152 for quick reference. See the following sections for function-by-function
153 documentation.
154
155 aio_open $pathname, $flags, $mode, $callback->($fh)
156 aio_close $fh, $callback->($status)
157 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
158 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
159 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
160 aio_readahead $fh,$offset,$length, $callback->($retval)
161 aio_stat $fh_or_path, $callback->($status)
162 aio_lstat $fh, $callback->($status)
163 aio_statvfs $fh_or_path, $callback->($statvfs)
164 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
165 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
166 aio_truncate $fh_or_path, $offset, $callback->($status)
167 aio_chmod $fh_or_path, $mode, $callback->($status)
168 aio_unlink $pathname, $callback->($status)
169 aio_mknod $path, $mode, $dev, $callback->($status)
170 aio_link $srcpath, $dstpath, $callback->($status)
171 aio_symlink $srcpath, $dstpath, $callback->($status)
172 aio_readlink $path, $callback->($link)
173 aio_rename $srcpath, $dstpath, $callback->($status)
174 aio_mkdir $pathname, $mode, $callback->($status)
175 aio_rmdir $pathname, $callback->($status)
176 aio_readdir $pathname, $callback->($entries)
177 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
178 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
179 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
180 aio_load $path, $data, $callback->($status)
181 aio_copy $srcpath, $dstpath, $callback->($status)
182 aio_move $srcpath, $dstpath, $callback->($status)
183 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
184 aio_rmtree $path, $callback->($status)
185 aio_sync $callback->($status)
186 aio_fsync $fh, $callback->($status)
187 aio_fdatasync $fh, $callback->($status)
188 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
189 aio_pathsync $path, $callback->($status)
190 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
191 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
192 aio_group $callback->(...)
193 aio_nop $callback->()
194
195 $prev_pri = aioreq_pri [$pri]
196 aioreq_nice $pri_adjust
197
198 IO::AIO::poll_wait
199 IO::AIO::poll_cb
200 IO::AIO::poll
201 IO::AIO::flush
202 IO::AIO::max_poll_reqs $nreqs
203 IO::AIO::max_poll_time $seconds
204 IO::AIO::min_parallel $nthreads
205 IO::AIO::max_parallel $nthreads
206 IO::AIO::max_idle $nthreads
207 IO::AIO::max_outstanding $maxreqs
208 IO::AIO::nreqs
209 IO::AIO::nready
210 IO::AIO::npending
211
212 IO::AIO::sendfile $ofh, $ifh, $offset, $count
213 IO::AIO::fadvise $fh, $offset, $len, $advice
214 IO::AIO::mlockall $flags
215 IO::AIO::munlockall
216
173 AIO REQUEST FUNCTIONS 217 AIO REQUEST FUNCTIONS
174 All the "aio_*" calls are more or less thin wrappers around the syscall 218 All the "aio_*" calls are more or less thin wrappers around the syscall
175 with the same name (sans "aio_"). The arguments are similar or 219 with the same name (sans "aio_"). The arguments are similar or
176 identical, and they all accept an additional (and optional) $callback 220 identical, and they all accept an additional (and optional) $callback
177 argument which must be a code reference. This code reference will get 221 argument which must be a code reference. This code reference will get
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313 more than one "aio_sendfile" per $out_fh, as they will interfere 357 more than one "aio_sendfile" per $out_fh, as they will interfere
314 with each other. 358 with each other.
315 359
316 This call tries to make use of a native "sendfile" syscall to 360 This call tries to make use of a native "sendfile" syscall to
317 provide zero-copy operation. For this to work, $out_fh should refer 361 provide zero-copy operation. For this to work, $out_fh should refer
318 to a socket, and $in_fh should refer to mmap'able file. 362 to a socket, and $in_fh should refer to an mmap'able file.
319 363
320 If the native sendfile call fails or is not implemented, it will be 364 If a native sendfile cannot be found or it fails with "ENOSYS",
365 "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or "ENOTSOCK",
321 emulated, so you can call "aio_sendfile" on any type of filehandle 366 it will be emulated, so you can call "aio_sendfile" on any type of
322 regardless of the limitations of the operating system. 367 filehandle regardless of the limitations of the operating system.
323 368
324 Please note, however, that "aio_sendfile" can read more bytes from 369 Please note, however, that "aio_sendfile" can read more bytes from
325 $in_fh than are written, and there is no way to find out how many 370 $in_fh than are written, and there is no way to find out how many
326 bytes have been read from "aio_sendfile" alone, as "aio_sendfile" 371 bytes have been read from "aio_sendfile" alone, as "aio_sendfile"
327 only provides the number of bytes written to $out_fh. Only if the 372 only provides the number of bytes written to $out_fh. Only if the
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362 aio_stat "/etc/passwd", sub { 407 aio_stat "/etc/passwd", sub {
363 $_[0] and die "stat failed: $!"; 408 $_[0] and die "stat failed: $!";
364 print "size is ", -s _, "\n"; 409 print "size is ", -s _, "\n";
365 }; 410 };
366 411
412 aio_statvfs $fh_or_path, $callback->($statvfs)
413 Works like the POSIX "statvfs" or "fstatvfs" syscalls, depending on
414 whether a file handle or path was passed.
415
416 On success, the callback is passed a hash reference with the
417 following members: "bsize", "frsize", "blocks", "bfree", "bavail",
418 "files", "ffree", "favail", "fsid", "flag" and "namemax". On
419 failure, "undef" is passed.
420
421 The following POSIX IO::AIO::ST_* constants are defined: "ST_RDONLY"
422 and "ST_NOSUID".
423
424 The following non-POSIX IO::AIO::ST_* flag masks are defined to
425 their correct value when available, or to 0 on systems that do not
426 support them: "ST_NODEV", "ST_NOEXEC", "ST_SYNCHRONOUS",
427 "ST_MANDLOCK", "ST_WRITE", "ST_APPEND", "ST_IMMUTABLE",
428 "ST_NOATIME", "ST_NODIRATIME" and "ST_RELATIME".
429
430 Example: stat "/wd" and dump out the data if successful.
431
432 aio_statvfs "/wd", sub {
433 my $f = $_[0]
434 or die "statvfs: $!";
435
436 use Data::Dumper;
437 say Dumper $f;
438 };
439
440 # result:
441 {
442 bsize => 1024,
443 bfree => 4333064312,
444 blocks => 10253828096,
445 files => 2050765568,
446 flag => 4096,
447 favail => 2042092649,
448 bavail => 4333064312,
449 ffree => 2042092649,
450 namemax => 255,
451 frsize => 1024,
452 fsid => 1810
453 }
454
367 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 455 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
368 Works like perl's "utime" function (including the special case of 456 Works like perl's "utime" function (including the special case of
369 $atime and $mtime being undef). Fractional times are supported if 457 $atime and $mtime being undef). Fractional times are supported if
370 the underlying syscalls support them. 458 the underlying syscalls support them.
371 459
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512 into memory. Status is the same as with aio_read. 600 into memory. Status is the same as with aio_read.
513 601
514 aio_copy $srcpath, $dstpath, $callback->($status) 602 aio_copy $srcpath, $dstpath, $callback->($status)
515 Try to copy the *file* (directories not supported as either source 603 Try to copy the *file* (directories not supported as either source
516 or destination) from $srcpath to $dstpath and call the callback with 604 or destination) from $srcpath to $dstpath and call the callback with
517 the 0 (error) or -1 ok. 605 a status of 0 (ok) or -1 (error, see $!).
518 606
519 This is a composite request that creates the destination file with 607 This is a composite request that creates the destination file with
520 mode 0200 and copies the contents of the source file into it using 608 mode 0200 and copies the contents of the source file into it using
521 "aio_sendfile", followed by restoring atime, mtime, access mode and 609 "aio_sendfile", followed by restoring atime, mtime, access mode and
522 uid/gid, in that order. 610 uid/gid, in that order.
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526 uid/gid, where errors are being ignored. 614 uid/gid, where errors are being ignored.
527 615
528 aio_move $srcpath, $dstpath, $callback->($status) 616 aio_move $srcpath, $dstpath, $callback->($status)
529 Try to move the *file* (directories not supported as either source 617 Try to move the *file* (directories not supported as either source
530 or destination) from $srcpath to $dstpath and call the callback with 618 or destination) from $srcpath to $dstpath and call the callback with
531 the 0 (error) or -1 ok. 619 a status of 0 (ok) or -1 (error, see $!).
532 620
533 This is a composite request that tries to rename(2) the file first; 621 This is a composite request that tries to rename(2) the file first;
534 if rename fails with "EXDEV", it copies the file with "aio_copy" 622 if rename fails with "EXDEV", it copies the file with "aio_copy"
535 and, if that is successful, unlinks the $srcpath. 623 and, if that is successful, unlinks the $srcpath.
536 624
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631 operations (E.g. rename). This might not work on all operating 719 operations (E.g. rename). This might not work on all operating
632 systems or have any specific effect, but usually it makes sure that 720 systems or have any specific effect, but usually it makes sure that
633 directory changes get written to disc. It works for anything that 721 directory changes get written to disc. It works for anything that
634 can be opened for read-only, not just directories. 722 can be opened for read-only, not just directories.
635 723
724 Future versions of this function might fall back to other methods
725 when "fsync" on the directory fails (such as calling "sync").
726
636 Passes 0 when everything went ok, and -1 on error. 727 Passes 0 when everything went ok, and -1 on error.
728
729 aio_msync $scalar, $offset = 0, $length = undef, flags = 0,
730 $callback->($status)
731 This is a rather advanced IO::AIO call, which only works on
732 mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it
733 also works on data scalars managed by the Sys::Mmap or Mmap modules,
734 note that the scalar must only be modified in-place while an aio
735 operation is pending on it).
736
737 It calls the "msync" function of your OS, if available, with the
738 memory area starting at $offset in the string and ending $length
739 bytes later. If $length is negative, counts from the end, and if
740 $length is "undef", then it goes till the end of the string. The
741 flags can be a combination of "IO::AIO::MS_ASYNC",
742 "IO::AIO::MS_INVALIDATE" and "IO::AIO::MS_SYNC".
743
744 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0,
745 $callback->($status)
746 This is a rather advanced IO::AIO call, which works best on
747 mmap(2)ed scalars.
748
749 It touches (reads or writes) all memory pages in the specified range
750 inside the scalar. All caveats and parameters are the same as for
751 "aio_msync", above, except for flags, which must be either 0 (which
752 reads all pages and ensures they are instantiated) or
753 "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading
754 and writing an octet from it, which dirties the page).
637 755
638 aio_group $callback->(...) 756 aio_group $callback->(...)
639 This is a very special aio request: Instead of doing something, it 757 This is a very special aio request: Instead of doing something, it
640 is a container for other aio requests, which is useful if you want 758 is a container for other aio requests, which is useful if you want
641 to bundle many requests into a single, composite, request with a 759 to bundle many requests into a single, composite, request with a
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757 875
758 $grp->cancel_subs 876 $grp->cancel_subs
759 Cancel all subrequests and clears any feeder, but not the group 877 Cancel all subrequests and clears any feeder, but not the group
760 request itself. Useful when you queued a lot of events but got a 878 request itself. Useful when you queued a lot of events but got a
761 result early. 879 result early.
880
881 The group request will finish normally (you cannot add requests to
882 the group).
762 883
763 $grp->result (...) 884 $grp->result (...)
764 Set the result value(s) that will be passed to the group callback 885 Set the result value(s) that will be passed to the group callback
765 when all subrequests have finished and set the groups errno to the 886 when all subrequests have finished and set the groups errno to the
766 current value of errno (just like calling "errno" without an error 887 current value of errno (just like calling "errno" without an error
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852 973
853 Event->io (fd => IO::AIO::poll_fileno, 974 Event->io (fd => IO::AIO::poll_fileno,
854 poll => 'r', async => 1, 975 poll => 'r', async => 1,
855 cb => \&IO::AIO::poll_cb); 976 cb => \&IO::AIO::poll_cb);
856 977
978 IO::AIO::poll_wait
979 If there are any outstanding requests and none of them in the result
980 phase, wait till the result filehandle becomes ready for reading
981 (simply does a "select" on the filehandle. This is useful if you
982 want to synchronously wait for some requests to finish).
983
984 See "nreqs" for an example.
985
986 IO::AIO::poll
987 Waits until some requests have been handled.
988
989 Returns the number of requests processed, but is otherwise strictly
990 equivalent to:
991
992 IO::AIO::poll_wait, IO::AIO::poll_cb
993
994 IO::AIO::flush
995 Wait till all outstanding AIO requests have been handled.
996
997 Strictly equivalent to:
998
999 IO::AIO::poll_wait, IO::AIO::poll_cb
1000 while IO::AIO::nreqs;
1001
857 IO::AIO::max_poll_reqs $nreqs 1002 IO::AIO::max_poll_reqs $nreqs
858 IO::AIO::max_poll_time $seconds 1003 IO::AIO::max_poll_time $seconds
859 These set the maximum number of requests (default 0, meaning 1004 These set the maximum number of requests (default 0, meaning
860 infinity) that are being processed by "IO::AIO::poll_cb" in one 1005 infinity) that are being processed by "IO::AIO::poll_cb" in one
861 call, respectively the maximum amount of time (default 0, meaning 1006 call, respectively the maximum amount of time (default 0, meaning
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884 # use a low priority so other tasks have priority 1029 # use a low priority so other tasks have priority
885 Event->io (fd => IO::AIO::poll_fileno, 1030 Event->io (fd => IO::AIO::poll_fileno,
886 poll => 'r', nice => 1, 1031 poll => 'r', nice => 1,
887 cb => &IO::AIO::poll_cb); 1032 cb => &IO::AIO::poll_cb);
888 1033
889 IO::AIO::poll_wait
890 If there are any outstanding requests and none of them in the result
891 phase, wait till the result filehandle becomes ready for reading
892 (simply does a "select" on the filehandle. This is useful if you
893 want to synchronously wait for some requests to finish).
894
895 See "nreqs" for an example.
896
897 IO::AIO::poll
898 Waits until some requests have been handled.
899
900 Returns the number of requests processed, but is otherwise strictly
901 equivalent to:
902
903 IO::AIO::poll_wait, IO::AIO::poll_cb
904
905 IO::AIO::flush
906 Wait till all outstanding AIO requests have been handled.
907
908 Strictly equivalent to:
909
910 IO::AIO::poll_wait, IO::AIO::poll_cb
911 while IO::AIO::nreqs;
912
913 CONTROLLING THE NUMBER OF THREADS 1034 CONTROLLING THE NUMBER OF THREADS
914 IO::AIO::min_parallel $nthreads 1035 IO::AIO::min_parallel $nthreads
915 Set the minimum number of AIO threads to $nthreads. The current 1036 Set the minimum number of AIO threads to $nthreads. The current
916 default is 8, which means eight asynchronous operations can execute 1037 default is 8, which means eight asynchronous operations can execute
917 concurrently at any one time (the number of outstanding requests, 1038 concurrently at any one time (the number of outstanding requests,
… …
1017 "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", 1138 "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE",
1018 "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". 1139 "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED".
1019 1140
1020 On systems that do not implement "posix_fadvise", this function 1141 On systems that do not implement "posix_fadvise", this function
1021 returns ENOSYS, otherwise the return value of "posix_fadvise". 1142 returns ENOSYS, otherwise the return value of "posix_fadvise".
1143
1144 IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1145 Memory-maps a file (or anonymous memory range) and attaches it to
1146 the given $scalar, which will act like a string scalar.
1147
1148 The only operations allowed on the scalar are "substr"/"vec" that
1149 don't change the string length, and most read-only operations such
1150 as copying it or searching it with regexes and so on.
1151
1152 Anything else is unsafe and will, at best, result in memory leaks.
1153
1154 The memory map associated with the $scalar is automatically removed
1155 when the $scalar is destroyed, or when the "IO::AIO::mmap" or
1156 "IO::AIO::munmap" functions are called.
1157
1158 This calls the "mmap"(2) function internally. See your system's
1159 manual page for details on the $length, $prot and $flags parameters.
1160
1161 The $length must be larger than zero and smaller than the actual
1162 filesize.
1163
1164 $prot is a combination of "IO::AIO::PROT_NONE",
1165 "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or
1166 "IO::AIO::PROT_WRITE",
1167
1168 $flags can be a combination of "IO::AIO::MAP_SHARED" or
1169 "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when
1170 not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS"
1171 (which is set to "MAP_ANON" if your system only provides this
1172 constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED",
1173 "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or
1174 "IO::AIO::MAP_NONBLOCK"
1175
1176 If $fh is "undef", then a file descriptor of -1 is passed.
1177
1178 $offset is the offset from the start of the file - it generally must
1179 be a multiple of "IO::AIO::PAGESIZE" and defaults to 0.
1180
1181 Example:
1182
1183 use Digest::MD5;
1184 use IO::AIO;
1185
1186 open my $fh, "<verybigfile"
1187 or die "$!";
1188
1189 IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
1190 or die "verybigfile: $!";
1191
1192 my $fast_md5 = md5 $data;
1193
1194 IO::AIO::munmap $scalar
1195 Removes a previous mmap and undefines the $scalar.
1196
1197 IO::AIO::mlockall $flags
1198 Calls the "mlockall" function with the given $flags (a combination
1199 of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL__FUTURE").
1200
1201 On systems that do not implement "mlockall", this function returns
1202 ENOSYS, otherwise the return value of "mlockall".
1203
1204 IO::AIO::munlockall
1205 Calls the "munlockall" function.
1206
1207 On systems that do not implement "munlockall", this function returns
1208 ENOSYS, otherwise the return value of "munlockall".
1209
1210EVENT LOOP INTEGRATION
1211 It is recommended to use AnyEvent::AIO to integrate IO::AIO
1212 automatically into many event loops:
1213
1214 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1215 use AnyEvent::AIO;
1216
1217 You can also integrate IO::AIO manually into many event loops, here are
1218 some examples of how to do this:
1219
1220 # EV integration
1221 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1222
1223 # Event integration
1224 Event->io (fd => IO::AIO::poll_fileno,
1225 poll => 'r',
1226 cb => \&IO::AIO::poll_cb);
1227
1228 # Glib/Gtk2 integration
1229 add_watch Glib::IO IO::AIO::poll_fileno,
1230 in => sub { IO::AIO::poll_cb; 1 };
1231
1232 # Tk integration
1233 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1234 readable => \&IO::AIO::poll_cb);
1235
1236 # Danga::Socket integration
1237 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1238 \&IO::AIO::poll_cb);
1022 1239
1023 FORK BEHAVIOUR 1240 FORK BEHAVIOUR
1024 This module should do "the right thing" when the process using it forks: 1241 This module should do "the right thing" when the process using it forks:
1025 1242
1026 Before the fork, IO::AIO enters a quiescent state where no requests can 1243 Before the fork, IO::AIO enters a quiescent state where no requests can

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