… | |
… | |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use IO::AIO; |
7 | use IO::AIO; |
8 | |
8 | |
9 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
9 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
10 | my $fh = shift |
10 | my $fh = shift |
11 | or die "/etc/passwd: $!"; |
11 | or die "/etc/passwd: $!"; |
12 | ... |
12 | ... |
13 | }; |
13 | }; |
14 | |
14 | |
… | |
… | |
76 | |
76 | |
77 | # register the IO::AIO callback with EV |
77 | # register the IO::AIO callback with EV |
78 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
78 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
79 | |
79 | |
80 | # queue the request to open /etc/passwd |
80 | # queue the request to open /etc/passwd |
81 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
81 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
82 | my $fh = shift |
82 | my $fh = shift |
83 | or die "error while opening: $!"; |
83 | or die "error while opening: $!"; |
84 | |
84 | |
85 | # stat'ing filehandles is generally non-blocking |
85 | # stat'ing filehandles is generally non-blocking |
86 | my $size = -s $fh; |
86 | my $size = -s $fh; |
… | |
… | |
168 | use common::sense; |
168 | use common::sense; |
169 | |
169 | |
170 | use base 'Exporter'; |
170 | use base 'Exporter'; |
171 | |
171 | |
172 | BEGIN { |
172 | BEGIN { |
173 | our $VERSION = '3.5'; |
173 | our $VERSION = '4.0'; |
174 | |
174 | |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
175 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
176 | aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx |
177 | aio_scandir aio_symlink aio_readlink aio_sync aio_fsync |
177 | aio_scandir aio_symlink aio_readlink aio_realpath aio_sync |
178 | aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead |
178 | aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate |
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179 | aio_pathsync aio_readahead |
179 | aio_rename aio_link aio_move aio_copy aio_group |
180 | aio_rename aio_link aio_move aio_copy aio_group |
180 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
181 | aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown |
181 | aio_chmod aio_utime aio_truncate |
182 | aio_chmod aio_utime aio_truncate |
182 | aio_msync aio_mtouch aio_statvfs); |
183 | aio_msync aio_mtouch aio_mlock aio_mlockall |
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184 | aio_statvfs |
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185 | aio_wd); |
183 | |
186 | |
184 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
187 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); |
185 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
188 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
186 | min_parallel max_parallel max_idle |
189 | min_parallel max_parallel max_idle idle_timeout |
187 | nreqs nready npending nthreads |
190 | nreqs nready npending nthreads |
188 | max_poll_time max_poll_reqs |
191 | max_poll_time max_poll_reqs |
189 | sendfile fadvise); |
192 | sendfile fadvise madvise |
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193 | mmap munmap munlock munlockall); |
190 | |
194 | |
191 | push @AIO_REQ, qw(aio_busy); # not exported |
195 | push @AIO_REQ, qw(aio_busy); # not exported |
192 | |
196 | |
193 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
197 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
194 | |
198 | |
… | |
… | |
202 | |
206 | |
203 | This section simply lists the prototypes of the most important functions |
207 | This section simply lists the prototypes of the most important functions |
204 | for quick reference. See the following sections for function-by-function |
208 | for quick reference. See the following sections for function-by-function |
205 | documentation. |
209 | documentation. |
206 | |
210 | |
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211 | aio_wd $pathname, $callback->($wd) |
207 | aio_open $pathname, $flags, $mode, $callback->($fh) |
212 | aio_open $pathname, $flags, $mode, $callback->($fh) |
208 | aio_close $fh, $callback->($status) |
213 | aio_close $fh, $callback->($status) |
209 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
214 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
210 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
215 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
211 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
216 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
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… | |
220 | aio_unlink $pathname, $callback->($status) |
225 | aio_unlink $pathname, $callback->($status) |
221 | aio_mknod $path, $mode, $dev, $callback->($status) |
226 | aio_mknod $path, $mode, $dev, $callback->($status) |
222 | aio_link $srcpath, $dstpath, $callback->($status) |
227 | aio_link $srcpath, $dstpath, $callback->($status) |
223 | aio_symlink $srcpath, $dstpath, $callback->($status) |
228 | aio_symlink $srcpath, $dstpath, $callback->($status) |
224 | aio_readlink $path, $callback->($link) |
229 | aio_readlink $path, $callback->($link) |
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230 | aio_realpath $path, $callback->($link) |
225 | aio_rename $srcpath, $dstpath, $callback->($status) |
231 | aio_rename $srcpath, $dstpath, $callback->($status) |
226 | aio_mkdir $pathname, $mode, $callback->($status) |
232 | aio_mkdir $pathname, $mode, $callback->($status) |
227 | aio_rmdir $pathname, $callback->($status) |
233 | aio_rmdir $pathname, $callback->($status) |
228 | aio_readdir $pathname, $callback->($entries) |
234 | aio_readdir $pathname, $callback->($entries) |
229 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
235 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
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… | |
233 | aio_copy $srcpath, $dstpath, $callback->($status) |
239 | aio_copy $srcpath, $dstpath, $callback->($status) |
234 | aio_move $srcpath, $dstpath, $callback->($status) |
240 | aio_move $srcpath, $dstpath, $callback->($status) |
235 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
241 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
236 | aio_rmtree $path, $callback->($status) |
242 | aio_rmtree $path, $callback->($status) |
237 | aio_sync $callback->($status) |
243 | aio_sync $callback->($status) |
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244 | aio_syncfs $fh, $callback->($status) |
238 | aio_fsync $fh, $callback->($status) |
245 | aio_fsync $fh, $callback->($status) |
239 | aio_fdatasync $fh, $callback->($status) |
246 | aio_fdatasync $fh, $callback->($status) |
240 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
247 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
241 | aio_pathsync $path, $callback->($status) |
248 | aio_pathsync $path, $callback->($status) |
242 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
249 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
243 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
250 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
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251 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
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252 | aio_mlockall $flags, $callback->($status) |
244 | aio_group $callback->(...) |
253 | aio_group $callback->(...) |
245 | aio_nop $callback->() |
254 | aio_nop $callback->() |
246 | |
255 | |
247 | $prev_pri = aioreq_pri [$pri] |
256 | $prev_pri = aioreq_pri [$pri] |
248 | aioreq_nice $pri_adjust |
257 | aioreq_nice $pri_adjust |
… | |
… | |
254 | IO::AIO::max_poll_reqs $nreqs |
263 | IO::AIO::max_poll_reqs $nreqs |
255 | IO::AIO::max_poll_time $seconds |
264 | IO::AIO::max_poll_time $seconds |
256 | IO::AIO::min_parallel $nthreads |
265 | IO::AIO::min_parallel $nthreads |
257 | IO::AIO::max_parallel $nthreads |
266 | IO::AIO::max_parallel $nthreads |
258 | IO::AIO::max_idle $nthreads |
267 | IO::AIO::max_idle $nthreads |
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268 | IO::AIO::idle_timeout $seconds |
259 | IO::AIO::max_outstanding $maxreqs |
269 | IO::AIO::max_outstanding $maxreqs |
260 | IO::AIO::nreqs |
270 | IO::AIO::nreqs |
261 | IO::AIO::nready |
271 | IO::AIO::nready |
262 | IO::AIO::npending |
272 | IO::AIO::npending |
263 | |
273 | |
264 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
274 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
265 | IO::AIO::fadvise $fh, $offset, $len, $advice |
275 | IO::AIO::fadvise $fh, $offset, $len, $advice |
266 | IO::AIO::mlockall $flags |
276 | IO::AIO::madvise $scalar, $offset, $length, $advice |
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277 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
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278 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
267 | IO::AIO::munlockall |
279 | IO::AIO::munlockall |
268 | |
280 | |
269 | =head2 AIO REQUEST FUNCTIONS |
281 | =head2 AIO REQUEST FUNCTIONS |
270 | |
282 | |
271 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
283 | All the C<aio_*> calls are more or less thin wrappers around the syscall |
… | |
… | |
352 | by the umask in effect then the request is being executed, so better never |
364 | by the umask in effect then the request is being executed, so better never |
353 | change the umask. |
365 | change the umask. |
354 | |
366 | |
355 | Example: |
367 | Example: |
356 | |
368 | |
357 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
369 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
358 | if ($_[0]) { |
370 | if ($_[0]) { |
359 | print "open successful, fh is $_[0]\n"; |
371 | print "open successful, fh is $_[0]\n"; |
360 | ... |
372 | ... |
361 | } else { |
373 | } else { |
362 | die "open failed: $!\n"; |
374 | die "open failed: $!\n"; |
363 | } |
375 | } |
364 | }; |
376 | }; |
365 | |
377 | |
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378 | In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>, |
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379 | C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the |
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380 | following POSIX and non-POSIX constants are available (missing ones on |
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381 | your system are, as usual, C<0>): |
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382 | |
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383 | C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, |
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384 | C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, |
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385 | C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. |
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386 | |
366 | |
387 | |
367 | =item aio_close $fh, $callback->($status) |
388 | =item aio_close $fh, $callback->($status) |
368 | |
389 | |
369 | Asynchronously close a file and call the callback with the result |
390 | Asynchronously close a file and call the callback with the result |
370 | code. |
391 | code. |
… | |
… | |
420 | |
441 | |
421 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
442 | Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts |
422 | reading at byte offset C<$in_offset>, and starts writing at the current |
443 | reading at byte offset C<$in_offset>, and starts writing at the current |
423 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
444 | file offset of C<$out_fh>. Because of that, it is not safe to issue more |
424 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
445 | than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each |
425 | other. |
446 | other. The same C<$in_fh> works fine though, as this function does not |
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447 | move or use the file offset of C<$in_fh>. |
426 | |
448 | |
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449 | Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than |
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450 | are written, and there is no way to find out how many more bytes have been |
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451 | read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the |
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452 | number of bytes written to C<$out_fh>. Only if the result value equals |
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453 | C<$length> one can assume that C<$length> bytes have been read. |
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454 | |
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455 | Unlike with other C<aio_> functions, it makes a lot of sense to use |
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456 | C<aio_sendfile> on non-blocking sockets, as long as one end (typically |
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457 | the C<$in_fh>) is a file - the file I/O will then be asynchronous, while |
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458 | the socket I/O will be non-blocking. Note, however, that you can run |
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459 | into a trap where C<aio_sendfile> reads some data with readahead, then |
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460 | fails to write all data, and when the socket is ready the next time, the |
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461 | data in the cache is already lost, forcing C<aio_sendfile> to again hit |
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462 | the disk. Explicit C<aio_read> + C<aio_write> let's you better control |
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463 | resource usage. |
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464 | |
427 | This call tries to make use of a native C<sendfile> syscall to provide |
465 | This call tries to make use of a native C<sendfile>-like syscall to |
428 | zero-copy operation. For this to work, C<$out_fh> should refer to a |
466 | provide zero-copy operation. For this to work, C<$out_fh> should refer to |
429 | socket, and C<$in_fh> should refer to mmap'able file. |
467 | a socket, and C<$in_fh> should refer to an mmap'able file. |
430 | |
468 | |
431 | If a native sendfile cannot be found or it fails with C<ENOSYS>, |
469 | If a native sendfile cannot be found or it fails with C<ENOSYS>, |
432 | C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>, |
470 | C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or |
433 | it will be emulated, so you can call C<aio_sendfile> on any type of |
471 | C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any |
434 | filehandle regardless of the limitations of the operating system. |
472 | type of filehandle regardless of the limitations of the operating system. |
435 | |
473 | |
436 | Please note, however, that C<aio_sendfile> can read more bytes from |
474 | As native sendfile syscalls (as practically any non-POSIX interface hacked |
437 | C<$in_fh> than are written, and there is no way to find out how many |
475 | together in a hurry to improve benchmark numbers) tend to be rather buggy |
438 | bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only |
476 | on many systems, this implementation tries to work around some known bugs |
439 | provides the number of bytes written to C<$out_fh>. Only if the result |
477 | in Linux and FreeBSD kernels (probably others, too), but that might fail, |
440 | value equals C<$length> one can assume that C<$length> bytes have been |
478 | so you really really should check the return value of C<aio_sendfile> - |
441 | read. |
479 | fewre bytes than expected might have been transferred. |
442 | |
480 | |
443 | |
481 | |
444 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
482 | =item aio_readahead $fh,$offset,$length, $callback->($retval) |
445 | |
483 | |
446 | C<aio_readahead> populates the page cache with data from a file so that |
484 | C<aio_readahead> populates the page cache with data from a file so that |
… | |
… | |
468 | for an explanation. |
506 | for an explanation. |
469 | |
507 | |
470 | Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
508 | Currently, the stats are always 64-bit-stats, i.e. instead of returning an |
471 | error when stat'ing a large file, the results will be silently truncated |
509 | error when stat'ing a large file, the results will be silently truncated |
472 | unless perl itself is compiled with large file support. |
510 | unless perl itself is compiled with large file support. |
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511 | |
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512 | To help interpret the mode and dev/rdev stat values, IO::AIO offers the |
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513 | following constants and functions (if not implemented, the constants will |
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514 | be C<0> and the functions will either C<croak> or fall back on traditional |
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515 | behaviour). |
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516 | |
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517 | C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>, |
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518 | C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>, |
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519 | C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>. |
473 | |
520 | |
474 | Example: Print the length of F</etc/passwd>: |
521 | Example: Print the length of F</etc/passwd>: |
475 | |
522 | |
476 | aio_stat "/etc/passwd", sub { |
523 | aio_stat "/etc/passwd", sub { |
477 | $_[0] and die "stat failed: $!"; |
524 | $_[0] and die "stat failed: $!"; |
… | |
… | |
579 | |
626 | |
580 | The only (POSIX-) portable way of calling this function is: |
627 | The only (POSIX-) portable way of calling this function is: |
581 | |
628 | |
582 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
629 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
583 | |
630 | |
|
|
631 | See C<aio_stat> for info about some potentially helpful extra constants |
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|
632 | and functions. |
584 | |
633 | |
585 | =item aio_link $srcpath, $dstpath, $callback->($status) |
634 | =item aio_link $srcpath, $dstpath, $callback->($status) |
586 | |
635 | |
587 | Asynchronously create a new link to the existing object at C<$srcpath> at |
636 | Asynchronously create a new link to the existing object at C<$srcpath> at |
588 | the path C<$dstpath> and call the callback with the result code. |
637 | the path C<$dstpath> and call the callback with the result code. |
… | |
… | |
599 | Asynchronously read the symlink specified by C<$path> and pass it to |
648 | Asynchronously read the symlink specified by C<$path> and pass it to |
600 | the callback. If an error occurs, nothing or undef gets passed to the |
649 | the callback. If an error occurs, nothing or undef gets passed to the |
601 | callback. |
650 | callback. |
602 | |
651 | |
603 | |
652 | |
|
|
653 | =item aio_realpath $path, $callback->($path) |
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654 | |
|
|
655 | Asynchronously make the path absolute and resolve any symlinks in |
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656 | C<$path>. The resulting path only consists of directories (Same as |
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657 | L<Cwd::realpath>). |
|
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658 | |
|
|
659 | This request can be used to get the absolute path of the current working |
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660 | directory by passing it a path of F<.> (a single dot). |
|
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661 | |
|
|
662 | |
604 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
663 | =item aio_rename $srcpath, $dstpath, $callback->($status) |
605 | |
664 | |
606 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
665 | Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as |
607 | rename(2) and call the callback with the result code. |
666 | rename(2) and call the callback with the result code. |
608 | |
667 | |
… | |
… | |
630 | array-ref with the filenames. |
689 | array-ref with the filenames. |
631 | |
690 | |
632 | |
691 | |
633 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
692 | =item aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
634 | |
693 | |
635 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune |
694 | Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to |
636 | behaviour and output format. In case of an error, C<$entries> will be |
695 | tune behaviour and output format. In case of an error, C<$entries> will be |
637 | C<undef>. |
696 | C<undef>. |
638 | |
697 | |
639 | The flags are a combination of the following constants, ORed together (the |
698 | The flags are a combination of the following constants, ORed together (the |
640 | flags will also be passed to the callback, possibly modified): |
699 | flags will also be passed to the callback, possibly modified): |
641 | |
700 | |
642 | =over 4 |
701 | =over 4 |
643 | |
702 | |
644 | =item IO::AIO::READDIR_DENTS |
703 | =item IO::AIO::READDIR_DENTS |
645 | |
704 | |
646 | When this flag is off, then the callback gets an arrayref with of names |
705 | When this flag is off, then the callback gets an arrayref consisting of |
647 | only (as with C<aio_readdir>), otherwise it gets an arrayref with |
706 | names only (as with C<aio_readdir>), otherwise it gets an arrayref with |
648 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
707 | C<[$name, $type, $inode]> arrayrefs, each describing a single directory |
649 | entry in more detail. |
708 | entry in more detail. |
650 | |
709 | |
651 | C<$name> is the name of the entry. |
710 | C<$name> is the name of the entry. |
652 | |
711 | |
… | |
… | |
665 | systems that do not deliver the inode information. |
724 | systems that do not deliver the inode information. |
666 | |
725 | |
667 | =item IO::AIO::READDIR_DIRS_FIRST |
726 | =item IO::AIO::READDIR_DIRS_FIRST |
668 | |
727 | |
669 | When this flag is set, then the names will be returned in an order where |
728 | When this flag is set, then the names will be returned in an order where |
670 | likely directories come first. This is useful when you need to quickly |
729 | likely directories come first, in optimal stat order. This is useful when |
671 | find directories, or you want to find all directories while avoiding to |
730 | you need to quickly find directories, or you want to find all directories |
672 | stat() each entry. |
731 | while avoiding to stat() each entry. |
673 | |
732 | |
674 | If the system returns type information in readdir, then this is used |
733 | If the system returns type information in readdir, then this is used |
675 | to find directories directly. Otherwise, likely directories are files |
734 | to find directories directly. Otherwise, likely directories are names |
676 | beginning with ".", or otherwise files with no dots, of which files with |
735 | beginning with ".", or otherwise names with no dots, of which names with |
677 | short names are tried first. |
736 | short names are tried first. |
678 | |
737 | |
679 | =item IO::AIO::READDIR_STAT_ORDER |
738 | =item IO::AIO::READDIR_STAT_ORDER |
680 | |
739 | |
681 | When this flag is set, then the names will be returned in an order |
740 | When this flag is set, then the names will be returned in an order |
… | |
… | |
688 | |
747 | |
689 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
748 | =item IO::AIO::READDIR_FOUND_UNKNOWN |
690 | |
749 | |
691 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
750 | This flag should not be set when calling C<aio_readdirx>. Instead, it |
692 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
751 | is being set by C<aio_readdirx>, when any of the C<$type>'s found were |
693 | C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all |
752 | C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all |
694 | C<$type>'s are known, which can be used to speed up some algorithms. |
753 | C<$type>'s are known, which can be used to speed up some algorithms. |
695 | |
754 | |
696 | =back |
755 | =back |
697 | |
756 | |
698 | |
757 | |
… | |
… | |
826 | if ($_[0] && $! == EXDEV) { |
885 | if ($_[0] && $! == EXDEV) { |
827 | aioreq_pri $pri; |
886 | aioreq_pri $pri; |
828 | add $grp aio_copy $src, $dst, sub { |
887 | add $grp aio_copy $src, $dst, sub { |
829 | $grp->result ($_[0]); |
888 | $grp->result ($_[0]); |
830 | |
889 | |
831 | if (!$_[0]) { |
890 | unless ($_[0]) { |
832 | aioreq_pri $pri; |
891 | aioreq_pri $pri; |
833 | add $grp aio_unlink $src; |
892 | add $grp aio_unlink $src; |
834 | } |
893 | } |
835 | }; |
894 | }; |
836 | } else { |
895 | } else { |
… | |
… | |
880 | Then entries will be sorted into likely directories a non-initial dot |
939 | Then entries will be sorted into likely directories a non-initial dot |
881 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
940 | currently) and likely non-directories (see C<aio_readdirx>). Then every |
882 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
941 | entry plus an appended C</.> will be C<stat>'ed, likely directories first, |
883 | in order of their inode numbers. If that succeeds, it assumes that the |
942 | in order of their inode numbers. If that succeeds, it assumes that the |
884 | entry is a directory or a symlink to directory (which will be checked |
943 | entry is a directory or a symlink to directory (which will be checked |
885 | seperately). This is often faster than stat'ing the entry itself because |
944 | separately). This is often faster than stat'ing the entry itself because |
886 | filesystems might detect the type of the entry without reading the inode |
945 | filesystems might detect the type of the entry without reading the inode |
887 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
946 | data (e.g. ext2fs filetype feature), even on systems that cannot return |
888 | the filetype information on readdir. |
947 | the filetype information on readdir. |
889 | |
948 | |
890 | If the known number of directories (link count - 2) has been reached, the |
949 | If the known number of directories (link count - 2) has been reached, the |
… | |
… | |
1028 | callback with the fdatasync result code. |
1087 | callback with the fdatasync result code. |
1029 | |
1088 | |
1030 | If this call isn't available because your OS lacks it or it couldn't be |
1089 | If this call isn't available because your OS lacks it or it couldn't be |
1031 | detected, it will be emulated by calling C<fsync> instead. |
1090 | detected, it will be emulated by calling C<fsync> instead. |
1032 | |
1091 | |
|
|
1092 | =item aio_syncfs $fh, $callback->($status) |
|
|
1093 | |
|
|
1094 | Asynchronously call the syncfs syscall to sync the filesystem associated |
|
|
1095 | to the given filehandle and call the callback with the syncfs result |
|
|
1096 | code. If syncfs is not available, calls sync(), but returns C<-1> and sets |
|
|
1097 | errno to C<ENOSYS> nevertheless. |
|
|
1098 | |
1033 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1099 | =item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
1034 | |
1100 | |
1035 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1101 | Sync the data portion of the file specified by C<$offset> and C<$length> |
1036 | to disk (but NOT the metadata), by calling the Linux-specific |
1102 | to disk (but NOT the metadata), by calling the Linux-specific |
1037 | sync_file_range call. If sync_file_range is not available or it returns |
1103 | sync_file_range call. If sync_file_range is not available or it returns |
… | |
… | |
1084 | } |
1150 | } |
1085 | |
1151 | |
1086 | =item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1152 | =item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
1087 | |
1153 | |
1088 | This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1154 | This is a rather advanced IO::AIO call, which only works on mmap(2)ed |
1089 | scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note |
1155 | scalars (see the C<IO::AIO::mmap> function, although it also works on data |
|
|
1156 | scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the |
1090 | that the scalar must only be modified in-place while an aio operation is |
1157 | scalar must only be modified in-place while an aio operation is pending on |
1091 | pending on it). |
1158 | it). |
1092 | |
1159 | |
1093 | It calls the C<msync> function of your OS, if available, with the memory |
1160 | It calls the C<msync> function of your OS, if available, with the memory |
1094 | area starting at C<$offset> in the string and ending C<$length> bytes |
1161 | area starting at C<$offset> in the string and ending C<$length> bytes |
1095 | later. If C<$length> is negative, counts from the end, and if C<$length> |
1162 | later. If C<$length> is negative, counts from the end, and if C<$length> |
1096 | is C<undef>, then it goes till the end of the string. The flags can be |
1163 | is C<undef>, then it goes till the end of the string. The flags can be |
… | |
… | |
1107 | as for C<aio_msync>, above, except for flags, which must be either |
1174 | as for C<aio_msync>, above, except for flags, which must be either |
1108 | C<0> (which reads all pages and ensures they are instantiated) or |
1175 | C<0> (which reads all pages and ensures they are instantiated) or |
1109 | C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and |
1176 | C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and |
1110 | writing an octet from it, which dirties the page). |
1177 | writing an octet from it, which dirties the page). |
1111 | |
1178 | |
|
|
1179 | =item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
|
|
1180 | |
|
|
1181 | This is a rather advanced IO::AIO call, which works best on mmap(2)ed |
|
|
1182 | scalars. |
|
|
1183 | |
|
|
1184 | It reads in all the pages of the underlying storage into memory (if any) |
|
|
1185 | and locks them, so they are not getting swapped/paged out or removed. |
|
|
1186 | |
|
|
1187 | If C<$length> is undefined, then the scalar will be locked till the end. |
|
|
1188 | |
|
|
1189 | On systems that do not implement C<mlock>, this function returns C<-1> |
|
|
1190 | and sets errno to C<ENOSYS>. |
|
|
1191 | |
|
|
1192 | Note that the corresponding C<munlock> is synchronous and is |
|
|
1193 | documented under L<MISCELLANEOUS FUNCTIONS>. |
|
|
1194 | |
|
|
1195 | Example: open a file, mmap and mlock it - both will be undone when |
|
|
1196 | C<$data> gets destroyed. |
|
|
1197 | |
|
|
1198 | open my $fh, "<", $path or die "$path: $!"; |
|
|
1199 | my $data; |
|
|
1200 | IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
|
|
1201 | aio_mlock $data; # mlock in background |
|
|
1202 | |
|
|
1203 | =item aio_mlockall $flags, $callback->($status) |
|
|
1204 | |
|
|
1205 | Calls the C<mlockall> function with the given C<$flags> (a combination of |
|
|
1206 | C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>). |
|
|
1207 | |
|
|
1208 | On systems that do not implement C<mlockall>, this function returns C<-1> |
|
|
1209 | and sets errno to C<ENOSYS>. |
|
|
1210 | |
|
|
1211 | Note that the corresponding C<munlockall> is synchronous and is |
|
|
1212 | documented under L<MISCELLANEOUS FUNCTIONS>. |
|
|
1213 | |
|
|
1214 | Example: asynchronously lock all current and future pages into memory. |
|
|
1215 | |
|
|
1216 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1217 | |
1112 | =item aio_group $callback->(...) |
1218 | =item aio_group $callback->(...) |
1113 | |
1219 | |
1114 | This is a very special aio request: Instead of doing something, it is a |
1220 | This is a very special aio request: Instead of doing something, it is a |
1115 | container for other aio requests, which is useful if you want to bundle |
1221 | container for other aio requests, which is useful if you want to bundle |
1116 | many requests into a single, composite, request with a definite callback |
1222 | many requests into a single, composite, request with a definite callback |
… | |
… | |
1339 | |
1445 | |
1340 | See C<poll_cb> for an example. |
1446 | See C<poll_cb> for an example. |
1341 | |
1447 | |
1342 | =item IO::AIO::poll_cb |
1448 | =item IO::AIO::poll_cb |
1343 | |
1449 | |
1344 | Process some outstanding events on the result pipe. You have to call this |
1450 | Process some outstanding events on the result pipe. You have to call |
1345 | regularly. Returns C<0> if all events could be processed, or C<-1> if it |
1451 | this regularly. Returns C<0> if all events could be processed (or there |
1346 | returned earlier for whatever reason. Returns immediately when no events |
1452 | were no events to process), or C<-1> if it returned earlier for whatever |
1347 | are outstanding. The amount of events processed depends on the settings of |
1453 | reason. Returns immediately when no events are outstanding. The amount of |
1348 | C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. |
1454 | events processed depends on the settings of C<IO::AIO::max_poll_req> and |
|
|
1455 | C<IO::AIO::max_poll_time>. |
1349 | |
1456 | |
1350 | If not all requests were processed for whatever reason, the filehandle |
1457 | If not all requests were processed for whatever reason, the filehandle |
1351 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1458 | will still be ready when C<poll_cb> returns, so normally you don't have to |
1352 | do anything special to have it called later. |
1459 | do anything special to have it called later. |
|
|
1460 | |
|
|
1461 | Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes |
|
|
1462 | ready, it can be beneficial to call this function from loops which submit |
|
|
1463 | a lot of requests, to make sure the results get processed when they become |
|
|
1464 | available and not just when the loop is finished and the event loop takes |
|
|
1465 | over again. This function returns very fast when there are no outstanding |
|
|
1466 | requests. |
1353 | |
1467 | |
1354 | Example: Install an Event watcher that automatically calls |
1468 | Example: Install an Event watcher that automatically calls |
1355 | IO::AIO::poll_cb with high priority (more examples can be found in the |
1469 | IO::AIO::poll_cb with high priority (more examples can be found in the |
1356 | SYNOPSIS section, at the top of this document): |
1470 | SYNOPSIS section, at the top of this document): |
1357 | |
1471 | |
… | |
… | |
1459 | |
1573 | |
1460 | Under normal circumstances you don't need to call this function. |
1574 | Under normal circumstances you don't need to call this function. |
1461 | |
1575 | |
1462 | =item IO::AIO::max_idle $nthreads |
1576 | =item IO::AIO::max_idle $nthreads |
1463 | |
1577 | |
1464 | Limit the number of threads (default: 4) that are allowed to idle (i.e., |
1578 | Limit the number of threads (default: 4) that are allowed to idle |
1465 | threads that did not get a request to process within 10 seconds). That |
1579 | (i.e., threads that did not get a request to process within the idle |
1466 | means if a thread becomes idle while C<$nthreads> other threads are also |
1580 | timeout (default: 10 seconds). That means if a thread becomes idle while |
1467 | idle, it will free its resources and exit. |
1581 | C<$nthreads> other threads are also idle, it will free its resources and |
|
|
1582 | exit. |
1468 | |
1583 | |
1469 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1584 | This is useful when you allow a large number of threads (e.g. 100 or 1000) |
1470 | to allow for extremely high load situations, but want to free resources |
1585 | to allow for extremely high load situations, but want to free resources |
1471 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1586 | under normal circumstances (1000 threads can easily consume 30MB of RAM). |
1472 | |
1587 | |
1473 | The default is probably ok in most situations, especially if thread |
1588 | The default is probably ok in most situations, especially if thread |
1474 | creation is fast. If thread creation is very slow on your system you might |
1589 | creation is fast. If thread creation is very slow on your system you might |
1475 | want to use larger values. |
1590 | want to use larger values. |
1476 | |
1591 | |
|
|
1592 | =item IO::AIO::idle_timeout $seconds |
|
|
1593 | |
|
|
1594 | Sets the minimum idle timeout (default 10) after which worker threads are |
|
|
1595 | allowed to exit. SEe C<IO::AIO::max_idle>. |
|
|
1596 | |
1477 | =item IO::AIO::max_outstanding $maxreqs |
1597 | =item IO::AIO::max_outstanding $maxreqs |
|
|
1598 | |
|
|
1599 | Sets the maximum number of outstanding requests to C<$nreqs>. If |
|
|
1600 | you do queue up more than this number of requests, the next call to |
|
|
1601 | C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as |
|
|
1602 | C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no |
|
|
1603 | longer exceeded. |
|
|
1604 | |
|
|
1605 | In other words, this setting does not enforce a queue limit, but can be |
|
|
1606 | used to make poll functions block if the limit is exceeded. |
1478 | |
1607 | |
1479 | This is a very bad function to use in interactive programs because it |
1608 | This is a very bad function to use in interactive programs because it |
1480 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1609 | blocks, and a bad way to reduce concurrency because it is inexact: Better |
1481 | use an C<aio_group> together with a feed callback. |
1610 | use an C<aio_group> together with a feed callback. |
1482 | |
1611 | |
1483 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
1612 | It's main use is in scripts without an event loop - when you want to stat |
1484 | do queue up more than this number of requests, the next call to the |
1613 | a lot of files, you can write somehting like this: |
1485 | C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) |
|
|
1486 | function will block until the limit is no longer exceeded. |
|
|
1487 | |
1614 | |
1488 | The default value is very large, so there is no practical limit on the |
1615 | IO::AIO::max_outstanding 32; |
1489 | number of outstanding requests. |
|
|
1490 | |
1616 | |
1491 | You can still queue as many requests as you want. Therefore, |
1617 | for my $path (...) { |
1492 | C<max_outstanding> is mainly useful in simple scripts (with low values) or |
1618 | aio_stat $path , ...; |
1493 | as a stop gap to shield against fatal memory overflow (with large values). |
1619 | IO::AIO::poll_cb; |
|
|
1620 | } |
|
|
1621 | |
|
|
1622 | IO::AIO::flush; |
|
|
1623 | |
|
|
1624 | The call to C<poll_cb> inside the loop will normally return instantly, but |
|
|
1625 | as soon as more thna C<32> reqeusts are in-flight, it will block until |
|
|
1626 | some requests have been handled. This keeps the loop from pushing a large |
|
|
1627 | number of C<aio_stat> requests onto the queue. |
|
|
1628 | |
|
|
1629 | The default value for C<max_outstanding> is very large, so there is no |
|
|
1630 | practical limit on the number of outstanding requests. |
1494 | |
1631 | |
1495 | =back |
1632 | =back |
1496 | |
1633 | |
1497 | =head3 STATISTICAL INFORMATION |
1634 | =head3 STATISTICAL INFORMATION |
1498 | |
1635 | |
… | |
… | |
1536 | |
1673 | |
1537 | Returns the number of bytes copied, or C<-1> on error. |
1674 | Returns the number of bytes copied, or C<-1> on error. |
1538 | |
1675 | |
1539 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1676 | =item IO::AIO::fadvise $fh, $offset, $len, $advice |
1540 | |
1677 | |
1541 | Simply calls the C<posix_fadvise> function (see it's |
1678 | Simply calls the C<posix_fadvise> function (see its |
1542 | manpage for details). The following advice constants are |
1679 | manpage for details). The following advice constants are |
1543 | avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1680 | available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, |
1544 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1681 | C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, |
1545 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1682 | C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. |
1546 | |
1683 | |
1547 | On systems that do not implement C<posix_fadvise>, this function returns |
1684 | On systems that do not implement C<posix_fadvise>, this function returns |
1548 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1685 | ENOSYS, otherwise the return value of C<posix_fadvise>. |
1549 | |
1686 | |
1550 | =item IO::AIO::mlockall $flags |
1687 | =item IO::AIO::madvise $scalar, $offset, $len, $advice |
1551 | |
1688 | |
1552 | Calls the C<mlockall> function with the given C<$flags> (a combination of |
1689 | Simply calls the C<posix_madvise> function (see its |
1553 | C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>). |
1690 | manpage for details). The following advice constants are |
|
|
1691 | available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, |
|
|
1692 | C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. |
1554 | |
1693 | |
|
|
1694 | On systems that do not implement C<posix_madvise>, this function returns |
|
|
1695 | ENOSYS, otherwise the return value of C<posix_madvise>. |
|
|
1696 | |
|
|
1697 | =item IO::AIO::mprotect $scalar, $offset, $len, $protect |
|
|
1698 | |
|
|
1699 | Simply calls the C<mprotect> function on the preferably AIO::mmap'ed |
|
|
1700 | $scalar (see its manpage for details). The following protect |
|
|
1701 | constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, |
|
|
1702 | C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. |
|
|
1703 | |
1555 | On systems that do not implement C<mlockall>, this function returns |
1704 | On systems that do not implement C<mprotect>, this function returns |
1556 | ENOSYS, otherwise the return value of C<mlockall>. |
1705 | ENOSYS, otherwise the return value of C<mprotect>. |
|
|
1706 | |
|
|
1707 | =item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
|
|
1708 | |
|
|
1709 | Memory-maps a file (or anonymous memory range) and attaches it to the |
|
|
1710 | given C<$scalar>, which will act like a string scalar. |
|
|
1711 | |
|
|
1712 | The only operations allowed on the scalar are C<substr>/C<vec> that don't |
|
|
1713 | change the string length, and most read-only operations such as copying it |
|
|
1714 | or searching it with regexes and so on. |
|
|
1715 | |
|
|
1716 | Anything else is unsafe and will, at best, result in memory leaks. |
|
|
1717 | |
|
|
1718 | The memory map associated with the C<$scalar> is automatically removed |
|
|
1719 | when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or |
|
|
1720 | C<IO::AIO::munmap> functions are called. |
|
|
1721 | |
|
|
1722 | This calls the C<mmap>(2) function internally. See your system's manual |
|
|
1723 | page for details on the C<$length>, C<$prot> and C<$flags> parameters. |
|
|
1724 | |
|
|
1725 | The C<$length> must be larger than zero and smaller than the actual |
|
|
1726 | filesize. |
|
|
1727 | |
|
|
1728 | C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, |
|
|
1729 | C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, |
|
|
1730 | |
|
|
1731 | C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or |
|
|
1732 | C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when |
|
|
1733 | not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> |
|
|
1734 | (which is set to C<MAP_ANON> if your system only provides this |
|
|
1735 | constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, |
|
|
1736 | C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or |
|
|
1737 | C<IO::AIO::MAP_NONBLOCK> |
|
|
1738 | |
|
|
1739 | If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. |
|
|
1740 | |
|
|
1741 | C<$offset> is the offset from the start of the file - it generally must be |
|
|
1742 | a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. |
|
|
1743 | |
|
|
1744 | Example: |
|
|
1745 | |
|
|
1746 | use Digest::MD5; |
|
|
1747 | use IO::AIO; |
|
|
1748 | |
|
|
1749 | open my $fh, "<verybigfile" |
|
|
1750 | or die "$!"; |
|
|
1751 | |
|
|
1752 | IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh |
|
|
1753 | or die "verybigfile: $!"; |
|
|
1754 | |
|
|
1755 | my $fast_md5 = md5 $data; |
|
|
1756 | |
|
|
1757 | =item IO::AIO::munmap $scalar |
|
|
1758 | |
|
|
1759 | Removes a previous mmap and undefines the C<$scalar>. |
|
|
1760 | |
|
|
1761 | =item IO::AIO::munlock $scalar, $offset = 0, $length = undef |
|
|
1762 | |
|
|
1763 | Calls the C<munlock> function, undoing the effects of a previous |
|
|
1764 | C<aio_mlock> call (see its description for details). |
1557 | |
1765 | |
1558 | =item IO::AIO::munlockall |
1766 | =item IO::AIO::munlockall |
1559 | |
1767 | |
1560 | Calls the C<munlockall> function. |
1768 | Calls the C<munlockall> function. |
1561 | |
1769 | |
… | |
… | |
1603 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1811 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
1604 | \&IO::AIO::poll_cb); |
1812 | \&IO::AIO::poll_cb); |
1605 | |
1813 | |
1606 | =head2 FORK BEHAVIOUR |
1814 | =head2 FORK BEHAVIOUR |
1607 | |
1815 | |
1608 | This module should do "the right thing" when the process using it forks: |
1816 | Usage of pthreads in a program changes the semantics of fork |
|
|
1817 | considerably. Specifically, only async-safe functions can be called after |
|
|
1818 | fork. Perl doesn't know about this, so in general, you cannot call fork |
|
|
1819 | with defined behaviour in perl if pthreads are involved. IO::AIO uses |
|
|
1820 | pthreads, so this applies, but many other extensions and (for inexplicable |
|
|
1821 | reasons) perl itself often is linked against pthreads, so this limitation |
|
|
1822 | applies to quite a lot of perls. |
1609 | |
1823 | |
1610 | Before the fork, IO::AIO enters a quiescent state where no requests |
1824 | This module no longer tries to fight your OS, or POSIX. That means IO::AIO |
1611 | can be added in other threads and no results will be processed. After |
1825 | only works in the process that loaded it. Forking is fully supported, but |
1612 | the fork the parent simply leaves the quiescent state and continues |
1826 | using IO::AIO in the child is not. |
1613 | request/result processing, while the child frees the request/result queue |
|
|
1614 | (so that the requests started before the fork will only be handled in the |
|
|
1615 | parent). Threads will be started on demand until the limit set in the |
|
|
1616 | parent process has been reached again. |
|
|
1617 | |
1827 | |
1618 | In short: the parent will, after a short pause, continue as if fork had |
1828 | You might get around by not I<using> IO::AIO before (or after) |
1619 | not been called, while the child will act as if IO::AIO has not been used |
1829 | forking. You could also try to call the L<IO::AIO::reinit> function in the |
1620 | yet. |
1830 | child: |
|
|
1831 | |
|
|
1832 | =over 4 |
|
|
1833 | |
|
|
1834 | =item IO::AIO::reinit |
|
|
1835 | |
|
|
1836 | Abandons all current requests and I/O threads and simply reinitialises all |
|
|
1837 | data structures. This is not an operation supported by any standards, but |
|
|
1838 | happens to work on GNU/Linux and some newer BSD systems. |
|
|
1839 | |
|
|
1840 | The only reasonable use for this function is to call it after forking, if |
|
|
1841 | C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in |
|
|
1842 | the process will result in undefined behaviour. Calling it at any time |
|
|
1843 | will also result in any undefined (by POSIX) behaviour. |
|
|
1844 | |
|
|
1845 | =back |
1621 | |
1846 | |
1622 | =head2 MEMORY USAGE |
1847 | =head2 MEMORY USAGE |
1623 | |
1848 | |
1624 | Per-request usage: |
1849 | Per-request usage: |
1625 | |
1850 | |