… | |
… | |
3 | |
3 | |
4 | SYNOPSIS |
4 | SYNOPSIS |
5 | use IO::AIO; |
5 | use IO::AIO; |
6 | |
6 | |
7 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
7 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
8 | my ($fh) = @_; |
8 | my $fh = shift |
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9 | or die "/etc/passwd: $!"; |
9 | ... |
10 | ... |
10 | }; |
11 | }; |
11 | |
12 | |
12 | aio_unlink "/tmp/file", sub { }; |
13 | aio_unlink "/tmp/file", sub { }; |
13 | |
14 | |
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23 | $req->cancel; # cancel request if still in queue |
24 | $req->cancel; # cancel request if still in queue |
24 | |
25 | |
25 | my $grp = aio_group sub { print "all stats done\n" }; |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
26 | add $grp aio_stat "..." for ...; |
27 | add $grp aio_stat "..." for ...; |
27 | |
28 | |
28 | # AnyEvent integration |
29 | # AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...) |
29 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
30 | open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; |
30 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
31 | my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb }); |
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32 | |
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33 | # EV integration |
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34 | my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
31 | |
35 | |
32 | # Event integration |
36 | # Event integration |
33 | Event->io (fd => IO::AIO::poll_fileno, |
37 | Event->io (fd => IO::AIO::poll_fileno, |
34 | poll => 'r', |
38 | poll => 'r', |
35 | cb => \&IO::AIO::poll_cb); |
39 | cb => \&IO::AIO::poll_cb); |
… | |
… | |
60 | faster on a RAID volume or over NFS when you do a number of stat |
64 | faster on a RAID volume or over NFS when you do a number of stat |
61 | operations concurrently. |
65 | operations concurrently. |
62 | |
66 | |
63 | While most of this works on all types of file descriptors (for example |
67 | While most of this works on all types of file descriptors (for example |
64 | sockets), using these functions on file descriptors that support |
68 | sockets), using these functions on file descriptors that support |
65 | nonblocking operation (again, sockets, pipes etc.) is very inefficient |
69 | nonblocking operation (again, sockets, pipes etc.) is very inefficient. |
66 | or might not work (aio_read fails on sockets/pipes/fifos). Use an event |
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67 | loop for that (such as the Event module): IO::AIO will naturally fit |
70 | Use an event loop for that (such as the Event module): IO::AIO will |
68 | into such an event loop itself. |
71 | naturally fit into such an event loop itself. |
69 | |
72 | |
70 | In this version, a number of threads are started that execute your |
73 | In this version, a number of threads are started that execute your |
71 | requests and signal their completion. You don't need thread support in |
74 | requests and signal their completion. You don't need thread support in |
72 | perl, and the threads created by this module will not be visible to |
75 | perl, and the threads created by this module will not be visible to |
73 | perl. In the future, this module might make use of the native aio |
76 | perl. In the future, this module might make use of the native aio |
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75 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
78 | not well-supported or restricted (GNU/Linux doesn't allow them on normal |
76 | files currently, for example), and they would only support aio_read and |
79 | files currently, for example), and they would only support aio_read and |
77 | aio_write, so the remaining functionality would have to be implemented |
80 | aio_write, so the remaining functionality would have to be implemented |
78 | using threads anyway. |
81 | using threads anyway. |
79 | |
82 | |
80 | Although the module will work with in the presence of other (Perl-) |
83 | Although the module will work in the presence of other (Perl-) threads, |
81 | threads, it is currently not reentrant in any way, so use appropriate |
84 | it is currently not reentrant in any way, so use appropriate locking |
82 | locking yourself, always call "poll_cb" from within the same thread, or |
85 | yourself, always call "poll_cb" from within the same thread, or never |
83 | never call "poll_cb" (or other "aio_" functions) recursively. |
86 | call "poll_cb" (or other "aio_" functions) recursively. |
84 | |
87 | |
85 | EXAMPLE |
88 | EXAMPLE |
86 | This is a simple example that uses the Event module and loads |
89 | This is a simple example that uses the Event module and loads |
87 | /etc/passwd asynchronously: |
90 | /etc/passwd asynchronously: |
88 | |
91 | |
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95 | poll => 'r', |
98 | poll => 'r', |
96 | cb => \&IO::AIO::poll_cb); |
99 | cb => \&IO::AIO::poll_cb); |
97 | |
100 | |
98 | # queue the request to open /etc/passwd |
101 | # queue the request to open /etc/passwd |
99 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
102 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
100 | my $fh = $_[0] |
103 | my $fh = shift |
101 | or die "error while opening: $!"; |
104 | or die "error while opening: $!"; |
102 | |
105 | |
103 | # stat'ing filehandles is generally non-blocking |
106 | # stat'ing filehandles is generally non-blocking |
104 | my $size = -s $fh; |
107 | my $size = -s $fh; |
105 | |
108 | |
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241 | They are the same as used by "sysopen". |
244 | They are the same as used by "sysopen". |
242 | |
245 | |
243 | Likewise, $mode specifies the mode of the newly created file, if it |
246 | Likewise, $mode specifies the mode of the newly created file, if it |
244 | didn't exist and "O_CREAT" has been given, just like perl's |
247 | didn't exist and "O_CREAT" has been given, just like perl's |
245 | "sysopen", except that it is mandatory (i.e. use 0 if you don't |
248 | "sysopen", except that it is mandatory (i.e. use 0 if you don't |
246 | create new files, and 0666 or 0777 if you do). |
249 | create new files, and 0666 or 0777 if you do). Note that the $mode |
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250 | will be modified by the umask in effect then the request is being |
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251 | executed, so better never change the umask. |
247 | |
252 | |
248 | Example: |
253 | Example: |
249 | |
254 | |
250 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
255 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
251 | if ($_[0]) { |
256 | if ($_[0]) { |
… | |
… | |
256 | } |
261 | } |
257 | }; |
262 | }; |
258 | |
263 | |
259 | aio_close $fh, $callback->($status) |
264 | aio_close $fh, $callback->($status) |
260 | Asynchronously close a file and call the callback with the result |
265 | Asynchronously close a file and call the callback with the result |
261 | code. *WARNING:* although accepted, you should not pass in a perl |
266 | code. |
262 | filehandle here, as perl will likely close the file descriptor |
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263 | another time when the filehandle is destroyed. Normally, you can |
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264 | safely call perls "close" or just let filehandles go out of scope. |
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265 | |
267 | |
266 | This is supposed to be a bug in the API, so that might change. It's |
268 | Unfortunately, you can't do this to perl. Perl *insists* very |
267 | therefore best to avoid this function. |
269 | strongly on closing the file descriptor associated with the |
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270 | filehandle itself. |
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271 | |
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272 | Therefore, "aio_close" will not close the filehandle - instead it |
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273 | will use dup2 to overwrite the file descriptor with the write-end of |
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274 | a pipe (the pipe fd will be created on demand and will be cached). |
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275 | |
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276 | Or in other words: the file descriptor will be closed, but it will |
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277 | not be free for reuse until the perl filehandle is closed. |
268 | |
278 | |
269 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
279 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
270 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
280 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
271 | Reads or writes "length" bytes from the specified "fh" and "offset" |
281 | Reads or writes $length bytes from the specified $fh and $offset |
272 | into the scalar given by "data" and offset "dataoffset" and calls |
282 | into the scalar given by $data and offset $dataoffset and calls the |
273 | the callback without the actual number of bytes read (or -1 on |
283 | callback without the actual number of bytes read (or -1 on error, |
274 | error, just like the syscall). |
284 | just like the syscall). |
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285 | |
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286 | If $offset is undefined, then the current file descriptor offset |
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287 | will be used (and updated), otherwise the file descriptor offset |
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288 | will not be changed by these calls. |
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289 | |
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290 | If $length is undefined in "aio_write", use the remaining length of |
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291 | $data. |
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292 | |
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293 | If $dataoffset is less than zero, it will be counted from the end of |
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294 | $data. |
275 | |
295 | |
276 | The $data scalar *MUST NOT* be modified in any way while the request |
296 | The $data scalar *MUST NOT* be modified in any way while the request |
277 | is outstanding. Modifying it can result in segfaults or WW3 (if the |
297 | is outstanding. Modifying it can result in segfaults or World War |
278 | necessary/optional hardware is installed). |
298 | III (if the necessary/optional hardware is installed). |
279 | |
299 | |
280 | Example: Read 15 bytes at offset 7 into scalar $buffer, starting at |
300 | Example: Read 15 bytes at offset 7 into scalar $buffer, starting at |
281 | offset 0 within the scalar: |
301 | offset 0 within the scalar: |
282 | |
302 | |
283 | aio_read $fh, 7, 15, $buffer, 0, sub { |
303 | aio_read $fh, 7, 15, $buffer, 0, sub { |
… | |
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341 | aio_stat "/etc/passwd", sub { |
361 | aio_stat "/etc/passwd", sub { |
342 | $_[0] and die "stat failed: $!"; |
362 | $_[0] and die "stat failed: $!"; |
343 | print "size is ", -s _, "\n"; |
363 | print "size is ", -s _, "\n"; |
344 | }; |
364 | }; |
345 | |
365 | |
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366 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
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367 | Works like perl's "utime" function (including the special case of |
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368 | $atime and $mtime being undef). Fractional times are supported if |
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369 | the underlying syscalls support them. |
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370 | |
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371 | When called with a pathname, uses utimes(2) if available, otherwise |
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372 | utime(2). If called on a file descriptor, uses futimes(2) if |
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373 | available, otherwise returns ENOSYS, so this is not portable. |
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374 | |
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375 | Examples: |
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376 | |
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377 | # set atime and mtime to current time (basically touch(1)): |
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378 | aio_utime "path", undef, undef; |
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379 | # set atime to current time and mtime to beginning of the epoch: |
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380 | aio_utime "path", time, undef; # undef==0 |
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381 | |
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382 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
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383 | Works like perl's "chown" function, except that "undef" for either |
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384 | $uid or $gid is being interpreted as "do not change" (but -1 can |
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385 | also be used). |
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386 | |
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387 | Examples: |
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388 | |
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389 | # same as "chown root path" in the shell: |
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390 | aio_chown "path", 0, -1; |
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391 | # same as above: |
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392 | aio_chown "path", 0, undef; |
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393 | |
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394 | aio_truncate $fh_or_path, $offset, $callback->($status) |
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395 | Works like truncate(2) or ftruncate(2). |
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396 | |
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397 | aio_chmod $fh_or_path, $mode, $callback->($status) |
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398 | Works like perl's "chmod" function. |
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399 | |
346 | aio_unlink $pathname, $callback->($status) |
400 | aio_unlink $pathname, $callback->($status) |
347 | Asynchronously unlink (delete) a file and call the callback with the |
401 | Asynchronously unlink (delete) a file and call the callback with the |
348 | result code. |
402 | result code. |
349 | |
403 | |
350 | aio_mknod $path, $mode, $dev, $callback->($status) |
404 | aio_mknod $path, $mode, $dev, $callback->($status) |
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372 | |
426 | |
373 | aio_rename $srcpath, $dstpath, $callback->($status) |
427 | aio_rename $srcpath, $dstpath, $callback->($status) |
374 | Asynchronously rename the object at $srcpath to $dstpath, just as |
428 | Asynchronously rename the object at $srcpath to $dstpath, just as |
375 | rename(2) and call the callback with the result code. |
429 | rename(2) and call the callback with the result code. |
376 | |
430 | |
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431 | aio_mkdir $pathname, $mode, $callback->($status) |
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432 | Asynchronously mkdir (create) a directory and call the callback with |
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433 | the result code. $mode will be modified by the umask at the time the |
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434 | request is executed, so do not change your umask. |
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435 | |
377 | aio_rmdir $pathname, $callback->($status) |
436 | aio_rmdir $pathname, $callback->($status) |
378 | Asynchronously rmdir (delete) a directory and call the callback with |
437 | Asynchronously rmdir (delete) a directory and call the callback with |
379 | the result code. |
438 | the result code. |
380 | |
439 | |
381 | aio_readdir $pathname, $callback->($entries) |
440 | aio_readdir $pathname, $callback->($entries) |
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383 | entire directory (i.e. opendir + readdir + closedir). The entries |
442 | entire directory (i.e. opendir + readdir + closedir). The entries |
384 | will not be sorted, and will NOT include the "." and ".." entries. |
443 | will not be sorted, and will NOT include the "." and ".." entries. |
385 | |
444 | |
386 | The callback a single argument which is either "undef" or an |
445 | The callback a single argument which is either "undef" or an |
387 | array-ref with the filenames. |
446 | array-ref with the filenames. |
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447 | |
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448 | aio_load $path, $data, $callback->($status) |
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449 | This is a composite request that tries to fully load the given file |
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450 | into memory. Status is the same as with aio_read. |
388 | |
451 | |
389 | aio_copy $srcpath, $dstpath, $callback->($status) |
452 | aio_copy $srcpath, $dstpath, $callback->($status) |
390 | Try to copy the *file* (directories not supported as either source |
453 | Try to copy the *file* (directories not supported as either source |
391 | or destination) from $srcpath to $dstpath and call the callback with |
454 | or destination) from $srcpath to $dstpath and call the callback with |
392 | the 0 (error) or -1 ok. |
455 | the 0 (error) or -1 ok. |
… | |
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460 | |
523 | |
461 | It will also likely work on non-POSIX filesystems with reduced |
524 | It will also likely work on non-POSIX filesystems with reduced |
462 | efficiency as those tend to return 0 or 1 as link counts, which |
525 | efficiency as those tend to return 0 or 1 as link counts, which |
463 | disables the directory counting heuristic. |
526 | disables the directory counting heuristic. |
464 | |
527 | |
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528 | aio_rmtree $path, $callback->($status) |
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529 | Delete a directory tree starting (and including) $path, return the |
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530 | status of the final "rmdir" only. This is a composite request that |
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531 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
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532 | everything else. |
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533 | |
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534 | aio_sync $callback->($status) |
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535 | Asynchronously call sync and call the callback when finished. |
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536 | |
465 | aio_fsync $fh, $callback->($status) |
537 | aio_fsync $fh, $callback->($status) |
466 | Asynchronously call fsync on the given filehandle and call the |
538 | Asynchronously call fsync on the given filehandle and call the |
467 | callback with the fsync result code. |
539 | callback with the fsync result code. |
468 | |
540 | |
469 | aio_fdatasync $fh, $callback->($status) |
541 | aio_fdatasync $fh, $callback->($status) |
470 | Asynchronously call fdatasync on the given filehandle and call the |
542 | Asynchronously call fdatasync on the given filehandle and call the |
471 | callback with the fdatasync result code. |
543 | callback with the fdatasync result code. |
472 | |
544 | |
473 | If this call isn't available because your OS lacks it or it couldn't |
545 | If this call isn't available because your OS lacks it or it couldn't |
474 | be detected, it will be emulated by calling "fsync" instead. |
546 | be detected, it will be emulated by calling "fsync" instead. |
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547 | |
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548 | aio_pathsync $path, $callback->($status) |
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549 | This request tries to open, fsync and close the given path. This is |
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550 | a composite request intended tosync directories after directory |
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551 | operations (E.g. rename). This might not work on all operating |
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552 | systems or have any specific effect, but usually it makes sure that |
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553 | directory changes get written to disc. It works for anything that |
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554 | can be opened for read-only, not just directories. |
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555 | |
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556 | Passes 0 when everything went ok, and -1 on error. |
475 | |
557 | |
476 | aio_group $callback->(...) |
558 | aio_group $callback->(...) |
477 | This is a very special aio request: Instead of doing something, it |
559 | This is a very special aio request: Instead of doing something, it |
478 | is a container for other aio requests, which is useful if you want |
560 | is a container for other aio requests, which is useful if you want |
479 | to bundle many requests into a single, composite, request with a |
561 | to bundle many requests into a single, composite, request with a |
… | |
… | |
561 | }; |
643 | }; |
562 | |
644 | |
563 | This makes it very easy to create composite requests (see the source of |
645 | This makes it very easy to create composite requests (see the source of |
564 | "aio_move" for an application) that work and feel like simple requests. |
646 | "aio_move" for an application) that work and feel like simple requests. |
565 | |
647 | |
566 | * The IO::AIO::GRP objects will be cleaned up during calls to |
648 | * The IO::AIO::GRP objects will be cleaned up during calls to |
567 | "IO::AIO::poll_cb", just like any other request. |
649 | "IO::AIO::poll_cb", just like any other request. |
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650 | |
568 | * They can be canceled like any other request. Canceling will cancel not |
651 | * They can be canceled like any other request. Canceling will cancel |
569 | only the request itself, but also all requests it contains. |
652 | not only the request itself, but also all requests it contains. |
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653 | |
570 | * They can also can also be added to other IO::AIO::GRP objects. |
654 | * They can also can also be added to other IO::AIO::GRP objects. |
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655 | |
571 | * You must not add requests to a group from within the group callback |
656 | * You must not add requests to a group from within the group callback |
572 | (or any later time). |
657 | (or any later time). |
573 | |
658 | |
574 | Their lifetime, simplified, looks like this: when they are empty, they |
659 | Their lifetime, simplified, looks like this: when they are empty, they |
575 | will finish very quickly. If they contain only requests that are in the |
660 | will finish very quickly. If they contain only requests that are in the |
576 | "done" state, they will also finish. Otherwise they will continue to |
661 | "done" state, they will also finish. Otherwise they will continue to |
577 | exist. |
662 | exist. |
… | |
… | |
594 | request itself. Useful when you queued a lot of events but got a |
679 | request itself. Useful when you queued a lot of events but got a |
595 | result early. |
680 | result early. |
596 | |
681 | |
597 | $grp->result (...) |
682 | $grp->result (...) |
598 | Set the result value(s) that will be passed to the group callback |
683 | Set the result value(s) that will be passed to the group callback |
599 | when all subrequests have finished and set thre groups errno to the |
684 | when all subrequests have finished and set the groups errno to the |
600 | current value of errno (just like calling "errno" without an error |
685 | current value of errno (just like calling "errno" without an error |
601 | number). By default, no argument will be passed and errno is zero. |
686 | number). By default, no argument will be passed and errno is zero. |
602 | |
687 | |
603 | $grp->errno ([$errno]) |
688 | $grp->errno ([$errno]) |
604 | Sets the group errno value to $errno, or the current value of errno |
689 | Sets the group errno value to $errno, or the current value of errno |
… | |
… | |
711 | Event->io (fd => IO::AIO::poll_fileno, |
796 | Event->io (fd => IO::AIO::poll_fileno, |
712 | poll => 'r', nice => 1, |
797 | poll => 'r', nice => 1, |
713 | cb => &IO::AIO::poll_cb); |
798 | cb => &IO::AIO::poll_cb); |
714 | |
799 | |
715 | IO::AIO::poll_wait |
800 | IO::AIO::poll_wait |
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801 | If there are any outstanding requests and none of them in the result |
716 | Wait till the result filehandle becomes ready for reading (simply |
802 | phase, wait till the result filehandle becomes ready for reading |
717 | does a "select" on the filehandle. This is useful if you want to |
803 | (simply does a "select" on the filehandle. This is useful if you |
718 | synchronously wait for some requests to finish). |
804 | want to synchronously wait for some requests to finish). |
719 | |
805 | |
720 | See "nreqs" for an example. |
806 | See "nreqs" for an example. |
721 | |
807 | |
722 | IO::AIO::poll |
808 | IO::AIO::poll |
723 | Waits until some requests have been handled. |
809 | Waits until some requests have been handled. |
724 | |
810 | |
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811 | Returns the number of requests processed, but is otherwise strictly |
725 | Strictly equivalent to: |
812 | equivalent to: |
726 | |
813 | |
727 | IO::AIO::poll_wait, IO::AIO::poll_cb |
814 | IO::AIO::poll_wait, IO::AIO::poll_cb |
728 | if IO::AIO::nreqs; |
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729 | |
815 | |
730 | IO::AIO::flush |
816 | IO::AIO::flush |
731 | Wait till all outstanding AIO requests have been handled. |
817 | Wait till all outstanding AIO requests have been handled. |
732 | |
818 | |
733 | Strictly equivalent to: |
819 | Strictly equivalent to: |
… | |
… | |
789 | $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
875 | $oldmaxreqs = IO::AIO::max_outstanding $maxreqs |
790 | This is a very bad function to use in interactive programs because |
876 | This is a very bad function to use in interactive programs because |
791 | it blocks, and a bad way to reduce concurrency because it is |
877 | it blocks, and a bad way to reduce concurrency because it is |
792 | inexact: Better use an "aio_group" together with a feed callback. |
878 | inexact: Better use an "aio_group" together with a feed callback. |
793 | |
879 | |
794 | Sets the maximum number of outstanding requests to $nreqs. If you to |
880 | Sets the maximum number of outstanding requests to $nreqs. If you do |
795 | queue up more than this number of requests, the next call to the |
881 | queue up more than this number of requests, the next call to the |
796 | "poll_cb" (and "poll_some" and other functions calling "poll_cb") |
882 | "poll_cb" (and "poll_some" and other functions calling "poll_cb") |
797 | function will block until the limit is no longer exceeded. |
883 | function will block until the limit is no longer exceeded. |
798 | |
884 | |
799 | The default value is very large, so there is no practical limit on |
885 | The default value is very large, so there is no practical limit on |
… | |
… | |
845 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
931 | bytes of memory. In addition, stat requests need a stat buffer (possibly |
846 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
932 | a few hundred bytes), readdir requires a result buffer and so on. Perl |
847 | scalars and other data passed into aio requests will also be locked and |
933 | scalars and other data passed into aio requests will also be locked and |
848 | will consume memory till the request has entered the done state. |
934 | will consume memory till the request has entered the done state. |
849 | |
935 | |
850 | This is now awfully much, so queuing lots of requests is not usually a |
936 | This is not awfully much, so queuing lots of requests is not usually a |
851 | problem. |
937 | problem. |
852 | |
938 | |
853 | Per-thread usage: |
939 | Per-thread usage: |
854 | |
940 | |
855 | In the execution phase, some aio requests require more memory for |
941 | In the execution phase, some aio requests require more memory for |