… | |
… | |
28 | |
28 | |
29 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
29 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
30 | use AnyEvent::AIO; |
30 | use AnyEvent::AIO; |
31 | |
31 | |
32 | # EV integration |
32 | # EV integration |
33 | my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
33 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
34 | |
34 | |
35 | # Event integration |
35 | # Event integration |
36 | Event->io (fd => IO::AIO::poll_fileno, |
36 | Event->io (fd => IO::AIO::poll_fileno, |
37 | poll => 'r', |
37 | poll => 'r', |
38 | cb => \&IO::AIO::poll_cb); |
38 | cb => \&IO::AIO::poll_cb); |
… | |
… | |
49 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
49 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
50 | \&IO::AIO::poll_cb); |
50 | \&IO::AIO::poll_cb); |
51 | |
51 | |
52 | DESCRIPTION |
52 | DESCRIPTION |
53 | This module implements asynchronous I/O using whatever means your |
53 | This module implements asynchronous I/O using whatever means your |
54 | operating system supports. |
54 | operating system supports. It is implemented as an interface to "libeio" |
|
|
55 | (<http://software.schmorp.de/pkg/libeio.html>). |
55 | |
56 | |
56 | Asynchronous means that operations that can normally block your program |
57 | Asynchronous means that operations that can normally block your program |
57 | (e.g. reading from disk) will be done asynchronously: the operation will |
58 | (e.g. reading from disk) will be done asynchronously: the operation will |
58 | still block, but you can do something else in the meantime. This is |
59 | still block, but you can do something else in the meantime. This is |
59 | extremely useful for programs that need to stay interactive even when |
60 | extremely useful for programs that need to stay interactive even when |
… | |
… | |
64 | operations concurrently. |
65 | operations concurrently. |
65 | |
66 | |
66 | 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 |
67 | sockets), using these functions on file descriptors that support |
68 | sockets), using these functions on file descriptors that support |
68 | nonblocking operation (again, sockets, pipes etc.) is very inefficient. |
69 | nonblocking operation (again, sockets, pipes etc.) is very inefficient. |
69 | Use an event loop for that (such as the Event module): IO::AIO will |
70 | Use an event loop for that (such as the EV module): IO::AIO will |
70 | naturally fit into such an event loop itself. |
71 | naturally fit into such an event loop itself. |
71 | |
72 | |
72 | 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 |
73 | 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 |
74 | 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 |
… | |
… | |
83 | it is currently not reentrant in any way, so use appropriate locking |
84 | it is currently not reentrant in any way, so use appropriate locking |
84 | yourself, always call "poll_cb" from within the same thread, or never |
85 | yourself, always call "poll_cb" from within the same thread, or never |
85 | call "poll_cb" (or other "aio_" functions) recursively. |
86 | call "poll_cb" (or other "aio_" functions) recursively. |
86 | |
87 | |
87 | EXAMPLE |
88 | EXAMPLE |
88 | This is a simple example that uses the Event module and loads |
89 | This is a simple example that uses the EV module and loads /etc/passwd |
89 | /etc/passwd asynchronously: |
90 | asynchronously: |
90 | |
91 | |
91 | use Fcntl; |
92 | use Fcntl; |
92 | use Event; |
93 | use EV; |
93 | use IO::AIO; |
94 | use IO::AIO; |
94 | |
95 | |
95 | # register the IO::AIO callback with Event |
96 | # register the IO::AIO callback with EV |
96 | Event->io (fd => IO::AIO::poll_fileno, |
97 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
97 | poll => 'r', |
|
|
98 | cb => \&IO::AIO::poll_cb); |
|
|
99 | |
98 | |
100 | # queue the request to open /etc/passwd |
99 | # queue the request to open /etc/passwd |
101 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
100 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
102 | my $fh = shift |
101 | my $fh = shift |
103 | or die "error while opening: $!"; |
102 | or die "error while opening: $!"; |
… | |
… | |
115 | |
114 | |
116 | # file contents now in $contents |
115 | # file contents now in $contents |
117 | print $contents; |
116 | print $contents; |
118 | |
117 | |
119 | # exit event loop and program |
118 | # exit event loop and program |
120 | Event::unloop; |
119 | EV::unloop; |
121 | }; |
120 | }; |
122 | }; |
121 | }; |
123 | |
122 | |
124 | # possibly queue up other requests, or open GUI windows, |
123 | # possibly queue up other requests, or open GUI windows, |
125 | # check for sockets etc. etc. |
124 | # check for sockets etc. etc. |
126 | |
125 | |
127 | # process events as long as there are some: |
126 | # process events as long as there are some: |
128 | Event::loop; |
127 | EV::loop; |
129 | |
128 | |
130 | REQUEST ANATOMY AND LIFETIME |
129 | REQUEST ANATOMY AND LIFETIME |
131 | Every "aio_*" function creates a request. which is a C data structure |
130 | Every "aio_*" function creates a request. which is a C data structure |
132 | not directly visible to Perl. |
131 | not directly visible to Perl. |
133 | |
132 | |
… | |
… | |
316 | |
315 | |
317 | This call tries to make use of a native "sendfile" syscall to |
316 | This call tries to make use of a native "sendfile" syscall to |
318 | provide zero-copy operation. For this to work, $out_fh should refer |
317 | provide zero-copy operation. For this to work, $out_fh should refer |
319 | to a socket, and $in_fh should refer to mmap'able file. |
318 | to a socket, and $in_fh should refer to mmap'able file. |
320 | |
319 | |
321 | If the native sendfile call fails or is not implemented, it will be |
320 | If a native sendfile cannot be found or it fails with "ENOSYS", |
|
|
321 | "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or "ENOTSOCK", |
322 | emulated, so you can call "aio_sendfile" on any type of filehandle |
322 | it will be emulated, so you can call "aio_sendfile" on any type of |
323 | regardless of the limitations of the operating system. |
323 | filehandle regardless of the limitations of the operating system. |
324 | |
324 | |
325 | Please note, however, that "aio_sendfile" can read more bytes from |
325 | Please note, however, that "aio_sendfile" can read more bytes from |
326 | $in_fh than are written, and there is no way to find out how many |
326 | $in_fh than are written, and there is no way to find out how many |
327 | bytes have been read from "aio_sendfile" alone, as "aio_sendfile" |
327 | bytes have been read from "aio_sendfile" alone, as "aio_sendfile" |
328 | only provides the number of bytes written to $out_fh. Only if the |
328 | only provides the number of bytes written to $out_fh. Only if the |
… | |
… | |
363 | aio_stat "/etc/passwd", sub { |
363 | aio_stat "/etc/passwd", sub { |
364 | $_[0] and die "stat failed: $!"; |
364 | $_[0] and die "stat failed: $!"; |
365 | print "size is ", -s _, "\n"; |
365 | print "size is ", -s _, "\n"; |
366 | }; |
366 | }; |
367 | |
367 | |
|
|
368 | aio_statvfs $fh_or_path, $callback->($statvfs) |
|
|
369 | Works like the POSIX "statvfs" or "fstatvfs" syscalls, depending on |
|
|
370 | whether a file handle or path was passed. |
|
|
371 | |
|
|
372 | On success, the callback is passed a hash reference with the |
|
|
373 | following members: "bsize", "frsize", "blocks", "bfree", "bavail", |
|
|
374 | "files", "ffree", "favail", "fsid", "flag" and "namemax". On |
|
|
375 | failure, "undef" is passed. |
|
|
376 | |
|
|
377 | The following POSIX IO::AIO::ST_* constants are defined: "ST_RDONLY" |
|
|
378 | and "ST_NOSUID". |
|
|
379 | |
|
|
380 | The following non-POSIX IO::AIO::ST_* flag masks are defined to |
|
|
381 | their correct value when available, or to 0 on systems that do not |
|
|
382 | support them: "ST_NODEV", "ST_NOEXEC", "ST_SYNCHRONOUS", |
|
|
383 | "ST_MANDLOCK", "ST_WRITE", "ST_APPEND", "ST_IMMUTABLE", |
|
|
384 | "ST_NOATIME", "ST_NODIRATIME" and "ST_RELATIME". |
|
|
385 | |
|
|
386 | Example: stat "/wd" and dump out the data if successful. |
|
|
387 | |
|
|
388 | aio_statvfs "/wd", sub { |
|
|
389 | my $f = $_[0] |
|
|
390 | or die "statvfs: $!"; |
|
|
391 | |
|
|
392 | use Data::Dumper; |
|
|
393 | say Dumper $f; |
|
|
394 | }; |
|
|
395 | |
|
|
396 | # result: |
|
|
397 | { |
|
|
398 | bsize => 1024, |
|
|
399 | bfree => 4333064312, |
|
|
400 | blocks => 10253828096, |
|
|
401 | files => 2050765568, |
|
|
402 | flag => 4096, |
|
|
403 | favail => 2042092649, |
|
|
404 | bavail => 4333064312, |
|
|
405 | ffree => 2042092649, |
|
|
406 | namemax => 255, |
|
|
407 | frsize => 1024, |
|
|
408 | fsid => 1810 |
|
|
409 | } |
|
|
410 | |
368 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
411 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
369 | Works like perl's "utime" function (including the special case of |
412 | Works like perl's "utime" function (including the special case of |
370 | $atime and $mtime being undef). Fractional times are supported if |
413 | $atime and $mtime being undef). Fractional times are supported if |
371 | the underlying syscalls support them. |
414 | the underlying syscalls support them. |
372 | |
415 | |
… | |
… | |
474 | you need to know, you have to run stat yourself. Also, for speed |
517 | you need to know, you have to run stat yourself. Also, for speed |
475 | reasons, the $type scalars are read-only: you can not modify |
518 | reasons, the $type scalars are read-only: you can not modify |
476 | them. |
519 | them. |
477 | |
520 | |
478 | $inode is the inode number (which might not be exact on systems |
521 | $inode is the inode number (which might not be exact on systems |
479 | with 64 bit inode numbers and 32 bit perls). On systems that do |
522 | with 64 bit inode numbers and 32 bit perls). This field has |
480 | not deliver the inode information, this will always be zero. |
523 | unspecified content on systems that do not deliver the inode |
|
|
524 | information. |
481 | |
525 | |
482 | IO::AIO::READDIR_DIRS_FIRST |
526 | IO::AIO::READDIR_DIRS_FIRST |
483 | When this flag is set, then the names will be returned in an |
527 | When this flag is set, then the names will be returned in an |
484 | order where likely directories come first. This is useful when |
528 | order where likely directories come first. This is useful when |
485 | you need to quickly find directories, or you want to find all |
529 | you need to quickly find directories, or you want to find all |
… | |
… | |
512 | into memory. Status is the same as with aio_read. |
556 | into memory. Status is the same as with aio_read. |
513 | |
557 | |
514 | aio_copy $srcpath, $dstpath, $callback->($status) |
558 | aio_copy $srcpath, $dstpath, $callback->($status) |
515 | Try to copy the *file* (directories not supported as either source |
559 | Try to copy the *file* (directories not supported as either source |
516 | or destination) from $srcpath to $dstpath and call the callback with |
560 | or destination) from $srcpath to $dstpath and call the callback with |
517 | the 0 (error) or -1 ok. |
561 | a status of 0 (ok) or -1 (error, see $!). |
518 | |
562 | |
519 | This is a composite request that creates the destination file with |
563 | 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 |
564 | mode 0200 and copies the contents of the source file into it using |
521 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
565 | "aio_sendfile", followed by restoring atime, mtime, access mode and |
522 | uid/gid, in that order. |
566 | uid/gid, in that order. |
… | |
… | |
526 | uid/gid, where errors are being ignored. |
570 | uid/gid, where errors are being ignored. |
527 | |
571 | |
528 | aio_move $srcpath, $dstpath, $callback->($status) |
572 | aio_move $srcpath, $dstpath, $callback->($status) |
529 | Try to move the *file* (directories not supported as either source |
573 | Try to move the *file* (directories not supported as either source |
530 | or destination) from $srcpath to $dstpath and call the callback with |
574 | or destination) from $srcpath to $dstpath and call the callback with |
531 | the 0 (error) or -1 ok. |
575 | a status of 0 (ok) or -1 (error, see $!). |
532 | |
576 | |
533 | This is a composite request that tries to rename(2) the file first; |
577 | 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" |
578 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
535 | and, if that is successful, unlinks the $srcpath. |
579 | and, if that is successful, unlinks the $srcpath. |
536 | |
580 | |
… | |
… | |
631 | operations (E.g. rename). This might not work on all operating |
675 | operations (E.g. rename). This might not work on all operating |
632 | systems or have any specific effect, but usually it makes sure that |
676 | systems or have any specific effect, but usually it makes sure that |
633 | directory changes get written to disc. It works for anything that |
677 | directory changes get written to disc. It works for anything that |
634 | can be opened for read-only, not just directories. |
678 | can be opened for read-only, not just directories. |
635 | |
679 | |
|
|
680 | Future versions of this function might fall back to other methods |
|
|
681 | when "fsync" on the directory fails (such as calling "sync"). |
|
|
682 | |
636 | Passes 0 when everything went ok, and -1 on error. |
683 | Passes 0 when everything went ok, and -1 on error. |
|
|
684 | |
|
|
685 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
|
|
686 | $callback->($status) |
|
|
687 | This is a rather advanced IO::AIO call, which only works on |
|
|
688 | mmap(2)ed scalars (see the Sys::Mmap or Mmap modules for details on |
|
|
689 | this, note that the scalar must only be modified in-place while an |
|
|
690 | aio operation is pending on it). |
|
|
691 | |
|
|
692 | It calls the "msync" function of your OS, if available, with the |
|
|
693 | memory area starting at $offset in the string and ending $length |
|
|
694 | bytes later. If $length is negative, counts from the end, and if |
|
|
695 | $length is "undef", then it goes till the end of the string. The |
|
|
696 | flags can be a combination of "IO::AIO::MS_ASYNC", |
|
|
697 | "IO::AIO::MS_INVALIDATE" and "IO::AIO::MS_SYNC". |
|
|
698 | |
|
|
699 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, |
|
|
700 | $callback->($status) |
|
|
701 | This is a rather advanced IO::AIO call, which works best on |
|
|
702 | mmap(2)ed scalars. |
|
|
703 | |
|
|
704 | It touches (reads or writes) all memory pages in the specified range |
|
|
705 | inside the scalar. All caveats and parameters are the same as for |
|
|
706 | "aio_msync", above, except for flags, which must be either 0 (which |
|
|
707 | reads all pages and ensures they are instantiated) or |
|
|
708 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
|
|
709 | and writing an octet from it, which dirties the page). |
637 | |
710 | |
638 | aio_group $callback->(...) |
711 | aio_group $callback->(...) |
639 | This is a very special aio request: Instead of doing something, it |
712 | 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 |
713 | 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 |
714 | to bundle many requests into a single, composite, request with a |
… | |
… | |
684 | |
757 | |
685 | cancel $req |
758 | cancel $req |
686 | Cancels the request, if possible. Has the effect of skipping |
759 | Cancels the request, if possible. Has the effect of skipping |
687 | execution when entering the execute state and skipping calling the |
760 | execution when entering the execute state and skipping calling the |
688 | callback when entering the the result state, but will leave the |
761 | callback when entering the the result state, but will leave the |
689 | request otherwise untouched. That means that requests that currently |
762 | request otherwise untouched (with the exception of readdir). That |
690 | execute will not be stopped and resources held by the request will |
763 | means that requests that currently execute will not be stopped and |
691 | not be freed prematurely. |
764 | resources held by the request will not be freed prematurely. |
692 | |
765 | |
693 | cb $req $callback->(...) |
766 | cb $req $callback->(...) |
694 | Replace (or simply set) the callback registered to the request. |
767 | Replace (or simply set) the callback registered to the request. |
695 | |
768 | |
696 | IO::AIO::GRP CLASS |
769 | IO::AIO::GRP CLASS |
… | |
… | |
757 | |
830 | |
758 | $grp->cancel_subs |
831 | $grp->cancel_subs |
759 | Cancel all subrequests and clears any feeder, but not the group |
832 | 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 |
833 | request itself. Useful when you queued a lot of events but got a |
761 | result early. |
834 | result early. |
|
|
835 | |
|
|
836 | The group request will finish normally (you cannot add requests to |
|
|
837 | the group). |
762 | |
838 | |
763 | $grp->result (...) |
839 | $grp->result (...) |
764 | Set the result value(s) that will be passed to the group callback |
840 | 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 |
841 | when all subrequests have finished and set the groups errno to the |
766 | current value of errno (just like calling "errno" without an error |
842 | current value of errno (just like calling "errno" without an error |
… | |
… | |
826 | SUPPORT FUNCTIONS |
902 | SUPPORT FUNCTIONS |
827 | EVENT PROCESSING AND EVENT LOOP INTEGRATION |
903 | EVENT PROCESSING AND EVENT LOOP INTEGRATION |
828 | $fileno = IO::AIO::poll_fileno |
904 | $fileno = IO::AIO::poll_fileno |
829 | Return the *request result pipe file descriptor*. This filehandle |
905 | Return the *request result pipe file descriptor*. This filehandle |
830 | must be polled for reading by some mechanism outside this module |
906 | must be polled for reading by some mechanism outside this module |
831 | (e.g. Event or select, see below or the SYNOPSIS). If the pipe |
907 | (e.g. EV, Glib, select and so on, see below or the SYNOPSIS). If the |
832 | becomes readable you have to call "poll_cb" to check the results. |
908 | pipe becomes readable you have to call "poll_cb" to check the |
|
|
909 | results. |
833 | |
910 | |
834 | See "poll_cb" for an example. |
911 | See "poll_cb" for an example. |
835 | |
912 | |
836 | IO::AIO::poll_cb |
913 | IO::AIO::poll_cb |
837 | Process some outstanding events on the result pipe. You have to call |
914 | Process some outstanding events on the result pipe. You have to call |
… | |
… | |
844 | If not all requests were processed for whatever reason, the |
921 | If not all requests were processed for whatever reason, the |
845 | filehandle will still be ready when "poll_cb" returns, so normally |
922 | filehandle will still be ready when "poll_cb" returns, so normally |
846 | you don't have to do anything special to have it called later. |
923 | you don't have to do anything special to have it called later. |
847 | |
924 | |
848 | Example: Install an Event watcher that automatically calls |
925 | Example: Install an Event watcher that automatically calls |
849 | IO::AIO::poll_cb with high priority: |
926 | IO::AIO::poll_cb with high priority (more examples can be found in |
|
|
927 | the SYNOPSIS section, at the top of this document): |
850 | |
928 | |
851 | Event->io (fd => IO::AIO::poll_fileno, |
929 | Event->io (fd => IO::AIO::poll_fileno, |
852 | poll => 'r', async => 1, |
930 | poll => 'r', async => 1, |
853 | cb => \&IO::AIO::poll_cb); |
931 | cb => \&IO::AIO::poll_cb); |
854 | |
932 | |
… | |
… | |
994 | |
1072 | |
995 | IO::AIO::npending |
1073 | IO::AIO::npending |
996 | Returns the number of requests currently in the pending state |
1074 | Returns the number of requests currently in the pending state |
997 | (executed, but not yet processed by poll_cb). |
1075 | (executed, but not yet processed by poll_cb). |
998 | |
1076 | |
|
|
1077 | MISCELLANEOUS FUNCTIONS |
|
|
1078 | IO::AIO implements some functions that might be useful, but are not |
|
|
1079 | asynchronous. |
|
|
1080 | |
|
|
1081 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
|
|
1082 | Calls the "eio_sendfile_sync" function, which is like |
|
|
1083 | "aio_sendfile", but is blocking (this makes most sense if you know |
|
|
1084 | the input data is likely cached already and the output filehandle is |
|
|
1085 | set to non-blocking operations). |
|
|
1086 | |
|
|
1087 | Returns the number of bytes copied, or -1 on error. |
|
|
1088 | |
|
|
1089 | IO::AIO::fadvise $fh, $offset, $len, $advice |
|
|
1090 | Simply calls the "posix_fadvise" function (see it's manpage for |
|
|
1091 | details). The following advice constants are avaiable: |
|
|
1092 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
|
|
1093 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
|
|
1094 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
|
|
1095 | |
|
|
1096 | On systems that do not implement "posix_fadvise", this function |
|
|
1097 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
|
|
1098 | |
999 | FORK BEHAVIOUR |
1099 | FORK BEHAVIOUR |
1000 | This module should do "the right thing" when the process using it forks: |
1100 | This module should do "the right thing" when the process using it forks: |
1001 | |
1101 | |
1002 | Before the fork, IO::AIO enters a quiescent state where no requests can |
1102 | Before the fork, IO::AIO enters a quiescent state where no requests can |
1003 | be added in other threads and no results will be processed. After the |
1103 | be added in other threads and no results will be processed. After the |