| … | |
… | |
| 64 | |
64 | |
| 65 | EXAMPLE |
65 | EXAMPLE |
| 66 | This is a simple example that uses the EV module and loads /etc/passwd |
66 | This is a simple example that uses the EV module and loads /etc/passwd |
| 67 | asynchronously: |
67 | asynchronously: |
| 68 | |
68 | |
| 69 | use Fcntl; |
|
|
| 70 | use EV; |
69 | use EV; |
| 71 | use IO::AIO; |
70 | use IO::AIO; |
| 72 | |
71 | |
| 73 | # register the IO::AIO callback with EV |
72 | # register the IO::AIO callback with EV |
| 74 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
73 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
| … | |
… | |
| 172 | aio_unlink $pathname, $callback->($status) |
171 | aio_unlink $pathname, $callback->($status) |
| 173 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
172 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
| 174 | aio_link $srcpath, $dstpath, $callback->($status) |
173 | aio_link $srcpath, $dstpath, $callback->($status) |
| 175 | aio_symlink $srcpath, $dstpath, $callback->($status) |
174 | aio_symlink $srcpath, $dstpath, $callback->($status) |
| 176 | aio_readlink $pathname, $callback->($link) |
175 | aio_readlink $pathname, $callback->($link) |
| 177 | aio_realpath $pathname, $callback->($link) |
176 | aio_realpath $pathname, $callback->($path) |
| 178 | aio_rename $srcpath, $dstpath, $callback->($status) |
177 | aio_rename $srcpath, $dstpath, $callback->($status) |
| 179 | aio_mkdir $pathname, $mode, $callback->($status) |
178 | aio_mkdir $pathname, $mode, $callback->($status) |
| 180 | aio_rmdir $pathname, $callback->($status) |
179 | aio_rmdir $pathname, $callback->($status) |
| 181 | aio_readdir $pathname, $callback->($entries) |
180 | aio_readdir $pathname, $callback->($entries) |
| 182 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
181 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
| … | |
… | |
| 530 | namemax => 255, |
529 | namemax => 255, |
| 531 | frsize => 1024, |
530 | frsize => 1024, |
| 532 | fsid => 1810 |
531 | fsid => 1810 |
| 533 | } |
532 | } |
| 534 | |
533 | |
| 535 | Here is a (likely partial) list of fsid values used by Linux - it is |
534 | Here is a (likely partial - send me updates!) list of fsid values |
| 536 | safe to hardcode these when the $^O is "linux": |
535 | used by Linux - it is safe to hardcode these when $^O is "linux": |
| 537 | |
536 | |
| 538 | 0x0000adf5 adfs |
537 | 0x0000adf5 adfs |
| 539 | 0x0000adff affs |
538 | 0x0000adff affs |
| 540 | 0x5346414f afs |
539 | 0x5346414f afs |
| 541 | 0x09041934 anon-inode filesystem |
540 | 0x09041934 anon-inode filesystem |
| … | |
… | |
| 644 | |
643 | |
| 645 | aio_truncate $fh_or_path, $offset, $callback->($status) |
644 | aio_truncate $fh_or_path, $offset, $callback->($status) |
| 646 | Works like truncate(2) or ftruncate(2). |
645 | Works like truncate(2) or ftruncate(2). |
| 647 | |
646 | |
| 648 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
647 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
| 649 | Allocates or freed disk space according to the $mode argument. See |
648 | Allocates or frees disk space according to the $mode argument. See |
| 650 | the linux "fallocate" docuemntation for details. |
649 | the linux "fallocate" documentation for details. |
| 651 | |
650 | |
| 652 | $mode can currently be 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to |
651 | $mode can currently be 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to |
| 653 | allocate space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE | |
652 | allocate space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE | |
| 654 | IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range. |
653 | IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range. |
| 655 | |
654 | |
| … | |
… | |
| 692 | the callback. If an error occurs, nothing or undef gets passed to |
691 | the callback. If an error occurs, nothing or undef gets passed to |
| 693 | the callback. |
692 | the callback. |
| 694 | |
693 | |
| 695 | aio_realpath $pathname, $callback->($path) |
694 | aio_realpath $pathname, $callback->($path) |
| 696 | Asynchronously make the path absolute and resolve any symlinks in |
695 | Asynchronously make the path absolute and resolve any symlinks in |
| 697 | $path. The resulting path only consists of directories (Same as |
696 | $path. The resulting path only consists of directories (same as |
| 698 | Cwd::realpath). |
697 | Cwd::realpath). |
| 699 | |
698 | |
| 700 | This request can be used to get the absolute path of the current |
699 | This request can be used to get the absolute path of the current |
| 701 | working directory by passing it a path of . (a single dot). |
700 | working directory by passing it a path of . (a single dot). |
| 702 | |
701 | |
| 703 | aio_rename $srcpath, $dstpath, $callback->($status) |
702 | aio_rename $srcpath, $dstpath, $callback->($status) |
| 704 | Asynchronously rename the object at $srcpath to $dstpath, just as |
703 | Asynchronously rename the object at $srcpath to $dstpath, just as |
| 705 | rename(2) and call the callback with the result code. |
704 | rename(2) and call the callback with the result code. |
|
|
705 | |
|
|
706 | On systems that support the AIO::WD working directory abstraction |
|
|
707 | natively, the case "[$wd, "."]" as $srcpath is specialcased - |
|
|
708 | instead of failing, "rename" is called on the absolute path of $wd. |
| 706 | |
709 | |
| 707 | aio_mkdir $pathname, $mode, $callback->($status) |
710 | aio_mkdir $pathname, $mode, $callback->($status) |
| 708 | Asynchronously mkdir (create) a directory and call the callback with |
711 | Asynchronously mkdir (create) a directory and call the callback with |
| 709 | the result code. $mode will be modified by the umask at the time the |
712 | the result code. $mode will be modified by the umask at the time the |
| 710 | request is executed, so do not change your umask. |
713 | request is executed, so do not change your umask. |
| 711 | |
714 | |
| 712 | aio_rmdir $pathname, $callback->($status) |
715 | aio_rmdir $pathname, $callback->($status) |
| 713 | Asynchronously rmdir (delete) a directory and call the callback with |
716 | Asynchronously rmdir (delete) a directory and call the callback with |
| 714 | the result code. |
717 | the result code. |
|
|
718 | |
|
|
719 | On systems that support the AIO::WD working directory abstraction |
|
|
720 | natively, the case "[$wd, "."]" is specialcased - instead of |
|
|
721 | failing, "rmdir" is called on the absolute path of $wd. |
| 715 | |
722 | |
| 716 | aio_readdir $pathname, $callback->($entries) |
723 | aio_readdir $pathname, $callback->($entries) |
| 717 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
724 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
| 718 | entire directory (i.e. opendir + readdir + closedir). The entries |
725 | entire directory (i.e. opendir + readdir + closedir). The entries |
| 719 | will not be sorted, and will NOT include the "." and ".." entries. |
726 | will not be sorted, and will NOT include the "." and ".." entries. |
| … | |
… | |
| 942 | |
949 | |
| 943 | It touches (reads or writes) all memory pages in the specified range |
950 | It touches (reads or writes) all memory pages in the specified range |
| 944 | inside the scalar. All caveats and parameters are the same as for |
951 | inside the scalar. All caveats and parameters are the same as for |
| 945 | "aio_msync", above, except for flags, which must be either 0 (which |
952 | "aio_msync", above, except for flags, which must be either 0 (which |
| 946 | reads all pages and ensures they are instantiated) or |
953 | reads all pages and ensures they are instantiated) or |
| 947 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
954 | "IO::AIO::MT_MODIFY", which modifies the memory pages (by reading |
| 948 | and writing an octet from it, which dirties the page). |
955 | and writing an octet from it, which dirties the page). |
| 949 | |
956 | |
| 950 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
957 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
| 951 | This is a rather advanced IO::AIO call, which works best on |
958 | This is a rather advanced IO::AIO call, which works best on |
| 952 | mmap(2)ed scalars. |
959 | mmap(2)ed scalars. |
| … | |
… | |
| 1121 | aio_stat [$etcdir, "passwd"], sub { |
1128 | aio_stat [$etcdir, "passwd"], sub { |
| 1122 | # yay |
1129 | # yay |
| 1123 | }; |
1130 | }; |
| 1124 | }; |
1131 | }; |
| 1125 | |
1132 | |
| 1126 | That "aio_wd" is a request and not a normal function shows that creating |
1133 | The fact that "aio_wd" is a request and not a normal function shows that |
| 1127 | an IO::AIO::WD object is itself a potentially blocking operation, which |
1134 | creating an IO::AIO::WD object is itself a potentially blocking |
| 1128 | is why it is done asynchronously. |
1135 | operation, which is why it is done asynchronously. |
| 1129 | |
1136 | |
| 1130 | To stat the directory obtained with "aio_wd" above, one could write |
1137 | To stat the directory obtained with "aio_wd" above, one could write |
| 1131 | either of the following three request calls: |
1138 | either of the following three request calls: |
| 1132 | |
1139 | |
| 1133 | aio_lstat "/etc" , sub { ... # pathname as normal string |
1140 | aio_lstat "/etc" , sub { ... # pathname as normal string |
| … | |
… | |
| 1153 | will still point to the original directory. Most functions accepting a |
1160 | will still point to the original directory. Most functions accepting a |
| 1154 | pathname will use the directory fd on newer systems, and the string on |
1161 | pathname will use the directory fd on newer systems, and the string on |
| 1155 | older systems. Some functions (such as realpath) will always rely on the |
1162 | older systems. Some functions (such as realpath) will always rely on the |
| 1156 | string form of the pathname. |
1163 | string form of the pathname. |
| 1157 | |
1164 | |
| 1158 | So this fucntionality is mainly useful to get some protection against |
1165 | So this functionality is mainly useful to get some protection against |
| 1159 | "chdir", to easily get an absolute path out of a relative path for |
1166 | "chdir", to easily get an absolute path out of a relative path for |
| 1160 | future reference, and to speed up doing many operations in the same |
1167 | future reference, and to speed up doing many operations in the same |
| 1161 | directory (e.g. when stat'ing all files in a directory). |
1168 | directory (e.g. when stat'ing all files in a directory). |
| 1162 | |
1169 | |
| 1163 | The following functions implement this working directory abstraction: |
1170 | The following functions implement this working directory abstraction: |
| … | |
… | |
| 1173 | Since passing "undef" as working directory component of a pathname |
1180 | Since passing "undef" as working directory component of a pathname |
| 1174 | fails the request with "ENOENT", there is often no need for error |
1181 | fails the request with "ENOENT", there is often no need for error |
| 1175 | checking in the "aio_wd" callback, as future requests using the |
1182 | checking in the "aio_wd" callback, as future requests using the |
| 1176 | value will fail in the expected way. |
1183 | value will fail in the expected way. |
| 1177 | |
1184 | |
| 1178 | If this call isn't available because your OS lacks it or it couldn't |
|
|
| 1179 | be detected, it will be emulated by calling "fsync" instead. |
|
|
| 1180 | |
|
|
| 1181 | IO::AIO::CWD |
1185 | IO::AIO::CWD |
| 1182 | This is a compiletime constant (object) that represents the process |
1186 | This is a compiletime constant (object) that represents the process |
| 1183 | current working directory. |
1187 | current working directory. |
| 1184 | |
1188 | |
| 1185 | Specifying this object as working directory object for a pathname is |
1189 | Specifying this object as working directory object for a pathname is |
| 1186 | as if the pathname would be specified directly, without a directory |
1190 | as if the pathname would be specified directly, without a directory |
| 1187 | object, e.g., these calls are functionally identical: |
1191 | object. For example, these calls are functionally identical: |
| 1188 | |
1192 | |
| 1189 | aio_stat "somefile", sub { ... }; |
1193 | aio_stat "somefile", sub { ... }; |
| 1190 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
1194 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1195 | |
|
|
1196 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1197 | "aio_realpath": |
|
|
1198 | |
|
|
1199 | aio_realpath $wd, sub { |
|
|
1200 | warn "path is $_[0]\n"; |
|
|
1201 | }; |
|
|
1202 | |
|
|
1203 | Currently, "aio_statvfs" always, and "aio_rename" and "aio_rmdir" |
|
|
1204 | sometimes, fall back to using an absolue path. |
| 1191 | |
1205 | |
| 1192 | IO::AIO::REQ CLASS |
1206 | IO::AIO::REQ CLASS |
| 1193 | All non-aggregate "aio_*" functions return an object of this class when |
1207 | All non-aggregate "aio_*" functions return an object of this class when |
| 1194 | called in non-void context. |
1208 | called in non-void context. |
| 1195 | |
1209 | |
| … | |
… | |
| 1347 | results. |
1361 | results. |
| 1348 | |
1362 | |
| 1349 | See "poll_cb" for an example. |
1363 | See "poll_cb" for an example. |
| 1350 | |
1364 | |
| 1351 | IO::AIO::poll_cb |
1365 | IO::AIO::poll_cb |
| 1352 | Process some outstanding events on the result pipe. You have to call |
1366 | Process some requests that have reached the result phase (i.e. they |
|
|
1367 | have been executed but the results are not yet reported). You have |
|
|
1368 | to call this "regularly" to finish outstanding requests. |
|
|
1369 | |
| 1353 | this regularly. Returns 0 if all events could be processed (or there |
1370 | Returns 0 if all events could be processed (or there were no events |
| 1354 | were no events to process), or -1 if it returned earlier for |
1371 | to process), or -1 if it returned earlier for whatever reason. |
| 1355 | whatever reason. Returns immediately when no events are outstanding. |
1372 | Returns immediately when no events are outstanding. The amount of |
| 1356 | The amount of events processed depends on the settings of |
1373 | events processed depends on the settings of "IO::AIO::max_poll_req", |
| 1357 | "IO::AIO::max_poll_req" and "IO::AIO::max_poll_time". |
1374 | "IO::AIO::max_poll_time" and "IO::AIO::max_outstanding". |
| 1358 | |
1375 | |
| 1359 | If not all requests were processed for whatever reason, the |
1376 | If not all requests were processed for whatever reason, the poll |
| 1360 | filehandle will still be ready when "poll_cb" returns, so normally |
1377 | file descriptor will still be ready when "poll_cb" returns, so |
| 1361 | you don't have to do anything special to have it called later. |
1378 | normally you don't have to do anything special to have it called |
|
|
1379 | later. |
| 1362 | |
1380 | |
| 1363 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
1381 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
| 1364 | becomes ready, it can be beneficial to call this function from loops |
1382 | becomes ready, it can be beneficial to call this function from loops |
| 1365 | which submit a lot of requests, to make sure the results get |
1383 | which submit a lot of requests, to make sure the results get |
| 1366 | processed when they become available and not just when the loop is |
1384 | processed when they become available and not just when the loop is |
| … | |
… | |
| 1374 | Event->io (fd => IO::AIO::poll_fileno, |
1392 | Event->io (fd => IO::AIO::poll_fileno, |
| 1375 | poll => 'r', async => 1, |
1393 | poll => 'r', async => 1, |
| 1376 | cb => \&IO::AIO::poll_cb); |
1394 | cb => \&IO::AIO::poll_cb); |
| 1377 | |
1395 | |
| 1378 | IO::AIO::poll_wait |
1396 | IO::AIO::poll_wait |
| 1379 | If there are any outstanding requests and none of them in the result |
1397 | Wait until either at least one request is in the result phase or no |
| 1380 | phase, wait till the result filehandle becomes ready for reading |
1398 | requests are outstanding anymore. |
| 1381 | (simply does a "select" on the filehandle. This is useful if you |
1399 | |
| 1382 | want to synchronously wait for some requests to finish). |
1400 | This is useful if you want to synchronously wait for some requests |
|
|
1401 | to become ready, without actually handling them. |
| 1383 | |
1402 | |
| 1384 | See "nreqs" for an example. |
1403 | See "nreqs" for an example. |
| 1385 | |
1404 | |
| 1386 | IO::AIO::poll |
1405 | IO::AIO::poll |
| 1387 | Waits until some requests have been handled. |
1406 | Waits until some requests have been handled. |
| … | |
… | |
| 1499 | |
1518 | |
| 1500 | This is a very bad function to use in interactive programs because |
1519 | This is a very bad function to use in interactive programs because |
| 1501 | it blocks, and a bad way to reduce concurrency because it is |
1520 | it blocks, and a bad way to reduce concurrency because it is |
| 1502 | inexact: Better use an "aio_group" together with a feed callback. |
1521 | inexact: Better use an "aio_group" together with a feed callback. |
| 1503 | |
1522 | |
| 1504 | It's main use is in scripts without an event loop - when you want to |
1523 | Its main use is in scripts without an event loop - when you want to |
| 1505 | stat a lot of files, you can write somehting like this: |
1524 | stat a lot of files, you can write somehting like this: |
| 1506 | |
1525 | |
| 1507 | IO::AIO::max_outstanding 32; |
1526 | IO::AIO::max_outstanding 32; |
| 1508 | |
1527 | |
| 1509 | for my $path (...) { |
1528 | for my $path (...) { |
| … | |
… | |
| 1540 | IO::AIO::npending |
1559 | IO::AIO::npending |
| 1541 | Returns the number of requests currently in the pending state |
1560 | Returns the number of requests currently in the pending state |
| 1542 | (executed, but not yet processed by poll_cb). |
1561 | (executed, but not yet processed by poll_cb). |
| 1543 | |
1562 | |
| 1544 | MISCELLANEOUS FUNCTIONS |
1563 | MISCELLANEOUS FUNCTIONS |
| 1545 | IO::AIO implements some functions that might be useful, but are not |
1564 | IO::AIO implements some functions that are useful when you want to use |
| 1546 | asynchronous. |
1565 | some "Advanced I/O" function not available to in Perl, without going the |
|
|
1566 | "Asynchronous I/O" route. Many of these have an asynchronous "aio_*" |
|
|
1567 | counterpart. |
| 1547 | |
1568 | |
| 1548 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1569 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
| 1549 | Calls the "eio_sendfile_sync" function, which is like |
1570 | Calls the "eio_sendfile_sync" function, which is like |
| 1550 | "aio_sendfile", but is blocking (this makes most sense if you know |
1571 | "aio_sendfile", but is blocking (this makes most sense if you know |
| 1551 | the input data is likely cached already and the output filehandle is |
1572 | the input data is likely cached already and the output filehandle is |
| … | |
… | |
| 1659 | "IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT". |
1680 | "IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT". |
| 1660 | |
1681 | |
| 1661 | See the splice(2) manpage for details. |
1682 | See the splice(2) manpage for details. |
| 1662 | |
1683 | |
| 1663 | IO::AIO::tee $r_fh, $w_fh, $length, $flags |
1684 | IO::AIO::tee $r_fh, $w_fh, $length, $flags |
| 1664 | Calls the GNU/Linux tee(2) syscall, see it's manpage and the |
1685 | Calls the GNU/Linux tee(2) syscall, see its manpage and the |
| 1665 | description for "IO::AIO::splice" above for details. |
1686 | description for "IO::AIO::splice" above for details. |
|
|
1687 | |
|
|
1688 | $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
1689 | Attempts to query or change the pipe buffer size. Obviously works |
|
|
1690 | only on pipes, and currently works only on GNU/Linux systems, and |
|
|
1691 | fails with -1/"ENOSYS" everywhere else. If anybody knows how to |
|
|
1692 | influence pipe buffer size on other systems, drop me a note. |
| 1666 | |
1693 | |
| 1667 | EVENT LOOP INTEGRATION |
1694 | EVENT LOOP INTEGRATION |
| 1668 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1695 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
| 1669 | automatically into many event loops: |
1696 | automatically into many event loops: |
| 1670 | |
1697 | |
