| … | |
… | |
| 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; |
| … | |
… | |
| 91 | |
90 | |
| 92 | # file contents now in $contents |
91 | # file contents now in $contents |
| 93 | print $contents; |
92 | print $contents; |
| 94 | |
93 | |
| 95 | # exit event loop and program |
94 | # exit event loop and program |
| 96 | EV::unloop; |
95 | EV::break; |
| 97 | }; |
96 | }; |
| 98 | }; |
97 | }; |
| 99 | |
98 | |
| 100 | # possibly queue up other requests, or open GUI windows, |
99 | # possibly queue up other requests, or open GUI windows, |
| 101 | # check for sockets etc. etc. |
100 | # check for sockets etc. etc. |
| 102 | |
101 | |
| 103 | # process events as long as there are some: |
102 | # process events as long as there are some: |
| 104 | EV::loop; |
103 | EV::run; |
| 105 | |
104 | |
| 106 | REQUEST ANATOMY AND LIFETIME |
105 | REQUEST ANATOMY AND LIFETIME |
| 107 | Every "aio_*" function creates a request. which is a C data structure |
106 | Every "aio_*" function creates a request. which is a C data structure |
| 108 | not directly visible to Perl. |
107 | not directly visible to Perl. |
| 109 | |
108 | |
| … | |
… | |
| 146 | the actual aio request is severed and calling its methods will |
145 | the actual aio request is severed and calling its methods will |
| 147 | either do nothing or result in a runtime error). |
146 | either do nothing or result in a runtime error). |
| 148 | |
147 | |
| 149 | FUNCTIONS |
148 | FUNCTIONS |
| 150 | QUICK OVERVIEW |
149 | QUICK OVERVIEW |
| 151 | This section simply lists the prototypes of the most important functions |
150 | This section simply lists the prototypes most of the functions for quick |
| 152 | for quick reference. See the following sections for function-by-function |
151 | reference. See the following sections for function-by-function |
| 153 | documentation. |
152 | documentation. |
| 154 | |
153 | |
|
|
154 | aio_wd $pathname, $callback->($wd) |
| 155 | aio_open $pathname, $flags, $mode, $callback->($fh) |
155 | aio_open $pathname, $flags, $mode, $callback->($fh) |
| 156 | aio_close $fh, $callback->($status) |
156 | aio_close $fh, $callback->($status) |
|
|
157 | aio_seek $fh,$offset,$whence, $callback->($offs) |
| 157 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
158 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 158 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
159 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 159 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
160 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
| 160 | aio_readahead $fh,$offset,$length, $callback->($retval) |
161 | aio_readahead $fh,$offset,$length, $callback->($retval) |
| 161 | aio_stat $fh_or_path, $callback->($status) |
162 | aio_stat $fh_or_path, $callback->($status) |
| 162 | aio_lstat $fh, $callback->($status) |
163 | aio_lstat $fh, $callback->($status) |
| 163 | aio_statvfs $fh_or_path, $callback->($statvfs) |
164 | aio_statvfs $fh_or_path, $callback->($statvfs) |
| 164 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
165 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
| 165 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
166 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
|
|
167 | aio_chmod $fh_or_path, $mode, $callback->($status) |
| 166 | aio_truncate $fh_or_path, $offset, $callback->($status) |
168 | aio_truncate $fh_or_path, $offset, $callback->($status) |
| 167 | aio_chmod $fh_or_path, $mode, $callback->($status) |
169 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
170 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
| 168 | aio_unlink $pathname, $callback->($status) |
171 | aio_unlink $pathname, $callback->($status) |
| 169 | aio_mknod $path, $mode, $dev, $callback->($status) |
172 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
| 170 | aio_link $srcpath, $dstpath, $callback->($status) |
173 | aio_link $srcpath, $dstpath, $callback->($status) |
| 171 | aio_symlink $srcpath, $dstpath, $callback->($status) |
174 | aio_symlink $srcpath, $dstpath, $callback->($status) |
| 172 | aio_readlink $path, $callback->($link) |
175 | aio_readlink $pathname, $callback->($link) |
|
|
176 | aio_realpath $pathname, $callback->($path) |
| 173 | aio_rename $srcpath, $dstpath, $callback->($status) |
177 | aio_rename $srcpath, $dstpath, $callback->($status) |
| 174 | aio_mkdir $pathname, $mode, $callback->($status) |
178 | aio_mkdir $pathname, $mode, $callback->($status) |
| 175 | aio_rmdir $pathname, $callback->($status) |
179 | aio_rmdir $pathname, $callback->($status) |
| 176 | aio_readdir $pathname, $callback->($entries) |
180 | aio_readdir $pathname, $callback->($entries) |
| 177 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
181 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
| 178 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
182 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
| 179 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
183 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
|
|
184 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
| 180 | aio_load $path, $data, $callback->($status) |
185 | aio_load $pathname, $data, $callback->($status) |
| 181 | aio_copy $srcpath, $dstpath, $callback->($status) |
186 | aio_copy $srcpath, $dstpath, $callback->($status) |
| 182 | aio_move $srcpath, $dstpath, $callback->($status) |
187 | aio_move $srcpath, $dstpath, $callback->($status) |
| 183 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
|
|
| 184 | aio_rmtree $path, $callback->($status) |
188 | aio_rmtree $pathname, $callback->($status) |
|
|
189 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
190 | aio_ioctl $fh, $request, $buf, $callback->($status) |
| 185 | aio_sync $callback->($status) |
191 | aio_sync $callback->($status) |
|
|
192 | aio_syncfs $fh, $callback->($status) |
| 186 | aio_fsync $fh, $callback->($status) |
193 | aio_fsync $fh, $callback->($status) |
| 187 | aio_fdatasync $fh, $callback->($status) |
194 | aio_fdatasync $fh, $callback->($status) |
| 188 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
195 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
| 189 | aio_pathsync $path, $callback->($status) |
196 | aio_pathsync $pathname, $callback->($status) |
| 190 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
197 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
| 191 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
198 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
| 192 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
199 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
| 193 | aio_mlockall $flags, $callback->($status) |
200 | aio_mlockall $flags, $callback->($status) |
| 194 | aio_group $callback->(...) |
201 | aio_group $callback->(...) |
| … | |
… | |
| 212 | IO::AIO::nready |
219 | IO::AIO::nready |
| 213 | IO::AIO::npending |
220 | IO::AIO::npending |
| 214 | |
221 | |
| 215 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
222 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
| 216 | IO::AIO::fadvise $fh, $offset, $len, $advice |
223 | IO::AIO::fadvise $fh, $offset, $len, $advice |
|
|
224 | IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
|
|
225 | IO::AIO::munmap $scalar |
| 217 | IO::AIO::madvise $scalar, $offset, $length, $advice |
226 | IO::AIO::madvise $scalar, $offset, $length, $advice |
| 218 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
227 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
| 219 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
228 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
| 220 | IO::AIO::munlockall |
229 | IO::AIO::munlockall |
| 221 | |
230 | |
| 222 | AIO REQUEST FUNCTIONS |
231 | API NOTES |
| 223 | All the "aio_*" calls are more or less thin wrappers around the syscall |
232 | All the "aio_*" calls are more or less thin wrappers around the syscall |
| 224 | with the same name (sans "aio_"). The arguments are similar or |
233 | with the same name (sans "aio_"). The arguments are similar or |
| 225 | identical, and they all accept an additional (and optional) $callback |
234 | identical, and they all accept an additional (and optional) $callback |
| 226 | argument which must be a code reference. This code reference will get |
235 | argument which must be a code reference. This code reference will be |
| 227 | called with the syscall return code (e.g. most syscalls return -1 on |
|
|
| 228 | error, unlike perl, which usually delivers "false") as its sole argument |
|
|
| 229 | after the given syscall has been executed asynchronously. |
236 | called after the syscall has been executed in an asynchronous fashion. |
|
|
237 | The results of the request will be passed as arguments to the callback |
|
|
238 | (and, if an error occured, in $!) - for most requests the syscall return |
|
|
239 | code (e.g. most syscalls return -1 on error, unlike perl, which usually |
|
|
240 | delivers "false"). |
|
|
241 | |
|
|
242 | Some requests (such as "aio_readdir") pass the actual results and |
|
|
243 | communicate failures by passing "undef". |
| 230 | |
244 | |
| 231 | All functions expecting a filehandle keep a copy of the filehandle |
245 | All functions expecting a filehandle keep a copy of the filehandle |
| 232 | internally until the request has finished. |
246 | internally until the request has finished. |
| 233 | |
247 | |
| 234 | All functions return request objects of type IO::AIO::REQ that allow |
248 | All functions return request objects of type IO::AIO::REQ that allow |
| 235 | further manipulation of those requests while they are in-flight. |
249 | further manipulation of those requests while they are in-flight. |
| 236 | |
250 | |
| 237 | The pathnames you pass to these routines *must* be absolute and encoded |
251 | The pathnames you pass to these routines *should* be absolute. The |
| 238 | as octets. The reason for the former is that at the time the request is |
252 | reason for this is that at the time the request is being executed, the |
| 239 | being executed, the current working directory could have changed. |
253 | current working directory could have changed. Alternatively, you can |
| 240 | Alternatively, you can make sure that you never change the current |
254 | make sure that you never change the current working directory anywhere |
| 241 | working directory anywhere in the program and then use relative paths. |
255 | in the program and then use relative paths. You can also take advantage |
|
|
256 | of IO::AIOs working directory abstraction, that lets you specify paths |
|
|
257 | relative to some previously-opened "working directory object" - see the |
|
|
258 | description of the "IO::AIO::WD" class later in this document. |
| 242 | |
259 | |
| 243 | To encode pathnames as octets, either make sure you either: a) always |
260 | To encode pathnames as octets, either make sure you either: a) always |
| 244 | pass in filenames you got from outside (command line, readdir etc.) |
261 | pass in filenames you got from outside (command line, readdir etc.) |
| 245 | without tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module |
262 | without tinkering, b) are in your native filesystem encoding, c) use the |
| 246 | and encode your pathnames to the locale (or other) encoding in effect in |
263 | Encode module and encode your pathnames to the locale (or other) |
| 247 | the user environment, d) use Glib::filename_from_unicode on unicode |
264 | encoding in effect in the user environment, d) use |
| 248 | filenames or e) use something else to ensure your scalar has the correct |
265 | Glib::filename_from_unicode on unicode filenames or e) use something |
| 249 | contents. |
266 | else to ensure your scalar has the correct contents. |
| 250 | |
267 | |
| 251 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
268 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
| 252 | handles correctly whether it is set or not. |
269 | handles correctly whether it is set or not. |
| 253 | |
270 | |
|
|
271 | AIO REQUEST FUNCTIONS |
| 254 | $prev_pri = aioreq_pri [$pri] |
272 | $prev_pri = aioreq_pri [$pri] |
| 255 | Returns the priority value that would be used for the next request |
273 | Returns the priority value that would be used for the next request |
| 256 | and, if $pri is given, sets the priority for the next aio request. |
274 | and, if $pri is given, sets the priority for the next aio request. |
| 257 | |
275 | |
| 258 | The default priority is 0, the minimum and maximum priorities are -4 |
276 | The default priority is 0, the minimum and maximum priorities are -4 |
| … | |
… | |
| 280 | Similar to "aioreq_pri", but subtracts the given value from the |
298 | Similar to "aioreq_pri", but subtracts the given value from the |
| 281 | current priority, so the effect is cumulative. |
299 | current priority, so the effect is cumulative. |
| 282 | |
300 | |
| 283 | aio_open $pathname, $flags, $mode, $callback->($fh) |
301 | aio_open $pathname, $flags, $mode, $callback->($fh) |
| 284 | Asynchronously open or create a file and call the callback with a |
302 | Asynchronously open or create a file and call the callback with a |
| 285 | newly created filehandle for the file. |
303 | newly created filehandle for the file (or "undef" in case of an |
|
|
304 | error). |
| 286 | |
305 | |
| 287 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
306 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
| 288 | above, for an explanation. |
307 | above, for an explanation. |
| 289 | |
308 | |
| 290 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
309 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
| … | |
… | |
| 313 | "O_APPEND"), the following POSIX and non-POSIX constants are |
332 | "O_APPEND"), the following POSIX and non-POSIX constants are |
| 314 | available (missing ones on your system are, as usual, 0): |
333 | available (missing ones on your system are, as usual, 0): |
| 315 | |
334 | |
| 316 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
335 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
| 317 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
336 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
| 318 | "O_DSYNC", "O_RSYNC", "O_SYNC" and "O_TTY_INIT". |
337 | "O_DSYNC", "O_RSYNC", "O_SYNC", "O_PATH", "O_TMPFILE", and |
|
|
338 | "O_TTY_INIT". |
| 319 | |
339 | |
| 320 | aio_close $fh, $callback->($status) |
340 | aio_close $fh, $callback->($status) |
| 321 | Asynchronously close a file and call the callback with the result |
341 | Asynchronously close a file and call the callback with the result |
| 322 | code. |
342 | code. |
| 323 | |
343 | |
| … | |
… | |
| 329 | will use dup2 to overwrite the file descriptor with the write-end of |
349 | will use dup2 to overwrite the file descriptor with the write-end of |
| 330 | a pipe (the pipe fd will be created on demand and will be cached). |
350 | a pipe (the pipe fd will be created on demand and will be cached). |
| 331 | |
351 | |
| 332 | Or in other words: the file descriptor will be closed, but it will |
352 | Or in other words: the file descriptor will be closed, but it will |
| 333 | not be free for reuse until the perl filehandle is closed. |
353 | not be free for reuse until the perl filehandle is closed. |
|
|
354 | |
|
|
355 | aio_seek $fh, $offset, $whence, $callback->($offs) |
|
|
356 | Seeks the filehandle to the new $offset, similarly to perl's |
|
|
357 | "sysseek". The $whence can use the traditional values (0 for |
|
|
358 | "IO::AIO::SEEK_SET", 1 for "IO::AIO::SEEK_CUR" or 2 for |
|
|
359 | "IO::AIO::SEEK_END"). |
|
|
360 | |
|
|
361 | The resulting absolute offset will be passed to the callback, or -1 |
|
|
362 | in case of an error. |
|
|
363 | |
|
|
364 | In theory, the $whence constants could be different than the |
|
|
365 | corresponding values from Fcntl, but perl guarantees they are the |
|
|
366 | same, so don't panic. |
|
|
367 | |
|
|
368 | As a GNU/Linux (and maybe Solaris) extension, also the constants |
|
|
369 | "IO::AIO::SEEK_DATA" and "IO::AIO::SEEK_HOLE" are available, if they |
|
|
370 | could be found. No guarantees about suitability for use in |
|
|
371 | "aio_seek" or Perl's "sysseek" can be made though, although I would |
|
|
372 | naively assume they "just work". |
| 334 | |
373 | |
| 335 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
374 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 336 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
375 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
| 337 | Reads or writes $length bytes from or to the specified $fh and |
376 | Reads or writes $length bytes from or to the specified $fh and |
| 338 | $offset into the scalar given by $data and offset $dataoffset and |
377 | $offset into the scalar given by $data and offset $dataoffset and |
| … | |
… | |
| 493 | namemax => 255, |
532 | namemax => 255, |
| 494 | frsize => 1024, |
533 | frsize => 1024, |
| 495 | fsid => 1810 |
534 | fsid => 1810 |
| 496 | } |
535 | } |
| 497 | |
536 | |
|
|
537 | Here is a (likely partial - send me updates!) list of fsid values |
|
|
538 | used by Linux - it is safe to hardcode these when $^O is "linux": |
|
|
539 | |
|
|
540 | 0x0000adf5 adfs |
|
|
541 | 0x0000adff affs |
|
|
542 | 0x5346414f afs |
|
|
543 | 0x09041934 anon-inode filesystem |
|
|
544 | 0x00000187 autofs |
|
|
545 | 0x42465331 befs |
|
|
546 | 0x1badface bfs |
|
|
547 | 0x42494e4d binfmt_misc |
|
|
548 | 0x9123683e btrfs |
|
|
549 | 0x0027e0eb cgroupfs |
|
|
550 | 0xff534d42 cifs |
|
|
551 | 0x73757245 coda |
|
|
552 | 0x012ff7b7 coh |
|
|
553 | 0x28cd3d45 cramfs |
|
|
554 | 0x453dcd28 cramfs-wend (wrong endianness) |
|
|
555 | 0x64626720 debugfs |
|
|
556 | 0x00001373 devfs |
|
|
557 | 0x00001cd1 devpts |
|
|
558 | 0x0000f15f ecryptfs |
|
|
559 | 0x00414a53 efs |
|
|
560 | 0x0000137d ext |
|
|
561 | 0x0000ef53 ext2/ext3/ext4 |
|
|
562 | 0x0000ef51 ext2 |
|
|
563 | 0xf2f52010 f2fs |
|
|
564 | 0x00004006 fat |
|
|
565 | 0x65735546 fuseblk |
|
|
566 | 0x65735543 fusectl |
|
|
567 | 0x0bad1dea futexfs |
|
|
568 | 0x01161970 gfs2 |
|
|
569 | 0x47504653 gpfs |
|
|
570 | 0x00004244 hfs |
|
|
571 | 0xf995e849 hpfs |
|
|
572 | 0x00c0ffee hostfs |
|
|
573 | 0x958458f6 hugetlbfs |
|
|
574 | 0x2bad1dea inotifyfs |
|
|
575 | 0x00009660 isofs |
|
|
576 | 0x000072b6 jffs2 |
|
|
577 | 0x3153464a jfs |
|
|
578 | 0x6b414653 k-afs |
|
|
579 | 0x0bd00bd0 lustre |
|
|
580 | 0x0000137f minix |
|
|
581 | 0x0000138f minix 30 char names |
|
|
582 | 0x00002468 minix v2 |
|
|
583 | 0x00002478 minix v2 30 char names |
|
|
584 | 0x00004d5a minix v3 |
|
|
585 | 0x19800202 mqueue |
|
|
586 | 0x00004d44 msdos |
|
|
587 | 0x0000564c novell |
|
|
588 | 0x00006969 nfs |
|
|
589 | 0x6e667364 nfsd |
|
|
590 | 0x00003434 nilfs |
|
|
591 | 0x5346544e ntfs |
|
|
592 | 0x00009fa1 openprom |
|
|
593 | 0x7461636F ocfs2 |
|
|
594 | 0x00009fa0 proc |
|
|
595 | 0x6165676c pstorefs |
|
|
596 | 0x0000002f qnx4 |
|
|
597 | 0x68191122 qnx6 |
|
|
598 | 0x858458f6 ramfs |
|
|
599 | 0x52654973 reiserfs |
|
|
600 | 0x00007275 romfs |
|
|
601 | 0x67596969 rpc_pipefs |
|
|
602 | 0x73636673 securityfs |
|
|
603 | 0xf97cff8c selinux |
|
|
604 | 0x0000517b smb |
|
|
605 | 0x534f434b sockfs |
|
|
606 | 0x73717368 squashfs |
|
|
607 | 0x62656572 sysfs |
|
|
608 | 0x012ff7b6 sysv2 |
|
|
609 | 0x012ff7b5 sysv4 |
|
|
610 | 0x01021994 tmpfs |
|
|
611 | 0x15013346 udf |
|
|
612 | 0x00011954 ufs |
|
|
613 | 0x54190100 ufs byteswapped |
|
|
614 | 0x00009fa2 usbdevfs |
|
|
615 | 0x01021997 v9fs |
|
|
616 | 0xa501fcf5 vxfs |
|
|
617 | 0xabba1974 xenfs |
|
|
618 | 0x012ff7b4 xenix |
|
|
619 | 0x58465342 xfs |
|
|
620 | 0x012fd16d xia |
|
|
621 | |
| 498 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
622 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
| 499 | Works like perl's "utime" function (including the special case of |
623 | Works like perl's "utime" function (including the special case of |
| 500 | $atime and $mtime being undef). Fractional times are supported if |
624 | $atime and $mtime being undef). Fractional times are supported if |
| 501 | the underlying syscalls support them. |
625 | the underlying syscalls support them. |
| 502 | |
626 | |
| … | |
… | |
| 524 | aio_chown "path", 0, undef; |
648 | aio_chown "path", 0, undef; |
| 525 | |
649 | |
| 526 | aio_truncate $fh_or_path, $offset, $callback->($status) |
650 | aio_truncate $fh_or_path, $offset, $callback->($status) |
| 527 | Works like truncate(2) or ftruncate(2). |
651 | Works like truncate(2) or ftruncate(2). |
| 528 | |
652 | |
|
|
653 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
654 | Allocates or frees disk space according to the $mode argument. See |
|
|
655 | the linux "fallocate" documentation for details. |
|
|
656 | |
|
|
657 | $mode is usually 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to allocate |
|
|
658 | space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE | |
|
|
659 | IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range. |
|
|
660 | |
|
|
661 | IO::AIO also supports "FALLOC_FL_COLLAPSE_RANGE", to remove a range |
|
|
662 | (without leaving a hole) and "FALLOC_FL_ZERO_RANGE", to zero a range |
|
|
663 | (see your fallocate(2) manpage). |
|
|
664 | |
|
|
665 | The file system block size used by "fallocate" is presumably the |
|
|
666 | "f_bsize" returned by "statvfs". |
|
|
667 | |
|
|
668 | If "fallocate" isn't available or cannot be emulated (currently no |
|
|
669 | emulation will be attempted), passes -1 and sets $! to "ENOSYS". |
|
|
670 | |
| 529 | aio_chmod $fh_or_path, $mode, $callback->($status) |
671 | aio_chmod $fh_or_path, $mode, $callback->($status) |
| 530 | Works like perl's "chmod" function. |
672 | Works like perl's "chmod" function. |
| 531 | |
673 | |
| 532 | aio_unlink $pathname, $callback->($status) |
674 | aio_unlink $pathname, $callback->($status) |
| 533 | Asynchronously unlink (delete) a file and call the callback with the |
675 | Asynchronously unlink (delete) a file and call the callback with the |
| 534 | result code. |
676 | result code. |
| 535 | |
677 | |
| 536 | aio_mknod $path, $mode, $dev, $callback->($status) |
678 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
| 537 | [EXPERIMENTAL] |
679 | [EXPERIMENTAL] |
| 538 | |
680 | |
| 539 | Asynchronously create a device node (or fifo). See mknod(2). |
681 | Asynchronously create a device node (or fifo). See mknod(2). |
| 540 | |
682 | |
| 541 | The only (POSIX-) portable way of calling this function is: |
683 | The only (POSIX-) portable way of calling this function is: |
| 542 | |
684 | |
| 543 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
685 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
| 544 | |
686 | |
| 545 | See "aio_stat" for info about some potentially helpful extra |
687 | See "aio_stat" for info about some potentially helpful extra |
| 546 | constants and functions. |
688 | constants and functions. |
| 547 | |
689 | |
| 548 | aio_link $srcpath, $dstpath, $callback->($status) |
690 | aio_link $srcpath, $dstpath, $callback->($status) |
| … | |
… | |
| 552 | aio_symlink $srcpath, $dstpath, $callback->($status) |
694 | aio_symlink $srcpath, $dstpath, $callback->($status) |
| 553 | Asynchronously create a new symbolic link to the existing object at |
695 | Asynchronously create a new symbolic link to the existing object at |
| 554 | $srcpath at the path $dstpath and call the callback with the result |
696 | $srcpath at the path $dstpath and call the callback with the result |
| 555 | code. |
697 | code. |
| 556 | |
698 | |
| 557 | aio_readlink $path, $callback->($link) |
699 | aio_readlink $pathname, $callback->($link) |
| 558 | Asynchronously read the symlink specified by $path and pass it to |
700 | Asynchronously read the symlink specified by $path and pass it to |
| 559 | the callback. If an error occurs, nothing or undef gets passed to |
701 | the callback. If an error occurs, nothing or undef gets passed to |
| 560 | the callback. |
702 | the callback. |
| 561 | |
703 | |
|
|
704 | aio_realpath $pathname, $callback->($path) |
|
|
705 | Asynchronously make the path absolute and resolve any symlinks in |
|
|
706 | $path. The resulting path only consists of directories (same as |
|
|
707 | Cwd::realpath). |
|
|
708 | |
|
|
709 | This request can be used to get the absolute path of the current |
|
|
710 | working directory by passing it a path of . (a single dot). |
|
|
711 | |
| 562 | aio_rename $srcpath, $dstpath, $callback->($status) |
712 | aio_rename $srcpath, $dstpath, $callback->($status) |
| 563 | Asynchronously rename the object at $srcpath to $dstpath, just as |
713 | Asynchronously rename the object at $srcpath to $dstpath, just as |
| 564 | rename(2) and call the callback with the result code. |
714 | rename(2) and call the callback with the result code. |
|
|
715 | |
|
|
716 | On systems that support the AIO::WD working directory abstraction |
|
|
717 | natively, the case "[$wd, "."]" as $srcpath is specialcased - |
|
|
718 | instead of failing, "rename" is called on the absolute path of $wd. |
| 565 | |
719 | |
| 566 | aio_mkdir $pathname, $mode, $callback->($status) |
720 | aio_mkdir $pathname, $mode, $callback->($status) |
| 567 | Asynchronously mkdir (create) a directory and call the callback with |
721 | Asynchronously mkdir (create) a directory and call the callback with |
| 568 | the result code. $mode will be modified by the umask at the time the |
722 | the result code. $mode will be modified by the umask at the time the |
| 569 | request is executed, so do not change your umask. |
723 | request is executed, so do not change your umask. |
| 570 | |
724 | |
| 571 | aio_rmdir $pathname, $callback->($status) |
725 | aio_rmdir $pathname, $callback->($status) |
| 572 | Asynchronously rmdir (delete) a directory and call the callback with |
726 | Asynchronously rmdir (delete) a directory and call the callback with |
| 573 | the result code. |
727 | the result code. |
| 574 | |
728 | |
|
|
729 | On systems that support the AIO::WD working directory abstraction |
|
|
730 | natively, the case "[$wd, "."]" is specialcased - instead of |
|
|
731 | failing, "rmdir" is called on the absolute path of $wd. |
|
|
732 | |
| 575 | aio_readdir $pathname, $callback->($entries) |
733 | aio_readdir $pathname, $callback->($entries) |
| 576 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
734 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
| 577 | entire directory (i.e. opendir + readdir + closedir). The entries |
735 | entire directory (i.e. opendir + readdir + closedir). The entries |
| 578 | will not be sorted, and will NOT include the "." and ".." entries. |
736 | will not be sorted, and will NOT include the "." and ".." entries. |
| 579 | |
737 | |
| 580 | The callback is passed a single argument which is either "undef" or |
738 | The callback is passed a single argument which is either "undef" or |
| 581 | an array-ref with the filenames. |
739 | an array-ref with the filenames. |
| 582 | |
740 | |
| 583 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
741 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
| 584 | Quite similar to "aio_readdir", but the $flags argument allows to |
742 | Quite similar to "aio_readdir", but the $flags argument allows one |
| 585 | tune behaviour and output format. In case of an error, $entries will |
743 | to tune behaviour and output format. In case of an error, $entries |
| 586 | be "undef". |
744 | will be "undef". |
| 587 | |
745 | |
| 588 | The flags are a combination of the following constants, ORed |
746 | The flags are a combination of the following constants, ORed |
| 589 | together (the flags will also be passed to the callback, possibly |
747 | together (the flags will also be passed to the callback, possibly |
| 590 | modified): |
748 | modified): |
| 591 | |
749 | |
| … | |
… | |
| 636 | optimal stat order. |
794 | optimal stat order. |
| 637 | |
795 | |
| 638 | IO::AIO::READDIR_FOUND_UNKNOWN |
796 | IO::AIO::READDIR_FOUND_UNKNOWN |
| 639 | This flag should not be set when calling "aio_readdirx". |
797 | This flag should not be set when calling "aio_readdirx". |
| 640 | Instead, it is being set by "aio_readdirx", when any of the |
798 | Instead, it is being set by "aio_readdirx", when any of the |
| 641 | $type's found were "IO::AIO::DT_UNKNOWN". The absense of this |
799 | $type's found were "IO::AIO::DT_UNKNOWN". The absence of this |
| 642 | flag therefore indicates that all $type's are known, which can |
800 | flag therefore indicates that all $type's are known, which can |
| 643 | be used to speed up some algorithms. |
801 | be used to speed up some algorithms. |
| 644 | |
802 | |
| 645 | aio_load $path, $data, $callback->($status) |
803 | aio_load $pathname, $data, $callback->($status) |
| 646 | This is a composite request that tries to fully load the given file |
804 | This is a composite request that tries to fully load the given file |
| 647 | into memory. Status is the same as with aio_read. |
805 | into memory. Status is the same as with aio_read. |
| 648 | |
806 | |
| 649 | aio_copy $srcpath, $dstpath, $callback->($status) |
807 | aio_copy $srcpath, $dstpath, $callback->($status) |
| 650 | Try to copy the *file* (directories not supported as either source |
808 | Try to copy the *file* (directories not supported as either source |
| … | |
… | |
| 667 | |
825 | |
| 668 | This is a composite request that tries to rename(2) the file first; |
826 | This is a composite request that tries to rename(2) the file first; |
| 669 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
827 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
| 670 | and, if that is successful, unlinks the $srcpath. |
828 | and, if that is successful, unlinks the $srcpath. |
| 671 | |
829 | |
| 672 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
830 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
| 673 | Scans a directory (similar to "aio_readdir") but additionally tries |
831 | Scans a directory (similar to "aio_readdir") but additionally tries |
| 674 | to efficiently separate the entries of directory $path into two sets |
832 | to efficiently separate the entries of directory $path into two sets |
| 675 | of names, directories you can recurse into (directories), and ones |
833 | of names, directories you can recurse into (directories), and ones |
| 676 | you cannot recurse into (everything else, including symlinks to |
834 | you cannot recurse into (everything else, including symlinks to |
| 677 | directories). |
835 | directories). |
| … | |
… | |
| 710 | Then entries will be sorted into likely directories a non-initial |
868 | Then entries will be sorted into likely directories a non-initial |
| 711 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
869 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
| 712 | every entry plus an appended "/." will be "stat"'ed, likely |
870 | every entry plus an appended "/." will be "stat"'ed, likely |
| 713 | directories first, in order of their inode numbers. If that |
871 | directories first, in order of their inode numbers. If that |
| 714 | succeeds, it assumes that the entry is a directory or a symlink to |
872 | succeeds, it assumes that the entry is a directory or a symlink to |
| 715 | directory (which will be checked seperately). This is often faster |
873 | directory (which will be checked separately). This is often faster |
| 716 | than stat'ing the entry itself because filesystems might detect the |
874 | than stat'ing the entry itself because filesystems might detect the |
| 717 | type of the entry without reading the inode data (e.g. ext2fs |
875 | type of the entry without reading the inode data (e.g. ext2fs |
| 718 | filetype feature), even on systems that cannot return the filetype |
876 | filetype feature), even on systems that cannot return the filetype |
| 719 | information on readdir. |
877 | information on readdir. |
| 720 | |
878 | |
| … | |
… | |
| 726 | |
884 | |
| 727 | It will also likely work on non-POSIX filesystems with reduced |
885 | It will also likely work on non-POSIX filesystems with reduced |
| 728 | efficiency as those tend to return 0 or 1 as link counts, which |
886 | efficiency as those tend to return 0 or 1 as link counts, which |
| 729 | disables the directory counting heuristic. |
887 | disables the directory counting heuristic. |
| 730 | |
888 | |
| 731 | aio_rmtree $path, $callback->($status) |
889 | aio_rmtree $pathname, $callback->($status) |
| 732 | Delete a directory tree starting (and including) $path, return the |
890 | Delete a directory tree starting (and including) $path, return the |
| 733 | status of the final "rmdir" only. This is a composite request that |
891 | status of the final "rmdir" only. This is a composite request that |
| 734 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
892 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
| 735 | everything else. |
893 | everything else. |
| 736 | |
894 | |
|
|
895 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
896 | aio_ioctl $fh, $request, $buf, $callback->($status) |
|
|
897 | These work just like the "fcntl" and "ioctl" built-in functions, |
|
|
898 | except they execute asynchronously and pass the return value to the |
|
|
899 | callback. |
|
|
900 | |
|
|
901 | Both calls can be used for a lot of things, some of which make more |
|
|
902 | sense to run asynchronously in their own thread, while some others |
|
|
903 | make less sense. For example, calls that block waiting for external |
|
|
904 | events, such as locking, will also lock down an I/O thread while it |
|
|
905 | is waiting, which can deadlock the whole I/O system. At the same |
|
|
906 | time, there might be no alternative to using a thread to wait. |
|
|
907 | |
|
|
908 | So in general, you should only use these calls for things that do |
|
|
909 | (filesystem) I/O, not for things that wait for other events |
|
|
910 | (network, other processes), although if you are careful and know |
|
|
911 | what you are doing, you still can. |
|
|
912 | |
| 737 | aio_sync $callback->($status) |
913 | aio_sync $callback->($status) |
| 738 | Asynchronously call sync and call the callback when finished. |
914 | Asynchronously call sync and call the callback when finished. |
| 739 | |
915 | |
| 740 | aio_fsync $fh, $callback->($status) |
916 | aio_fsync $fh, $callback->($status) |
| 741 | Asynchronously call fsync on the given filehandle and call the |
917 | Asynchronously call fsync on the given filehandle and call the |
| … | |
… | |
| 745 | Asynchronously call fdatasync on the given filehandle and call the |
921 | Asynchronously call fdatasync on the given filehandle and call the |
| 746 | callback with the fdatasync result code. |
922 | callback with the fdatasync result code. |
| 747 | |
923 | |
| 748 | If this call isn't available because your OS lacks it or it couldn't |
924 | If this call isn't available because your OS lacks it or it couldn't |
| 749 | be detected, it will be emulated by calling "fsync" instead. |
925 | be detected, it will be emulated by calling "fsync" instead. |
|
|
926 | |
|
|
927 | aio_syncfs $fh, $callback->($status) |
|
|
928 | Asynchronously call the syncfs syscall to sync the filesystem |
|
|
929 | associated to the given filehandle and call the callback with the |
|
|
930 | syncfs result code. If syncfs is not available, calls sync(), but |
|
|
931 | returns -1 and sets errno to "ENOSYS" nevertheless. |
| 750 | |
932 | |
| 751 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
933 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
| 752 | Sync the data portion of the file specified by $offset and $length |
934 | Sync the data portion of the file specified by $offset and $length |
| 753 | to disk (but NOT the metadata), by calling the Linux-specific |
935 | to disk (but NOT the metadata), by calling the Linux-specific |
| 754 | sync_file_range call. If sync_file_range is not available or it |
936 | sync_file_range call. If sync_file_range is not available or it |
| … | |
… | |
| 758 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
940 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
| 759 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
941 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
| 760 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
942 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
| 761 | manpage for details. |
943 | manpage for details. |
| 762 | |
944 | |
| 763 | aio_pathsync $path, $callback->($status) |
945 | aio_pathsync $pathname, $callback->($status) |
| 764 | This request tries to open, fsync and close the given path. This is |
946 | This request tries to open, fsync and close the given path. This is |
| 765 | a composite request intended to sync directories after directory |
947 | a composite request intended to sync directories after directory |
| 766 | operations (E.g. rename). This might not work on all operating |
948 | operations (E.g. rename). This might not work on all operating |
| 767 | systems or have any specific effect, but usually it makes sure that |
949 | systems or have any specific effect, but usually it makes sure that |
| 768 | directory changes get written to disc. It works for anything that |
950 | directory changes get written to disc. It works for anything that |
| … | |
… | |
| 795 | |
977 | |
| 796 | It touches (reads or writes) all memory pages in the specified range |
978 | It touches (reads or writes) all memory pages in the specified range |
| 797 | inside the scalar. All caveats and parameters are the same as for |
979 | inside the scalar. All caveats and parameters are the same as for |
| 798 | "aio_msync", above, except for flags, which must be either 0 (which |
980 | "aio_msync", above, except for flags, which must be either 0 (which |
| 799 | reads all pages and ensures they are instantiated) or |
981 | reads all pages and ensures they are instantiated) or |
| 800 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
982 | "IO::AIO::MT_MODIFY", which modifies the memory pages (by reading |
| 801 | and writing an octet from it, which dirties the page). |
983 | and writing an octet from it, which dirties the page). |
| 802 | |
984 | |
| 803 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
985 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
| 804 | This is a rather advanced IO::AIO call, which works best on |
986 | This is a rather advanced IO::AIO call, which works best on |
| 805 | mmap(2)ed scalars. |
987 | mmap(2)ed scalars. |
| … | |
… | |
| 837 | |
1019 | |
| 838 | Example: asynchronously lock all current and future pages into |
1020 | Example: asynchronously lock all current and future pages into |
| 839 | memory. |
1021 | memory. |
| 840 | |
1022 | |
| 841 | aio_mlockall IO::AIO::MCL_FUTURE; |
1023 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1024 | |
|
|
1025 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
1026 | Queries the extents of the given file (by calling the Linux "FIEMAP" |
|
|
1027 | ioctl, see <http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for |
|
|
1028 | details). If the ioctl is not available on your OS, then this |
|
|
1029 | request will fail with "ENOSYS". |
|
|
1030 | |
|
|
1031 | $start is the starting offset to query extents for, $length is the |
|
|
1032 | size of the range to query - if it is "undef", then the whole file |
|
|
1033 | will be queried. |
|
|
1034 | |
|
|
1035 | $flags is a combination of flags ("IO::AIO::FIEMAP_FLAG_SYNC" or |
|
|
1036 | "IO::AIO::FIEMAP_FLAG_XATTR" - "IO::AIO::FIEMAP_FLAGS_COMPAT" is |
|
|
1037 | also exported), and is normally 0 or "IO::AIO::FIEMAP_FLAG_SYNC" to |
|
|
1038 | query the data portion. |
|
|
1039 | |
|
|
1040 | $count is the maximum number of extent records to return. If it is |
|
|
1041 | "undef", then IO::AIO queries all extents of the range. As a very |
|
|
1042 | special case, if it is 0, then the callback receives the number of |
|
|
1043 | extents instead of the extents themselves (which is unreliable, see |
|
|
1044 | below). |
|
|
1045 | |
|
|
1046 | If an error occurs, the callback receives no arguments. The special |
|
|
1047 | "errno" value "IO::AIO::EBADR" is available to test for flag errors. |
|
|
1048 | |
|
|
1049 | Otherwise, the callback receives an array reference with extent |
|
|
1050 | structures. Each extent structure is an array reference itself, with |
|
|
1051 | the following members: |
|
|
1052 | |
|
|
1053 | [$logical, $physical, $length, $flags] |
|
|
1054 | |
|
|
1055 | Flags is any combination of the following flag values (typically |
|
|
1056 | either 0 or "IO::AIO::FIEMAP_EXTENT_LAST" (1)): |
|
|
1057 | |
|
|
1058 | "IO::AIO::FIEMAP_EXTENT_LAST", "IO::AIO::FIEMAP_EXTENT_UNKNOWN", |
|
|
1059 | "IO::AIO::FIEMAP_EXTENT_DELALLOC", "IO::AIO::FIEMAP_EXTENT_ENCODED", |
|
|
1060 | "IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED", |
|
|
1061 | "IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED", |
|
|
1062 | "IO::AIO::FIEMAP_EXTENT_DATA_INLINE", |
|
|
1063 | "IO::AIO::FIEMAP_EXTENT_DATA_TAIL", |
|
|
1064 | "IO::AIO::FIEMAP_EXTENT_UNWRITTEN", "IO::AIO::FIEMAP_EXTENT_MERGED" |
|
|
1065 | or "IO::AIO::FIEMAP_EXTENT_SHARED". |
|
|
1066 | |
|
|
1067 | At the time of this writing (Linux 3.2), this requets is unreliable |
|
|
1068 | unless $count is "undef", as the kernel has all sorts of bugs |
|
|
1069 | preventing it to return all extents of a range for files with large |
|
|
1070 | number of extents. The code works around all these issues if $count |
|
|
1071 | is undef. |
| 842 | |
1072 | |
| 843 | aio_group $callback->(...) |
1073 | aio_group $callback->(...) |
| 844 | This is a very special aio request: Instead of doing something, it |
1074 | This is a very special aio request: Instead of doing something, it |
| 845 | is a container for other aio requests, which is useful if you want |
1075 | is a container for other aio requests, which is useful if you want |
| 846 | to bundle many requests into a single, composite, request with a |
1076 | to bundle many requests into a single, composite, request with a |
| … | |
… | |
| 880 | While it is theoretically handy to have simple I/O scheduling |
1110 | While it is theoretically handy to have simple I/O scheduling |
| 881 | requests like sleep and file handle readable/writable, the overhead |
1111 | requests like sleep and file handle readable/writable, the overhead |
| 882 | this creates is immense (it blocks a thread for a long time) so do |
1112 | this creates is immense (it blocks a thread for a long time) so do |
| 883 | not use this function except to put your application under |
1113 | not use this function except to put your application under |
| 884 | artificial I/O pressure. |
1114 | artificial I/O pressure. |
|
|
1115 | |
|
|
1116 | IO::AIO::WD - multiple working directories |
|
|
1117 | Your process only has one current working directory, which is used by |
|
|
1118 | all threads. This makes it hard to use relative paths (some other |
|
|
1119 | component could call "chdir" at any time, and it is hard to control when |
|
|
1120 | the path will be used by IO::AIO). |
|
|
1121 | |
|
|
1122 | One solution for this is to always use absolute paths. This usually |
|
|
1123 | works, but can be quite slow (the kernel has to walk the whole path on |
|
|
1124 | every access), and can also be a hassle to implement. |
|
|
1125 | |
|
|
1126 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1127 | futimensat and so on) that make it possible to specify working |
|
|
1128 | directories per operation. |
|
|
1129 | |
|
|
1130 | For portability, and because the clowns who "designed", or shall I |
|
|
1131 | write, perpetrated this new interface were obviously half-drunk, this |
|
|
1132 | abstraction cannot be perfect, though. |
|
|
1133 | |
|
|
1134 | IO::AIO allows you to convert directory paths into a so-called |
|
|
1135 | IO::AIO::WD object. This object stores the canonicalised, absolute |
|
|
1136 | version of the path, and on systems that allow it, also a directory file |
|
|
1137 | descriptor. |
|
|
1138 | |
|
|
1139 | Everywhere where a pathname is accepted by IO::AIO (e.g. in "aio_stat" |
|
|
1140 | or "aio_unlink"), one can specify an array reference with an IO::AIO::WD |
|
|
1141 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1142 | gets interpreted as "[$wd, "."]"). If the pathname is absolute, the |
|
|
1143 | IO::AIO::WD object is ignored, otherwise the pathname is resolved |
|
|
1144 | relative to that IO::AIO::WD object. |
|
|
1145 | |
|
|
1146 | For example, to get a wd object for /etc and then stat passwd inside, |
|
|
1147 | you would write: |
|
|
1148 | |
|
|
1149 | aio_wd "/etc", sub { |
|
|
1150 | my $etcdir = shift; |
|
|
1151 | |
|
|
1152 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1153 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1154 | # when $etcdir is undef. |
|
|
1155 | |
|
|
1156 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1157 | # yay |
|
|
1158 | }; |
|
|
1159 | }; |
|
|
1160 | |
|
|
1161 | The fact that "aio_wd" is a request and not a normal function shows that |
|
|
1162 | creating an IO::AIO::WD object is itself a potentially blocking |
|
|
1163 | operation, which is why it is done asynchronously. |
|
|
1164 | |
|
|
1165 | To stat the directory obtained with "aio_wd" above, one could write |
|
|
1166 | either of the following three request calls: |
|
|
1167 | |
|
|
1168 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1169 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1170 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1171 | |
|
|
1172 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1173 | object and the pathname string, so you could write the following without |
|
|
1174 | causing any issues due to $path getting reused: |
|
|
1175 | |
|
|
1176 | my $path = [$wd, undef]; |
|
|
1177 | |
|
|
1178 | for my $name (qw(abc def ghi)) { |
|
|
1179 | $path->[1] = $name; |
|
|
1180 | aio_stat $path, sub { |
|
|
1181 | # ... |
|
|
1182 | }; |
|
|
1183 | } |
|
|
1184 | |
|
|
1185 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1186 | pathname string doesn't change, so will point to the new directory (or |
|
|
1187 | nowhere at all), while the directory fd, if available on the system, |
|
|
1188 | will still point to the original directory. Most functions accepting a |
|
|
1189 | pathname will use the directory fd on newer systems, and the string on |
|
|
1190 | older systems. Some functions (such as realpath) will always rely on the |
|
|
1191 | string form of the pathname. |
|
|
1192 | |
|
|
1193 | So this functionality is mainly useful to get some protection against |
|
|
1194 | "chdir", to easily get an absolute path out of a relative path for |
|
|
1195 | future reference, and to speed up doing many operations in the same |
|
|
1196 | directory (e.g. when stat'ing all files in a directory). |
|
|
1197 | |
|
|
1198 | The following functions implement this working directory abstraction: |
|
|
1199 | |
|
|
1200 | aio_wd $pathname, $callback->($wd) |
|
|
1201 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1202 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1203 | system, also open a directory fd to speed up pathname resolution |
|
|
1204 | relative to this working directory. |
|
|
1205 | |
|
|
1206 | If something goes wrong, then "undef" is passwd to the callback |
|
|
1207 | instead of a working directory object and $! is set appropriately. |
|
|
1208 | Since passing "undef" as working directory component of a pathname |
|
|
1209 | fails the request with "ENOENT", there is often no need for error |
|
|
1210 | checking in the "aio_wd" callback, as future requests using the |
|
|
1211 | value will fail in the expected way. |
|
|
1212 | |
|
|
1213 | IO::AIO::CWD |
|
|
1214 | This is a compiletime constant (object) that represents the process |
|
|
1215 | current working directory. |
|
|
1216 | |
|
|
1217 | Specifying this object as working directory object for a pathname is |
|
|
1218 | as if the pathname would be specified directly, without a directory |
|
|
1219 | object. For example, these calls are functionally identical: |
|
|
1220 | |
|
|
1221 | aio_stat "somefile", sub { ... }; |
|
|
1222 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1223 | |
|
|
1224 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1225 | "aio_realpath": |
|
|
1226 | |
|
|
1227 | aio_realpath $wd, sub { |
|
|
1228 | warn "path is $_[0]\n"; |
|
|
1229 | }; |
|
|
1230 | |
|
|
1231 | Currently, "aio_statvfs" always, and "aio_rename" and "aio_rmdir" |
|
|
1232 | sometimes, fall back to using an absolue path. |
| 885 | |
1233 | |
| 886 | IO::AIO::REQ CLASS |
1234 | IO::AIO::REQ CLASS |
| 887 | All non-aggregate "aio_*" functions return an object of this class when |
1235 | All non-aggregate "aio_*" functions return an object of this class when |
| 888 | called in non-void context. |
1236 | called in non-void context. |
| 889 | |
1237 | |
| … | |
… | |
| 989 | Sets a feeder/generator on this group: every group can have an |
1337 | Sets a feeder/generator on this group: every group can have an |
| 990 | attached generator that generates requests if idle. The idea behind |
1338 | attached generator that generates requests if idle. The idea behind |
| 991 | this is that, although you could just queue as many requests as you |
1339 | this is that, although you could just queue as many requests as you |
| 992 | want in a group, this might starve other requests for a potentially |
1340 | want in a group, this might starve other requests for a potentially |
| 993 | long time. For example, "aio_scandir" might generate hundreds of |
1341 | long time. For example, "aio_scandir" might generate hundreds of |
| 994 | thousands "aio_stat" requests, delaying any later requests for a |
1342 | thousands of "aio_stat" requests, delaying any later requests for a |
| 995 | long time. |
1343 | long time. |
| 996 | |
1344 | |
| 997 | To avoid this, and allow incremental generation of requests, you can |
1345 | To avoid this, and allow incremental generation of requests, you can |
| 998 | instead a group and set a feeder on it that generates those |
1346 | instead a group and set a feeder on it that generates those |
| 999 | requests. The feed callback will be called whenever there are few |
1347 | requests. The feed callback will be called whenever there are few |
| … | |
… | |
| 1041 | results. |
1389 | results. |
| 1042 | |
1390 | |
| 1043 | See "poll_cb" for an example. |
1391 | See "poll_cb" for an example. |
| 1044 | |
1392 | |
| 1045 | IO::AIO::poll_cb |
1393 | IO::AIO::poll_cb |
| 1046 | Process some outstanding events on the result pipe. You have to call |
1394 | Process some requests that have reached the result phase (i.e. they |
|
|
1395 | have been executed but the results are not yet reported). You have |
|
|
1396 | to call this "regularly" to finish outstanding requests. |
|
|
1397 | |
| 1047 | this regularly. Returns 0 if all events could be processed (or there |
1398 | Returns 0 if all events could be processed (or there were no events |
| 1048 | were no events to process), or -1 if it returned earlier for |
1399 | to process), or -1 if it returned earlier for whatever reason. |
| 1049 | whatever reason. Returns immediately when no events are outstanding. |
1400 | Returns immediately when no events are outstanding. The amount of |
| 1050 | The amount of events processed depends on the settings of |
1401 | events processed depends on the settings of "IO::AIO::max_poll_req", |
| 1051 | "IO::AIO::max_poll_req" and "IO::AIO::max_poll_time". |
1402 | "IO::AIO::max_poll_time" and "IO::AIO::max_outstanding". |
| 1052 | |
1403 | |
| 1053 | If not all requests were processed for whatever reason, the |
1404 | If not all requests were processed for whatever reason, the poll |
| 1054 | filehandle will still be ready when "poll_cb" returns, so normally |
1405 | file descriptor will still be ready when "poll_cb" returns, so |
| 1055 | you don't have to do anything special to have it called later. |
1406 | normally you don't have to do anything special to have it called |
|
|
1407 | later. |
| 1056 | |
1408 | |
| 1057 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
1409 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
| 1058 | becomes ready, it can be beneficial to call this function from loops |
1410 | becomes ready, it can be beneficial to call this function from loops |
| 1059 | which submit a lot of requests, to make sure the results get |
1411 | which submit a lot of requests, to make sure the results get |
| 1060 | processed when they become available and not just when the loop is |
1412 | processed when they become available and not just when the loop is |
| … | |
… | |
| 1068 | Event->io (fd => IO::AIO::poll_fileno, |
1420 | Event->io (fd => IO::AIO::poll_fileno, |
| 1069 | poll => 'r', async => 1, |
1421 | poll => 'r', async => 1, |
| 1070 | cb => \&IO::AIO::poll_cb); |
1422 | cb => \&IO::AIO::poll_cb); |
| 1071 | |
1423 | |
| 1072 | IO::AIO::poll_wait |
1424 | IO::AIO::poll_wait |
| 1073 | If there are any outstanding requests and none of them in the result |
1425 | Wait until either at least one request is in the result phase or no |
| 1074 | phase, wait till the result filehandle becomes ready for reading |
1426 | requests are outstanding anymore. |
| 1075 | (simply does a "select" on the filehandle. This is useful if you |
1427 | |
| 1076 | want to synchronously wait for some requests to finish). |
1428 | This is useful if you want to synchronously wait for some requests |
|
|
1429 | to become ready, without actually handling them. |
| 1077 | |
1430 | |
| 1078 | See "nreqs" for an example. |
1431 | See "nreqs" for an example. |
| 1079 | |
1432 | |
| 1080 | IO::AIO::poll |
1433 | IO::AIO::poll |
| 1081 | Waits until some requests have been handled. |
1434 | Waits until some requests have been handled. |
| … | |
… | |
| 1193 | |
1546 | |
| 1194 | This is a very bad function to use in interactive programs because |
1547 | This is a very bad function to use in interactive programs because |
| 1195 | it blocks, and a bad way to reduce concurrency because it is |
1548 | it blocks, and a bad way to reduce concurrency because it is |
| 1196 | inexact: Better use an "aio_group" together with a feed callback. |
1549 | inexact: Better use an "aio_group" together with a feed callback. |
| 1197 | |
1550 | |
| 1198 | It's main use is in scripts without an event loop - when you want to |
1551 | Its main use is in scripts without an event loop - when you want to |
| 1199 | stat a lot of files, you can write somehting like this: |
1552 | stat a lot of files, you can write somehting like this: |
| 1200 | |
1553 | |
| 1201 | IO::AIO::max_outstanding 32; |
1554 | IO::AIO::max_outstanding 32; |
| 1202 | |
1555 | |
| 1203 | for my $path (...) { |
1556 | for my $path (...) { |
| … | |
… | |
| 1234 | IO::AIO::npending |
1587 | IO::AIO::npending |
| 1235 | Returns the number of requests currently in the pending state |
1588 | Returns the number of requests currently in the pending state |
| 1236 | (executed, but not yet processed by poll_cb). |
1589 | (executed, but not yet processed by poll_cb). |
| 1237 | |
1590 | |
| 1238 | MISCELLANEOUS FUNCTIONS |
1591 | MISCELLANEOUS FUNCTIONS |
| 1239 | IO::AIO implements some functions that might be useful, but are not |
1592 | IO::AIO implements some functions that are useful when you want to use |
| 1240 | asynchronous. |
1593 | some "Advanced I/O" function not available to in Perl, without going the |
|
|
1594 | "Asynchronous I/O" route. Many of these have an asynchronous "aio_*" |
|
|
1595 | counterpart. |
| 1241 | |
1596 | |
| 1242 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1597 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
| 1243 | Calls the "eio_sendfile_sync" function, which is like |
1598 | Calls the "eio_sendfile_sync" function, which is like |
| 1244 | "aio_sendfile", but is blocking (this makes most sense if you know |
1599 | "aio_sendfile", but is blocking (this makes most sense if you know |
| 1245 | the input data is likely cached already and the output filehandle is |
1600 | the input data is likely cached already and the output filehandle is |
| … | |
… | |
| 1247 | |
1602 | |
| 1248 | Returns the number of bytes copied, or -1 on error. |
1603 | Returns the number of bytes copied, or -1 on error. |
| 1249 | |
1604 | |
| 1250 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1605 | IO::AIO::fadvise $fh, $offset, $len, $advice |
| 1251 | Simply calls the "posix_fadvise" function (see its manpage for |
1606 | Simply calls the "posix_fadvise" function (see its manpage for |
| 1252 | details). The following advice constants are avaiable: |
1607 | details). The following advice constants are available: |
| 1253 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1608 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
| 1254 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1609 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
| 1255 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1610 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
| 1256 | |
1611 | |
| 1257 | On systems that do not implement "posix_fadvise", this function |
1612 | On systems that do not implement "posix_fadvise", this function |
| 1258 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1613 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
| 1259 | |
1614 | |
| 1260 | IO::AIO::madvise $scalar, $offset, $len, $advice |
1615 | IO::AIO::madvise $scalar, $offset, $len, $advice |
| 1261 | Simply calls the "posix_madvise" function (see its manpage for |
1616 | Simply calls the "posix_madvise" function (see its manpage for |
| 1262 | details). The following advice constants are avaiable: |
1617 | details). The following advice constants are available: |
| 1263 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
1618 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
| 1264 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
1619 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
| 1265 | "IO::AIO::MADV_DONTNEED". |
1620 | "IO::AIO::MADV_DONTNEED". |
| 1266 | |
1621 | |
| 1267 | On systems that do not implement "posix_madvise", this function |
1622 | On systems that do not implement "posix_madvise", this function |
| 1268 | returns ENOSYS, otherwise the return value of "posix_madvise". |
1623 | returns ENOSYS, otherwise the return value of "posix_madvise". |
| 1269 | |
1624 | |
| 1270 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
1625 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
| 1271 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
1626 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
| 1272 | $scalar (see its manpage for details). The following protect |
1627 | $scalar (see its manpage for details). The following protect |
| 1273 | constants are avaiable: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
1628 | constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
| 1274 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
1629 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
| 1275 | |
1630 | |
| 1276 | On systems that do not implement "mprotect", this function returns |
1631 | On systems that do not implement "mprotect", this function returns |
| 1277 | ENOSYS, otherwise the return value of "mprotect". |
1632 | ENOSYS, otherwise the return value of "mprotect". |
| 1278 | |
1633 | |
| 1279 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1634 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
| 1280 | Memory-maps a file (or anonymous memory range) and attaches it to |
1635 | Memory-maps a file (or anonymous memory range) and attaches it to |
| 1281 | the given $scalar, which will act like a string scalar. |
1636 | the given $scalar, which will act like a string scalar. Returns true |
|
|
1637 | on success, and false otherwise. |
| 1282 | |
1638 | |
| 1283 | The only operations allowed on the scalar are "substr"/"vec" that |
1639 | The only operations allowed on the scalar are "substr"/"vec" that |
| 1284 | don't change the string length, and most read-only operations such |
1640 | don't change the string length, and most read-only operations such |
| 1285 | as copying it or searching it with regexes and so on. |
1641 | as copying it or searching it with regexes and so on. |
| 1286 | |
1642 | |
| … | |
… | |
| 1300 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
1656 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
| 1301 | "IO::AIO::PROT_WRITE", |
1657 | "IO::AIO::PROT_WRITE", |
| 1302 | |
1658 | |
| 1303 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
1659 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
| 1304 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
1660 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
| 1305 | not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS" |
1661 | not available, the are 0): "IO::AIO::MAP_ANONYMOUS" (which is set to |
| 1306 | (which is set to "MAP_ANON" if your system only provides this |
1662 | "MAP_ANON" if your system only provides this constant), |
|
|
1663 | "IO::AIO::MAP_LOCKED", "IO::AIO::MAP_NORESERVE", |
| 1307 | constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
1664 | "IO::AIO::MAP_POPULATE", "IO::AIO::MAP_NONBLOCK", |
|
|
1665 | "IO::AIO::MAP_FIXED", "IO::AIO::MAP_GROWSDOWN", |
| 1308 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or |
1666 | "IO::AIO::MAP_32BIT", "IO::AIO::MAP_HUGETLB" or |
| 1309 | "IO::AIO::MAP_NONBLOCK" |
1667 | "IO::AIO::MAP_STACK". |
| 1310 | |
1668 | |
| 1311 | If $fh is "undef", then a file descriptor of -1 is passed. |
1669 | If $fh is "undef", then a file descriptor of -1 is passed. |
| 1312 | |
1670 | |
| 1313 | $offset is the offset from the start of the file - it generally must |
1671 | $offset is the offset from the start of the file - it generally must |
| 1314 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
1672 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
| … | |
… | |
| 1336 | IO::AIO::munlockall |
1694 | IO::AIO::munlockall |
| 1337 | Calls the "munlockall" function. |
1695 | Calls the "munlockall" function. |
| 1338 | |
1696 | |
| 1339 | On systems that do not implement "munlockall", this function returns |
1697 | On systems that do not implement "munlockall", this function returns |
| 1340 | ENOSYS, otherwise the return value of "munlockall". |
1698 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1699 | |
|
|
1700 | IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
|
|
1701 | Calls the GNU/Linux splice(2) syscall, if available. If $r_off or |
|
|
1702 | $w_off are "undef", then "NULL" is passed for these, otherwise they |
|
|
1703 | should be the file offset. |
|
|
1704 | |
|
|
1705 | $r_fh and $w_fh should not refer to the same file, as splice might |
|
|
1706 | silently corrupt the data in this case. |
|
|
1707 | |
|
|
1708 | The following symbol flag values are available: |
|
|
1709 | "IO::AIO::SPLICE_F_MOVE", "IO::AIO::SPLICE_F_NONBLOCK", |
|
|
1710 | "IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT". |
|
|
1711 | |
|
|
1712 | See the splice(2) manpage for details. |
|
|
1713 | |
|
|
1714 | IO::AIO::tee $r_fh, $w_fh, $length, $flags |
|
|
1715 | Calls the GNU/Linux tee(2) syscall, see its manpage and the |
|
|
1716 | description for "IO::AIO::splice" above for details. |
|
|
1717 | |
|
|
1718 | $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
1719 | Attempts to query or change the pipe buffer size. Obviously works |
|
|
1720 | only on pipes, and currently works only on GNU/Linux systems, and |
|
|
1721 | fails with -1/"ENOSYS" everywhere else. If anybody knows how to |
|
|
1722 | influence pipe buffer size on other systems, drop me a note. |
|
|
1723 | |
|
|
1724 | ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
|
|
1725 | This is a direct interface to the Linux pipe2(2) system call. If |
|
|
1726 | $flags is missing or 0, then this should be the same as a call to |
|
|
1727 | perl's built-in "pipe" function and create a new pipe, and works on |
|
|
1728 | systems that lack the pipe2 syscall. On win32, this case invokes |
|
|
1729 | "_pipe (..., 4096, O_BINARY)". |
|
|
1730 | |
|
|
1731 | If $flags is non-zero, it tries to invoke the pipe2 system call with |
|
|
1732 | the given flags (Linux 2.6.27, glibc 2.9). |
|
|
1733 | |
|
|
1734 | On success, the read and write file handles are returned. |
|
|
1735 | |
|
|
1736 | On error, nothing will be returned. If the pipe2 syscall is missing |
|
|
1737 | and $flags is non-zero, fails with "ENOSYS". |
|
|
1738 | |
|
|
1739 | Please refer to pipe2(2) for more info on the $flags, but at the |
|
|
1740 | time of this writing, "IO::AIO::O_CLOEXEC", "IO::AIO::O_NONBLOCK" |
|
|
1741 | and "IO::AIO::O_DIRECT" (Linux 3.4, for packet-based pipes) were |
|
|
1742 | supported. |
| 1341 | |
1743 | |
| 1342 | EVENT LOOP INTEGRATION |
1744 | EVENT LOOP INTEGRATION |
| 1343 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1745 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
| 1344 | automatically into many event loops: |
1746 | automatically into many event loops: |
| 1345 | |
1747 | |
| … | |
… | |
| 1371 | |
1773 | |
| 1372 | FORK BEHAVIOUR |
1774 | FORK BEHAVIOUR |
| 1373 | Usage of pthreads in a program changes the semantics of fork |
1775 | Usage of pthreads in a program changes the semantics of fork |
| 1374 | considerably. Specifically, only async-safe functions can be called |
1776 | considerably. Specifically, only async-safe functions can be called |
| 1375 | after fork. Perl doesn't know about this, so in general, you cannot call |
1777 | after fork. Perl doesn't know about this, so in general, you cannot call |
| 1376 | fork with defined behaviour in perl. IO::AIO uses pthreads, so this |
1778 | fork with defined behaviour in perl if pthreads are involved. IO::AIO |
| 1377 | applies, but many other extensions and (for inexplicable reasons) perl |
1779 | uses pthreads, so this applies, but many other extensions and (for |
| 1378 | itself often is linked against pthreads, so this limitation applies. |
1780 | inexplicable reasons) perl itself often is linked against pthreads, so |
|
|
1781 | this limitation applies to quite a lot of perls. |
| 1379 | |
1782 | |
| 1380 | Some operating systems have extensions that allow safe use of fork, and |
1783 | This module no longer tries to fight your OS, or POSIX. That means |
| 1381 | this module should do "the right thing" on those, and tries on others. |
1784 | IO::AIO only works in the process that loaded it. Forking is fully |
| 1382 | At the time of this writing (2011) only GNU/Linux supports these |
1785 | supported, but using IO::AIO in the child is not. |
| 1383 | extensions to POSIX. |
1786 | |
|
|
1787 | You might get around by not *using* IO::AIO before (or after) forking. |
|
|
1788 | You could also try to call the IO::AIO::reinit function in the child: |
|
|
1789 | |
|
|
1790 | IO::AIO::reinit |
|
|
1791 | Abandons all current requests and I/O threads and simply |
|
|
1792 | reinitialises all data structures. This is not an operation |
|
|
1793 | supported by any standards, but happens to work on GNU/Linux and |
|
|
1794 | some newer BSD systems. |
|
|
1795 | |
|
|
1796 | The only reasonable use for this function is to call it after |
|
|
1797 | forking, if "IO::AIO" was used in the parent. Calling it while |
|
|
1798 | IO::AIO is active in the process will result in undefined behaviour. |
|
|
1799 | Calling it at any time will also result in any undefined (by POSIX) |
|
|
1800 | behaviour. |
| 1384 | |
1801 | |
| 1385 | MEMORY USAGE |
1802 | MEMORY USAGE |
| 1386 | Per-request usage: |
1803 | Per-request usage: |
| 1387 | |
1804 | |
| 1388 | Each aio request uses - depending on your architecture - around 100-200 |
1805 | Each aio request uses - depending on your architecture - around 100-200 |
