… | |
… | |
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) |
185 | aio_sync $callback->($status) |
189 | aio_sync $callback->($status) |
|
|
190 | aio_syncfs $fh, $callback->($status) |
186 | aio_fsync $fh, $callback->($status) |
191 | aio_fsync $fh, $callback->($status) |
187 | aio_fdatasync $fh, $callback->($status) |
192 | aio_fdatasync $fh, $callback->($status) |
188 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
193 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
189 | aio_pathsync $path, $callback->($status) |
194 | aio_pathsync $pathname, $callback->($status) |
190 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
195 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
191 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
196 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
192 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
197 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
193 | aio_mlockall $flags, $callback->($status) |
198 | aio_mlockall $flags, $callback->($status) |
194 | aio_group $callback->(...) |
199 | aio_group $callback->(...) |
… | |
… | |
212 | IO::AIO::nready |
217 | IO::AIO::nready |
213 | IO::AIO::npending |
218 | IO::AIO::npending |
214 | |
219 | |
215 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
220 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
216 | IO::AIO::fadvise $fh, $offset, $len, $advice |
221 | IO::AIO::fadvise $fh, $offset, $len, $advice |
|
|
222 | IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
|
|
223 | IO::AIO::munmap $scalar |
217 | IO::AIO::madvise $scalar, $offset, $length, $advice |
224 | IO::AIO::madvise $scalar, $offset, $length, $advice |
218 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
225 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
219 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
226 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
220 | IO::AIO::munlockall |
227 | IO::AIO::munlockall |
221 | |
228 | |
222 | AIO REQUEST FUNCTIONS |
229 | API NOTES |
223 | All the "aio_*" calls are more or less thin wrappers around the syscall |
230 | 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 |
231 | with the same name (sans "aio_"). The arguments are similar or |
225 | identical, and they all accept an additional (and optional) $callback |
232 | identical, and they all accept an additional (and optional) $callback |
226 | argument which must be a code reference. This code reference will get |
233 | 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. |
234 | called after the syscall has been executed in an asynchronous fashion. |
|
|
235 | The results of the request will be passed as arguments to the callback |
|
|
236 | (and, if an error occured, in $!) - for most requests the syscall return |
|
|
237 | code (e.g. most syscalls return -1 on error, unlike perl, which usually |
|
|
238 | delivers "false"). |
|
|
239 | |
|
|
240 | Some requests (such as "aio_readdir") pass the actual results and |
|
|
241 | communicate failures by passing "undef". |
230 | |
242 | |
231 | All functions expecting a filehandle keep a copy of the filehandle |
243 | All functions expecting a filehandle keep a copy of the filehandle |
232 | internally until the request has finished. |
244 | internally until the request has finished. |
233 | |
245 | |
234 | All functions return request objects of type IO::AIO::REQ that allow |
246 | All functions return request objects of type IO::AIO::REQ that allow |
235 | further manipulation of those requests while they are in-flight. |
247 | further manipulation of those requests while they are in-flight. |
236 | |
248 | |
237 | The pathnames you pass to these routines *must* be absolute and encoded |
249 | 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 |
250 | reason for this is that at the time the request is being executed, the |
239 | being executed, the current working directory could have changed. |
251 | current working directory could have changed. Alternatively, you can |
240 | Alternatively, you can make sure that you never change the current |
252 | make sure that you never change the current working directory anywhere |
241 | working directory anywhere in the program and then use relative paths. |
253 | in the program and then use relative paths. You can also take advantage |
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|
254 | of IO::AIOs working directory abstraction, that lets you specify paths |
|
|
255 | relative to some previously-opened "working directory object" - see the |
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|
256 | description of the "IO::AIO::WD" class later in this document. |
242 | |
257 | |
243 | To encode pathnames as octets, either make sure you either: a) always |
258 | To encode pathnames as octets, either make sure you either: a) always |
244 | pass in filenames you got from outside (command line, readdir etc.) |
259 | 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 |
260 | 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 |
261 | Encode module and encode your pathnames to the locale (or other) |
247 | the user environment, d) use Glib::filename_from_unicode on unicode |
262 | encoding in effect in the user environment, d) use |
248 | filenames or e) use something else to ensure your scalar has the correct |
263 | Glib::filename_from_unicode on unicode filenames or e) use something |
249 | contents. |
264 | else to ensure your scalar has the correct contents. |
250 | |
265 | |
251 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
266 | This works, btw. independent of the internal UTF-8 bit, which IO::AIO |
252 | handles correctly whether it is set or not. |
267 | handles correctly whether it is set or not. |
253 | |
268 | |
|
|
269 | AIO REQUEST FUNCTIONS |
254 | $prev_pri = aioreq_pri [$pri] |
270 | $prev_pri = aioreq_pri [$pri] |
255 | Returns the priority value that would be used for the next request |
271 | 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. |
272 | and, if $pri is given, sets the priority for the next aio request. |
257 | |
273 | |
258 | The default priority is 0, the minimum and maximum priorities are -4 |
274 | The default priority is 0, the minimum and maximum priorities are -4 |
… | |
… | |
280 | Similar to "aioreq_pri", but subtracts the given value from the |
296 | Similar to "aioreq_pri", but subtracts the given value from the |
281 | current priority, so the effect is cumulative. |
297 | current priority, so the effect is cumulative. |
282 | |
298 | |
283 | aio_open $pathname, $flags, $mode, $callback->($fh) |
299 | aio_open $pathname, $flags, $mode, $callback->($fh) |
284 | Asynchronously open or create a file and call the callback with a |
300 | Asynchronously open or create a file and call the callback with a |
285 | newly created filehandle for the file. |
301 | newly created filehandle for the file (or "undef" in case of an |
|
|
302 | error). |
286 | |
303 | |
287 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
304 | The pathname passed to "aio_open" must be absolute. See API NOTES, |
288 | above, for an explanation. |
305 | above, for an explanation. |
289 | |
306 | |
290 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
307 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
… | |
… | |
313 | "O_APPEND"), the following POSIX and non-POSIX constants are |
330 | "O_APPEND"), the following POSIX and non-POSIX constants are |
314 | available (missing ones on your system are, as usual, 0): |
331 | available (missing ones on your system are, as usual, 0): |
315 | |
332 | |
316 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
333 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
317 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
334 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
318 | "O_DSYNC", "O_RSYNC", "O_SYNC" and "O_TTY_INIT". |
335 | "O_DSYNC", "O_RSYNC", "O_SYNC", "O_PATH", "O_TMPFILE", and |
|
|
336 | "O_TTY_INIT". |
319 | |
337 | |
320 | aio_close $fh, $callback->($status) |
338 | aio_close $fh, $callback->($status) |
321 | Asynchronously close a file and call the callback with the result |
339 | Asynchronously close a file and call the callback with the result |
322 | code. |
340 | code. |
323 | |
341 | |
… | |
… | |
329 | will use dup2 to overwrite the file descriptor with the write-end of |
347 | 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). |
348 | a pipe (the pipe fd will be created on demand and will be cached). |
331 | |
349 | |
332 | Or in other words: the file descriptor will be closed, but it will |
350 | 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. |
351 | not be free for reuse until the perl filehandle is closed. |
|
|
352 | |
|
|
353 | aio_seek $fh, $offset, $whence, $callback->($offs) |
|
|
354 | Seeks the filehandle to the new $offset, similarly to perl's |
|
|
355 | "sysseek". The $whence can use the traditional values (0 for |
|
|
356 | "IO::AIO::SEEK_SET", 1 for "IO::AIO::SEEK_CUR" or 2 for |
|
|
357 | "IO::AIO::SEEK_END"). |
|
|
358 | |
|
|
359 | The resulting absolute offset will be passed to the callback, or -1 |
|
|
360 | in case of an error. |
|
|
361 | |
|
|
362 | In theory, the $whence constants could be different than the |
|
|
363 | corresponding values from Fcntl, but perl guarantees they are the |
|
|
364 | same, so don't panic. |
|
|
365 | |
|
|
366 | As a GNU/Linux (and maybe Solaris) extension, also the constants |
|
|
367 | "IO::AIO::SEEK_DATA" and "IO::AIO::SEEK_HOLE" are available, if they |
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368 | could be found. No guarantees about suitability for use in |
|
|
369 | "aio_seek" or Perl's "sysseek" can be made though, although I would |
|
|
370 | naively assume they "just work". |
334 | |
371 | |
335 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
372 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
336 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
373 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
337 | Reads or writes $length bytes from or to the specified $fh and |
374 | Reads or writes $length bytes from or to the specified $fh and |
338 | $offset into the scalar given by $data and offset $dataoffset and |
375 | $offset into the scalar given by $data and offset $dataoffset and |
… | |
… | |
493 | namemax => 255, |
530 | namemax => 255, |
494 | frsize => 1024, |
531 | frsize => 1024, |
495 | fsid => 1810 |
532 | fsid => 1810 |
496 | } |
533 | } |
497 | |
534 | |
|
|
535 | Here is a (likely partial - send me updates!) list of fsid values |
|
|
536 | used by Linux - it is safe to hardcode these when $^O is "linux": |
|
|
537 | |
|
|
538 | 0x0000adf5 adfs |
|
|
539 | 0x0000adff affs |
|
|
540 | 0x5346414f afs |
|
|
541 | 0x09041934 anon-inode filesystem |
|
|
542 | 0x00000187 autofs |
|
|
543 | 0x42465331 befs |
|
|
544 | 0x1badface bfs |
|
|
545 | 0x42494e4d binfmt_misc |
|
|
546 | 0x9123683e btrfs |
|
|
547 | 0x0027e0eb cgroupfs |
|
|
548 | 0xff534d42 cifs |
|
|
549 | 0x73757245 coda |
|
|
550 | 0x012ff7b7 coh |
|
|
551 | 0x28cd3d45 cramfs |
|
|
552 | 0x453dcd28 cramfs-wend (wrong endianness) |
|
|
553 | 0x64626720 debugfs |
|
|
554 | 0x00001373 devfs |
|
|
555 | 0x00001cd1 devpts |
|
|
556 | 0x0000f15f ecryptfs |
|
|
557 | 0x00414a53 efs |
|
|
558 | 0x0000137d ext |
|
|
559 | 0x0000ef53 ext2/ext3/ext4 |
|
|
560 | 0x0000ef51 ext2 |
|
|
561 | 0xf2f52010 f2fs |
|
|
562 | 0x00004006 fat |
|
|
563 | 0x65735546 fuseblk |
|
|
564 | 0x65735543 fusectl |
|
|
565 | 0x0bad1dea futexfs |
|
|
566 | 0x01161970 gfs2 |
|
|
567 | 0x47504653 gpfs |
|
|
568 | 0x00004244 hfs |
|
|
569 | 0xf995e849 hpfs |
|
|
570 | 0x00c0ffee hostfs |
|
|
571 | 0x958458f6 hugetlbfs |
|
|
572 | 0x2bad1dea inotifyfs |
|
|
573 | 0x00009660 isofs |
|
|
574 | 0x000072b6 jffs2 |
|
|
575 | 0x3153464a jfs |
|
|
576 | 0x6b414653 k-afs |
|
|
577 | 0x0bd00bd0 lustre |
|
|
578 | 0x0000137f minix |
|
|
579 | 0x0000138f minix 30 char names |
|
|
580 | 0x00002468 minix v2 |
|
|
581 | 0x00002478 minix v2 30 char names |
|
|
582 | 0x00004d5a minix v3 |
|
|
583 | 0x19800202 mqueue |
|
|
584 | 0x00004d44 msdos |
|
|
585 | 0x0000564c novell |
|
|
586 | 0x00006969 nfs |
|
|
587 | 0x6e667364 nfsd |
|
|
588 | 0x00003434 nilfs |
|
|
589 | 0x5346544e ntfs |
|
|
590 | 0x00009fa1 openprom |
|
|
591 | 0x7461636F ocfs2 |
|
|
592 | 0x00009fa0 proc |
|
|
593 | 0x6165676c pstorefs |
|
|
594 | 0x0000002f qnx4 |
|
|
595 | 0x68191122 qnx6 |
|
|
596 | 0x858458f6 ramfs |
|
|
597 | 0x52654973 reiserfs |
|
|
598 | 0x00007275 romfs |
|
|
599 | 0x67596969 rpc_pipefs |
|
|
600 | 0x73636673 securityfs |
|
|
601 | 0xf97cff8c selinux |
|
|
602 | 0x0000517b smb |
|
|
603 | 0x534f434b sockfs |
|
|
604 | 0x73717368 squashfs |
|
|
605 | 0x62656572 sysfs |
|
|
606 | 0x012ff7b6 sysv2 |
|
|
607 | 0x012ff7b5 sysv4 |
|
|
608 | 0x01021994 tmpfs |
|
|
609 | 0x15013346 udf |
|
|
610 | 0x00011954 ufs |
|
|
611 | 0x54190100 ufs byteswapped |
|
|
612 | 0x00009fa2 usbdevfs |
|
|
613 | 0x01021997 v9fs |
|
|
614 | 0xa501fcf5 vxfs |
|
|
615 | 0xabba1974 xenfs |
|
|
616 | 0x012ff7b4 xenix |
|
|
617 | 0x58465342 xfs |
|
|
618 | 0x012fd16d xia |
|
|
619 | |
498 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
620 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
499 | Works like perl's "utime" function (including the special case of |
621 | Works like perl's "utime" function (including the special case of |
500 | $atime and $mtime being undef). Fractional times are supported if |
622 | $atime and $mtime being undef). Fractional times are supported if |
501 | the underlying syscalls support them. |
623 | the underlying syscalls support them. |
502 | |
624 | |
… | |
… | |
524 | aio_chown "path", 0, undef; |
646 | aio_chown "path", 0, undef; |
525 | |
647 | |
526 | aio_truncate $fh_or_path, $offset, $callback->($status) |
648 | aio_truncate $fh_or_path, $offset, $callback->($status) |
527 | Works like truncate(2) or ftruncate(2). |
649 | Works like truncate(2) or ftruncate(2). |
528 | |
650 | |
|
|
651 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
652 | Allocates or frees disk space according to the $mode argument. See |
|
|
653 | the linux "fallocate" documentation for details. |
|
|
654 | |
|
|
655 | $mode is usually 0 or "IO::AIO::FALLOC_FL_KEEP_SIZE" to allocate |
|
|
656 | space, or "IO::AIO::FALLOC_FL_PUNCH_HOLE | |
|
|
657 | IO::AIO::FALLOC_FL_KEEP_SIZE", to deallocate a file range. |
|
|
658 | |
|
|
659 | IO::AIO also supports "FALLOC_FL_COLLAPSE_RANGE", to remove a range |
|
|
660 | (without leaving a hole) and "FALLOC_FL_ZERO_RANGE", to zero a range |
|
|
661 | (see your fallocate(2) manpage). |
|
|
662 | |
|
|
663 | The file system block size used by "fallocate" is presumably the |
|
|
664 | "f_bsize" returned by "statvfs". |
|
|
665 | |
|
|
666 | If "fallocate" isn't available or cannot be emulated (currently no |
|
|
667 | emulation will be attempted), passes -1 and sets $! to "ENOSYS". |
|
|
668 | |
529 | aio_chmod $fh_or_path, $mode, $callback->($status) |
669 | aio_chmod $fh_or_path, $mode, $callback->($status) |
530 | Works like perl's "chmod" function. |
670 | Works like perl's "chmod" function. |
531 | |
671 | |
532 | aio_unlink $pathname, $callback->($status) |
672 | aio_unlink $pathname, $callback->($status) |
533 | Asynchronously unlink (delete) a file and call the callback with the |
673 | Asynchronously unlink (delete) a file and call the callback with the |
534 | result code. |
674 | result code. |
535 | |
675 | |
536 | aio_mknod $path, $mode, $dev, $callback->($status) |
676 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
537 | [EXPERIMENTAL] |
677 | [EXPERIMENTAL] |
538 | |
678 | |
539 | Asynchronously create a device node (or fifo). See mknod(2). |
679 | Asynchronously create a device node (or fifo). See mknod(2). |
540 | |
680 | |
541 | The only (POSIX-) portable way of calling this function is: |
681 | The only (POSIX-) portable way of calling this function is: |
542 | |
682 | |
543 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
683 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
544 | |
684 | |
545 | See "aio_stat" for info about some potentially helpful extra |
685 | See "aio_stat" for info about some potentially helpful extra |
546 | constants and functions. |
686 | constants and functions. |
547 | |
687 | |
548 | aio_link $srcpath, $dstpath, $callback->($status) |
688 | aio_link $srcpath, $dstpath, $callback->($status) |
… | |
… | |
552 | aio_symlink $srcpath, $dstpath, $callback->($status) |
692 | aio_symlink $srcpath, $dstpath, $callback->($status) |
553 | Asynchronously create a new symbolic link to the existing object at |
693 | Asynchronously create a new symbolic link to the existing object at |
554 | $srcpath at the path $dstpath and call the callback with the result |
694 | $srcpath at the path $dstpath and call the callback with the result |
555 | code. |
695 | code. |
556 | |
696 | |
557 | aio_readlink $path, $callback->($link) |
697 | aio_readlink $pathname, $callback->($link) |
558 | Asynchronously read the symlink specified by $path and pass it to |
698 | Asynchronously read the symlink specified by $path and pass it to |
559 | the callback. If an error occurs, nothing or undef gets passed to |
699 | the callback. If an error occurs, nothing or undef gets passed to |
560 | the callback. |
700 | the callback. |
561 | |
701 | |
|
|
702 | aio_realpath $pathname, $callback->($path) |
|
|
703 | Asynchronously make the path absolute and resolve any symlinks in |
|
|
704 | $path. The resulting path only consists of directories (same as |
|
|
705 | Cwd::realpath). |
|
|
706 | |
|
|
707 | This request can be used to get the absolute path of the current |
|
|
708 | working directory by passing it a path of . (a single dot). |
|
|
709 | |
562 | aio_rename $srcpath, $dstpath, $callback->($status) |
710 | aio_rename $srcpath, $dstpath, $callback->($status) |
563 | Asynchronously rename the object at $srcpath to $dstpath, just as |
711 | Asynchronously rename the object at $srcpath to $dstpath, just as |
564 | rename(2) and call the callback with the result code. |
712 | rename(2) and call the callback with the result code. |
|
|
713 | |
|
|
714 | On systems that support the AIO::WD working directory abstraction |
|
|
715 | natively, the case "[$wd, "."]" as $srcpath is specialcased - |
|
|
716 | instead of failing, "rename" is called on the absolute path of $wd. |
565 | |
717 | |
566 | aio_mkdir $pathname, $mode, $callback->($status) |
718 | aio_mkdir $pathname, $mode, $callback->($status) |
567 | Asynchronously mkdir (create) a directory and call the callback with |
719 | 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 |
720 | the result code. $mode will be modified by the umask at the time the |
569 | request is executed, so do not change your umask. |
721 | request is executed, so do not change your umask. |
570 | |
722 | |
571 | aio_rmdir $pathname, $callback->($status) |
723 | aio_rmdir $pathname, $callback->($status) |
572 | Asynchronously rmdir (delete) a directory and call the callback with |
724 | Asynchronously rmdir (delete) a directory and call the callback with |
573 | the result code. |
725 | the result code. |
574 | |
726 | |
|
|
727 | On systems that support the AIO::WD working directory abstraction |
|
|
728 | natively, the case "[$wd, "."]" is specialcased - instead of |
|
|
729 | failing, "rmdir" is called on the absolute path of $wd. |
|
|
730 | |
575 | aio_readdir $pathname, $callback->($entries) |
731 | aio_readdir $pathname, $callback->($entries) |
576 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
732 | Unlike the POSIX call of the same name, "aio_readdir" reads an |
577 | entire directory (i.e. opendir + readdir + closedir). The entries |
733 | entire directory (i.e. opendir + readdir + closedir). The entries |
578 | will not be sorted, and will NOT include the "." and ".." entries. |
734 | will not be sorted, and will NOT include the "." and ".." entries. |
579 | |
735 | |
580 | The callback is passed a single argument which is either "undef" or |
736 | The callback is passed a single argument which is either "undef" or |
581 | an array-ref with the filenames. |
737 | an array-ref with the filenames. |
582 | |
738 | |
583 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
739 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
584 | Quite similar to "aio_readdir", but the $flags argument allows to |
740 | Quite similar to "aio_readdir", but the $flags argument allows one |
585 | tune behaviour and output format. In case of an error, $entries will |
741 | to tune behaviour and output format. In case of an error, $entries |
586 | be "undef". |
742 | will be "undef". |
587 | |
743 | |
588 | The flags are a combination of the following constants, ORed |
744 | The flags are a combination of the following constants, ORed |
589 | together (the flags will also be passed to the callback, possibly |
745 | together (the flags will also be passed to the callback, possibly |
590 | modified): |
746 | modified): |
591 | |
747 | |
… | |
… | |
636 | optimal stat order. |
792 | optimal stat order. |
637 | |
793 | |
638 | IO::AIO::READDIR_FOUND_UNKNOWN |
794 | IO::AIO::READDIR_FOUND_UNKNOWN |
639 | This flag should not be set when calling "aio_readdirx". |
795 | This flag should not be set when calling "aio_readdirx". |
640 | Instead, it is being set by "aio_readdirx", when any of the |
796 | 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 |
797 | $type's found were "IO::AIO::DT_UNKNOWN". The absence of this |
642 | flag therefore indicates that all $type's are known, which can |
798 | flag therefore indicates that all $type's are known, which can |
643 | be used to speed up some algorithms. |
799 | be used to speed up some algorithms. |
644 | |
800 | |
645 | aio_load $path, $data, $callback->($status) |
801 | aio_load $pathname, $data, $callback->($status) |
646 | This is a composite request that tries to fully load the given file |
802 | This is a composite request that tries to fully load the given file |
647 | into memory. Status is the same as with aio_read. |
803 | into memory. Status is the same as with aio_read. |
648 | |
804 | |
649 | aio_copy $srcpath, $dstpath, $callback->($status) |
805 | aio_copy $srcpath, $dstpath, $callback->($status) |
650 | Try to copy the *file* (directories not supported as either source |
806 | Try to copy the *file* (directories not supported as either source |
… | |
… | |
667 | |
823 | |
668 | This is a composite request that tries to rename(2) the file first; |
824 | 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" |
825 | if rename fails with "EXDEV", it copies the file with "aio_copy" |
670 | and, if that is successful, unlinks the $srcpath. |
826 | and, if that is successful, unlinks the $srcpath. |
671 | |
827 | |
672 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
828 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
673 | Scans a directory (similar to "aio_readdir") but additionally tries |
829 | Scans a directory (similar to "aio_readdir") but additionally tries |
674 | to efficiently separate the entries of directory $path into two sets |
830 | to efficiently separate the entries of directory $path into two sets |
675 | of names, directories you can recurse into (directories), and ones |
831 | of names, directories you can recurse into (directories), and ones |
676 | you cannot recurse into (everything else, including symlinks to |
832 | you cannot recurse into (everything else, including symlinks to |
677 | directories). |
833 | directories). |
… | |
… | |
710 | Then entries will be sorted into likely directories a non-initial |
866 | Then entries will be sorted into likely directories a non-initial |
711 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
867 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
712 | every entry plus an appended "/." will be "stat"'ed, likely |
868 | every entry plus an appended "/." will be "stat"'ed, likely |
713 | directories first, in order of their inode numbers. If that |
869 | directories first, in order of their inode numbers. If that |
714 | succeeds, it assumes that the entry is a directory or a symlink to |
870 | succeeds, it assumes that the entry is a directory or a symlink to |
715 | directory (which will be checked seperately). This is often faster |
871 | directory (which will be checked separately). This is often faster |
716 | than stat'ing the entry itself because filesystems might detect the |
872 | than stat'ing the entry itself because filesystems might detect the |
717 | type of the entry without reading the inode data (e.g. ext2fs |
873 | type of the entry without reading the inode data (e.g. ext2fs |
718 | filetype feature), even on systems that cannot return the filetype |
874 | filetype feature), even on systems that cannot return the filetype |
719 | information on readdir. |
875 | information on readdir. |
720 | |
876 | |
… | |
… | |
726 | |
882 | |
727 | It will also likely work on non-POSIX filesystems with reduced |
883 | 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 |
884 | efficiency as those tend to return 0 or 1 as link counts, which |
729 | disables the directory counting heuristic. |
885 | disables the directory counting heuristic. |
730 | |
886 | |
731 | aio_rmtree $path, $callback->($status) |
887 | aio_rmtree $pathname, $callback->($status) |
732 | Delete a directory tree starting (and including) $path, return the |
888 | Delete a directory tree starting (and including) $path, return the |
733 | status of the final "rmdir" only. This is a composite request that |
889 | status of the final "rmdir" only. This is a composite request that |
734 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
890 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
735 | everything else. |
891 | everything else. |
736 | |
892 | |
… | |
… | |
745 | Asynchronously call fdatasync on the given filehandle and call the |
901 | Asynchronously call fdatasync on the given filehandle and call the |
746 | callback with the fdatasync result code. |
902 | callback with the fdatasync result code. |
747 | |
903 | |
748 | If this call isn't available because your OS lacks it or it couldn't |
904 | 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. |
905 | be detected, it will be emulated by calling "fsync" instead. |
|
|
906 | |
|
|
907 | aio_syncfs $fh, $callback->($status) |
|
|
908 | Asynchronously call the syncfs syscall to sync the filesystem |
|
|
909 | associated to the given filehandle and call the callback with the |
|
|
910 | syncfs result code. If syncfs is not available, calls sync(), but |
|
|
911 | returns -1 and sets errno to "ENOSYS" nevertheless. |
750 | |
912 | |
751 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
913 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
752 | Sync the data portion of the file specified by $offset and $length |
914 | Sync the data portion of the file specified by $offset and $length |
753 | to disk (but NOT the metadata), by calling the Linux-specific |
915 | 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 |
916 | sync_file_range call. If sync_file_range is not available or it |
… | |
… | |
758 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
920 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
759 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
921 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
760 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
922 | "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range |
761 | manpage for details. |
923 | manpage for details. |
762 | |
924 | |
763 | aio_pathsync $path, $callback->($status) |
925 | aio_pathsync $pathname, $callback->($status) |
764 | This request tries to open, fsync and close the given path. This is |
926 | This request tries to open, fsync and close the given path. This is |
765 | a composite request intended to sync directories after directory |
927 | a composite request intended to sync directories after directory |
766 | operations (E.g. rename). This might not work on all operating |
928 | operations (E.g. rename). This might not work on all operating |
767 | systems or have any specific effect, but usually it makes sure that |
929 | systems or have any specific effect, but usually it makes sure that |
768 | directory changes get written to disc. It works for anything that |
930 | directory changes get written to disc. It works for anything that |
… | |
… | |
795 | |
957 | |
796 | It touches (reads or writes) all memory pages in the specified range |
958 | 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 |
959 | 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 |
960 | "aio_msync", above, except for flags, which must be either 0 (which |
799 | reads all pages and ensures they are instantiated) or |
961 | reads all pages and ensures they are instantiated) or |
800 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
962 | "IO::AIO::MT_MODIFY", which modifies the memory pages (by reading |
801 | and writing an octet from it, which dirties the page). |
963 | and writing an octet from it, which dirties the page). |
802 | |
964 | |
803 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
965 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
804 | This is a rather advanced IO::AIO call, which works best on |
966 | This is a rather advanced IO::AIO call, which works best on |
805 | mmap(2)ed scalars. |
967 | mmap(2)ed scalars. |
… | |
… | |
837 | |
999 | |
838 | Example: asynchronously lock all current and future pages into |
1000 | Example: asynchronously lock all current and future pages into |
839 | memory. |
1001 | memory. |
840 | |
1002 | |
841 | aio_mlockall IO::AIO::MCL_FUTURE; |
1003 | aio_mlockall IO::AIO::MCL_FUTURE; |
|
|
1004 | |
|
|
1005 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
1006 | Queries the extents of the given file (by calling the Linux "FIEMAP" |
|
|
1007 | ioctl, see <http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for |
|
|
1008 | details). If the ioctl is not available on your OS, then this |
|
|
1009 | request will fail with "ENOSYS". |
|
|
1010 | |
|
|
1011 | $start is the starting offset to query extents for, $length is the |
|
|
1012 | size of the range to query - if it is "undef", then the whole file |
|
|
1013 | will be queried. |
|
|
1014 | |
|
|
1015 | $flags is a combination of flags ("IO::AIO::FIEMAP_FLAG_SYNC" or |
|
|
1016 | "IO::AIO::FIEMAP_FLAG_XATTR" - "IO::AIO::FIEMAP_FLAGS_COMPAT" is |
|
|
1017 | also exported), and is normally 0 or "IO::AIO::FIEMAP_FLAG_SYNC" to |
|
|
1018 | query the data portion. |
|
|
1019 | |
|
|
1020 | $count is the maximum number of extent records to return. If it is |
|
|
1021 | "undef", then IO::AIO queries all extents of the range. As a very |
|
|
1022 | special case, if it is 0, then the callback receives the number of |
|
|
1023 | extents instead of the extents themselves (which is unreliable, see |
|
|
1024 | below). |
|
|
1025 | |
|
|
1026 | If an error occurs, the callback receives no arguments. The special |
|
|
1027 | "errno" value "IO::AIO::EBADR" is available to test for flag errors. |
|
|
1028 | |
|
|
1029 | Otherwise, the callback receives an array reference with extent |
|
|
1030 | structures. Each extent structure is an array reference itself, with |
|
|
1031 | the following members: |
|
|
1032 | |
|
|
1033 | [$logical, $physical, $length, $flags] |
|
|
1034 | |
|
|
1035 | Flags is any combination of the following flag values (typically |
|
|
1036 | either 0 or "IO::AIO::FIEMAP_EXTENT_LAST" (1)): |
|
|
1037 | |
|
|
1038 | "IO::AIO::FIEMAP_EXTENT_LAST", "IO::AIO::FIEMAP_EXTENT_UNKNOWN", |
|
|
1039 | "IO::AIO::FIEMAP_EXTENT_DELALLOC", "IO::AIO::FIEMAP_EXTENT_ENCODED", |
|
|
1040 | "IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED", |
|
|
1041 | "IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED", |
|
|
1042 | "IO::AIO::FIEMAP_EXTENT_DATA_INLINE", |
|
|
1043 | "IO::AIO::FIEMAP_EXTENT_DATA_TAIL", |
|
|
1044 | "IO::AIO::FIEMAP_EXTENT_UNWRITTEN", "IO::AIO::FIEMAP_EXTENT_MERGED" |
|
|
1045 | or "IO::AIO::FIEMAP_EXTENT_SHARED". |
|
|
1046 | |
|
|
1047 | At the time of this writing (Linux 3.2), this requets is unreliable |
|
|
1048 | unless $count is "undef", as the kernel has all sorts of bugs |
|
|
1049 | preventing it to return all extents of a range for files with large |
|
|
1050 | number of extents. The code works around all these issues if $count |
|
|
1051 | is undef. |
842 | |
1052 | |
843 | aio_group $callback->(...) |
1053 | aio_group $callback->(...) |
844 | This is a very special aio request: Instead of doing something, it |
1054 | 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 |
1055 | 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 |
1056 | to bundle many requests into a single, composite, request with a |
… | |
… | |
880 | While it is theoretically handy to have simple I/O scheduling |
1090 | While it is theoretically handy to have simple I/O scheduling |
881 | requests like sleep and file handle readable/writable, the overhead |
1091 | 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 |
1092 | 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 |
1093 | not use this function except to put your application under |
884 | artificial I/O pressure. |
1094 | artificial I/O pressure. |
|
|
1095 | |
|
|
1096 | IO::AIO::WD - multiple working directories |
|
|
1097 | Your process only has one current working directory, which is used by |
|
|
1098 | all threads. This makes it hard to use relative paths (some other |
|
|
1099 | component could call "chdir" at any time, and it is hard to control when |
|
|
1100 | the path will be used by IO::AIO). |
|
|
1101 | |
|
|
1102 | One solution for this is to always use absolute paths. This usually |
|
|
1103 | works, but can be quite slow (the kernel has to walk the whole path on |
|
|
1104 | every access), and can also be a hassle to implement. |
|
|
1105 | |
|
|
1106 | Newer POSIX systems have a number of functions (openat, fdopendir, |
|
|
1107 | futimensat and so on) that make it possible to specify working |
|
|
1108 | directories per operation. |
|
|
1109 | |
|
|
1110 | For portability, and because the clowns who "designed", or shall I |
|
|
1111 | write, perpetrated this new interface were obviously half-drunk, this |
|
|
1112 | abstraction cannot be perfect, though. |
|
|
1113 | |
|
|
1114 | IO::AIO allows you to convert directory paths into a so-called |
|
|
1115 | IO::AIO::WD object. This object stores the canonicalised, absolute |
|
|
1116 | version of the path, and on systems that allow it, also a directory file |
|
|
1117 | descriptor. |
|
|
1118 | |
|
|
1119 | Everywhere where a pathname is accepted by IO::AIO (e.g. in "aio_stat" |
|
|
1120 | or "aio_unlink"), one can specify an array reference with an IO::AIO::WD |
|
|
1121 | object and a pathname instead (or the IO::AIO::WD object alone, which |
|
|
1122 | gets interpreted as "[$wd, "."]"). If the pathname is absolute, the |
|
|
1123 | IO::AIO::WD object is ignored, otherwise the pathname is resolved |
|
|
1124 | relative to that IO::AIO::WD object. |
|
|
1125 | |
|
|
1126 | For example, to get a wd object for /etc and then stat passwd inside, |
|
|
1127 | you would write: |
|
|
1128 | |
|
|
1129 | aio_wd "/etc", sub { |
|
|
1130 | my $etcdir = shift; |
|
|
1131 | |
|
|
1132 | # although $etcdir can be undef on error, there is generally no reason |
|
|
1133 | # to check for errors here, as aio_stat will fail with ENOENT |
|
|
1134 | # when $etcdir is undef. |
|
|
1135 | |
|
|
1136 | aio_stat [$etcdir, "passwd"], sub { |
|
|
1137 | # yay |
|
|
1138 | }; |
|
|
1139 | }; |
|
|
1140 | |
|
|
1141 | The fact that "aio_wd" is a request and not a normal function shows that |
|
|
1142 | creating an IO::AIO::WD object is itself a potentially blocking |
|
|
1143 | operation, which is why it is done asynchronously. |
|
|
1144 | |
|
|
1145 | To stat the directory obtained with "aio_wd" above, one could write |
|
|
1146 | either of the following three request calls: |
|
|
1147 | |
|
|
1148 | aio_lstat "/etc" , sub { ... # pathname as normal string |
|
|
1149 | aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself) |
|
|
1150 | aio_lstat $wd , sub { ... # shorthand for the previous |
|
|
1151 | |
|
|
1152 | As with normal pathnames, IO::AIO keeps a copy of the working directory |
|
|
1153 | object and the pathname string, so you could write the following without |
|
|
1154 | causing any issues due to $path getting reused: |
|
|
1155 | |
|
|
1156 | my $path = [$wd, undef]; |
|
|
1157 | |
|
|
1158 | for my $name (qw(abc def ghi)) { |
|
|
1159 | $path->[1] = $name; |
|
|
1160 | aio_stat $path, sub { |
|
|
1161 | # ... |
|
|
1162 | }; |
|
|
1163 | } |
|
|
1164 | |
|
|
1165 | There are some caveats: when directories get renamed (or deleted), the |
|
|
1166 | pathname string doesn't change, so will point to the new directory (or |
|
|
1167 | nowhere at all), while the directory fd, if available on the system, |
|
|
1168 | will still point to the original directory. Most functions accepting a |
|
|
1169 | pathname will use the directory fd on newer systems, and the string on |
|
|
1170 | older systems. Some functions (such as realpath) will always rely on the |
|
|
1171 | string form of the pathname. |
|
|
1172 | |
|
|
1173 | So this functionality is mainly useful to get some protection against |
|
|
1174 | "chdir", to easily get an absolute path out of a relative path for |
|
|
1175 | future reference, and to speed up doing many operations in the same |
|
|
1176 | directory (e.g. when stat'ing all files in a directory). |
|
|
1177 | |
|
|
1178 | The following functions implement this working directory abstraction: |
|
|
1179 | |
|
|
1180 | aio_wd $pathname, $callback->($wd) |
|
|
1181 | Asynchonously canonicalise the given pathname and convert it to an |
|
|
1182 | IO::AIO::WD object representing it. If possible and supported on the |
|
|
1183 | system, also open a directory fd to speed up pathname resolution |
|
|
1184 | relative to this working directory. |
|
|
1185 | |
|
|
1186 | If something goes wrong, then "undef" is passwd to the callback |
|
|
1187 | instead of a working directory object and $! is set appropriately. |
|
|
1188 | Since passing "undef" as working directory component of a pathname |
|
|
1189 | fails the request with "ENOENT", there is often no need for error |
|
|
1190 | checking in the "aio_wd" callback, as future requests using the |
|
|
1191 | value will fail in the expected way. |
|
|
1192 | |
|
|
1193 | IO::AIO::CWD |
|
|
1194 | This is a compiletime constant (object) that represents the process |
|
|
1195 | current working directory. |
|
|
1196 | |
|
|
1197 | Specifying this object as working directory object for a pathname is |
|
|
1198 | as if the pathname would be specified directly, without a directory |
|
|
1199 | object. For example, these calls are functionally identical: |
|
|
1200 | |
|
|
1201 | aio_stat "somefile", sub { ... }; |
|
|
1202 | aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; |
|
|
1203 | |
|
|
1204 | To recover the path associated with an IO::AIO::WD object, you can use |
|
|
1205 | "aio_realpath": |
|
|
1206 | |
|
|
1207 | aio_realpath $wd, sub { |
|
|
1208 | warn "path is $_[0]\n"; |
|
|
1209 | }; |
|
|
1210 | |
|
|
1211 | Currently, "aio_statvfs" always, and "aio_rename" and "aio_rmdir" |
|
|
1212 | sometimes, fall back to using an absolue path. |
885 | |
1213 | |
886 | IO::AIO::REQ CLASS |
1214 | IO::AIO::REQ CLASS |
887 | All non-aggregate "aio_*" functions return an object of this class when |
1215 | All non-aggregate "aio_*" functions return an object of this class when |
888 | called in non-void context. |
1216 | called in non-void context. |
889 | |
1217 | |
… | |
… | |
989 | Sets a feeder/generator on this group: every group can have an |
1317 | Sets a feeder/generator on this group: every group can have an |
990 | attached generator that generates requests if idle. The idea behind |
1318 | attached generator that generates requests if idle. The idea behind |
991 | this is that, although you could just queue as many requests as you |
1319 | 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 |
1320 | want in a group, this might starve other requests for a potentially |
993 | long time. For example, "aio_scandir" might generate hundreds of |
1321 | long time. For example, "aio_scandir" might generate hundreds of |
994 | thousands "aio_stat" requests, delaying any later requests for a |
1322 | thousands of "aio_stat" requests, delaying any later requests for a |
995 | long time. |
1323 | long time. |
996 | |
1324 | |
997 | To avoid this, and allow incremental generation of requests, you can |
1325 | To avoid this, and allow incremental generation of requests, you can |
998 | instead a group and set a feeder on it that generates those |
1326 | instead a group and set a feeder on it that generates those |
999 | requests. The feed callback will be called whenever there are few |
1327 | requests. The feed callback will be called whenever there are few |
… | |
… | |
1041 | results. |
1369 | results. |
1042 | |
1370 | |
1043 | See "poll_cb" for an example. |
1371 | See "poll_cb" for an example. |
1044 | |
1372 | |
1045 | IO::AIO::poll_cb |
1373 | IO::AIO::poll_cb |
1046 | Process some outstanding events on the result pipe. You have to call |
1374 | Process some requests that have reached the result phase (i.e. they |
|
|
1375 | have been executed but the results are not yet reported). You have |
|
|
1376 | to call this "regularly" to finish outstanding requests. |
|
|
1377 | |
1047 | this regularly. Returns 0 if all events could be processed (or there |
1378 | 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 |
1379 | to process), or -1 if it returned earlier for whatever reason. |
1049 | whatever reason. Returns immediately when no events are outstanding. |
1380 | Returns immediately when no events are outstanding. The amount of |
1050 | The amount of events processed depends on the settings of |
1381 | events processed depends on the settings of "IO::AIO::max_poll_req", |
1051 | "IO::AIO::max_poll_req" and "IO::AIO::max_poll_time". |
1382 | "IO::AIO::max_poll_time" and "IO::AIO::max_outstanding". |
1052 | |
1383 | |
1053 | If not all requests were processed for whatever reason, the |
1384 | If not all requests were processed for whatever reason, the poll |
1054 | filehandle will still be ready when "poll_cb" returns, so normally |
1385 | 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. |
1386 | normally you don't have to do anything special to have it called |
|
|
1387 | later. |
1056 | |
1388 | |
1057 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
1389 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
1058 | becomes ready, it can be beneficial to call this function from loops |
1390 | 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 |
1391 | 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 |
1392 | processed when they become available and not just when the loop is |
… | |
… | |
1068 | Event->io (fd => IO::AIO::poll_fileno, |
1400 | Event->io (fd => IO::AIO::poll_fileno, |
1069 | poll => 'r', async => 1, |
1401 | poll => 'r', async => 1, |
1070 | cb => \&IO::AIO::poll_cb); |
1402 | cb => \&IO::AIO::poll_cb); |
1071 | |
1403 | |
1072 | IO::AIO::poll_wait |
1404 | IO::AIO::poll_wait |
1073 | If there are any outstanding requests and none of them in the result |
1405 | 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 |
1406 | requests are outstanding anymore. |
1075 | (simply does a "select" on the filehandle. This is useful if you |
1407 | |
1076 | want to synchronously wait for some requests to finish). |
1408 | This is useful if you want to synchronously wait for some requests |
|
|
1409 | to become ready, without actually handling them. |
1077 | |
1410 | |
1078 | See "nreqs" for an example. |
1411 | See "nreqs" for an example. |
1079 | |
1412 | |
1080 | IO::AIO::poll |
1413 | IO::AIO::poll |
1081 | Waits until some requests have been handled. |
1414 | Waits until some requests have been handled. |
… | |
… | |
1193 | |
1526 | |
1194 | This is a very bad function to use in interactive programs because |
1527 | 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 |
1528 | it blocks, and a bad way to reduce concurrency because it is |
1196 | inexact: Better use an "aio_group" together with a feed callback. |
1529 | inexact: Better use an "aio_group" together with a feed callback. |
1197 | |
1530 | |
1198 | It's main use is in scripts without an event loop - when you want to |
1531 | 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: |
1532 | stat a lot of files, you can write somehting like this: |
1200 | |
1533 | |
1201 | IO::AIO::max_outstanding 32; |
1534 | IO::AIO::max_outstanding 32; |
1202 | |
1535 | |
1203 | for my $path (...) { |
1536 | for my $path (...) { |
… | |
… | |
1234 | IO::AIO::npending |
1567 | IO::AIO::npending |
1235 | Returns the number of requests currently in the pending state |
1568 | Returns the number of requests currently in the pending state |
1236 | (executed, but not yet processed by poll_cb). |
1569 | (executed, but not yet processed by poll_cb). |
1237 | |
1570 | |
1238 | MISCELLANEOUS FUNCTIONS |
1571 | MISCELLANEOUS FUNCTIONS |
1239 | IO::AIO implements some functions that might be useful, but are not |
1572 | IO::AIO implements some functions that are useful when you want to use |
1240 | asynchronous. |
1573 | some "Advanced I/O" function not available to in Perl, without going the |
|
|
1574 | "Asynchronous I/O" route. Many of these have an asynchronous "aio_*" |
|
|
1575 | counterpart. |
1241 | |
1576 | |
1242 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1577 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1243 | Calls the "eio_sendfile_sync" function, which is like |
1578 | Calls the "eio_sendfile_sync" function, which is like |
1244 | "aio_sendfile", but is blocking (this makes most sense if you know |
1579 | "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 |
1580 | the input data is likely cached already and the output filehandle is |
… | |
… | |
1247 | |
1582 | |
1248 | Returns the number of bytes copied, or -1 on error. |
1583 | Returns the number of bytes copied, or -1 on error. |
1249 | |
1584 | |
1250 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1585 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1251 | Simply calls the "posix_fadvise" function (see its manpage for |
1586 | Simply calls the "posix_fadvise" function (see its manpage for |
1252 | details). The following advice constants are avaiable: |
1587 | details). The following advice constants are available: |
1253 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1588 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1254 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1589 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1255 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1590 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1256 | |
1591 | |
1257 | On systems that do not implement "posix_fadvise", this function |
1592 | On systems that do not implement "posix_fadvise", this function |
1258 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1593 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1259 | |
1594 | |
1260 | IO::AIO::madvise $scalar, $offset, $len, $advice |
1595 | IO::AIO::madvise $scalar, $offset, $len, $advice |
1261 | Simply calls the "posix_madvise" function (see its manpage for |
1596 | Simply calls the "posix_madvise" function (see its manpage for |
1262 | details). The following advice constants are avaiable: |
1597 | details). The following advice constants are available: |
1263 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
1598 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
1264 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
1599 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
1265 | "IO::AIO::MADV_DONTNEED". |
1600 | "IO::AIO::MADV_DONTNEED". |
1266 | |
1601 | |
1267 | On systems that do not implement "posix_madvise", this function |
1602 | On systems that do not implement "posix_madvise", this function |
1268 | returns ENOSYS, otherwise the return value of "posix_madvise". |
1603 | returns ENOSYS, otherwise the return value of "posix_madvise". |
1269 | |
1604 | |
1270 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
1605 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
1271 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
1606 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
1272 | $scalar (see its manpage for details). The following protect |
1607 | $scalar (see its manpage for details). The following protect |
1273 | constants are avaiable: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
1608 | constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
1274 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
1609 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
1275 | |
1610 | |
1276 | On systems that do not implement "mprotect", this function returns |
1611 | On systems that do not implement "mprotect", this function returns |
1277 | ENOSYS, otherwise the return value of "mprotect". |
1612 | ENOSYS, otherwise the return value of "mprotect". |
1278 | |
1613 | |
1279 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1614 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
1280 | Memory-maps a file (or anonymous memory range) and attaches it to |
1615 | Memory-maps a file (or anonymous memory range) and attaches it to |
1281 | the given $scalar, which will act like a string scalar. |
1616 | the given $scalar, which will act like a string scalar. Returns true |
|
|
1617 | on success, and false otherwise. |
1282 | |
1618 | |
1283 | The only operations allowed on the scalar are "substr"/"vec" that |
1619 | The only operations allowed on the scalar are "substr"/"vec" that |
1284 | don't change the string length, and most read-only operations such |
1620 | don't change the string length, and most read-only operations such |
1285 | as copying it or searching it with regexes and so on. |
1621 | as copying it or searching it with regexes and so on. |
1286 | |
1622 | |
… | |
… | |
1300 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
1636 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
1301 | "IO::AIO::PROT_WRITE", |
1637 | "IO::AIO::PROT_WRITE", |
1302 | |
1638 | |
1303 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
1639 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
1304 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
1640 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
1305 | not available, the are defined as 0): "IO::AIO::MAP_ANONYMOUS" |
1641 | 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 |
1642 | "MAP_ANON" if your system only provides this constant), |
1307 | constant), "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
1643 | "IO::AIO::MAP_HUGETLB", "IO::AIO::MAP_LOCKED", |
1308 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE" or |
1644 | "IO::AIO::MAP_NORESERVE", "IO::AIO::MAP_POPULATE", |
1309 | "IO::AIO::MAP_NONBLOCK" |
1645 | "IO::AIO::MAP_NONBLOCK", "IO::AIO::MAP_FIXED", |
|
|
1646 | "IO::AIO::MAP_GROWSDOWN", "IO::AIO::MAP_32BIT", |
|
|
1647 | "IO::AIO::MAP_HUGETLB" or "IO::AIO::MAP_STACK". |
1310 | |
1648 | |
1311 | If $fh is "undef", then a file descriptor of -1 is passed. |
1649 | If $fh is "undef", then a file descriptor of -1 is passed. |
1312 | |
1650 | |
1313 | $offset is the offset from the start of the file - it generally must |
1651 | $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. |
1652 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
… | |
… | |
1336 | IO::AIO::munlockall |
1674 | IO::AIO::munlockall |
1337 | Calls the "munlockall" function. |
1675 | Calls the "munlockall" function. |
1338 | |
1676 | |
1339 | On systems that do not implement "munlockall", this function returns |
1677 | On systems that do not implement "munlockall", this function returns |
1340 | ENOSYS, otherwise the return value of "munlockall". |
1678 | ENOSYS, otherwise the return value of "munlockall". |
|
|
1679 | |
|
|
1680 | IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags |
|
|
1681 | Calls the GNU/Linux splice(2) syscall, if available. If $r_off or |
|
|
1682 | $w_off are "undef", then "NULL" is passed for these, otherwise they |
|
|
1683 | should be the file offset. |
|
|
1684 | |
|
|
1685 | $r_fh and $w_fh should not refer to the same file, as splice might |
|
|
1686 | silently corrupt the data in this case. |
|
|
1687 | |
|
|
1688 | The following symbol flag values are available: |
|
|
1689 | "IO::AIO::SPLICE_F_MOVE", "IO::AIO::SPLICE_F_NONBLOCK", |
|
|
1690 | "IO::AIO::SPLICE_F_MORE" and "IO::AIO::SPLICE_F_GIFT". |
|
|
1691 | |
|
|
1692 | See the splice(2) manpage for details. |
|
|
1693 | |
|
|
1694 | IO::AIO::tee $r_fh, $w_fh, $length, $flags |
|
|
1695 | Calls the GNU/Linux tee(2) syscall, see its manpage and the |
|
|
1696 | description for "IO::AIO::splice" above for details. |
|
|
1697 | |
|
|
1698 | $actual_size = IO::AIO::pipesize $r_fh[, $new_size] |
|
|
1699 | Attempts to query or change the pipe buffer size. Obviously works |
|
|
1700 | only on pipes, and currently works only on GNU/Linux systems, and |
|
|
1701 | fails with -1/"ENOSYS" everywhere else. If anybody knows how to |
|
|
1702 | influence pipe buffer size on other systems, drop me a note. |
|
|
1703 | |
|
|
1704 | ($rfh, $wfh) = IO::AIO::pipe2 [$flags] |
|
|
1705 | This is a direct interface to the Linux pipe2(2) system call. If |
|
|
1706 | $flags is missing or 0, then this should be the same as a call to |
|
|
1707 | perl's built-in "pipe" function and create a new pipe, and works on |
|
|
1708 | systems that lack the pipe2 syscall. On win32, this case invokes |
|
|
1709 | "_pipe (..., 4096, O_BINARY)". |
|
|
1710 | |
|
|
1711 | If $flags is non-zero, it tries to invoke the pipe2 system call with |
|
|
1712 | the given flags (Linux 2.6.27, glibc 2.9). |
|
|
1713 | |
|
|
1714 | On success, the read and write file handles are returned. |
|
|
1715 | |
|
|
1716 | On error, nothing will be returned. If the pipe2 syscall is missing |
|
|
1717 | and $flags is non-zero, fails with "ENOSYS". |
|
|
1718 | |
|
|
1719 | Please refer to pipe2(2) for more info on the $flags, but at the |
|
|
1720 | time of this writing, "IO::AIO::O_CLOEXEC", "IO::AIO::O_NONBLOCK" |
|
|
1721 | and "IO::AIO::O_DIRECT" (Linux 3.4, for packet-based pipes) were |
|
|
1722 | supported. |
1341 | |
1723 | |
1342 | EVENT LOOP INTEGRATION |
1724 | EVENT LOOP INTEGRATION |
1343 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1725 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
1344 | automatically into many event loops: |
1726 | automatically into many event loops: |
1345 | |
1727 | |
… | |
… | |
1371 | |
1753 | |
1372 | FORK BEHAVIOUR |
1754 | FORK BEHAVIOUR |
1373 | Usage of pthreads in a program changes the semantics of fork |
1755 | Usage of pthreads in a program changes the semantics of fork |
1374 | considerably. Specifically, only async-safe functions can be called |
1756 | considerably. Specifically, only async-safe functions can be called |
1375 | after fork. Perl doesn't know about this, so in general, you cannot call |
1757 | 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 |
1758 | fork with defined behaviour in perl if pthreads are involved. IO::AIO |
1377 | applies, but many other extensions and (for inexplicable reasons) perl |
1759 | uses pthreads, so this applies, but many other extensions and (for |
1378 | itself often is linked against pthreads, so this limitation applies. |
1760 | inexplicable reasons) perl itself often is linked against pthreads, so |
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1761 | this limitation applies to quite a lot of perls. |
1379 | |
1762 | |
1380 | Some operating systems have extensions that allow safe use of fork, and |
1763 | 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. |
1764 | 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 |
1765 | supported, but using IO::AIO in the child is not. |
1383 | extensions to POSIX. |
1766 | |
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1767 | You might get around by not *using* IO::AIO before (or after) forking. |
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1768 | You could also try to call the IO::AIO::reinit function in the child: |
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1769 | |
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1770 | IO::AIO::reinit |
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1771 | Abandons all current requests and I/O threads and simply |
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1772 | reinitialises all data structures. This is not an operation |
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1773 | supported by any standards, but happens to work on GNU/Linux and |
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1774 | some newer BSD systems. |
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1775 | |
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1776 | The only reasonable use for this function is to call it after |
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1777 | forking, if "IO::AIO" was used in the parent. Calling it while |
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1778 | IO::AIO is active in the process will result in undefined behaviour. |
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1779 | Calling it at any time will also result in any undefined (by POSIX) |
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1780 | behaviour. |
1384 | |
1781 | |
1385 | MEMORY USAGE |
1782 | MEMORY USAGE |
1386 | Per-request usage: |
1783 | Per-request usage: |
1387 | |
1784 | |
1388 | Each aio request uses - depending on your architecture - around 100-200 |
1785 | Each aio request uses - depending on your architecture - around 100-200 |