… | |
… | |
2 | IO::AIO - Asynchronous Input/Output |
2 | IO::AIO - Asynchronous Input/Output |
3 | |
3 | |
4 | SYNOPSIS |
4 | SYNOPSIS |
5 | use IO::AIO; |
5 | use IO::AIO; |
6 | |
6 | |
7 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
7 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
8 | my $fh = shift |
8 | my $fh = shift |
9 | or die "/etc/passwd: $!"; |
9 | or die "/etc/passwd: $!"; |
10 | ... |
10 | ... |
11 | }; |
11 | }; |
12 | |
12 | |
… | |
… | |
23 | my $req = aio_unlink "/tmp/file", sub { }; |
23 | my $req = aio_unlink "/tmp/file", sub { }; |
24 | $req->cancel; # cancel request if still in queue |
24 | $req->cancel; # cancel request if still in queue |
25 | |
25 | |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
27 | add $grp aio_stat "..." for ...; |
27 | add $grp aio_stat "..." for ...; |
28 | |
|
|
29 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
|
|
30 | use AnyEvent::AIO; |
|
|
31 | |
|
|
32 | # EV integration |
|
|
33 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
|
|
34 | |
|
|
35 | # Event integration |
|
|
36 | Event->io (fd => IO::AIO::poll_fileno, |
|
|
37 | poll => 'r', |
|
|
38 | cb => \&IO::AIO::poll_cb); |
|
|
39 | |
|
|
40 | # Glib/Gtk2 integration |
|
|
41 | add_watch Glib::IO IO::AIO::poll_fileno, |
|
|
42 | in => sub { IO::AIO::poll_cb; 1 }; |
|
|
43 | |
|
|
44 | # Tk integration |
|
|
45 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
|
|
46 | readable => \&IO::AIO::poll_cb); |
|
|
47 | |
|
|
48 | # Danga::Socket integration |
|
|
49 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
|
|
50 | \&IO::AIO::poll_cb); |
|
|
51 | |
28 | |
52 | DESCRIPTION |
29 | DESCRIPTION |
53 | This module implements asynchronous I/O using whatever means your |
30 | This module implements asynchronous I/O using whatever means your |
54 | operating system supports. It is implemented as an interface to "libeio" |
31 | operating system supports. It is implemented as an interface to "libeio" |
55 | (<http://software.schmorp.de/pkg/libeio.html>). |
32 | (<http://software.schmorp.de/pkg/libeio.html>). |
… | |
… | |
87 | |
64 | |
88 | EXAMPLE |
65 | EXAMPLE |
89 | 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 |
90 | asynchronously: |
67 | asynchronously: |
91 | |
68 | |
92 | use Fcntl; |
|
|
93 | use EV; |
69 | use EV; |
94 | use IO::AIO; |
70 | use IO::AIO; |
95 | |
71 | |
96 | # register the IO::AIO callback with EV |
72 | # register the IO::AIO callback with EV |
97 | 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; |
98 | |
74 | |
99 | # queue the request to open /etc/passwd |
75 | # queue the request to open /etc/passwd |
100 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
76 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
101 | my $fh = shift |
77 | my $fh = shift |
102 | or die "error while opening: $!"; |
78 | or die "error while opening: $!"; |
103 | |
79 | |
104 | # stat'ing filehandles is generally non-blocking |
80 | # stat'ing filehandles is generally non-blocking |
105 | my $size = -s $fh; |
81 | my $size = -s $fh; |
… | |
… | |
114 | |
90 | |
115 | # file contents now in $contents |
91 | # file contents now in $contents |
116 | print $contents; |
92 | print $contents; |
117 | |
93 | |
118 | # exit event loop and program |
94 | # exit event loop and program |
119 | EV::unloop; |
95 | EV::break; |
120 | }; |
96 | }; |
121 | }; |
97 | }; |
122 | |
98 | |
123 | # possibly queue up other requests, or open GUI windows, |
99 | # possibly queue up other requests, or open GUI windows, |
124 | # check for sockets etc. etc. |
100 | # check for sockets etc. etc. |
125 | |
101 | |
126 | # process events as long as there are some: |
102 | # process events as long as there are some: |
127 | EV::loop; |
103 | EV::run; |
128 | |
104 | |
129 | REQUEST ANATOMY AND LIFETIME |
105 | REQUEST ANATOMY AND LIFETIME |
130 | 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 |
131 | not directly visible to Perl. |
107 | not directly visible to Perl. |
132 | |
108 | |
… | |
… | |
168 | anymore (except possibly for the Perl object, but its connection to |
144 | anymore (except possibly for the Perl object, but its connection to |
169 | the actual aio request is severed and calling its methods will |
145 | the actual aio request is severed and calling its methods will |
170 | either do nothing or result in a runtime error). |
146 | either do nothing or result in a runtime error). |
171 | |
147 | |
172 | FUNCTIONS |
148 | FUNCTIONS |
173 | AIO REQUEST FUNCTIONS |
149 | QUICK OVERVIEW |
|
|
150 | This section simply lists the prototypes most of the functions for quick |
|
|
151 | reference. See the following sections for function-by-function |
|
|
152 | documentation. |
|
|
153 | |
|
|
154 | aio_wd $pathname, $callback->($wd) |
|
|
155 | aio_open $pathname, $flags, $mode, $callback->($fh) |
|
|
156 | aio_close $fh, $callback->($status) |
|
|
157 | aio_seek $fh,$offset,$whence, $callback->($offs) |
|
|
158 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
|
|
159 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
|
|
160 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
|
|
161 | aio_readahead $fh,$offset,$length, $callback->($retval) |
|
|
162 | aio_stat $fh_or_path, $callback->($status) |
|
|
163 | aio_lstat $fh, $callback->($status) |
|
|
164 | aio_statvfs $fh_or_path, $callback->($statvfs) |
|
|
165 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
|
|
166 | aio_chown $fh_or_path, $uid, $gid, $callback->($status) |
|
|
167 | aio_chmod $fh_or_path, $mode, $callback->($status) |
|
|
168 | aio_truncate $fh_or_path, $offset, $callback->($status) |
|
|
169 | aio_allocate $fh, $mode, $offset, $len, $callback->($status) |
|
|
170 | aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) |
|
|
171 | aio_unlink $pathname, $callback->($status) |
|
|
172 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
|
|
173 | aio_link $srcpath, $dstpath, $callback->($status) |
|
|
174 | aio_symlink $srcpath, $dstpath, $callback->($status) |
|
|
175 | aio_readlink $pathname, $callback->($link) |
|
|
176 | aio_realpath $pathname, $callback->($path) |
|
|
177 | aio_rename $srcpath, $dstpath, $callback->($status) |
|
|
178 | aio_mkdir $pathname, $mode, $callback->($status) |
|
|
179 | aio_rmdir $pathname, $callback->($status) |
|
|
180 | aio_readdir $pathname, $callback->($entries) |
|
|
181 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
|
|
182 | IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST |
|
|
183 | IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN |
|
|
184 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
|
|
185 | aio_load $pathname, $data, $callback->($status) |
|
|
186 | aio_copy $srcpath, $dstpath, $callback->($status) |
|
|
187 | aio_move $srcpath, $dstpath, $callback->($status) |
|
|
188 | aio_rmtree $pathname, $callback->($status) |
|
|
189 | aio_fcntl $fh, $cmd, $arg, $callback->($status) |
|
|
190 | aio_ioctl $fh, $request, $buf, $callback->($status) |
|
|
191 | aio_sync $callback->($status) |
|
|
192 | aio_syncfs $fh, $callback->($status) |
|
|
193 | aio_fsync $fh, $callback->($status) |
|
|
194 | aio_fdatasync $fh, $callback->($status) |
|
|
195 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
|
|
196 | aio_pathsync $pathname, $callback->($status) |
|
|
197 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
|
|
198 | aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) |
|
|
199 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
|
|
200 | aio_mlockall $flags, $callback->($status) |
|
|
201 | aio_group $callback->(...) |
|
|
202 | aio_nop $callback->() |
|
|
203 | |
|
|
204 | $prev_pri = aioreq_pri [$pri] |
|
|
205 | aioreq_nice $pri_adjust |
|
|
206 | |
|
|
207 | IO::AIO::poll_wait |
|
|
208 | IO::AIO::poll_cb |
|
|
209 | IO::AIO::poll |
|
|
210 | IO::AIO::flush |
|
|
211 | IO::AIO::max_poll_reqs $nreqs |
|
|
212 | IO::AIO::max_poll_time $seconds |
|
|
213 | IO::AIO::min_parallel $nthreads |
|
|
214 | IO::AIO::max_parallel $nthreads |
|
|
215 | IO::AIO::max_idle $nthreads |
|
|
216 | IO::AIO::idle_timeout $seconds |
|
|
217 | IO::AIO::max_outstanding $maxreqs |
|
|
218 | IO::AIO::nreqs |
|
|
219 | IO::AIO::nready |
|
|
220 | IO::AIO::npending |
|
|
221 | |
|
|
222 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
|
|
223 | IO::AIO::fadvise $fh, $offset, $len, $advice |
|
|
224 | IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]] |
|
|
225 | IO::AIO::munmap $scalar |
|
|
226 | IO::AIO::madvise $scalar, $offset, $length, $advice |
|
|
227 | IO::AIO::mprotect $scalar, $offset, $length, $protect |
|
|
228 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
|
|
229 | IO::AIO::munlockall |
|
|
230 | |
|
|
231 | API NOTES |
174 | 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 |
175 | with the same name (sans "aio_"). The arguments are similar or |
233 | with the same name (sans "aio_"). The arguments are similar or |
176 | identical, and they all accept an additional (and optional) $callback |
234 | identical, and they all accept an additional (and optional) $callback |
177 | 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 |
178 | called with the syscall return code (e.g. most syscalls return -1 on |
|
|
179 | error, unlike perl, which usually delivers "false") as its sole argument |
|
|
180 | 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". |
181 | |
244 | |
182 | All functions expecting a filehandle keep a copy of the filehandle |
245 | All functions expecting a filehandle keep a copy of the filehandle |
183 | internally until the request has finished. |
246 | internally until the request has finished. |
184 | |
247 | |
185 | 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 |
186 | further manipulation of those requests while they are in-flight. |
249 | further manipulation of those requests while they are in-flight. |
187 | |
250 | |
188 | The pathnames you pass to these routines *must* be absolute and encoded |
251 | The pathnames you pass to these routines *should* be absolute. The |
189 | 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 |
190 | being executed, the current working directory could have changed. |
253 | current working directory could have changed. Alternatively, you can |
191 | Alternatively, you can make sure that you never change the current |
254 | make sure that you never change the current working directory anywhere |
192 | 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. |
193 | |
259 | |
194 | 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 |
195 | pass in filenames you got from outside (command line, readdir etc.) |
261 | pass in filenames you got from outside (command line, readdir etc.) |
196 | 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 |
197 | 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) |
198 | the user environment, d) use Glib::filename_from_unicode on unicode |
264 | encoding in effect in the user environment, d) use |
199 | 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 |
200 | contents. |
266 | else to ensure your scalar has the correct contents. |
201 | |
267 | |
202 | 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 |
203 | handles correctly whether it is set or not. |
269 | handles correctly whether it is set or not. |
204 | |
270 | |
|
|
271 | AIO REQUEST FUNCTIONS |
205 | $prev_pri = aioreq_pri [$pri] |
272 | $prev_pri = aioreq_pri [$pri] |
206 | 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 |
207 | 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. |
208 | |
275 | |
209 | 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 |
… | |
… | |
231 | Similar to "aioreq_pri", but subtracts the given value from the |
298 | Similar to "aioreq_pri", but subtracts the given value from the |
232 | current priority, so the effect is cumulative. |
299 | current priority, so the effect is cumulative. |
233 | |
300 | |
234 | aio_open $pathname, $flags, $mode, $callback->($fh) |
301 | aio_open $pathname, $flags, $mode, $callback->($fh) |
235 | 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 |
236 | newly created filehandle for the file. |
303 | newly created filehandle for the file (or "undef" in case of an |
|
|
304 | error). |
237 | |
305 | |
238 | 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, |
239 | above, for an explanation. |
307 | above, for an explanation. |
240 | |
308 | |
241 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
309 | The $flags argument is a bitmask. See the "Fcntl" module for a list. |
… | |
… | |
248 | will be modified by the umask in effect then the request is being |
316 | will be modified by the umask in effect then the request is being |
249 | executed, so better never change the umask. |
317 | executed, so better never change the umask. |
250 | |
318 | |
251 | Example: |
319 | Example: |
252 | |
320 | |
253 | aio_open "/etc/passwd", O_RDONLY, 0, sub { |
321 | aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub { |
254 | if ($_[0]) { |
322 | if ($_[0]) { |
255 | print "open successful, fh is $_[0]\n"; |
323 | print "open successful, fh is $_[0]\n"; |
256 | ... |
324 | ... |
257 | } else { |
325 | } else { |
258 | die "open failed: $!\n"; |
326 | die "open failed: $!\n"; |
259 | } |
327 | } |
260 | }; |
328 | }; |
261 | |
329 | |
|
|
330 | In addition to all the common open modes/flags ("O_RDONLY", |
|
|
331 | "O_WRONLY", "O_RDWR", "O_CREAT", "O_TRUNC", "O_EXCL" and |
|
|
332 | "O_APPEND"), the following POSIX and non-POSIX constants are |
|
|
333 | available (missing ones on your system are, as usual, 0): |
|
|
334 | |
|
|
335 | "O_ASYNC", "O_DIRECT", "O_NOATIME", "O_CLOEXEC", "O_NOCTTY", |
|
|
336 | "O_NOFOLLOW", "O_NONBLOCK", "O_EXEC", "O_SEARCH", "O_DIRECTORY", |
|
|
337 | "O_DSYNC", "O_RSYNC", "O_SYNC", "O_PATH", "O_TMPFILE", and |
|
|
338 | "O_TTY_INIT". |
|
|
339 | |
262 | aio_close $fh, $callback->($status) |
340 | aio_close $fh, $callback->($status) |
263 | Asynchronously close a file and call the callback with the result |
341 | Asynchronously close a file and call the callback with the result |
264 | code. |
342 | code. |
265 | |
343 | |
266 | Unfortunately, you can't do this to perl. Perl *insists* very |
344 | Unfortunately, you can't do this to perl. Perl *insists* very |
… | |
… | |
271 | 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 |
272 | 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). |
273 | |
351 | |
274 | 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 |
275 | 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". |
276 | |
373 | |
277 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
374 | aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
278 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
375 | aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) |
279 | 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 |
280 | $offset into the scalar given by $data and offset $dataoffset and |
377 | $offset into the scalar given by $data and offset $dataoffset and |
… | |
… | |
309 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
406 | aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) |
310 | Tries to copy $length bytes from $in_fh to $out_fh. It starts |
407 | Tries to copy $length bytes from $in_fh to $out_fh. It starts |
311 | reading at byte offset $in_offset, and starts writing at the current |
408 | reading at byte offset $in_offset, and starts writing at the current |
312 | file offset of $out_fh. Because of that, it is not safe to issue |
409 | file offset of $out_fh. Because of that, it is not safe to issue |
313 | more than one "aio_sendfile" per $out_fh, as they will interfere |
410 | more than one "aio_sendfile" per $out_fh, as they will interfere |
314 | with each other. |
411 | with each other. The same $in_fh works fine though, as this function |
|
|
412 | does not move or use the file offset of $in_fh. |
315 | |
413 | |
|
|
414 | Please note that "aio_sendfile" can read more bytes from $in_fh than |
|
|
415 | are written, and there is no way to find out how many more bytes |
|
|
416 | have been read from "aio_sendfile" alone, as "aio_sendfile" only |
|
|
417 | provides the number of bytes written to $out_fh. Only if the result |
|
|
418 | value equals $length one can assume that $length bytes have been |
|
|
419 | read. |
|
|
420 | |
|
|
421 | Unlike with other "aio_" functions, it makes a lot of sense to use |
|
|
422 | "aio_sendfile" on non-blocking sockets, as long as one end |
|
|
423 | (typically the $in_fh) is a file - the file I/O will then be |
|
|
424 | asynchronous, while the socket I/O will be non-blocking. Note, |
|
|
425 | however, that you can run into a trap where "aio_sendfile" reads |
|
|
426 | some data with readahead, then fails to write all data, and when the |
|
|
427 | socket is ready the next time, the data in the cache is already |
|
|
428 | lost, forcing "aio_sendfile" to again hit the disk. Explicit |
|
|
429 | "aio_read" + "aio_write" let's you better control resource usage. |
|
|
430 | |
316 | This call tries to make use of a native "sendfile" syscall to |
431 | This call tries to make use of a native "sendfile"-like syscall to |
317 | provide zero-copy operation. For this to work, $out_fh should refer |
432 | provide zero-copy operation. For this to work, $out_fh should refer |
318 | to a socket, and $in_fh should refer to mmap'able file. |
433 | to a socket, and $in_fh should refer to an mmap'able file. |
319 | |
434 | |
320 | If a native sendfile cannot be found or it fails with "ENOSYS", |
435 | If a native sendfile cannot be found or it fails with "ENOSYS", |
321 | "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or "ENOTSOCK", |
436 | "EINVAL", "ENOTSUP", "EOPNOTSUPP", "EAFNOSUPPORT", "EPROTOTYPE" or |
322 | it will be emulated, so you can call "aio_sendfile" on any type of |
437 | "ENOTSOCK", it will be emulated, so you can call "aio_sendfile" on |
323 | filehandle regardless of the limitations of the operating system. |
438 | any type of filehandle regardless of the limitations of the |
|
|
439 | operating system. |
324 | |
440 | |
325 | Please note, however, that "aio_sendfile" can read more bytes from |
441 | As native sendfile syscalls (as practically any non-POSIX interface |
326 | $in_fh than are written, and there is no way to find out how many |
442 | hacked together in a hurry to improve benchmark numbers) tend to be |
327 | bytes have been read from "aio_sendfile" alone, as "aio_sendfile" |
443 | rather buggy on many systems, this implementation tries to work |
328 | only provides the number of bytes written to $out_fh. Only if the |
444 | around some known bugs in Linux and FreeBSD kernels (probably |
329 | result value equals $length one can assume that $length bytes have |
445 | others, too), but that might fail, so you really really should check |
330 | been read. |
446 | the return value of "aio_sendfile" - fewre bytes than expected might |
|
|
447 | have been transferred. |
331 | |
448 | |
332 | aio_readahead $fh,$offset,$length, $callback->($retval) |
449 | aio_readahead $fh,$offset,$length, $callback->($retval) |
333 | "aio_readahead" populates the page cache with data from a file so |
450 | "aio_readahead" populates the page cache with data from a file so |
334 | that subsequent reads from that file will not block on disk I/O. The |
451 | that subsequent reads from that file will not block on disk I/O. The |
335 | $offset argument specifies the starting point from which data is to |
452 | $offset argument specifies the starting point from which data is to |
… | |
… | |
355 | |
472 | |
356 | Currently, the stats are always 64-bit-stats, i.e. instead of |
473 | Currently, the stats are always 64-bit-stats, i.e. instead of |
357 | returning an error when stat'ing a large file, the results will be |
474 | returning an error when stat'ing a large file, the results will be |
358 | silently truncated unless perl itself is compiled with large file |
475 | silently truncated unless perl itself is compiled with large file |
359 | support. |
476 | support. |
|
|
477 | |
|
|
478 | To help interpret the mode and dev/rdev stat values, IO::AIO offers |
|
|
479 | the following constants and functions (if not implemented, the |
|
|
480 | constants will be 0 and the functions will either "croak" or fall |
|
|
481 | back on traditional behaviour). |
|
|
482 | |
|
|
483 | "S_IFMT", "S_IFIFO", "S_IFCHR", "S_IFBLK", "S_IFLNK", "S_IFREG", |
|
|
484 | "S_IFDIR", "S_IFWHT", "S_IFSOCK", "IO::AIO::major $dev_t", |
|
|
485 | "IO::AIO::minor $dev_t", "IO::AIO::makedev $major, $minor". |
360 | |
486 | |
361 | Example: Print the length of /etc/passwd: |
487 | Example: Print the length of /etc/passwd: |
362 | |
488 | |
363 | aio_stat "/etc/passwd", sub { |
489 | aio_stat "/etc/passwd", sub { |
364 | $_[0] and die "stat failed: $!"; |
490 | $_[0] and die "stat failed: $!"; |
… | |
… | |
406 | namemax => 255, |
532 | namemax => 255, |
407 | frsize => 1024, |
533 | frsize => 1024, |
408 | fsid => 1810 |
534 | fsid => 1810 |
409 | } |
535 | } |
410 | |
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 | |
411 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
622 | aio_utime $fh_or_path, $atime, $mtime, $callback->($status) |
412 | Works like perl's "utime" function (including the special case of |
623 | Works like perl's "utime" function (including the special case of |
413 | $atime and $mtime being undef). Fractional times are supported if |
624 | $atime and $mtime being undef). Fractional times are supported if |
414 | the underlying syscalls support them. |
625 | the underlying syscalls support them. |
415 | |
626 | |
… | |
… | |
437 | aio_chown "path", 0, undef; |
648 | aio_chown "path", 0, undef; |
438 | |
649 | |
439 | aio_truncate $fh_or_path, $offset, $callback->($status) |
650 | aio_truncate $fh_or_path, $offset, $callback->($status) |
440 | Works like truncate(2) or ftruncate(2). |
651 | Works like truncate(2) or ftruncate(2). |
441 | |
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 | |
442 | aio_chmod $fh_or_path, $mode, $callback->($status) |
671 | aio_chmod $fh_or_path, $mode, $callback->($status) |
443 | Works like perl's "chmod" function. |
672 | Works like perl's "chmod" function. |
444 | |
673 | |
445 | aio_unlink $pathname, $callback->($status) |
674 | aio_unlink $pathname, $callback->($status) |
446 | Asynchronously unlink (delete) a file and call the callback with the |
675 | Asynchronously unlink (delete) a file and call the callback with the |
447 | result code. |
676 | result code. |
448 | |
677 | |
449 | aio_mknod $path, $mode, $dev, $callback->($status) |
678 | aio_mknod $pathname, $mode, $dev, $callback->($status) |
450 | [EXPERIMENTAL] |
679 | [EXPERIMENTAL] |
451 | |
680 | |
452 | Asynchronously create a device node (or fifo). See mknod(2). |
681 | Asynchronously create a device node (or fifo). See mknod(2). |
453 | |
682 | |
454 | The only (POSIX-) portable way of calling this function is: |
683 | The only (POSIX-) portable way of calling this function is: |
455 | |
684 | |
456 | aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
685 | aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ... |
|
|
686 | |
|
|
687 | See "aio_stat" for info about some potentially helpful extra |
|
|
688 | constants and functions. |
457 | |
689 | |
458 | aio_link $srcpath, $dstpath, $callback->($status) |
690 | aio_link $srcpath, $dstpath, $callback->($status) |
459 | Asynchronously create a new link to the existing object at $srcpath |
691 | Asynchronously create a new link to the existing object at $srcpath |
460 | at the path $dstpath and call the callback with the result code. |
692 | at the path $dstpath and call the callback with the result code. |
461 | |
693 | |
462 | aio_symlink $srcpath, $dstpath, $callback->($status) |
694 | aio_symlink $srcpath, $dstpath, $callback->($status) |
463 | Asynchronously create a new symbolic link to the existing object at |
695 | Asynchronously create a new symbolic link to the existing object at |
464 | $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 |
465 | code. |
697 | code. |
466 | |
698 | |
467 | aio_readlink $path, $callback->($link) |
699 | aio_readlink $pathname, $callback->($link) |
468 | Asynchronously read the symlink specified by $path and pass it to |
700 | Asynchronously read the symlink specified by $path and pass it to |
469 | 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 |
470 | the callback. |
702 | the callback. |
471 | |
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 | |
472 | aio_rename $srcpath, $dstpath, $callback->($status) |
712 | aio_rename $srcpath, $dstpath, $callback->($status) |
473 | Asynchronously rename the object at $srcpath to $dstpath, just as |
713 | Asynchronously rename the object at $srcpath to $dstpath, just as |
474 | rename(2) and call the callback with the result code. |
714 | rename(2) and call the callback with the result code. |
|
|
715 | |
|
|
716 | On systems that support the AIO::WD working directory abstraction |
|
|
717 | natively, the case "[$wd, "."]" as $srcpath is specialcased - |
|
|
718 | instead of failing, "rename" is called on the absolute path of $wd. |
475 | |
719 | |
476 | aio_mkdir $pathname, $mode, $callback->($status) |
720 | aio_mkdir $pathname, $mode, $callback->($status) |
477 | Asynchronously mkdir (create) a directory and call the callback with |
721 | Asynchronously mkdir (create) a directory and call the callback with |
478 | 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 |
479 | request is executed, so do not change your umask. |
723 | request is executed, so do not change your umask. |
480 | |
724 | |
481 | aio_rmdir $pathname, $callback->($status) |
725 | aio_rmdir $pathname, $callback->($status) |
482 | Asynchronously rmdir (delete) a directory and call the callback with |
726 | Asynchronously rmdir (delete) a directory and call the callback with |
483 | the result code. |
727 | the result code. |
484 | |
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 | |
485 | aio_readdir $pathname, $callback->($entries) |
733 | aio_readdir $pathname, $callback->($entries) |
486 | 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 |
487 | entire directory (i.e. opendir + readdir + closedir). The entries |
735 | entire directory (i.e. opendir + readdir + closedir). The entries |
488 | will not be sorted, and will NOT include the "." and ".." entries. |
736 | will not be sorted, and will NOT include the "." and ".." entries. |
489 | |
737 | |
490 | 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 |
491 | an array-ref with the filenames. |
739 | an array-ref with the filenames. |
492 | |
740 | |
493 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
741 | aio_readdirx $pathname, $flags, $callback->($entries, $flags) |
494 | Quite similar to "aio_readdir", but the $flags argument allows to |
742 | Quite similar to "aio_readdir", but the $flags argument allows one |
495 | tune behaviour and output format. In case of an error, $entries will |
743 | to tune behaviour and output format. In case of an error, $entries |
496 | be "undef". |
744 | will be "undef". |
497 | |
745 | |
498 | The flags are a combination of the following constants, ORed |
746 | The flags are a combination of the following constants, ORed |
499 | together (the flags will also be passed to the callback, possibly |
747 | together (the flags will also be passed to the callback, possibly |
500 | modified): |
748 | modified): |
501 | |
749 | |
502 | IO::AIO::READDIR_DENTS |
750 | IO::AIO::READDIR_DENTS |
503 | When this flag is off, then the callback gets an arrayref with |
751 | When this flag is off, then the callback gets an arrayref |
504 | of names only (as with "aio_readdir"), otherwise it gets an |
752 | consisting of names only (as with "aio_readdir"), otherwise it |
505 | arrayref with "[$name, $type, $inode]" arrayrefs, each |
753 | gets an arrayref with "[$name, $type, $inode]" arrayrefs, each |
506 | describing a single directory entry in more detail. |
754 | describing a single directory entry in more detail. |
507 | |
755 | |
508 | $name is the name of the entry. |
756 | $name is the name of the entry. |
509 | |
757 | |
510 | $type is one of the "IO::AIO::DT_xxx" constants: |
758 | $type is one of the "IO::AIO::DT_xxx" constants: |
… | |
… | |
523 | unspecified content on systems that do not deliver the inode |
771 | unspecified content on systems that do not deliver the inode |
524 | information. |
772 | information. |
525 | |
773 | |
526 | IO::AIO::READDIR_DIRS_FIRST |
774 | IO::AIO::READDIR_DIRS_FIRST |
527 | When this flag is set, then the names will be returned in an |
775 | When this flag is set, then the names will be returned in an |
528 | order where likely directories come first. This is useful when |
776 | order where likely directories come first, in optimal stat |
529 | you need to quickly find directories, or you want to find all |
777 | order. This is useful when you need to quickly find directories, |
530 | directories while avoiding to stat() each entry. |
778 | or you want to find all directories while avoiding to stat() |
|
|
779 | each entry. |
531 | |
780 | |
532 | If the system returns type information in readdir, then this is |
781 | If the system returns type information in readdir, then this is |
533 | used to find directories directly. Otherwise, likely directories |
782 | used to find directories directly. Otherwise, likely directories |
534 | are files beginning with ".", or otherwise files with no dots, |
783 | are names beginning with ".", or otherwise names with no dots, |
535 | of which files with short names are tried first. |
784 | of which names with short names are tried first. |
536 | |
785 | |
537 | IO::AIO::READDIR_STAT_ORDER |
786 | IO::AIO::READDIR_STAT_ORDER |
538 | When this flag is set, then the names will be returned in an |
787 | When this flag is set, then the names will be returned in an |
539 | order suitable for stat()'ing each one. That is, when you plan |
788 | order suitable for stat()'ing each one. That is, when you plan |
540 | to stat() all files in the given directory, then the returned |
789 | to stat() all files in the given directory, then the returned |
… | |
… | |
545 | optimal stat order. |
794 | optimal stat order. |
546 | |
795 | |
547 | IO::AIO::READDIR_FOUND_UNKNOWN |
796 | IO::AIO::READDIR_FOUND_UNKNOWN |
548 | This flag should not be set when calling "aio_readdirx". |
797 | This flag should not be set when calling "aio_readdirx". |
549 | 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 |
550 | $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 |
551 | flag therefore indicates that all $type's are known, which can |
800 | flag therefore indicates that all $type's are known, which can |
552 | be used to speed up some algorithms. |
801 | be used to speed up some algorithms. |
553 | |
802 | |
554 | aio_load $path, $data, $callback->($status) |
803 | aio_load $pathname, $data, $callback->($status) |
555 | 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 |
556 | into memory. Status is the same as with aio_read. |
805 | into memory. Status is the same as with aio_read. |
557 | |
806 | |
558 | aio_copy $srcpath, $dstpath, $callback->($status) |
807 | aio_copy $srcpath, $dstpath, $callback->($status) |
559 | Try to copy the *file* (directories not supported as either source |
808 | Try to copy the *file* (directories not supported as either source |
… | |
… | |
576 | |
825 | |
577 | 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; |
578 | 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" |
579 | and, if that is successful, unlinks the $srcpath. |
828 | and, if that is successful, unlinks the $srcpath. |
580 | |
829 | |
581 | aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) |
830 | aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) |
582 | Scans a directory (similar to "aio_readdir") but additionally tries |
831 | Scans a directory (similar to "aio_readdir") but additionally tries |
583 | to efficiently separate the entries of directory $path into two sets |
832 | to efficiently separate the entries of directory $path into two sets |
584 | of names, directories you can recurse into (directories), and ones |
833 | of names, directories you can recurse into (directories), and ones |
585 | you cannot recurse into (everything else, including symlinks to |
834 | you cannot recurse into (everything else, including symlinks to |
586 | directories). |
835 | directories). |
… | |
… | |
619 | Then entries will be sorted into likely directories a non-initial |
868 | Then entries will be sorted into likely directories a non-initial |
620 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
869 | dot currently) and likely non-directories (see "aio_readdirx"). Then |
621 | every entry plus an appended "/." will be "stat"'ed, likely |
870 | every entry plus an appended "/." will be "stat"'ed, likely |
622 | directories first, in order of their inode numbers. If that |
871 | directories first, in order of their inode numbers. If that |
623 | 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 |
624 | directory (which will be checked seperately). This is often faster |
873 | directory (which will be checked separately). This is often faster |
625 | than stat'ing the entry itself because filesystems might detect the |
874 | than stat'ing the entry itself because filesystems might detect the |
626 | 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 |
627 | filetype feature), even on systems that cannot return the filetype |
876 | filetype feature), even on systems that cannot return the filetype |
628 | information on readdir. |
877 | information on readdir. |
629 | |
878 | |
… | |
… | |
635 | |
884 | |
636 | It will also likely work on non-POSIX filesystems with reduced |
885 | It will also likely work on non-POSIX filesystems with reduced |
637 | 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 |
638 | disables the directory counting heuristic. |
887 | disables the directory counting heuristic. |
639 | |
888 | |
640 | aio_rmtree $path, $callback->($status) |
889 | aio_rmtree $pathname, $callback->($status) |
641 | Delete a directory tree starting (and including) $path, return the |
890 | Delete a directory tree starting (and including) $path, return the |
642 | 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 |
643 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
892 | uses "aio_scandir" to recurse into and rmdir directories, and unlink |
644 | everything else. |
893 | everything else. |
645 | |
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 | |
646 | aio_sync $callback->($status) |
913 | aio_sync $callback->($status) |
647 | Asynchronously call sync and call the callback when finished. |
914 | Asynchronously call sync and call the callback when finished. |
648 | |
915 | |
649 | aio_fsync $fh, $callback->($status) |
916 | aio_fsync $fh, $callback->($status) |
650 | Asynchronously call fsync on the given filehandle and call the |
917 | Asynchronously call fsync on the given filehandle and call the |
… | |
… | |
654 | Asynchronously call fdatasync on the given filehandle and call the |
921 | Asynchronously call fdatasync on the given filehandle and call the |
655 | callback with the fdatasync result code. |
922 | callback with the fdatasync result code. |
656 | |
923 | |
657 | 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 |
658 | 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. |
659 | |
932 | |
660 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
933 | aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) |
661 | 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 |
662 | to disk (but NOT the metadata), by calling the Linux-specific |
935 | to disk (but NOT the metadata), by calling the Linux-specific |
663 | 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 |
… | |
… | |
667 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
940 | "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE", |
668 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
941 | "IO::AIO::SYNC_FILE_RANGE_WRITE" and |
669 | "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 |
670 | manpage for details. |
943 | manpage for details. |
671 | |
944 | |
672 | aio_pathsync $path, $callback->($status) |
945 | aio_pathsync $pathname, $callback->($status) |
673 | 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 |
674 | a composite request intended to sync directories after directory |
947 | a composite request intended to sync directories after directory |
675 | operations (E.g. rename). This might not work on all operating |
948 | operations (E.g. rename). This might not work on all operating |
676 | 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 |
677 | directory changes get written to disc. It works for anything that |
950 | directory changes get written to disc. It works for anything that |
… | |
… | |
683 | Passes 0 when everything went ok, and -1 on error. |
956 | Passes 0 when everything went ok, and -1 on error. |
684 | |
957 | |
685 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
958 | aio_msync $scalar, $offset = 0, $length = undef, flags = 0, |
686 | $callback->($status) |
959 | $callback->($status) |
687 | This is a rather advanced IO::AIO call, which only works on |
960 | This is a rather advanced IO::AIO call, which only works on |
688 | mmap(2)ed scalars (see the Sys::Mmap or Mmap modules for details on |
961 | mmap(2)ed scalars (see the "IO::AIO::mmap" function, although it |
|
|
962 | also works on data scalars managed by the Sys::Mmap or Mmap modules, |
689 | this, note that the scalar must only be modified in-place while an |
963 | note that the scalar must only be modified in-place while an aio |
690 | aio operation is pending on it). |
964 | operation is pending on it). |
691 | |
965 | |
692 | It calls the "msync" function of your OS, if available, with the |
966 | It calls the "msync" function of your OS, if available, with the |
693 | memory area starting at $offset in the string and ending $length |
967 | memory area starting at $offset in the string and ending $length |
694 | bytes later. If $length is negative, counts from the end, and if |
968 | bytes later. If $length is negative, counts from the end, and if |
695 | $length is "undef", then it goes till the end of the string. The |
969 | $length is "undef", then it goes till the end of the string. The |
… | |
… | |
703 | |
977 | |
704 | 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 |
705 | 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 |
706 | "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 |
707 | reads all pages and ensures they are instantiated) or |
981 | reads all pages and ensures they are instantiated) or |
708 | "IO::AIO::MT_MODIFY", which modifies the memory page s(by reading |
982 | "IO::AIO::MT_MODIFY", which modifies the memory pages (by reading |
709 | and writing an octet from it, which dirties the page). |
983 | and writing an octet from it, which dirties the page). |
|
|
984 | |
|
|
985 | aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) |
|
|
986 | This is a rather advanced IO::AIO call, which works best on |
|
|
987 | mmap(2)ed scalars. |
|
|
988 | |
|
|
989 | It reads in all the pages of the underlying storage into memory (if |
|
|
990 | any) and locks them, so they are not getting swapped/paged out or |
|
|
991 | removed. |
|
|
992 | |
|
|
993 | If $length is undefined, then the scalar will be locked till the |
|
|
994 | end. |
|
|
995 | |
|
|
996 | On systems that do not implement "mlock", this function returns -1 |
|
|
997 | and sets errno to "ENOSYS". |
|
|
998 | |
|
|
999 | Note that the corresponding "munlock" is synchronous and is |
|
|
1000 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
1001 | |
|
|
1002 | Example: open a file, mmap and mlock it - both will be undone when |
|
|
1003 | $data gets destroyed. |
|
|
1004 | |
|
|
1005 | open my $fh, "<", $path or die "$path: $!"; |
|
|
1006 | my $data; |
|
|
1007 | IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh; |
|
|
1008 | aio_mlock $data; # mlock in background |
|
|
1009 | |
|
|
1010 | aio_mlockall $flags, $callback->($status) |
|
|
1011 | Calls the "mlockall" function with the given $flags (a combination |
|
|
1012 | of "IO::AIO::MCL_CURRENT" and "IO::AIO::MCL_FUTURE"). |
|
|
1013 | |
|
|
1014 | On systems that do not implement "mlockall", this function returns |
|
|
1015 | -1 and sets errno to "ENOSYS". |
|
|
1016 | |
|
|
1017 | Note that the corresponding "munlockall" is synchronous and is |
|
|
1018 | documented under "MISCELLANEOUS FUNCTIONS". |
|
|
1019 | |
|
|
1020 | Example: asynchronously lock all current and future pages into |
|
|
1021 | memory. |
|
|
1022 | |
|
|
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. |
710 | |
1072 | |
711 | aio_group $callback->(...) |
1073 | aio_group $callback->(...) |
712 | 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 |
713 | 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 |
714 | to bundle many requests into a single, composite, request with a |
1076 | to bundle many requests into a single, composite, request with a |
… | |
… | |
748 | While it is theoretically handy to have simple I/O scheduling |
1110 | While it is theoretically handy to have simple I/O scheduling |
749 | requests like sleep and file handle readable/writable, the overhead |
1111 | requests like sleep and file handle readable/writable, the overhead |
750 | 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 |
751 | not use this function except to put your application under |
1113 | not use this function except to put your application under |
752 | 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. |
753 | |
1233 | |
754 | IO::AIO::REQ CLASS |
1234 | IO::AIO::REQ CLASS |
755 | 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 |
756 | called in non-void context. |
1236 | called in non-void context. |
757 | |
1237 | |
… | |
… | |
857 | 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 |
858 | attached generator that generates requests if idle. The idea behind |
1338 | attached generator that generates requests if idle. The idea behind |
859 | 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 |
860 | 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 |
861 | long time. For example, "aio_scandir" might generate hundreds of |
1341 | long time. For example, "aio_scandir" might generate hundreds of |
862 | thousands "aio_stat" requests, delaying any later requests for a |
1342 | thousands of "aio_stat" requests, delaying any later requests for a |
863 | long time. |
1343 | long time. |
864 | |
1344 | |
865 | To avoid this, and allow incremental generation of requests, you can |
1345 | To avoid this, and allow incremental generation of requests, you can |
866 | 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 |
867 | requests. The feed callback will be called whenever there are few |
1347 | requests. The feed callback will be called whenever there are few |
… | |
… | |
909 | results. |
1389 | results. |
910 | |
1390 | |
911 | See "poll_cb" for an example. |
1391 | See "poll_cb" for an example. |
912 | |
1392 | |
913 | IO::AIO::poll_cb |
1393 | IO::AIO::poll_cb |
914 | 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 |
915 | this regularly. Returns 0 if all events could be processed, or -1 if |
1395 | have been executed but the results are not yet reported). You have |
916 | it returned earlier for whatever reason. Returns immediately when no |
1396 | to call this "regularly" to finish outstanding requests. |
917 | events are outstanding. The amount of events processed depends on |
|
|
918 | the settings of "IO::AIO::max_poll_req" and |
|
|
919 | "IO::AIO::max_poll_time". |
|
|
920 | |
1397 | |
|
|
1398 | Returns 0 if all events could be processed (or there were no events |
|
|
1399 | to process), or -1 if it returned earlier for whatever reason. |
|
|
1400 | Returns immediately when no events are outstanding. The amount of |
|
|
1401 | events processed depends on the settings of "IO::AIO::max_poll_req", |
|
|
1402 | "IO::AIO::max_poll_time" and "IO::AIO::max_outstanding". |
|
|
1403 | |
921 | If not all requests were processed for whatever reason, the |
1404 | If not all requests were processed for whatever reason, the poll |
922 | filehandle will still be ready when "poll_cb" returns, so normally |
1405 | file descriptor will still be ready when "poll_cb" returns, so |
923 | 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. |
|
|
1408 | |
|
|
1409 | Apart from calling "IO::AIO::poll_cb" when the event filehandle |
|
|
1410 | becomes ready, it can be beneficial to call this function from loops |
|
|
1411 | which submit a lot of requests, to make sure the results get |
|
|
1412 | processed when they become available and not just when the loop is |
|
|
1413 | finished and the event loop takes over again. This function returns |
|
|
1414 | very fast when there are no outstanding requests. |
924 | |
1415 | |
925 | Example: Install an Event watcher that automatically calls |
1416 | Example: Install an Event watcher that automatically calls |
926 | IO::AIO::poll_cb with high priority (more examples can be found in |
1417 | IO::AIO::poll_cb with high priority (more examples can be found in |
927 | the SYNOPSIS section, at the top of this document): |
1418 | the SYNOPSIS section, at the top of this document): |
928 | |
1419 | |
929 | Event->io (fd => IO::AIO::poll_fileno, |
1420 | Event->io (fd => IO::AIO::poll_fileno, |
930 | poll => 'r', async => 1, |
1421 | poll => 'r', async => 1, |
931 | cb => \&IO::AIO::poll_cb); |
1422 | cb => \&IO::AIO::poll_cb); |
|
|
1423 | |
|
|
1424 | IO::AIO::poll_wait |
|
|
1425 | Wait until either at least one request is in the result phase or no |
|
|
1426 | requests are outstanding anymore. |
|
|
1427 | |
|
|
1428 | This is useful if you want to synchronously wait for some requests |
|
|
1429 | to become ready, without actually handling them. |
|
|
1430 | |
|
|
1431 | See "nreqs" for an example. |
|
|
1432 | |
|
|
1433 | IO::AIO::poll |
|
|
1434 | Waits until some requests have been handled. |
|
|
1435 | |
|
|
1436 | Returns the number of requests processed, but is otherwise strictly |
|
|
1437 | equivalent to: |
|
|
1438 | |
|
|
1439 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1440 | |
|
|
1441 | IO::AIO::flush |
|
|
1442 | Wait till all outstanding AIO requests have been handled. |
|
|
1443 | |
|
|
1444 | Strictly equivalent to: |
|
|
1445 | |
|
|
1446 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
1447 | while IO::AIO::nreqs; |
932 | |
1448 | |
933 | IO::AIO::max_poll_reqs $nreqs |
1449 | IO::AIO::max_poll_reqs $nreqs |
934 | IO::AIO::max_poll_time $seconds |
1450 | IO::AIO::max_poll_time $seconds |
935 | These set the maximum number of requests (default 0, meaning |
1451 | These set the maximum number of requests (default 0, meaning |
936 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
1452 | infinity) that are being processed by "IO::AIO::poll_cb" in one |
… | |
… | |
960 | # use a low priority so other tasks have priority |
1476 | # use a low priority so other tasks have priority |
961 | Event->io (fd => IO::AIO::poll_fileno, |
1477 | Event->io (fd => IO::AIO::poll_fileno, |
962 | poll => 'r', nice => 1, |
1478 | poll => 'r', nice => 1, |
963 | cb => &IO::AIO::poll_cb); |
1479 | cb => &IO::AIO::poll_cb); |
964 | |
1480 | |
965 | IO::AIO::poll_wait |
|
|
966 | If there are any outstanding requests and none of them in the result |
|
|
967 | phase, wait till the result filehandle becomes ready for reading |
|
|
968 | (simply does a "select" on the filehandle. This is useful if you |
|
|
969 | want to synchronously wait for some requests to finish). |
|
|
970 | |
|
|
971 | See "nreqs" for an example. |
|
|
972 | |
|
|
973 | IO::AIO::poll |
|
|
974 | Waits until some requests have been handled. |
|
|
975 | |
|
|
976 | Returns the number of requests processed, but is otherwise strictly |
|
|
977 | equivalent to: |
|
|
978 | |
|
|
979 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
980 | |
|
|
981 | IO::AIO::flush |
|
|
982 | Wait till all outstanding AIO requests have been handled. |
|
|
983 | |
|
|
984 | Strictly equivalent to: |
|
|
985 | |
|
|
986 | IO::AIO::poll_wait, IO::AIO::poll_cb |
|
|
987 | while IO::AIO::nreqs; |
|
|
988 | |
|
|
989 | CONTROLLING THE NUMBER OF THREADS |
1481 | CONTROLLING THE NUMBER OF THREADS |
990 | IO::AIO::min_parallel $nthreads |
1482 | IO::AIO::min_parallel $nthreads |
991 | Set the minimum number of AIO threads to $nthreads. The current |
1483 | Set the minimum number of AIO threads to $nthreads. The current |
992 | default is 8, which means eight asynchronous operations can execute |
1484 | default is 8, which means eight asynchronous operations can execute |
993 | concurrently at any one time (the number of outstanding requests, |
1485 | concurrently at any one time (the number of outstanding requests, |
… | |
… | |
1022 | |
1514 | |
1023 | Under normal circumstances you don't need to call this function. |
1515 | Under normal circumstances you don't need to call this function. |
1024 | |
1516 | |
1025 | IO::AIO::max_idle $nthreads |
1517 | IO::AIO::max_idle $nthreads |
1026 | Limit the number of threads (default: 4) that are allowed to idle |
1518 | Limit the number of threads (default: 4) that are allowed to idle |
1027 | (i.e., threads that did not get a request to process within 10 |
1519 | (i.e., threads that did not get a request to process within the idle |
1028 | seconds). That means if a thread becomes idle while $nthreads other |
1520 | timeout (default: 10 seconds). That means if a thread becomes idle |
1029 | threads are also idle, it will free its resources and exit. |
1521 | while $nthreads other threads are also idle, it will free its |
|
|
1522 | resources and exit. |
1030 | |
1523 | |
1031 | This is useful when you allow a large number of threads (e.g. 100 or |
1524 | This is useful when you allow a large number of threads (e.g. 100 or |
1032 | 1000) to allow for extremely high load situations, but want to free |
1525 | 1000) to allow for extremely high load situations, but want to free |
1033 | resources under normal circumstances (1000 threads can easily |
1526 | resources under normal circumstances (1000 threads can easily |
1034 | consume 30MB of RAM). |
1527 | consume 30MB of RAM). |
1035 | |
1528 | |
1036 | The default is probably ok in most situations, especially if thread |
1529 | The default is probably ok in most situations, especially if thread |
1037 | creation is fast. If thread creation is very slow on your system you |
1530 | creation is fast. If thread creation is very slow on your system you |
1038 | might want to use larger values. |
1531 | might want to use larger values. |
1039 | |
1532 | |
|
|
1533 | IO::AIO::idle_timeout $seconds |
|
|
1534 | Sets the minimum idle timeout (default 10) after which worker |
|
|
1535 | threads are allowed to exit. SEe "IO::AIO::max_idle". |
|
|
1536 | |
1040 | IO::AIO::max_outstanding $maxreqs |
1537 | IO::AIO::max_outstanding $maxreqs |
|
|
1538 | Sets the maximum number of outstanding requests to $nreqs. If you do |
|
|
1539 | queue up more than this number of requests, the next call to |
|
|
1540 | "IO::AIO::poll_cb" (and other functions calling "poll_cb", such as |
|
|
1541 | "IO::AIO::flush" or "IO::AIO::poll") will block until the limit is |
|
|
1542 | no longer exceeded. |
|
|
1543 | |
|
|
1544 | In other words, this setting does not enforce a queue limit, but can |
|
|
1545 | be used to make poll functions block if the limit is exceeded. |
|
|
1546 | |
1041 | 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 |
1042 | 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 |
1043 | inexact: Better use an "aio_group" together with a feed callback. |
1549 | inexact: Better use an "aio_group" together with a feed callback. |
1044 | |
1550 | |
1045 | Sets the maximum number of outstanding requests to $nreqs. If you do |
1551 | Its main use is in scripts without an event loop - when you want to |
1046 | queue up more than this number of requests, the next call to the |
1552 | stat a lot of files, you can write somehting like this: |
1047 | "poll_cb" (and "poll_some" and other functions calling "poll_cb") |
|
|
1048 | function will block until the limit is no longer exceeded. |
|
|
1049 | |
1553 | |
1050 | The default value is very large, so there is no practical limit on |
1554 | IO::AIO::max_outstanding 32; |
|
|
1555 | |
|
|
1556 | for my $path (...) { |
|
|
1557 | aio_stat $path , ...; |
|
|
1558 | IO::AIO::poll_cb; |
|
|
1559 | } |
|
|
1560 | |
|
|
1561 | IO::AIO::flush; |
|
|
1562 | |
|
|
1563 | The call to "poll_cb" inside the loop will normally return |
|
|
1564 | instantly, but as soon as more thna 32 reqeusts are in-flight, it |
|
|
1565 | will block until some requests have been handled. This keeps the |
|
|
1566 | loop from pushing a large number of "aio_stat" requests onto the |
|
|
1567 | queue. |
|
|
1568 | |
|
|
1569 | The default value for "max_outstanding" is very large, so there is |
1051 | the number of outstanding requests. |
1570 | no practical limit on the number of outstanding requests. |
1052 | |
|
|
1053 | You can still queue as many requests as you want. Therefore, |
|
|
1054 | "max_outstanding" is mainly useful in simple scripts (with low |
|
|
1055 | values) or as a stop gap to shield against fatal memory overflow |
|
|
1056 | (with large values). |
|
|
1057 | |
1571 | |
1058 | STATISTICAL INFORMATION |
1572 | STATISTICAL INFORMATION |
1059 | IO::AIO::nreqs |
1573 | IO::AIO::nreqs |
1060 | Returns the number of requests currently in the ready, execute or |
1574 | Returns the number of requests currently in the ready, execute or |
1061 | pending states (i.e. for which their callback has not been invoked |
1575 | pending states (i.e. for which their callback has not been invoked |
… | |
… | |
1073 | IO::AIO::npending |
1587 | IO::AIO::npending |
1074 | Returns the number of requests currently in the pending state |
1588 | Returns the number of requests currently in the pending state |
1075 | (executed, but not yet processed by poll_cb). |
1589 | (executed, but not yet processed by poll_cb). |
1076 | |
1590 | |
1077 | MISCELLANEOUS FUNCTIONS |
1591 | MISCELLANEOUS FUNCTIONS |
1078 | 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 |
1079 | 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. |
1080 | |
1596 | |
1081 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1597 | IO::AIO::sendfile $ofh, $ifh, $offset, $count |
1082 | Calls the "eio_sendfile_sync" function, which is like |
1598 | Calls the "eio_sendfile_sync" function, which is like |
1083 | "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 |
1084 | 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 |
1085 | set to non-blocking operations). |
1601 | set to non-blocking operations). |
1086 | |
1602 | |
1087 | Returns the number of bytes copied, or -1 on error. |
1603 | Returns the number of bytes copied, or -1 on error. |
1088 | |
1604 | |
1089 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1605 | IO::AIO::fadvise $fh, $offset, $len, $advice |
1090 | Simply calls the "posix_fadvise" function (see it's manpage for |
1606 | Simply calls the "posix_fadvise" function (see its manpage for |
1091 | details). The following advice constants are avaiable: |
1607 | details). The following advice constants are available: |
1092 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1608 | "IO::AIO::FADV_NORMAL", "IO::AIO::FADV_SEQUENTIAL", |
1093 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1609 | "IO::AIO::FADV_RANDOM", "IO::AIO::FADV_NOREUSE", |
1094 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1610 | "IO::AIO::FADV_WILLNEED", "IO::AIO::FADV_DONTNEED". |
1095 | |
1611 | |
1096 | On systems that do not implement "posix_fadvise", this function |
1612 | On systems that do not implement "posix_fadvise", this function |
1097 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1613 | returns ENOSYS, otherwise the return value of "posix_fadvise". |
1098 | |
1614 | |
|
|
1615 | IO::AIO::madvise $scalar, $offset, $len, $advice |
|
|
1616 | Simply calls the "posix_madvise" function (see its manpage for |
|
|
1617 | details). The following advice constants are available: |
|
|
1618 | "IO::AIO::MADV_NORMAL", "IO::AIO::MADV_SEQUENTIAL", |
|
|
1619 | "IO::AIO::MADV_RANDOM", "IO::AIO::MADV_WILLNEED", |
|
|
1620 | "IO::AIO::MADV_DONTNEED". |
|
|
1621 | |
|
|
1622 | On systems that do not implement "posix_madvise", this function |
|
|
1623 | returns ENOSYS, otherwise the return value of "posix_madvise". |
|
|
1624 | |
|
|
1625 | IO::AIO::mprotect $scalar, $offset, $len, $protect |
|
|
1626 | Simply calls the "mprotect" function on the preferably AIO::mmap'ed |
|
|
1627 | $scalar (see its manpage for details). The following protect |
|
|
1628 | constants are available: "IO::AIO::PROT_NONE", "IO::AIO::PROT_READ", |
|
|
1629 | "IO::AIO::PROT_WRITE", "IO::AIO::PROT_EXEC". |
|
|
1630 | |
|
|
1631 | On systems that do not implement "mprotect", this function returns |
|
|
1632 | ENOSYS, otherwise the return value of "mprotect". |
|
|
1633 | |
|
|
1634 | IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] |
|
|
1635 | Memory-maps a file (or anonymous memory range) and attaches it to |
|
|
1636 | the given $scalar, which will act like a string scalar. Returns true |
|
|
1637 | on success, and false otherwise. |
|
|
1638 | |
|
|
1639 | The only operations allowed on the scalar are "substr"/"vec" that |
|
|
1640 | don't change the string length, and most read-only operations such |
|
|
1641 | as copying it or searching it with regexes and so on. |
|
|
1642 | |
|
|
1643 | Anything else is unsafe and will, at best, result in memory leaks. |
|
|
1644 | |
|
|
1645 | The memory map associated with the $scalar is automatically removed |
|
|
1646 | when the $scalar is destroyed, or when the "IO::AIO::mmap" or |
|
|
1647 | "IO::AIO::munmap" functions are called. |
|
|
1648 | |
|
|
1649 | This calls the "mmap"(2) function internally. See your system's |
|
|
1650 | manual page for details on the $length, $prot and $flags parameters. |
|
|
1651 | |
|
|
1652 | The $length must be larger than zero and smaller than the actual |
|
|
1653 | filesize. |
|
|
1654 | |
|
|
1655 | $prot is a combination of "IO::AIO::PROT_NONE", |
|
|
1656 | "IO::AIO::PROT_EXEC", "IO::AIO::PROT_READ" and/or |
|
|
1657 | "IO::AIO::PROT_WRITE", |
|
|
1658 | |
|
|
1659 | $flags can be a combination of "IO::AIO::MAP_SHARED" or |
|
|
1660 | "IO::AIO::MAP_PRIVATE", or a number of system-specific flags (when |
|
|
1661 | not available, the are 0): "IO::AIO::MAP_ANONYMOUS" (which is set to |
|
|
1662 | "MAP_ANON" if your system only provides this constant), |
|
|
1663 | "IO::AIO::MAP_LOCKED", "IO::AIO::MAP_NORESERVE", |
|
|
1664 | "IO::AIO::MAP_POPULATE", "IO::AIO::MAP_NONBLOCK", |
|
|
1665 | "IO::AIO::MAP_FIXED", "IO::AIO::MAP_GROWSDOWN", |
|
|
1666 | "IO::AIO::MAP_32BIT", "IO::AIO::MAP_HUGETLB" or |
|
|
1667 | "IO::AIO::MAP_STACK". |
|
|
1668 | |
|
|
1669 | If $fh is "undef", then a file descriptor of -1 is passed. |
|
|
1670 | |
|
|
1671 | $offset is the offset from the start of the file - it generally must |
|
|
1672 | be a multiple of "IO::AIO::PAGESIZE" and defaults to 0. |
|
|
1673 | |
|
|
1674 | Example: |
|
|
1675 | |
|
|
1676 | use Digest::MD5; |
|
|
1677 | use IO::AIO; |
|
|
1678 | |
|
|
1679 | open my $fh, "<verybigfile" |
|
|
1680 | or die "$!"; |
|
|
1681 | |
|
|
1682 | IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh |
|
|
1683 | or die "verybigfile: $!"; |
|
|
1684 | |
|
|
1685 | my $fast_md5 = md5 $data; |
|
|
1686 | |
|
|
1687 | IO::AIO::munmap $scalar |
|
|
1688 | Removes a previous mmap and undefines the $scalar. |
|
|
1689 | |
|
|
1690 | IO::AIO::munlock $scalar, $offset = 0, $length = undef |
|
|
1691 | Calls the "munlock" function, undoing the effects of a previous |
|
|
1692 | "aio_mlock" call (see its description for details). |
|
|
1693 | |
|
|
1694 | IO::AIO::munlockall |
|
|
1695 | Calls the "munlockall" function. |
|
|
1696 | |
|
|
1697 | On systems that do not implement "munlockall", this function returns |
|
|
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. |
|
|
1743 | |
|
|
1744 | EVENT LOOP INTEGRATION |
|
|
1745 | It is recommended to use AnyEvent::AIO to integrate IO::AIO |
|
|
1746 | automatically into many event loops: |
|
|
1747 | |
|
|
1748 | # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...) |
|
|
1749 | use AnyEvent::AIO; |
|
|
1750 | |
|
|
1751 | You can also integrate IO::AIO manually into many event loops, here are |
|
|
1752 | some examples of how to do this: |
|
|
1753 | |
|
|
1754 | # EV integration |
|
|
1755 | my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; |
|
|
1756 | |
|
|
1757 | # Event integration |
|
|
1758 | Event->io (fd => IO::AIO::poll_fileno, |
|
|
1759 | poll => 'r', |
|
|
1760 | cb => \&IO::AIO::poll_cb); |
|
|
1761 | |
|
|
1762 | # Glib/Gtk2 integration |
|
|
1763 | add_watch Glib::IO IO::AIO::poll_fileno, |
|
|
1764 | in => sub { IO::AIO::poll_cb; 1 }; |
|
|
1765 | |
|
|
1766 | # Tk integration |
|
|
1767 | Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "", |
|
|
1768 | readable => \&IO::AIO::poll_cb); |
|
|
1769 | |
|
|
1770 | # Danga::Socket integration |
|
|
1771 | Danga::Socket->AddOtherFds (IO::AIO::poll_fileno => |
|
|
1772 | \&IO::AIO::poll_cb); |
|
|
1773 | |
1099 | FORK BEHAVIOUR |
1774 | FORK BEHAVIOUR |
1100 | This module should do "the right thing" when the process using it forks: |
1775 | Usage of pthreads in a program changes the semantics of fork |
|
|
1776 | considerably. Specifically, only async-safe functions can be called |
|
|
1777 | after fork. Perl doesn't know about this, so in general, you cannot call |
|
|
1778 | fork with defined behaviour in perl if pthreads are involved. IO::AIO |
|
|
1779 | uses pthreads, so this applies, but many other extensions and (for |
|
|
1780 | inexplicable reasons) perl itself often is linked against pthreads, so |
|
|
1781 | this limitation applies to quite a lot of perls. |
1101 | |
1782 | |
1102 | Before the fork, IO::AIO enters a quiescent state where no requests can |
1783 | This module no longer tries to fight your OS, or POSIX. That means |
1103 | be added in other threads and no results will be processed. After the |
1784 | IO::AIO only works in the process that loaded it. Forking is fully |
1104 | fork the parent simply leaves the quiescent state and continues |
1785 | supported, but using IO::AIO in the child is not. |
1105 | request/result processing, while the child frees the request/result |
|
|
1106 | queue (so that the requests started before the fork will only be handled |
|
|
1107 | in the parent). Threads will be started on demand until the limit set in |
|
|
1108 | the parent process has been reached again. |
|
|
1109 | |
1786 | |
1110 | In short: the parent will, after a short pause, continue as if fork had |
1787 | You might get around by not *using* IO::AIO before (or after) forking. |
1111 | not been called, while the child will act as if IO::AIO has not been |
1788 | You could also try to call the IO::AIO::reinit function in the child: |
1112 | used yet. |
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. |
1113 | |
1801 | |
1114 | MEMORY USAGE |
1802 | MEMORY USAGE |
1115 | Per-request usage: |
1803 | Per-request usage: |
1116 | |
1804 | |
1117 | Each aio request uses - depending on your architecture - around 100-200 |
1805 | Each aio request uses - depending on your architecture - around 100-200 |