| … | |
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| 2 | |
2 | |
| 3 | AnyEvent::Fork::RPC - simple RPC extension for AnyEvent::Fork |
3 | AnyEvent::Fork::RPC - simple RPC extension for AnyEvent::Fork |
| 4 | |
4 | |
| 5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
| 6 | |
6 | |
| 7 | use AnyEvent::Fork; |
|
|
| 8 | use AnyEvent::Fork::RPC; |
7 | use AnyEvent::Fork::RPC; |
|
|
8 | # use AnyEvent::Fork is not needed |
| 9 | |
9 | |
| 10 | my $rpc = AnyEvent::Fork |
10 | my $rpc = AnyEvent::Fork |
| 11 | ->new |
11 | ->new |
| 12 | ->require ("MyModule") |
12 | ->require ("MyModule") |
| 13 | ->AnyEvent::Fork::RPC::run ( |
13 | ->AnyEvent::Fork::RPC::run ( |
| … | |
… | |
| 33 | normal function call, and an asynchronous one that can run multiple jobs |
33 | normal function call, and an asynchronous one that can run multiple jobs |
| 34 | concurrently in the child, using AnyEvent. |
34 | concurrently in the child, using AnyEvent. |
| 35 | |
35 | |
| 36 | It also implements an asynchronous event mechanism from the child to the |
36 | It also implements an asynchronous event mechanism from the child to the |
| 37 | parent, that could be used for progress indications or other information. |
37 | parent, that could be used for progress indications or other information. |
|
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38 | |
|
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39 | Loading this module also always loads L<AnyEvent::Fork>, so you can make a |
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40 | separate C<use AnyEvent::Fork> if you wish, but you don't have to. |
| 38 | |
41 | |
| 39 | =head1 EXAMPLES |
42 | =head1 EXAMPLES |
| 40 | |
43 | |
| 41 | =head2 Synchronous Backend |
44 | =head2 Synchronous Backend |
| 42 | |
45 | |
| … | |
… | |
| 103 | dies with a fatal error - obviously, you must never let this happen :). |
106 | dies with a fatal error - obviously, you must never let this happen :). |
| 104 | |
107 | |
| 105 | Eventually it returns the status value true if the command was successful, |
108 | Eventually it returns the status value true if the command was successful, |
| 106 | or the status value 0 and the stringified error message. |
109 | or the status value 0 and the stringified error message. |
| 107 | |
110 | |
| 108 | On my system, running the first cdoe fragment with the given |
111 | On my system, running the first code fragment with the given |
| 109 | F<MyWorker.pm> in the current directory yields: |
112 | F<MyWorker.pm> in the current directory yields: |
| 110 | |
113 | |
| 111 | /tmp/somepath/1: No such file or directory |
114 | /tmp/somepath/1: No such file or directory |
| 112 | /tmp/somepath/2: No such file or directory |
115 | /tmp/somepath/2: No such file or directory |
| 113 | 3 requests handled |
116 | 3 requests handled |
| … | |
… | |
| 150 | |
153 | |
| 151 | use Errno (); |
154 | use Errno (); |
| 152 | use Guard (); |
155 | use Guard (); |
| 153 | |
156 | |
| 154 | use AnyEvent; |
157 | use AnyEvent; |
| 155 | #use AnyEvent::Fork; |
158 | use AnyEvent::Fork; # we don't actually depend on it, this is for convenience |
| 156 | |
159 | |
| 157 | our $VERSION = 0.1; |
160 | our $VERSION = 0.1; |
| 158 | |
161 | |
| 159 | =item my $rpc = AnyEvent::Fork::RPC::run $fork, $function, [key => value...] |
162 | =item my $rpc = AnyEvent::Fork::RPC::run $fork, $function, [key => value...] |
| 160 | |
163 | |
| … | |
… | |
| 198 | |
201 | |
| 199 | Called when the C<$rpc> object has been destroyed and all requests have |
202 | Called when the C<$rpc> object has been destroyed and all requests have |
| 200 | been successfully handled. This is useful when you queue some requests and |
203 | been successfully handled. This is useful when you queue some requests and |
| 201 | want the child to go away after it has handled them. The problem is that |
204 | want the child to go away after it has handled them. The problem is that |
| 202 | the parent must not exit either until all requests have been handled, and |
205 | the parent must not exit either until all requests have been handled, and |
| 203 | this cna be accomplished by waiting for this callback. |
206 | this can be accomplished by waiting for this callback. |
| 204 | |
207 | |
| 205 | =item init => $function (default none) |
208 | =item init => $function (default none) |
| 206 | |
209 | |
| 207 | When specified (by name), this function is called in the child as the very |
210 | When specified (by name), this function is called in the child as the very |
| 208 | first thing when taking over the process, with all the arguments normally |
211 | first thing when taking over the process, with all the arguments normally |
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| 231 | If you want to pre-load the actual back-end modules to enable memory |
234 | If you want to pre-load the actual back-end modules to enable memory |
| 232 | sharing, then you should load C<AnyEvent::Fork::RPC::Sync> for |
235 | sharing, then you should load C<AnyEvent::Fork::RPC::Sync> for |
| 233 | synchronous, and C<AnyEvent::Fork::RPC::Async> for asynchronous mode. |
236 | synchronous, and C<AnyEvent::Fork::RPC::Async> for asynchronous mode. |
| 234 | |
237 | |
| 235 | If you use a template process and want to fork both sync and async |
238 | If you use a template process and want to fork both sync and async |
| 236 | children, then it is permissible to laod both modules. |
239 | children, then it is permissible to load both modules. |
| 237 | |
240 | |
| 238 | =item serialiser => $string (default: '(sub { pack "(w/a*)*", @_ }, sub { unpack "(w/a*)*", shift })') |
241 | =item serialiser => $string (default: '(sub { pack "(w/a*)*", @_ }, sub { unpack "(w/a*)*", shift })') |
| 239 | |
242 | |
| 240 | All arguments, result data and event data have to be serialised to be |
243 | All arguments, result data and event data have to be serialised to be |
| 241 | transferred between the processes. For this, they have to be frozen and |
244 | transferred between the processes. For this, they have to be frozen and |
| … | |
… | |
| 253 | If you need an external module for serialisation, then you can either |
256 | If you need an external module for serialisation, then you can either |
| 254 | pre-load it into your L<AnyEvent::Fork> process, or you can add a C<use> |
257 | pre-load it into your L<AnyEvent::Fork> process, or you can add a C<use> |
| 255 | or C<require> statement into the serialiser string. Or both. |
258 | or C<require> statement into the serialiser string. Or both. |
| 256 | |
259 | |
| 257 | =back |
260 | =back |
|
|
261 | |
|
|
262 | See the examples section earlier in this document for some actual |
|
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263 | examples. |
| 258 | |
264 | |
| 259 | =cut |
265 | =cut |
| 260 | |
266 | |
| 261 | our $STRING_SERIALISER = '(sub { pack "(w/a*)*", @_ }, sub { unpack "(w/a*)*", shift })'; |
267 | our $STRING_SERIALISER = '(sub { pack "(w/a*)*", @_ }, sub { unpack "(w/a*)*", shift })'; |
| 262 | |
268 | |
| … | |
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| 276 | # default for on_event is to raise an error |
282 | # default for on_event is to raise an error |
| 277 | $on_event ||= sub { $on_error->("event received, but no on_event handler") }; |
283 | $on_event ||= sub { $on_error->("event received, but no on_event handler") }; |
| 278 | |
284 | |
| 279 | my ($f, $t) = eval $serialiser; die $@ if $@; |
285 | my ($f, $t) = eval $serialiser; die $@ if $@; |
| 280 | |
286 | |
| 281 | my (@rcb, $fh, $shutdown, $wbuf, $ww, $rw); |
287 | my (@rcb, %rcb, $fh, $shutdown, $wbuf, $ww); |
| 282 | my ($rlen, $rbuf) = 512 - 16; |
288 | my ($rlen, $rbuf, $rw) = 512 - 16; |
| 283 | |
289 | |
| 284 | my $wcb = sub { |
290 | my $wcb = sub { |
| 285 | my $len = syswrite $fh, $wbuf; |
291 | my $len = syswrite $fh, $wbuf; |
| 286 | |
292 | |
| 287 | if (!defined $len) { |
293 | unless (defined $len) { |
| 288 | if ($! != Errno::EAGAIN && $! != Errno::EWOULDBLOCK) { |
294 | if ($! != Errno::EAGAIN && $! != Errno::EWOULDBLOCK) { |
| 289 | undef $rw; undef $ww; # it ends here |
295 | undef $rw; undef $ww; # it ends here |
| 290 | $on_error->("$!"); |
296 | $on_error->("$!"); |
| 291 | } |
297 | } |
| 292 | } |
298 | } |
| … | |
… | |
| 303 | |
309 | |
| 304 | $self->require ($module) |
310 | $self->require ($module) |
| 305 | ->send_arg ($function, $arg{init}, $serialiser) |
311 | ->send_arg ($function, $arg{init}, $serialiser) |
| 306 | ->run ("$module\::run", sub { |
312 | ->run ("$module\::run", sub { |
| 307 | $fh = shift; |
313 | $fh = shift; |
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314 | |
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315 | my ($id, $len); |
| 308 | $rw = AE::io $fh, 0, sub { |
316 | $rw = AE::io $fh, 0, sub { |
| 309 | $rlen = $rlen * 2 + 16 if $rlen - 128 < length $rbuf; |
317 | $rlen = $rlen * 2 + 16 if $rlen - 128 < length $rbuf; |
| 310 | my $len = sysread $fh, $rbuf, $rlen - length $rbuf, length $rbuf; |
318 | $len = sysread $fh, $rbuf, $rlen - length $rbuf, length $rbuf; |
| 311 | |
319 | |
| 312 | if ($len) { |
320 | if ($len) { |
| 313 | while (5 <= length $rbuf) { |
321 | while (8 <= length $rbuf) { |
| 314 | $len = unpack "L", $rbuf; |
322 | ($id, $len) = unpack "LL", $rbuf; |
| 315 | 4 + $len <= length $rbuf |
323 | 8 + $len <= length $rbuf |
| 316 | or last; |
324 | or last; |
| 317 | |
325 | |
| 318 | my @r = $t->(substr $rbuf, 4, $len); |
326 | my @r = $t->(substr $rbuf, 8, $len); |
| 319 | substr $rbuf, 0, $len + 4, ""; |
327 | substr $rbuf, 0, 8 + $len, ""; |
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328 | |
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329 | if ($id) { |
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330 | if (@rcb) { |
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331 | (shift @rcb)->(@r); |
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332 | } elsif (my $cb = delete $rcb{$id}) { |
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333 | $cb->(@r); |
|
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334 | } else { |
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335 | undef $rw; undef $ww; |
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336 | $on_error->("unexpected data from child"); |
| 320 | |
337 | } |
| 321 | if (pop @r) { |
338 | } else { |
| 322 | $on_event->(@r); |
339 | $on_event->(@r); |
| 323 | } elsif (@rcb) { |
|
|
| 324 | (shift @rcb)->(@r); |
|
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| 325 | } else { |
|
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| 326 | undef $rw; undef $ww; |
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| 327 | $on_error->("unexpected data from child"); |
|
|
| 328 | } |
340 | } |
| 329 | } |
341 | } |
| 330 | } elsif (defined $len) { |
342 | } elsif (defined $len) { |
| 331 | undef $rw; undef $ww; # it ends here |
343 | undef $rw; undef $ww; # it ends here |
| 332 | |
344 | |
| 333 | if (@rcb) { |
345 | if (@rcb || %rcb) { |
|
|
346 | use Data::Dump;ddx[\@rcb,\%rcb];#d# |
| 334 | $on_error->("unexpected eof"); |
347 | $on_error->("unexpected eof"); |
| 335 | } else { |
348 | } else { |
| 336 | $on_destroy->(); |
349 | $on_destroy->(); |
| 337 | } |
350 | } |
| 338 | } elsif ($! != Errno::EAGAIN && $! != Errno::EWOULDBLOCK) { |
351 | } elsif ($! != Errno::EAGAIN && $! != Errno::EWOULDBLOCK) { |
| … | |
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| 347 | my $guard = Guard::guard { |
360 | my $guard = Guard::guard { |
| 348 | $shutdown = 1; |
361 | $shutdown = 1; |
| 349 | $ww ||= $fh && AE::io $fh, 1, $wcb; |
362 | $ww ||= $fh && AE::io $fh, 1, $wcb; |
| 350 | }; |
363 | }; |
| 351 | |
364 | |
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365 | my $id; |
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366 | |
|
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367 | $arg{async} |
| 352 | sub { |
368 | ? sub { |
| 353 | push @rcb, pop; |
369 | $id = ($id == 0xffffffff ? 0 : $id) + 1; |
|
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370 | $id = ($id == 0xffffffff ? 0 : $id) + 1 while exists $rcb{$id}; # rarely loops |
| 354 | |
371 | |
|
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372 | $rcb{$id} = pop; |
|
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373 | |
| 355 | $guard; # keep it alive |
374 | $guard; # keep it alive |
| 356 | |
375 | |
| 357 | $wbuf .= pack "L/a*", &$f; |
376 | $wbuf .= pack "LL/a*", $id, &$f; |
| 358 | $ww ||= $fh && AE::io $fh, 1, $wcb; |
377 | $ww ||= $fh && AE::io $fh, 1, $wcb; |
| 359 | } |
378 | } |
|
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379 | : sub { |
|
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380 | push @rcb, pop; |
|
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381 | |
|
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382 | $guard; # keep it alive |
|
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383 | |
|
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384 | $wbuf .= pack "L/a*", &$f; |
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385 | $ww ||= $fh && AE::io $fh, 1, $wcb; |
|
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386 | } |
| 360 | } |
387 | } |
| 361 | |
388 | |
| 362 | =item $rpc->(..., $cb->(...)) |
389 | =item $rpc->(..., $cb->(...)) |
| 363 | |
390 | |
| 364 | The RPC object returned by C<AnyEvent::Fork::RPC::run> is actually a code |
391 | The RPC object returned by C<AnyEvent::Fork::RPC::run> is actually a code |
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| 379 | |
406 | |
| 380 | The other thing that can be done with the RPC object is to destroy it. In |
407 | The other thing that can be done with the RPC object is to destroy it. In |
| 381 | this case, the child process will execute all remaining RPC calls, report |
408 | this case, the child process will execute all remaining RPC calls, report |
| 382 | their results, and then exit. |
409 | their results, and then exit. |
| 383 | |
410 | |
|
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411 | See the examples section earlier in this document for some actual |
|
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412 | examples. |
|
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413 | |
| 384 | =back |
414 | =back |
| 385 | |
415 | |
| 386 | =head1 CHILD PROCESS USAGE |
416 | =head1 CHILD PROCESS USAGE |
| 387 | |
417 | |
| 388 | The following function is not available in this module. They are only |
418 | The following function is not available in this module. They are only |
| … | |
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| 396 | |
426 | |
| 397 | Send an event to the parent. Events are a bit like RPC calls made by the |
427 | Send an event to the parent. Events are a bit like RPC calls made by the |
| 398 | child process to the parent, except that there is no notion of return |
428 | child process to the parent, except that there is no notion of return |
| 399 | values. |
429 | values. |
| 400 | |
430 | |
|
|
431 | See the examples section earlier in this document for some actual |
|
|
432 | examples. |
|
|
433 | |
| 401 | =back |
434 | =back |
| 402 | |
435 | |
| 403 | =head1 SEE ALSO |
436 | =head1 SEE ALSO |
| 404 | |
437 | |
| 405 | L<AnyEvent::Fork> (to create the processes in the first place), |
438 | L<AnyEvent::Fork> (to create the processes in the first place), |
