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Revision 1.288 by root, Mon Feb 21 13:38:02 2011 UTC vs.
Revision 1.337 by root, Sun Oct 4 13:10:22 2015 UTC

16 cede; # yield to coro 16 cede; # yield to coro
17 print "3\n"; 17 print "3\n";
18 cede; # and again 18 cede; # and again
19 19
20 # use locking 20 # use locking
21 use Coro::Semaphore;
22 my $lock = new Coro::Semaphore; 21 my $lock = new Coro::Semaphore;
23 my $locked; 22 my $locked;
24 23
25 $lock->down; 24 $lock->down;
26 $locked = 1; 25 $locked = 1;
90 } 1, 2, 3; 89 } 1, 2, 3;
91 90
92This creates a new coro thread and puts it into the ready queue, meaning 91This creates a new coro thread and puts it into the ready queue, meaning
93it will run as soon as the CPU is free for it. 92it will run as soon as the CPU is free for it.
94 93
95C<async> will return a coro object - you can store this for future 94C<async> will return a Coro object - you can store this for future
96reference or ignore it, the thread itself will keep a reference to it's 95reference or ignore it - a thread that is running, ready to run or waiting
97thread object - threads are alive on their own. 96for some event is alive on it's own.
98 97
99Another way to create a thread is to call the C<new> constructor with a 98Another way to create a thread is to call the C<new> constructor with a
100code-reference: 99code-reference:
101 100
102 new Coro sub { 101 new Coro sub {
131A lot can happen after the coro thread has started running. Quite usually, 130A lot can happen after the coro thread has started running. Quite usually,
132it will not run to the end in one go (because you could use a function 131it will not run to the end in one go (because you could use a function
133instead), but it will give up the CPU regularly because it waits for 132instead), but it will give up the CPU regularly because it waits for
134external events. 133external events.
135 134
136As long as a coro thread runs, it's coro object is available in the global 135As long as a coro thread runs, its Coro object is available in the global
137variable C<$Coro::current>. 136variable C<$Coro::current>.
138 137
139The low-level way to give up the CPU is to call the scheduler, which 138The low-level way to give up the CPU is to call the scheduler, which
140selects a new coro thread to run: 139selects a new coro thread to run:
141 140
196 195
197 async { 196 async {
198 Coro::terminate "return value 1", "return value 2"; 197 Coro::terminate "return value 1", "return value 2";
199 }; 198 };
200 199
201And yet another way is to C<< ->cancel >> the coro thread from another 200Yet another way is to C<< ->cancel >> (or C<< ->safe_cancel >>) the coro
202thread: 201thread from another thread:
203 202
204 my $coro = async { 203 my $coro = async {
205 exit 1; 204 exit 1;
206 }; 205 };
207 206
208 $coro->cancel; # an also accept values for ->join to retrieve 207 $coro->cancel; # also accepts values for ->join to retrieve
209 208
210Cancellation I<can> be dangerous - it's a bit like calling C<exit> without 209Cancellation I<can> be dangerous - it's a bit like calling C<exit> without
211actually exiting, and might leave C libraries and XS modules in a weird 210actually exiting, and might leave C libraries and XS modules in a weird
212state. Unlike other thread implementations, however, Coro is exceptionally 211state. Unlike other thread implementations, however, Coro is exceptionally
213safe with regards to cancellation, as perl will always be in a consistent 212safe with regards to cancellation, as perl will always be in a consistent
214state. 213state, and for those cases where you want to do truly marvellous things
214with your coro while it is being cancelled - that is, make sure all
215cleanup code is executed from the thread being cancelled - there is even a
216C<< ->safe_cancel >> method.
215 217
216So, cancelling a thread that runs in an XS event loop might not be the 218So, cancelling a thread that runs in an XS event loop might not be the
217best idea, but any other combination that deals with perl only (cancelling 219best idea, but any other combination that deals with perl only (cancelling
218when a thread is in a C<tie> method or an C<AUTOLOAD> for example) is 220when a thread is in a C<tie> method or an C<AUTOLOAD> for example) is
219safe. 221safe.
220 222
223Last not least, a coro thread object that isn't referenced is C<<
224->cancel >>'ed automatically - just like other objects in Perl. This
225is not such a common case, however - a running thread is referencedy by
226C<$Coro::current>, a thread ready to run is referenced by the ready queue,
227a thread waiting on a lock or semaphore is referenced by being in some
228wait list and so on. But a thread that isn't in any of those queues gets
229cancelled:
230
231 async {
232 schedule; # cede to other coros, don't go into the ready queue
233 };
234
235 cede;
236 # now the async above is destroyed, as it is not referenced by anything.
237
238A slightly embellished example might make it clearer:
239
240 async {
241 my $guard = Guard::guard { print "destroyed\n" };
242 schedule while 1;
243 };
244
245 cede;
246
247Superficially one might not expect any output - since the C<async>
248implements an endless loop, the C<$guard> will not be cleaned up. However,
249since the thread object returned by C<async> is not stored anywhere, the
250thread is initially referenced because it is in the ready queue, when it
251runs it is referenced by C<$Coro::current>, but when it calls C<schedule>,
252it gets C<cancel>ed causing the guard object to be destroyed (see the next
253section), and printing it's message.
254
255If this seems a bit drastic, remember that this only happens when nothing
256references the thread anymore, which means there is no way to further
257execute it, ever. The only options at this point are leaking the thread,
258or cleaning it up, which brings us to...
259
221=item 5. Cleanup 260=item 5. Cleanup
222 261
223Threads will allocate various resources. Most but not all will be returned 262Threads will allocate various resources. Most but not all will be returned
224when a thread terminates, during clean-up. 263when a thread terminates, during clean-up.
225 264
243 282
244 my $sem = new Coro::Semaphore; 283 my $sem = new Coro::Semaphore;
245 284
246 async { 285 async {
247 my $lock_guard = $sem->guard; 286 my $lock_guard = $sem->guard;
248 # if we reutrn, or die or get cancelled, here, 287 # if we return, or die or get cancelled, here,
249 # then the semaphore will be "up"ed. 288 # then the semaphore will be "up"ed.
250 }; 289 };
251 290
252The C<Guard::guard> function comes in handy for any custom cleanup you 291The C<Guard::guard> function comes in handy for any custom cleanup you
253might want to do: 292might want to do (but you cannot switch to other coroutines from those
293code blocks):
254 294
255 async { 295 async {
256 my $window = new Gtk2::Window "toplevel"; 296 my $window = new Gtk2::Window "toplevel";
257 # The window will not be cleaned up automatically, even when $window 297 # The window will not be cleaned up automatically, even when $window
258 # gets freed, so use a guard to ensure it's destruction 298 # gets freed, so use a guard to ensure it's destruction
271 # if we return or die here, the description will be restored 311 # if we return or die here, the description will be restored
272 } 312 }
273 313
274=item 6. Viva La Zombie Muerte 314=item 6. Viva La Zombie Muerte
275 315
276Even after a thread has terminated and cleaned up it's resources, the coro 316Even after a thread has terminated and cleaned up its resources, the Coro
277object still is there and stores the return values of the thread. Only in 317object still is there and stores the return values of the thread.
278this state will the coro object be "reference counted" in the normal perl
279sense: the thread code keeps a reference to it when it is active, but not
280after it has terminated.
281 318
282The means the coro object gets freed automatically when the thread has 319When there are no other references, it will simply be cleaned up and
283terminated and cleaned up and there arenot other references. 320freed.
284 321
285If there are, the coro object will stay around, and you can call C<< 322If there areany references, the Coro object will stay around, and you
286->join >> as many times as you wish to retrieve the result values: 323can call C<< ->join >> as many times as you wish to retrieve the result
324values:
287 325
288 async { 326 async {
289 print "hi\n"; 327 print "hi\n";
290 1 328 1
291 }; 329 };
328 366
329our $idle; # idle handler 367our $idle; # idle handler
330our $main; # main coro 368our $main; # main coro
331our $current; # current coro 369our $current; # current coro
332 370
333our $VERSION = 5.371; 371our $VERSION = 6.48;
334 372
335our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub rouse_cb rouse_wait); 373our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub rouse_cb rouse_wait);
336our %EXPORT_TAGS = ( 374our %EXPORT_TAGS = (
337 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)], 375 prio => [qw(PRIO_MAX PRIO_HIGH PRIO_NORMAL PRIO_LOW PRIO_IDLE PRIO_MIN)],
338); 376);
343=over 4 381=over 4
344 382
345=item $Coro::main 383=item $Coro::main
346 384
347This variable stores the Coro object that represents the main 385This variable stores the Coro object that represents the main
348program. While you cna C<ready> it and do most other things you can do to 386program. While you can C<ready> it and do most other things you can do to
349coro, it is mainly useful to compare again C<$Coro::current>, to see 387coro, it is mainly useful to compare again C<$Coro::current>, to see
350whether you are running in the main program or not. 388whether you are running in the main program or not.
351 389
352=cut 390=cut
353 391
399our @destroy; 437our @destroy;
400our $manager; 438our $manager;
401 439
402$manager = new Coro sub { 440$manager = new Coro sub {
403 while () { 441 while () {
404 Coro::State::cancel shift @destroy 442 _destroy shift @destroy
405 while @destroy; 443 while @destroy;
406 444
407 &schedule; 445 &schedule;
408 } 446 }
409}; 447};
543coro, regardless of priority. This is useful sometimes to ensure 581coro, regardless of priority. This is useful sometimes to ensure
544progress is made. 582progress is made.
545 583
546=item terminate [arg...] 584=item terminate [arg...]
547 585
548Terminates the current coro with the given status values (see L<cancel>). 586Terminates the current coro with the given status values (see
587L<cancel>). The values will not be copied, but referenced directly.
549 588
550=item Coro::on_enter BLOCK, Coro::on_leave BLOCK 589=item Coro::on_enter BLOCK, Coro::on_leave BLOCK
551 590
552These function install enter and leave winders in the current scope. The 591These function install enter and leave winders in the current scope. The
553enter block will be executed when on_enter is called and whenever the 592enter block will be executed when on_enter is called and whenever the
613 Coro::on_enter { 652 Coro::on_enter {
614 # on entering the thread, we set an VTALRM handler to cede 653 # on entering the thread, we set an VTALRM handler to cede
615 $SIG{VTALRM} = sub { cede }; 654 $SIG{VTALRM} = sub { cede };
616 # and then start the interval timer 655 # and then start the interval timer
617 Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0.01, 0.01; 656 Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0.01, 0.01;
618 }; 657 };
619 Coro::on_leave { 658 Coro::on_leave {
620 # on leaving the thread, we stop the interval timer again 659 # on leaving the thread, we stop the interval timer again
621 Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0, 0; 660 Time::HiRes::setitimer &Time::HiRes::ITIMER_VIRTUAL, 0, 0;
622 }; 661 };
623 662
624 &{+shift}; 663 &{+shift};
625 } 664 }
626 665
627 # use like this: 666 # use like this:
628 timeslice { 667 timeslice {
629 # The following is an endless loop that would normally 668 # The following is an endless loop that would normally
630 # monopolise the process. Since it runs in a timesliced 669 # monopolise the process. Since it runs in a timesliced
631 # environment, it will regularly cede to other threads. 670 # environment, it will regularly cede to other threads.
632 while () { } 671 while () { }
633 }; 672 };
634 673
635 674
636=item killall 675=item killall
637 676
638Kills/terminates/cancels all coros except the currently running one. 677Kills/terminates/cancels all coros except the currently running one.
709To avoid this, it is best to put a suspended coro into the ready queue 748To avoid this, it is best to put a suspended coro into the ready queue
710unconditionally, as every synchronisation mechanism must protect itself 749unconditionally, as every synchronisation mechanism must protect itself
711against spurious wakeups, and the one in the Coro family certainly do 750against spurious wakeups, and the one in the Coro family certainly do
712that. 751that.
713 752
753=item $state->is_new
754
755Returns true iff this Coro object is "new", i.e. has never been run
756yet. Those states basically consist of only the code reference to call and
757the arguments, but consumes very little other resources. New states will
758automatically get assigned a perl interpreter when they are transfered to.
759
760=item $state->is_zombie
761
762Returns true iff the Coro object has been cancelled, i.e.
763it's resources freed because they were C<cancel>'ed, C<terminate>'d,
764C<safe_cancel>'ed or simply went out of scope.
765
766The name "zombie" stems from UNIX culture, where a process that has
767exited and only stores and exit status and no other resources is called a
768"zombie".
769
714=item $is_ready = $coro->is_ready 770=item $is_ready = $coro->is_ready
715 771
716Returns true iff the Coro object is in the ready queue. Unless the Coro 772Returns true iff the Coro object is in the ready queue. Unless the Coro
717object gets destroyed, it will eventually be scheduled by the scheduler. 773object gets destroyed, it will eventually be scheduled by the scheduler.
718 774
727Returns true iff this Coro object has been suspended. Suspended Coros will 783Returns true iff this Coro object has been suspended. Suspended Coros will
728not ever be scheduled. 784not ever be scheduled.
729 785
730=item $coro->cancel (arg...) 786=item $coro->cancel (arg...)
731 787
732Terminates the given Coro and makes it return the given arguments as 788Terminates the given Coro thread and makes it return the given arguments as
733status (default: the empty list). Never returns if the Coro is the 789status (default: an empty list). Never returns if the Coro is the
734current Coro. 790current Coro.
735 791
736=cut 792This is a rather brutal way to free a coro, with some limitations - if
793the thread is inside a C callback that doesn't expect to be canceled,
794bad things can happen, or if the cancelled thread insists on running
795complicated cleanup handlers that rely on its thread context, things will
796not work.
737 797
738sub cancel { 798Any cleanup code being run (e.g. from C<guard> blocks, destructors and so
739 my $self = shift; 799on) will be run without a thread context, and is not allowed to switch
800to other threads. A common mistake is to call C<< ->cancel >> from a
801destructor called by die'ing inside the thread to be cancelled for
802example.
740 803
741 if ($current == $self) { 804On the plus side, C<< ->cancel >> will always clean up the thread, no
742 terminate @_; 805matter what. If your cleanup code is complex or you want to avoid
743 } else { 806cancelling a C-thread that doesn't know how to clean up itself, it can be
744 $self->{_status} = [@_]; 807better to C<< ->throw >> an exception, or use C<< ->safe_cancel >>.
745 Coro::State::cancel $self; 808
809The arguments to C<< ->cancel >> are not copied, but instead will
810be referenced directly (e.g. if you pass C<$var> and after the call
811change that variable, then you might change the return values passed to
812e.g. C<join>, so don't do that).
813
814The resources of the Coro are usually freed (or destructed) before this
815call returns, but this can be delayed for an indefinite amount of time, as
816in some cases the manager thread has to run first to actually destruct the
817Coro object.
818
819=item $coro->safe_cancel ($arg...)
820
821Works mostly like C<< ->cancel >>, but is inherently "safer", and
822consequently, can fail with an exception in cases the thread is not in a
823cancellable state. Essentially, C<< ->safe_cancel >> is a C<< ->cancel >>
824with extra checks before canceling.
825
826It works a bit like throwing an exception that cannot be caught -
827specifically, it will clean up the thread from within itself, so all
828cleanup handlers (e.g. C<guard> blocks) are run with full thread
829context and can block if they wish. The downside is that there is no
830guarantee that the thread can be cancelled when you call this method, and
831therefore, it might fail. It is also considerably slower than C<cancel> or
832C<terminate>.
833
834A thread is in a safe-cancellable state if it either hasn't been run yet,
835or it has no C context attached and is inside an SLF function.
836
837The latter two basically mean that the thread isn't currently inside a
838perl callback called from some C function (usually via some XS modules)
839and isn't currently executing inside some C function itself (via Coro's XS
840API).
841
842This call returns true when it could cancel the thread, or croaks with an
843error otherwise (i.e. it either returns true or doesn't return at all).
844
845Why the weird interface? Well, there are two common models on how and
846when to cancel things. In the first, you have the expectation that your
847coro thread can be cancelled when you want to cancel it - if the thread
848isn't cancellable, this would be a bug somewhere, so C<< ->safe_cancel >>
849croaks to notify of the bug.
850
851In the second model you sometimes want to ask nicely to cancel a thread,
852but if it's not a good time, well, then don't cancel. This can be done
853relatively easy like this:
854
855 if (! eval { $coro->safe_cancel }) {
856 warn "unable to cancel thread: $@";
746 } 857 }
747} 858
859However, what you never should do is first try to cancel "safely" and
860if that fails, cancel the "hard" way with C<< ->cancel >>. That makes
861no sense: either you rely on being able to execute cleanup code in your
862thread context, or you don't. If you do, then C<< ->safe_cancel >> is the
863only way, and if you don't, then C<< ->cancel >> is always faster and more
864direct.
748 865
749=item $coro->schedule_to 866=item $coro->schedule_to
750 867
751Puts the current coro to sleep (like C<Coro::schedule>), but instead 868Puts the current coro to sleep (like C<Coro::schedule>), but instead
752of continuing with the next coro from the ready queue, always switch to 869of continuing with the next coro from the ready queue, always switch to
771inside the coro at the next convenient point in time. Otherwise 888inside the coro at the next convenient point in time. Otherwise
772clears the exception object. 889clears the exception object.
773 890
774Coro will check for the exception each time a schedule-like-function 891Coro will check for the exception each time a schedule-like-function
775returns, i.e. after each C<schedule>, C<cede>, C<< Coro::Semaphore->down 892returns, i.e. after each C<schedule>, C<cede>, C<< Coro::Semaphore->down
776>>, C<< Coro::Handle->readable >> and so on. Most of these functions 893>>, C<< Coro::Handle->readable >> and so on. Most of those functions (all
777detect this case and return early in case an exception is pending. 894that are part of Coro itself) detect this case and return early in case an
895exception is pending.
778 896
779The exception object will be thrown "as is" with the specified scalar in 897The exception object will be thrown "as is" with the specified scalar in
780C<$@>, i.e. if it is a string, no line number or newline will be appended 898C<$@>, i.e. if it is a string, no line number or newline will be appended
781(unlike with C<die>). 899(unlike with C<die>).
782 900
783This can be used as a softer means than C<cancel> to ask a coro to 901This can be used as a softer means than either C<cancel> or C<safe_cancel
784end itself, although there is no guarantee that the exception will lead to 902>to ask a coro to end itself, although there is no guarantee that the
785termination, and if the exception isn't caught it might well end the whole 903exception will lead to termination, and if the exception isn't caught it
786program. 904might well end the whole program.
787 905
788You might also think of C<throw> as being the moral equivalent of 906You might also think of C<throw> as being the moral equivalent of
789C<kill>ing a coro with a signal (in this case, a scalar). 907C<kill>ing a coro with a signal (in this case, a scalar).
790 908
791=item $coro->join 909=item $coro->join
792 910
793Wait until the coro terminates and return any values given to the 911Wait until the coro terminates and return any values given to the
794C<terminate> or C<cancel> functions. C<join> can be called concurrently 912C<terminate> or C<cancel> functions. C<join> can be called concurrently
795from multiple coro, and all will be resumed and given the status 913from multiple threads, and all will be resumed and given the status
796return once the C<$coro> terminates. 914return once the C<$coro> terminates.
797 915
798=cut
799
800sub join {
801 my $self = shift;
802
803 unless ($self->{_status}) {
804 my $current = $current;
805
806 push @{$self->{_on_destroy}}, sub {
807 $current->ready;
808 undef $current;
809 };
810
811 &schedule while $current;
812 }
813
814 wantarray ? @{$self->{_status}} : $self->{_status}[0];
815}
816
817=item $coro->on_destroy (\&cb) 916=item $coro->on_destroy (\&cb)
818 917
819Registers a callback that is called when this coro thread gets destroyed, 918Registers a callback that is called when this coro thread gets destroyed,
820but before it is joined. The callback gets passed the terminate arguments, 919that is, after it's resources have been freed but before it is joined. The
920callback gets passed the terminate/cancel arguments, if any, and I<must
821if any, and I<must not> die, under any circumstances. 921not> die, under any circumstances.
822 922
823There can be any number of C<on_destroy> callbacks per coro. 923There can be any number of C<on_destroy> callbacks per coro, and there is
824 924currently no way to remove a callback once added.
825=cut
826
827sub on_destroy {
828 my ($self, $cb) = @_;
829
830 push @{ $self->{_on_destroy} }, $cb;
831}
832 925
833=item $oldprio = $coro->prio ($newprio) 926=item $oldprio = $coro->prio ($newprio)
834 927
835Sets (or gets, if the argument is missing) the priority of the 928Sets (or gets, if the argument is missing) the priority of the
836coro thread. Higher priority coro get run before lower priority 929coro thread. Higher priority coro get run before lower priority
863coro thread. This is just a free-form string you can associate with a 956coro thread. This is just a free-form string you can associate with a
864coro. 957coro.
865 958
866This method simply sets the C<< $coro->{desc} >> member to the given 959This method simply sets the C<< $coro->{desc} >> member to the given
867string. You can modify this member directly if you wish, and in fact, this 960string. You can modify this member directly if you wish, and in fact, this
868is often preferred to indicate major processing states that cna then be 961is often preferred to indicate major processing states that can then be
869seen for example in a L<Coro::Debug> session: 962seen for example in a L<Coro::Debug> session:
870 963
871 sub my_long_function { 964 sub my_long_function {
872 local $Coro::current->{desc} = "now in my_long_function"; 965 local $Coro::current->{desc} = "now in my_long_function";
873 ... 966 ...
928otherwise you might suffer from crashes or worse. The only event library 1021otherwise you might suffer from crashes or worse. The only event library
929currently known that is safe to use without C<unblock_sub> is L<EV> (but 1022currently known that is safe to use without C<unblock_sub> is L<EV> (but
930you might still run into deadlocks if all event loops are blocked). 1023you might still run into deadlocks if all event loops are blocked).
931 1024
932Coro will try to catch you when you block in the event loop 1025Coro will try to catch you when you block in the event loop
933("FATAL:$Coro::IDLE blocked itself"), but this is just best effort and 1026("FATAL: $Coro::idle blocked itself"), but this is just best effort and
934only works when you do not run your own event loop. 1027only works when you do not run your own event loop.
935 1028
936This function allows your callbacks to block by executing them in another 1029This function allows your callbacks to block by executing them in another
937coro where it is safe to block. One example where blocking is handy 1030coro where it is safe to block. One example where blocking is handy
938is when you use the L<Coro::AIO|Coro::AIO> functions to save results to 1031is when you use the L<Coro::AIO|Coro::AIO> functions to save results to
1042But from within a coro, you often just want to write this: 1135But from within a coro, you often just want to write this:
1043 1136
1044 my $status = wait_for_child $pid; 1137 my $status = wait_for_child $pid;
1045 1138
1046Coro offers two functions specifically designed to make this easy, 1139Coro offers two functions specifically designed to make this easy,
1047C<Coro::rouse_cb> and C<Coro::rouse_wait>. 1140C<rouse_cb> and C<rouse_wait>.
1048 1141
1049The first function, C<rouse_cb>, generates and returns a callback that, 1142The first function, C<rouse_cb>, generates and returns a callback that,
1050when invoked, will save its arguments and notify the coro that 1143when invoked, will save its arguments and notify the coro that
1051created the callback. 1144created the callback.
1052 1145
1058function mentioned above: 1151function mentioned above:
1059 1152
1060 sub wait_for_child($) { 1153 sub wait_for_child($) {
1061 my ($pid) = @_; 1154 my ($pid) = @_;
1062 1155
1063 my $watcher = AnyEvent->child (pid => $pid, cb => Coro::rouse_cb); 1156 my $watcher = AnyEvent->child (pid => $pid, cb => rouse_cb);
1064 1157
1065 my ($rpid, $rstatus) = Coro::rouse_wait; 1158 my ($rpid, $rstatus) = rouse_wait;
1066 $rstatus 1159 $rstatus
1067 } 1160 }
1068 1161
1069In the case where C<rouse_cb> and C<rouse_wait> are not flexible enough, 1162In the case where C<rouse_cb> and C<rouse_wait> are not flexible enough,
1070you can roll your own, using C<schedule>: 1163you can roll your own, using C<schedule> and C<ready>:
1071 1164
1072 sub wait_for_child($) { 1165 sub wait_for_child($) {
1073 my ($pid) = @_; 1166 my ($pid) = @_;
1074 1167
1075 # store the current coro in $current, 1168 # store the current coro in $current,
1078 my ($done, $rstatus); 1171 my ($done, $rstatus);
1079 1172
1080 # pass a closure to ->child 1173 # pass a closure to ->child
1081 my $watcher = AnyEvent->child (pid => $pid, cb => sub { 1174 my $watcher = AnyEvent->child (pid => $pid, cb => sub {
1082 $rstatus = $_[1]; # remember rstatus 1175 $rstatus = $_[1]; # remember rstatus
1083 $done = 1; # mark $rstatus as valud 1176 $done = 1; # mark $rstatus as valid
1177 $current->ready; # wake up the waiting thread
1084 }); 1178 });
1085 1179
1086 # wait until the closure has been called 1180 # wait until the closure has been called
1087 schedule while !$done; 1181 schedule while !$done;
1088 1182
1107module from the first thread (this requirement might be removed in the 1201module from the first thread (this requirement might be removed in the
1108future to allow per-thread schedulers, but Coro::State does not yet allow 1202future to allow per-thread schedulers, but Coro::State does not yet allow
1109this). I recommend disabling thread support and using processes, as having 1203this). I recommend disabling thread support and using processes, as having
1110the windows process emulation enabled under unix roughly halves perl 1204the windows process emulation enabled under unix roughly halves perl
1111performance, even when not used. 1205performance, even when not used.
1206
1207Attempts to use threads created in another emulated process will crash
1208("cleanly", with a null pointer exception).
1112 1209
1113=item coro switching is not signal safe 1210=item coro switching is not signal safe
1114 1211
1115You must not switch to another coro from within a signal handler (only 1212You must not switch to another coro from within a signal handler (only
1116relevant with %SIG - most event libraries provide safe signals), I<unless> 1213relevant with %SIG - most event libraries provide safe signals), I<unless>
1204 1301
1205XS API: L<Coro::MakeMaker>. 1302XS API: L<Coro::MakeMaker>.
1206 1303
1207Low level Configuration, Thread Environment, Continuations: L<Coro::State>. 1304Low level Configuration, Thread Environment, Continuations: L<Coro::State>.
1208 1305
1209=head1 AUTHOR 1306=head1 AUTHOR/SUPPORT/CONTACT
1210 1307
1211 Marc Lehmann <schmorp@schmorp.de> 1308 Marc A. Lehmann <schmorp@schmorp.de>
1212 http://home.schmorp.de/ 1309 http://software.schmorp.de/pkg/Coro.html
1213 1310
1214=cut 1311=cut
1215 1312

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