--- Coro/Coro.pm 2007/01/05 16:55:01 1.105 +++ Coro/Coro.pm 2008/04/05 22:29:54 1.173 @@ -8,22 +8,29 @@ async { # some asynchronous thread of execution + print "2\n"; + cede; # yield back to main + print "4\n"; }; - - # alternatively create an async coroutine like this: - - sub some_func : Coro { - # some more async code - } - - cede; + print "1\n"; + cede; # yield to coroutine + print "3\n"; + cede; # and again + + # use locking + my $lock = new Coro::Semaphore; + my $locked; + + $lock->down; + $locked = 1; + $lock->up; =head1 DESCRIPTION This module collection manages coroutines. Coroutines are similar to threads but don't run in parallel at the same time even on SMP -machines. The specific flavor of coroutine use din this module also -guarentees you that it will not switch between coroutines unless +machines. The specific flavor of coroutine used in this module also +guarantees you that it will not switch between coroutines unless necessary, at easily-identified points in your program, so locking and parallel access are rarely an issue, making coroutine programming much safer than threads programming. @@ -35,7 +42,7 @@ In this module, coroutines are defined as "callchain + lexical variables + @_ + $_ + $@ + $/ + C stack), that is, a coroutine has its own callchain, its own set of lexicals and its own set of perls most important global -variables. +variables (see L for more configuration). =cut @@ -52,7 +59,7 @@ our $main; # main coroutine our $current; # current coroutine -our $VERSION = '3.3'; +our $VERSION = '4.47'; our @EXPORT = qw(async async_pool cede schedule terminate current unblock_sub); our %EXPORT_TAGS = ( @@ -110,13 +117,15 @@ is C<$main> (of course). This variable is B I. It is provided for performance -reasons. If performance is not essentiel you are encouraged to use the +reasons. If performance is not essential you are encouraged to use the C function instead. =cut +$main->{desc} = "[main::]"; + # maybe some other module used Coro::Specific before... -$main->{specific} = $current->{specific} +$main->{_specific} = $current->{_specific} if $current; _set_current $main; @@ -134,7 +143,7 @@ coroutine so the scheduler can run it. Please note that if your callback recursively invokes perl (e.g. for event -handlers), then it must be prepared to be called recursively. +handlers), then it must be prepared to be called recursively itself. =cut @@ -151,8 +160,8 @@ or return; # call all destruction callbacks - $_->(@{$self->{status}}) - for @{(delete $self->{destroy_cb}) || []}; + $_->(@{$self->{_status}}) + for @{(delete $self->{_on_destroy}) || []}; } # this coroutine is necessary because a coroutine @@ -168,7 +177,7 @@ &schedule; } }; - +$manager->desc ("[coro manager]"); $manager->prio (PRIO_MAX); # static methods. not really. @@ -187,10 +196,12 @@ (usually unused). When the sub returns the new coroutine is automatically terminated. -Calling C in a coroutine will not work correctly, so do not do that. +See the C constructor for info about the coroutine +environment in which coroutines run. -When the coroutine dies, the program will exit, just as in the main -program. +Calling C in a coroutine will do the same as calling exit outside +the coroutine. Likewise, when the coroutine dies, the program will exit, +just as it would in the main program. # create a new coroutine that just prints its arguments async { @@ -212,44 +223,55 @@ that might have executed other code already (which can be good or bad :). Also, the block is executed in an C context and a warning will be -issued in case of an exception instead of terminating the program, as C does. - -The priority will be reset to C<0> after each job, otherwise the coroutine -will be re-used "as-is". +issued in case of an exception instead of terminating the program, as +C does. As the coroutine is being reused, stuff like C +will not work in the expected way, unless you call terminate or cancel, +which somehow defeats the purpose of pooling. + +The priority will be reset to C<0> after each job, tracing will be +disabled, the description will be reset and the default output filehandle +gets restored, so you can change alkl these. Otherwise the coroutine will +be re-used "as-is": most notably if you change other per-coroutine global +stuff such as C<$/> you need to revert that change, which is most simply +done by using local as in C< local $/ >. The pool size is limited to 8 idle coroutines (this can be adjusted by changing $Coro::POOL_SIZE), and there can be as many non-idle coros as required. If you are concerned about pooled coroutines growing a lot because a -single C used a lot of stackspace you can e.g. C once per second or so to slowly replenish the pool. +single C used a lot of stackspace you can e.g. C once per second or so to slowly replenish the pool. In +addition to that, when the stacks used by a handler grows larger than 16kb +(adjustable with $Coro::POOL_RSS) it will also exit. =cut our $POOL_SIZE = 8; -our @pool; +our $POOL_RSS = 16 * 1024; +our @async_pool; sub pool_handler { - while () { - my ($cb, @arg) = @{ delete $current->{_invoke} }; + my $cb; + while () { eval { - $cb->(@arg); + while () { + _pool_1 $cb; + &$cb; + _pool_2 $cb; + &schedule; + } }; - warn $@ if $@; - last if @pool >= $POOL_SIZE; - push @pool, $current; - - $current->prio (0); - schedule; - } -} + last if $@ eq "\3async_pool terminate\2\n"; + warn $@ if $@; + } +} sub async_pool(&@) { # this is also inlined into the unlock_scheduler - my $coro = (pop @pool or new Coro \&pool_handler); + my $coro = (pop @async_pool) || new Coro \&pool_handler; $coro->{_invoke} = [@_]; $coro->ready; @@ -277,7 +299,7 @@ undef $current; }; - # call schedule until event occured. + # call schedule until event occurred. # in case we are woken up for other reasons # (current still defined), loop. Coro::schedule while $current; @@ -298,12 +320,25 @@ Terminates the current coroutine with the given status values (see L). +=item killall + +Kills/terminates/cancels all coroutines except the currently running +one. This is useful after a fork, either in the child or the parent, as +usually only one of them should inherit the running coroutines. + =cut sub terminate { $current->cancel (@_); } +sub killall { + for (Coro::State::list) { + $_->cancel + if $_ != $current && UNIVERSAL::isa $_, "Coro"; + } +} + =back # dynamic methods @@ -321,7 +356,8 @@ called. To make the coroutine run you must first put it into the ready queue by calling the ready method. -Calling C in a coroutine will not work correctly, so do not do that. +See C and C for additional info about the +coroutine environment. =cut @@ -355,7 +391,7 @@ sub cancel { my $self = shift; - $self->{status} = [@_]; + $self->{_status} = [@_]; if ($current == $self) { push @destroy, $self; @@ -369,18 +405,18 @@ =item $coroutine->join Wait until the coroutine terminates and return any values given to the -C or C functions. C can be called multiple times -from multiple coroutine. +C or C functions. C can be called concurrently +from multiple coroutines. =cut sub join { my $self = shift; - unless ($self->{status}) { + unless ($self->{_status}) { my $current = $current; - push @{$self->{destroy_cb}}, sub { + push @{$self->{_on_destroy}}, sub { $current->ready; undef $current; }; @@ -388,7 +424,7 @@ &schedule while $current; } - wantarray ? @{$self->{status}} : $self->{status}[0]; + wantarray ? @{$self->{_status}} : $self->{_status}[0]; } =item $coroutine->on_destroy (\&cb) @@ -402,7 +438,7 @@ sub on_destroy { my ($self, $cb) = @_; - push @{ $self->{destroy_cb} }, $cb; + push @{ $self->{_on_destroy} }, $cb; } =item $oldprio = $coroutine->prio ($newprio) @@ -437,6 +473,25 @@ Sets (or gets in case the argument is missing) the description for this coroutine. This is just a free-form string you can associate with a coroutine. +This method simply sets the C<< $coroutine->{desc} >> member to the given string. You +can modify this member directly if you wish. + +=item $coroutine->throw ([$scalar]) + +If C<$throw> is specified and defined, it will be thrown as an exception +inside the coroutine at the next convinient point in time (usually after +it gains control at the next schedule/transfer/cede). Otherwise clears the +exception object. + +The exception object will be thrown "as is" with the specified scalar in +C<$@>, i.e. if it is a string, no line number or newline will be appended +(unlike with C). + +This can be used as a softer means than C to ask a coroutine to +end itself, although there is no guarentee that the exception will lead to +termination, and if the exception isn't caught it might well end the whole +program. + =cut sub desc { @@ -454,14 +509,14 @@ =item Coro::nready Returns the number of coroutines that are currently in the ready state, -i.e. that can be swicthed to. The value C<0> means that the only runnable +i.e. that can be switched to. The value C<0> means that the only runnable coroutine is the currently running one, so C would have no effect, and C would cause a deadlock unless there is an idle handler that wakes up some coroutines. =item my $guard = Coro::guard { ... } -This creates and returns a guard object. Nothing happens until the objetc +This creates and returns a guard object. Nothing happens until the object gets destroyed, in which case the codeblock given as argument will be executed. This is useful to free locks or other resources in case of a runtime error or when the coroutine gets canceled, as in both cases the @@ -500,7 +555,7 @@ immediately without blocking, returning nothing, while the original code ref will be called (with parameters) from within its own coroutine. -The reason this fucntion exists is that many event libraries (such as the +The reason this function exists is that many event libraries (such as the venerable L module) are not coroutine-safe (a weaker form of thread-safety). This means you must not block within event callbacks, otherwise you might suffer from crashes or worse. @@ -521,11 +576,11 @@ # to reduce pressure on the coro pool (because most callbacks # return immediately and can be reused) and because we cannot cede # inside an event callback. -our $unblock_scheduler = async { +our $unblock_scheduler = new Coro sub { while () { while (my $cb = pop @unblock_queue) { # this is an inlined copy of async_pool - my $coro = (pop @pool or new Coro \&pool_handler); + my $coro = (pop @async_pool) || new Coro \&pool_handler; $coro->{_invoke} = $cb; $coro->ready; @@ -534,6 +589,7 @@ schedule; # sleep well } }; +$unblock_scheduler->desc ("[unblock_sub scheduler]"); sub unblock_sub(&) { my $cb = shift; @@ -556,19 +612,25 @@ destruction. very bad things might happen otherwise (usually segfaults). - this module is not thread-safe. You should only ever use this module - from the same thread (this requirement might be losened in the future + from the same thread (this requirement might be loosened in the future to allow per-thread schedulers, but Coro::State does not yet allow this). =head1 SEE ALSO -Support/Utility: L, L, L, L. +Lower level Configuration, Coroutine Environment: L. + +Debugging: L. + +Support/Utility: L, L. Locking/IPC: L, L, L, L, L. -Event/IO: L, L, L, L, L. +Event/IO: L, L, L, L. + +Compatibility: L, L, L. -Embedding: L +Embedding: L. =head1 AUTHOR