perl - Multiplexing callbacks -

suppose have number of tasks in 1 application may finish in order. , need run code when of tasks have finished. if matters, application running under anyevent, without coro.

to extent, anyevent's $cv->begin/$cv->end allow want. however, i'd have more fine-grained control. instance, i'd unable "finish" task twice. ability gather data tasks nice.

of course, can done. set lots of callbacks share hash; delete keys hash whenever task finishes; call megacallback when hash empty. wonder if there's more civilized way of doing it, maybe cpan module?

for instance, here's imaginary api fill need.

#!/usr/bin/perl -w  use strict;  use some::module;  # set goals $cb = some::module->new( sub { 'boom!' } ); $cb->begin( qw(foo bar) );  # later, tasks start getting done $cb->end( foo => 42 );       # "return" value task 'foo' $cb->begin( 'baz' );         # can add more tasks, why not $cb->end( 'bar' );           # finish task 'bar' # still waiting 'baz' finish @ point  # finally, last hanging task done $cb->end( baz => 137 );      # boom! # @ point, sub {}->( { foo=>42, bar=>undef, baz=>137 } )  #     has been called 

see perlmonks question.

it there this?

you might want consider future.

specifically, waiting on many things complete, can use future->needs_all or similar:

my @things = ... # generate futures represent each thing  future->needs_all( @things )   ->on_done( sub {      # code here when things done    }); 

alternatively, try async::mergepoint gives api closer had in mind:

my $mp = async::mergepoint->new( needs => [qw( foo bar )] ); $mp->close( on_done => sub {    # code here when things done });  $mp->done( foo => $value ); $mp->done( bar => );