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Util(3)		      User Contributed Perl Documentation	       Util(3)

       Coro::Util - various utility functions.

	use Coro::Util;

       This module implements various utility functions, mostly	replacing perl
       functions by non-blocking counterparts.

       Many of these functions exist for the sole purpose of emulating
       existing	interfaces, no matter how bad or limited they are (e.g.	no
       IPv6 support).

       This module is an AnyEvent user.	Refer to the AnyEvent documentation to
       see how to integrate it into your own programs.

       $ipn = Coro::Util::inet_aton $hostname || $ip
	   Works almost	exactly	like its "Socket::inet_aton" counterpart,
	   except that it does not block other coroutines.

	   Does	not handle multihomed hosts or IPv6 - consider using
	   "AnyEvent::Socket::resolve_sockaddr"	with the Coro rouse functions

       gethostbyname, gethostbyaddr
	   Work	similarly to their Perl	counterparts, but do not block.	Uses
	   "AnyEvent::Util::inet_aton" internally.

	   Does	not handle multihomed hosts or IPv6 - consider using
	   "AnyEvent::Socket::resolve_sockaddr"	or
	   "AnyEvent::DNS::reverse_lookup" with	the Coro rouse functions

       @result = Coro::Util::fork_eval { ... },	@args
	   Executes the	given code block or code reference with	the given
	   arguments in	a separate process, returning the results. The return
	   values must be serialisable with Coro::Storable. It may, of course,

	   Note	that using event handling in the sub is	not usually a good
	   idea	as you will inherit a mixed set	of watchers from the parent.

	   Exceptions will be correctly	forwarded to the caller.

	   This	function is useful for pushing cpu-intensive computations into
	   a different process,	for example to take advantage of multiple
	   CPU's. Its also useful if you want to simply	run some blocking
	   functions (such as "system()") and do not care about	the overhead
	   enough to code your own pid watcher etc.

	   This	function might keep a pool of processes	in some	future
	   version, as fork can	be rather slow in large	processes.

	   You should also look	at "AnyEvent::Util::fork_eval",	which is newer
	   and more compatible to totally broken Perl implementations such as
	   the one from	ActiveState.

	   Example: execute some external program (convert image to rgba raw
	   form) and add a long	computation (extract the alpha channel)	in a
	   separate process, making sure that never more then $NUMCPUS
	   processes are being run.

	      my $cpulock = new	Coro::Semaphore	$NUMCPUS;

	      sub do_it	{
		 my ($path) = @_;

		 my $guard = $cpulock->guard;

		 Coro::Util::fork_eval {
		    open my $fh, "convert -depth 8 \Q$path\E rgba:"
		       or die "$path: $!";

		    local $/;
		    # make my eyes hurt
		    pack "C*", unpack "(xxxC)*", <$fh>

	      my $alphachannel = do_it "/tmp/img.png";

	  Marc A. Lehmann <>

perl v5.32.1			  2020-07-29			       Util(3)


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