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 instead.
- 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
instead.
- @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, block.
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 <[email protected]>
http://software.schmorp.de/pkg/Coro.html