IO::Async::Loop::Select - use IO::Async with select(2)
IO::Async::Loop::Select
IO::Async
select(2)
Normally an instance of this class would not be directly constructed by a program. It may however, be useful for runinng IO::Async with an existing program already using a select call.
select
use IO::Async::Loop::Select; my $loop = IO::Async::Loop::Select->new; $loop->add( ... ); while(1) { my ( $rvec, $wvec, $evec ) = ('') x 3; my $timeout; $loop->pre_select( \$rvec, \$wvec, \$evec, \$timeout ); ... my $ret = select( $rvec, $wvec, $evec, $timeout ); ... $loop->post_select( $rvec, $evec, $wvec ); }
This subclass of IO::Async::Loop uses the select(2) syscall to perform read-ready and write-ready tests.
IO::Async::Loop
To integrate with an existing select-based event loop, a pair of methods pre_select and post_select can be called immediately before and after a select call. The relevant bits in the read-ready, write-ready and exceptional-state bitvectors are set by the pre_select method, and tested by the post_select method to pick which event callbacks to invoke.
pre_select
post_select
This function returns a new instance of a IO::Async::Loop::Select object. It takes no special arguments.
This method prepares the bitvectors for a select call, setting the bits that the Loop is interested in. It will also adjust the $timeout value if appropriate, reducing it if the next event timeout the Loop requires is sooner than the current value.
$timeout
Scalar references to the reading, writing and exception bitvectors
Scalar reference to the timeout value
This method checks the returned bitvectors from a select call, and calls any of the callbacks that are appropriate.
Scalars containing the read-ready, write-ready and exception bitvectors
This method calls the pre_select method to prepare the bitvectors for a select syscall, performs it, then calls post_select to process the result. It returns the total number of callbacks invoked by the post_select method, or undef if the underlying select(2) syscall returned an error.
undef
IO::Select - OO interface to select system call
Paul Evans <leonerd@leonerd.org.uk>
To install IO::Async, copy and paste the appropriate command in to your terminal.
cpanm
cpanm IO::Async
CPAN shell
perl -MCPAN -e shell install IO::Async
For more information on module installation, please visit the detailed CPAN module installation guide.