Glib::Signal(3pm) User Contributed Perl Documentation Glib::Signal(3pm)NAMEGlib::Signal - Object customization and general purpose notification
DESCRIPTION
This page describes some functions related to signals in Glib. Since
most things you can do with signals are tied to Glib::Object instances,
the majority of the signal functions are documented there.
Thread safety
Some libraries, most notably GStreamer, sometimes invoke signal
handlers from a foreign thread that has no Perl interpreter associated
with it. When this happens, we have no choice but to hand the
marshalling over to the main loop which in turn later wakes up the main
thread and lets it handle the request. We cannot invoke the signal
handler from the foreign thread since the Perl interpreter may not be
used concurrently.
The downside to this approach is that the foreign thread is blocked
until the main thread has finished executing the signal handler. This
might lead to deadlocks. It might help in this case to wrap the
crucial parts of the signal handler inside a Glib::Idle callback so
that the signal handler can return directly.
METHODS
integer = Glib->install_exception_handler ($func, $data=undef)
· $func (subroutine)
· $data (scalar)
Install a subroutine to be executed when a signal emission traps an
exception (a croak or die). $func should return boolean (true if the
handler should remain installed) and expect to receive a single scalar.
This scalar will be a private copy of $@ which the handler can mangle
to its heart's content.
Returns an identifier that may be used with "remove_exception_handler".
See "gperl_install_exception_handler()" in Glib::xsapi.
Glib->remove_exception_handler ($tag)
· $tag (integer)
Remove the exception handler identified by $tag, as returned by
"install_exception_handler". If $tag cannot be found, this does
nothing.
WARNING: Do not call this function from within an exception handler.
If you want to remove your handler during its execution just have it
return false.
See "gperl_remove_exception_handler()" in Glib::xsapi.
ENUMS AND FLAGS
flags Glib::SignalFlags
· 'run-first' / 'G_SIGNAL_RUN_FIRST'
· 'run-last' / 'G_SIGNAL_RUN_LAST'
· 'run-cleanup' / 'G_SIGNAL_RUN_CLEANUP'
· 'no-recurse' / 'G_SIGNAL_NO_RECURSE'
· 'detailed' / 'G_SIGNAL_DETAILED'
· 'action' / 'G_SIGNAL_ACTION'
· 'no-hooks' / 'G_SIGNAL_NO_HOOKS'
SEE ALSO
Glib, Glib::Object
COPYRIGHT
Copyright (C) 2003-2011 by the gtk2-perl team.
This software is licensed under the LGPL. See Glib for a full notice.
perl v5.18.1 2014-01-08 Glib::Signal(3pm)
