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Comparing libev/ev.pod (file contents):
Revision 1.277 by root, Thu Dec 31 06:50:17 2009 UTC vs.
Revision 1.278 by root, Thu Dec 31 06:59:47 2009 UTC

… …
374 374
375=item C<EVFLAG_SIGNALFD> 375=item C<EVFLAG_SIGNALFD>
376 376
377When this flag is specified, then libev will attempt to use the 377When this flag is specified, then libev will attempt to use the
378I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This API 378I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This API
379delivers signals synchronously, which makes is both faster and might make 379delivers signals synchronously, which makes it both faster and might make
380it possible to get the queued signal data. 380it possible to get the queued signal data. It can also simplify signal
381handling with threads, as long as you properly block signals in your
382threads that are not interested in handling them.
381 383
382Signalfd will not be used by default as this changes your signal mask, and 384Signalfd will not be used by default as this changes your signal mask, and
383there are a lot of shoddy libraries and programs (glib's threadpool for 385there are a lot of shoddy libraries and programs (glib's threadpool for
384example) that can't properly initialise their signal masks. 386example) that can't properly initialise their signal masks.
385 387
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2160In current versions of libev, the signal will not be blocked indefinitely 2162In current versions of libev, the signal will not be blocked indefinitely
2161unless you use the C<signalfd> API (C<EV_SIGNALFD>). While this reduces 2163unless you use the C<signalfd> API (C<EV_SIGNALFD>). While this reduces
2162the window of opportunity for problems, it will not go away, as libev 2164the window of opportunity for problems, it will not go away, as libev
2163I<has> to modify the signal mask, at least temporarily. 2165I<has> to modify the signal mask, at least temporarily.
2164 2166
2165So I can't stress this enough I<if you do not reset your signal mask 2167So I can't stress this enough: I<If you do not reset your signal mask when
2166when you expect it to be empty, you have a race condition in your 2168you expect it to be empty, you have a race condition in your code>. This
2167program>. This is not a libev-specific thing, this is true for most event 2169is not a libev-specific thing, this is true for most event libraries.
2168libraries.
2169 2170
2170=head3 Watcher-Specific Functions and Data Members 2171=head3 Watcher-Specific Functions and Data Members
2171 2172
2172=over 4 2173=over 4
2173 2174

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