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master
Marc Alexander Lehmann 14 years ago
parent
commit
9c8a026cf3
  1. 1
      Changes
  2. 10
      ev.c
  3. 56
      ev.pod

1
Changes

@ -4,6 +4,7 @@ Revision history for libev, a high-performance and full-featured event loop
- implement ev_async watchers.
- only initialise signal pipe on demand.
- make use of sig_atomic_t configurable.
- improved ev_child documentation.
3.0 Mon Jan 28 13:14:47 CET 2008
- API/ABI bump to version 3.0.

10
ev.c

@ -914,7 +914,7 @@ static ev_signal childev;
#endif
void inline_speed
child_reap (EV_P_ ev_signal *sw, int chain, int pid, int status)
child_reap (EV_P_ int chain, int pid, int status)
{
ev_child *w;
int traced = WIFSTOPPED (status) || WIFCONTINUED (status);
@ -924,7 +924,7 @@ child_reap (EV_P_ ev_signal *sw, int chain, int pid, int status)
if ((w->pid == pid || !w->pid)
&& (!traced || (w->flags & 1)))
{
ev_set_priority (w, ev_priority (sw)); /* need to do it *now* */
ev_set_priority (w, EV_MAXPRI); /* need to do it *now*, this *must* be the same prio as the signal watcher itself */
w->rpid = pid;
w->rstatus = status;
ev_feed_event (EV_A_ (W)w, EV_CHILD);
@ -948,13 +948,13 @@ childcb (EV_P_ ev_signal *sw, int revents)
|| 0 >= (pid = waitpid (-1, &status, WNOHANG | WUNTRACED)))
return;
/* make sure we are called again until all childs have been reaped */
/* make sure we are called again until all children have been reaped */
/* we need to do it this way so that the callback gets called before we continue */
ev_feed_event (EV_A_ (W)sw, EV_SIGNAL);
child_reap (EV_A_ sw, pid, pid, status);
child_reap (EV_A_ pid, pid, status);
if (EV_PID_HASHSIZE > 1)
child_reap (EV_A_ sw, 0, pid, status); /* this might trigger a watcher twice, but feed_event catches that */
child_reap (EV_A_ 0, pid, status); /* this might trigger a watcher twice, but feed_event catches that */
}
#endif

56
ev.pod

@ -1456,7 +1456,32 @@ Example: Try to exit cleanly on SIGINT and SIGTERM.
=head2 C<ev_child> - watch out for process status changes
Child watchers trigger when your process receives a SIGCHLD in response to
some child status changes (most typically when a child of yours dies).
some child status changes (most typically when a child of yours dies). It
is permissible to install a child watcher I<after> the child has been
forked (which implies it might have already exited), as long as the event
loop isn't entered (or is continued from a watcher).
Only the default event loop is capable of handling signals, and therefore
you can only rgeister child watchers in the default event loop.
=head3 Process Interaction
Libev grabs C<SIGCHLD> as soon as the default event loop is
initialised. This is necessary to guarantee proper behaviour even if
the first child watcher is started after the child exits. The occurance
of C<SIGCHLD> is recorded asynchronously, but child reaping is done
synchronously as part of the event loop processing. Libev always reaps all
children, even ones not watched.
=head3 Overriding the Built-In Processing
Libev offers no special support for overriding the built-in child
processing, but if your application collides with libev's default child
handler, you can override it easily by installing your own handler for
C<SIGCHLD> after initialising the default loop, and making sure the
default loop never gets destroyed. You are encouraged, however, to use an
event-based approach to child reaping and thus use libev's support for
that, so other libev users can use C<ev_child> watchers freely.
=head3 Watcher-Specific Functions and Data Members
@ -1490,6 +1515,35 @@ C<waitpid> and C<sys/wait.h> documentation for details).
=back
=head3 Examples
Example: C<fork()> a new process and install a child handler to wait for
its completion.
ev_child cw;
static void
child_cb (EV_P_ struct ev_child *w, int revents)
{
ev_child_stop (EV_A_ w);
printf ("process %d exited with status %x\n", w->rpid, w->rstatus);
}
pid_t pid = fork ();
if (pid < 0)
// error
else if (pid == 0)
{
// the forked child executes here
exit (1);
}
else
{
ev_child_init (&cw, child_cb, pid, 0);
ev_child_start (EV_DEFAULT_ &cw);
}
=head2 C<ev_stat> - did the file attributes just change?

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