Darwin/Mac OS X: There is apparently no convenient way to keep deceased

children from waiting until the parent reaps status, so when the APR
app doesn't care about such status we need to have a handler driven
and call one of the wait functions.

PR:		9168


git-svn-id: http://svn.apache.org/repos/asf/apr/apr/trunk@63423 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 20 insertions, 0 deletions

diff --git a/threadproc/unix/signals.c b/threadproc/unix/signals.c
index 2affb84a2..5127868b9 100644
--- a/threadproc/unix/signals.c
+++ b/threadproc/unix/signals.c
@@ -87,6 +87,17 @@ APR_DECLARE(apr_status_t) apr_proc_kill(apr_proc_t *proc, int signum)
 
 #if APR_HAVE_SIGACTION
 
+#ifdef DARWIN
+static void avoid_zombies(int signo)
+{
+    int exit_status;
+
+    while (waitpid(-1, &exit_status, WNOHANG) > 0) {
+        /* do nothing */
+    }
+}
+#endif /* DARWIN */
+
 /*
  * Replace standard signal() with the more reliable sigaction equivalent
  * from W. Richard Stevens' "Advanced Programming in the UNIX Environment"
@@ -112,6 +123,15 @@ APR_DECLARE(apr_sigfunc_t *) apr_signal(int signo, apr_sigfunc_t * func)
         act.sa_flags |= SA_NOCLDWAIT;
     }
 #endif
+#ifdef DARWIN
+    /* ignoring SIGCHLD or leaving the default disposition doesn't avoid zombies,
+     * and there is no SA_NOCLDWAIT flag, so catch the signal and reap status in 
+     * the handler to avoid zombies
+     */
+    if ((signo == SIGCHLD) && (func == SIG_IGN)) {
+        act.sa_handler = avoid_zombies;
+    }
+#endif
     if (sigaction(signo, &act, &oact) < 0)
         return SIG_ERR;
     return oact.sa_handler;