first pass at updating head branch to be to be the same as the SAMBA_2_0 branch

[kai/samba-autobuild/.git] / source3 / lib / signal.c

diff --git a/source3/lib/signal.c b/source3/lib/signal.c
index bb1c6fe189b5d98ea3d9bb554b16b6370593b494..5651e942d78db1cd06407bde92e676f6ea9782f3 100644 (file)
--- a/source3/lib/signal.c
+++ b/source3/lib/signal.c
@@ -22,22 +22,51 @@
 
 #include "includes.h"
 
-
 /****************************************************************************
-catch child exits
+ Catch child exits and reap the child zombie status.
 ****************************************************************************/
+
 static void sig_cld(int signum)
 {
-       while (sys_waitpid((pid_t)-1,(int *)NULL, WNOHANG) > 0) ;
+       while (sys_waitpid((pid_t)-1,(int *)NULL, WNOHANG) > 0)
+               ;
+
+       /*
+        * Turns out it's *really* important not to
+        * restore the signal handler here if we have real POSIX
+        * signal handling. If we do, then we get the signal re-delivered
+        * immediately - hey presto - instant loop ! JRA.
+        */
 
+#if !defined(HAVE_SIGACTION)
        CatchSignal(SIGCLD, sig_cld);
+#endif
 }
 
+/****************************************************************************
+catch child exits - leave status;
+****************************************************************************/
 
+static void sig_cld_leave_status(int signum)
+{
+       /*
+        * Turns out it's *really* important not to
+        * restore the signal handler here if we have real POSIX
+        * signal handling. If we do, then we get the signal re-delivered
+        * immediately - hey presto - instant loop ! JRA.
+        */
+
+#if !defined(HAVE_SIGACTION)
+       CatchSignal(SIGCLD, sig_cld_leave_status);
+#else
+       ;
+#endif
+}
 
 /*******************************************************************
-block sigs
+ Block sigs.
 ********************************************************************/
+
 void BlockSignals(BOOL block,int signum)
 {
 #ifdef HAVE_SIGPROCMASK
@@ -63,14 +92,13 @@ void BlockSignals(BOOL block,int signum)
 #endif
 }
 
-
-
 /*******************************************************************
-catch a signal. This should implement the following semantics:
+ Catch a signal. This should implement the following semantics:
 
-1) the handler remains installed after being called
-2) the signal should be blocked during handler execution
+ 1) The handler remains installed after being called.
+ 2) The signal should be blocked during handler execution.
 ********************************************************************/
+
 void CatchSignal(int signum,void (*handler)(int ))
 {
 #ifdef HAVE_SIGACTION
@@ -80,23 +108,35 @@ void CatchSignal(int signum,void (*handler)(int ))
 
        act.sa_handler = handler;
 #ifdef SA_RESTART
-       act.sa_flags = SA_RESTART;
+       /*
+        * We *want* SIGALRM to interrupt a system call.
+        */
+       if(signum != SIGALRM)
+               act.sa_flags = SA_RESTART;
 #endif
        sigemptyset(&act.sa_mask);
        sigaddset(&act.sa_mask,signum);
        sigaction(signum,&act,NULL);
-#else
+#else /* !HAVE_SIGACTION */
        /* FIXME: need to handle sigvec and systems with broken signal() */
        signal(signum, handler);
 #endif
 }
 
-
-
 /*******************************************************************
-ignore SIGCLD via whatever means is necessary for this OS
+ Ignore SIGCLD via whatever means is necessary for this OS.
 ********************************************************************/
+
 void CatchChild(void)
 {
        CatchSignal(SIGCLD, sig_cld);
 }
+
+/*******************************************************************
+ Catch SIGCLD but leave the child around so it's status can be reaped.
+********************************************************************/
+
+void CatchChildLeaveStatus(void)
+{
+       CatchSignal(SIGCLD, sig_cld_leave_status);
+}