19809: improve NO_TRAPS_ASYNC by queueing traps alone

4 files changed, 48 insertions, 10 deletions

diff --git a/ChangeLog b/ChangeLog
index 7246c1268..a0a4f29ff 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2004-04-21  Peter Stephenson  <pws@csr.com>
+
+	* 19809: Src/jobs.c, Src/signals.c, Src/signals.h: improve
+	zsh-users/7365 by only queuing traps when TRAPS_ASYNC is set.
+	This avoids any nasty races, including one reported by Vincent
+	Stemen.
+
 2004-04-21  Oliver Kiddle  <opk@zsh.org>
 
 	* 19806: Src/prompt.c: fix bug with %v expansion and negative index
diff --git a/Src/jobs.c b/Src/jobs.c
index 072a91744..7d89a7dbb 100644
--- a/Src/jobs.c
+++ b/Src/jobs.c
@@ -994,11 +994,8 @@ zwaitjob(int job, int sig)
     int q = queue_signal_level();
     Job jn = jobtab + job;
 
-    queue_not_sigchld++;
-    if (isset(TRAPSASYNC))
-	dont_queue_signals();
-    else
-	queue_signals();
+    dont_queue_signals();
+    queue_traps();
     child_block();		 /* unblocked during child_suspend() */
     if (jn->procs || jn->auxprocs) { /* if any forks were done         */
 	jn->stat |= STAT_LOCKED;
@@ -1029,10 +1026,8 @@ zwaitjob(int job, int sig)
 	numpipestats = 1;
     }
     child_unblock();
+    dont_queue_traps();
     restore_queue_signals(q);
-    if (!queueing_enabled)
-	run_queued_signals();
-    queue_not_sigchld--;
 }
 
 /* wait for running job to finish */
diff --git a/Src/signals.c b/Src/signals.c
index 8939d1ba1..25febc85d 100644
--- a/Src/signals.c
+++ b/Src/signals.c
@@ -49,12 +49,19 @@ mod_export int nsigtrapped;
 /* Variables used by signal queueing */
 
 /**/
-mod_export int queueing_enabled, queue_front, queue_rear, queue_not_sigchld;
+mod_export int queueing_enabled, queue_front, queue_rear;
 /**/
 mod_export int signal_queue[MAX_QUEUE_SIZE];
 /**/
 mod_export sigset_t signal_mask_queue[MAX_QUEUE_SIZE];
 
+/* Variables used by trap queueing */
+
+/**/
+mod_export int trap_queueing_enabled, trap_queue_front, trap_queue_rear;
+/**/
+mod_export int trap_queue[MAX_QUEUE_SIZE];
+
 /* This is only used on machines that don't understand signal sets.  *
  * On SYSV machines this will represent the signals that are blocked *
  * (held) using sighold.  On machines which can't block signals at   *
@@ -426,7 +433,7 @@ zhandler(int sig)
 #endif
 
     /* Are we queueing signals now?      */
-    if (queueing_enabled && (sig != SIGCHLD || !queue_not_sigchld)) {
+    if (queueing_enabled) {
         int temp_rear = ++queue_rear % MAX_QUEUE_SIZE;
 
 	DPUTS(temp_rear == queue_front, "BUG: signal queue full");
@@ -1058,5 +1065,17 @@ dotrap(int sig)
     if ((sigtrapped[sig] & ZSIG_IGNORED) || !sigfuncs[sig] || errflag)
 	return;
 
+    /* Adapted from signal queueing in zhandler */
+    if (trap_queueing_enabled && !isset(TRAPSASYNC)) {
+	int temp_rear = ++trap_queue_rear % MAX_QUEUE_SIZE;
+
+	DPUTS(temp_rear == trap_queue_front, "BUG: trap queue full");
+	if (temp_rear != trap_queue_front) {
+	    trap_queue_rear = temp_rear;
+	    trap_queue[trap_queue_rear] = sig;
+	}
+	return;
+    }
+
     dotrapargs(sig, sigtrapped+sig, sigfuncs[sig]);
 }
diff --git a/Src/signals.h b/Src/signals.h
index 4b8197d84..e86906ebc 100644
--- a/Src/signals.h
+++ b/Src/signals.h
@@ -101,6 +101,23 @@
 
 #define restore_queue_signals(q) (queueing_enabled = (q))
 
+/*
+ * Similar (but simpler) mechanism used for queueing traps.
+ * Only needed if NO_TRAPS_ASYNC is set.
+ */
+#define queue_traps()	(trap_queueing_enabled++)
+
+#define run_queued_traps() do { \
+    while (trap_queue_front != trap_queue_rear) { /* while traps in queue */ \
+	trap_queue_front = (trap_queue_front + 1) % MAX_QUEUE_SIZE; \
+	dotrap(trap_queue[trap_queue_front]);  /* handle queued trap   */ \
+    } \
+} while (0)
+
+#define dont_queue_traps() do { \
+    trap_queueing_enabled = 0; \
+    run_queued_traps(); \
+} while (0)
 
 /* Make some signal functions faster. */