Don't do signal blocking; simply set a semaphore flag indicating it is

in critical code, and let the main loop deal with the flag being set.
This saves on context switches into the kernel for this rare condition.

1 files changed, 22 insertions, 85 deletions

diff --git a/server/subscr.c b/server/subscr.c
index 790e8f5..cb2b110 100644
--- a/server/subscr.c
+++ b/server/subscr.c
@@ -162,20 +162,11 @@ subscr_subscribe_real(who, newsubs, notice)
 	ZSTRING *sender;
 	ZSubscr_t *subs2, *subs3, *subs;
 	int relation;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
 
 	sender = make_zstring(notice->z_sender,0);
-#ifdef POSIX
-	(void) sigemptyset(&mask);
-	(void) sigaddset(&mask, SIGFPE);
-	(void) sigprocmask(SIG_BLOCK, &mask, &omask);
-#else
-	omask = sigblock(sigmask(SIGFPE)); /* don't let db dumps start */
-#endif
+
+	START_CRITICAL_CODE;
+
 	for (subs = newsubs->q_forw;
 	     subs != newsubs;
 	     subs = subs->q_forw) {
@@ -245,11 +236,7 @@ subscr_subscribe_real(who, newsubs, notice)
 
 		if (!(subs3 = (ZSubscr_t *) xmalloc(sizeof(ZSubscr_t)))) {
 			free_subscriptions(newsubs);
-#ifdef POSIX
-			(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-			(void) sigsetmask(omask);
-#endif
+			END_CRITICAL_CODE;
 			return(ENOMEM);
 		}
 
@@ -263,11 +250,7 @@ subscr_subscribe_real(who, newsubs, notice)
 		if ((retval = class_register(who, subs)) != ZERR_NONE) {
 		    xfree(subs3);
 		    free_subscriptions(newsubs);
-#ifdef POSIX
-		    (void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-		    (void) sigsetmask(omask);
-#endif
+		    END_CRITICAL_CODE;
 		    return(retval);
 		}
 
@@ -276,11 +259,8 @@ subscr_subscribe_real(who, newsubs, notice)
  duplicate:
 		;
 	}
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
 
 	free_subscriptions(newsubs);
 	return(ZERR_NONE);
@@ -430,11 +410,6 @@ subscr_cancel(sin, notice)
 	Code_t retval;
 	int found = 0;
 	int relation;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
 
 #if 0
 	zdbug((LOG_DEBUG,"subscr_cancel"));
@@ -448,14 +423,8 @@ subscr_cancel(sin, notice)
 	if (!(subs = extract_subscriptions(notice)))
 		return(ZERR_NONE);	/* no subscr -> no error */
 
-	
-#ifdef POSIX
-	(void) sigemptyset(&mask);
-	(void) sigaddset(&mask, SIGFPE);
-	(void) sigprocmask(SIG_BLOCK, &mask, &omask);
-#else
-	omask = sigblock(sigmask(SIGFPE)); /* don't let db dumps start */
-#endif
+	START_CRITICAL_CODE;
+
 	for (subs4 = subs->q_forw; subs4 != subs; subs4 = subs4->q_forw) {
 	    for (subs2 = who->zct_subs->q_forw;
 		 subs2 != who->zct_subs;) {
@@ -493,20 +462,13 @@ subscr_cancel(sin, notice)
 	       subs2 = subs2->q_forw)
 	    if ((retval = class_register(who, subs2)) != ZERR_NONE) {
 	      free_subscriptions(subs);
-#ifdef POSIX
-	      (void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	      (void) sigsetmask(omask);
-#endif
+	      END_CRITICAL_CODE;
 	      return(retval);
 	    }
 	}
 
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+	END_CRITICAL_CODE;
+
 	free_subscriptions(subs);
 	if (found) {
 #if 0
@@ -530,11 +492,6 @@ subscr_cancel_client(client)
      ZClient_t *client;
 {
 	register ZSubscr_t *subs;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
 
 #if 0
 	zdbug((LOG_DEBUG,"subscr_cancel_client %s",
@@ -542,14 +499,9 @@ subscr_cancel_client(client)
 #endif
 	if (!client->zct_subs)
 		return;
-	
-#ifdef POSIX
-	(void) sigemptyset(&mask);
-	(void) sigaddset(&mask, SIGFPE);
-	(void) sigprocmask(SIG_BLOCK, &mask, &omask);
-#else
-	omask = sigblock(sigmask(SIGFPE)); /* don't let db dumps start */
-#endif
+
+	START_CRITICAL_CODE;
+
 	for (subs = client->zct_subs->q_forw;
 	     subs != client->zct_subs;
 	     subs = client->zct_subs->q_forw) {
@@ -577,11 +529,8 @@ subscr_cancel_client(client)
 	xfree(subs);
 	client->zct_subs = NULLZST;
 
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+	END_CRITICAL_CODE;
+
 	return;
 }
 
@@ -597,32 +546,20 @@ struct in_addr *addr;
 {
 	register ZHostList_t *hosts;
 	register ZClientList_t *clist = NULLZCLT, *clt;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
 
 	/* find the host */
 	if (!(hosts = hostm_find_host(addr)))
 		return(ZSRV_HNOTFOUND);
 	clist = hosts->zh_clients;
 
-#ifdef POSIX
-	(void) sigemptyset(&mask);
-	(void) sigaddset(&mask, SIGFPE);
-	(void) sigprocmask(SIG_BLOCK, &mask, &omask);
-#else
-	omask = sigblock(sigmask(SIGFPE)); /* don't let db dumps start */
-#endif
+	START_CRITICAL_CODE;
+
 	/* flush each one */
 	for (clt = clist->q_forw; clt != clist; clt = clt->q_forw)
 		(void) subscr_cancel_client(clt->zclt_client);
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+
 	return(ZERR_NONE);
 }
 #endif