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, 51 insertions, 173 deletions

diff --git a/server/hostm.c b/server/hostm.c
index aa7a3d5..4a029ea 100644
--- a/server/hostm.c
+++ b/server/hostm.c
@@ -237,14 +237,8 @@ hostm_flush(host, server)
 {
 	register ZClientList_t *clist = NULLZCLT, *clt;
 	losinghost *lhp, *lhp2;
-#ifdef POSIX
-	sigset_t mask, omask;
-	(void) sigemptyset(&mask);
-	(void) sigaddset(&mask, SIGFPE);
-	(void) sigprocmask(SIG_BLOCK, &mask, &omask);
-#else
-	int omask = sigblock(sigmask(SIGFPE)); /* don't let db dumps start */
-#endif
+
+	START_CRITICAL_CODE;
 
 	if (!host) {
 	    syslog(LOG_WARNING, "null host flush");
@@ -283,11 +277,9 @@ hostm_flush(host, server)
 
 	uloc_hflush(&host->zh_addr.sin_addr);
 	host_detach(host, server);
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+
 	return;
 }
 
@@ -399,15 +391,9 @@ host_lost(arg)
 	Code_t retval;
 	char *buffer;
 	int len;
-#ifdef POSIX
-	sigset_t mask, omask;
-	(void) sigemptyset(&mask);
-	(void) sigaddset(&mask, SIGFPE);
-	(void) sigprocmask(SIG_BLOCK, &mask, &omask);
-#else
-	int omask = sigblock(sigmask(SIGFPE)); /* don't let db dumps start */
-#endif
 
+	START_CRITICAL_CODE;
+	
 	server = hostm_find_server(&which->lh_host->zh_addr.sin_addr);
 #if 1
 	zdbug ((LOG_DEBUG,"lost host %s (server %s)",
@@ -421,11 +407,7 @@ host_lost(arg)
 #endif
 		xremque(which);
 		xfree(which);
-#ifdef POSIX
-		(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-		(void) sigsetmask(omask);
-#endif
+		END_CRITICAL_CODE;
 		return;
 	}
 	xremque(which);
@@ -461,11 +443,9 @@ host_lost(arg)
 	server_forward(&notice, 0, &who); /* unauthentic */
 
 	xfree(which);
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+
 	return;
 }
 
@@ -478,21 +458,12 @@ host_not_losing(who)
      struct sockaddr_in *who;
 {
 	losinghost *lhp, *lhp2;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
 
 	if (!losing_hosts)
 		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 (lhp = losing_hosts->q_forw;
 	     lhp != losing_hosts;)
 		if (lhp->lh_host->zh_addr.sin_addr.s_addr == who->sin_addr.s_addr) {
@@ -520,11 +491,9 @@ host_not_losing(who)
 			lhp = lhp2->q_forw;
 		} else
 			lhp = lhp->q_forw;
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+
 	return;
 }
 
@@ -538,22 +507,12 @@ hostm_lose_ignore(client)
      ZClient_t *client;
 {
 	losinghost *lhp, *lhp2;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
 	
 	if (!losing_hosts)
 		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 (lhp = losing_hosts->q_forw;
 	     lhp != losing_hosts;)
 		/* if client matches, remove it */
@@ -573,11 +532,9 @@ hostm_lose_ignore(client)
 			lhp = lhp2->q_forw;
 		} else
 			lhp = lhp->q_forw;
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+	
 	return;
 }
 
@@ -591,14 +548,7 @@ hostm_transfer(host, server)
      ZHostList_t *host;
      ZServerDesc_t *server;
 {
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
-
 	/* we need to unlink and relink him, and change the table entry */
-
 #if 1
 	if (zdebug)
 	    syslog (LOG_DEBUG, "hostm_transfer %s to %s",
@@ -609,13 +559,8 @@ hostm_transfer(host, server)
 	if (hostm_find_server(&host->zh_addr.sin_addr) == server)
 		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;
+	
 	/* remove from old server's queue */
 	xremque(host);
 
@@ -625,11 +570,9 @@ hostm_transfer(host, server)
 
 	/* insert in our queue */
 	xinsque(host, server->zs_hosts);
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+
 	return;
 }
 
@@ -645,14 +588,8 @@ host_attach(who, server)
 {
 	register ZHostList_t *hlist;
 	register ZClientList_t *clist;
-#ifdef POSIX
-	sigset_t mask, omask;
-	(void) sigemptyset(&mask);
-	(void) sigaddset(&mask, SIGFPE);
-	(void) sigprocmask(SIG_BLOCK, &mask, &omask);
-#else
-	int omask = sigblock(sigmask(SIGFPE)); /* don't let db dumps start */
-#endif
+
+	START_CRITICAL_CODE;
 
 #if 0
 	if (zdebug)
@@ -662,21 +599,13 @@ host_attach(who, server)
 	/* allocate a header */
 	if (!(hlist = (ZHostList_t *) xmalloc(sizeof(ZHostList_t)))) {
 		syslog(LOG_WARNING, "hm_attach alloc");
-#ifdef POSIX
-		(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-		(void) sigsetmask(omask);
-#endif
+		END_CRITICAL_CODE;
 		return(ENOMEM);
 	}
 	/* set up */
 	if (!(clist = (ZClientList_t *)xmalloc(sizeof(ZClientList_t)))) {
 	        xfree(hlist);
-#ifdef POSIX
-		(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-		(void) sigsetmask(omask);
-#endif
+		END_CRITICAL_CODE;
 		return(ENOMEM);
 	}
 	clist->zclt_client = NULLZCNT;
@@ -692,11 +621,9 @@ host_attach(who, server)
 
 	/* chain in to the end of the list */
 	xinsque(hlist, server->zs_hosts->q_back);
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+
 	return(ZERR_NONE);
 }
 
@@ -712,20 +639,10 @@ host_detach(host, server)
      ZServerDesc_t *server;
 {
 	ZServerDesc_t *server2;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
+
+	START_CRITICAL_CODE;
 
 	/* undo what we did in host_attach */
-#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
 	server2 = hostm_find_server (&host->zh_addr.sin_addr);
 
 	if (server2 != server) {
@@ -734,11 +651,7 @@ host_detach(host, server)
 		       inet_ntoa (host->zh_addr.sin_addr),
 		       server->addr,
 		       server2->addr);
-#ifdef POSIX
-		(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-		(void) sigsetmask(omask);
-#endif
+		END_CRITICAL_CODE;
 		return;
 	}
 
@@ -753,11 +666,9 @@ host_detach(host, server)
 	remove_host(host);
 
 	xfree(host);
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+	
 	return;
 }
 
@@ -982,11 +893,6 @@ insert_host(host, server)
 {
 	struct hostlist *oldlist;
 	register int i = 0;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
 
 #if 0
 	zdbug ((LOG_DEBUG,"insert_host %s %s",
@@ -995,13 +901,7 @@ insert_host(host, server)
 	if (hostm_find_host(&host->zh_addr.sin_addr))
 		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;
 
 	num_hosts++;
 	oldlist = all_hosts;
@@ -1014,11 +914,7 @@ insert_host(host, server)
 	if (!oldlist) {			/* this is the first */
 		all_hosts[0].host = host;
 		all_hosts[0].server_index = server - otherservers;
-#ifdef POSIX
-		(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-		(void) sigsetmask(omask);
-#endif
+		END_CRITICAL_CODE;
 		return;
 	}
 
@@ -1038,11 +934,9 @@ insert_host(host, server)
 		i++;
 	}
 	xfree(oldlist);
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+
 #if defined (DEBUG) && 0
         if (zdebug) {
                 register int i = 0;
@@ -1065,11 +959,6 @@ remove_host(host)
 {
 	struct hostlist *oldlist;
 	register int i = 0;
-#ifdef POSIX
-	sigset_t mask, omask;
-#else
-	int omask;
-#endif
 
 #if 0
 	zdbug((LOG_DEBUG,"remove_host %s", inet_ntoa(host->zh_addr.sin_addr)));
@@ -1077,24 +966,15 @@ remove_host(host)
 	if (!hostm_find_host(&host->zh_addr.sin_addr))
 		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;
+	
 	if (--num_hosts == 0) {
 #if 0
 		zdbug((LOG_DEBUG,"last host"));
 #endif
 		xfree (all_hosts);
 		all_hosts = NULLHLT;
-#ifdef POSIX
-		(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-		(void) sigsetmask(omask);
-#endif
+		END_CRITICAL_CODE;
 		return;
 	}
 
@@ -1119,11 +999,9 @@ remove_host(host)
 		i++;
 	}
 	xfree (oldlist);
-#ifdef POSIX
-	(void) sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0);
-#else
-	(void) sigsetmask(omask);
-#endif
+
+	END_CRITICAL_CODE;
+
 	return;
 }