From: Andre <maan@p133.(none)>
Date: Tue, 21 Feb 2006 17:04:43 +0000 (+0100)
Subject: Avoid busy loop if someone nasty removes the semaphores currently in use.
X-Git-Tag: v0.2.11~61
X-Git-Url: http://git.tue.mpg.de/?a=commitdiff_plain;h=746589429fb545c096837fe59c9d9199f01070a1;p=paraslash.git

Avoid busy loop if someone nasty removes the semaphores currently in use.

Just die if semop failed 500 times.
---

diff --git a/ipc.c b/ipc.c
index ae9ad574..973a9eaf 100644
--- a/ipc.c
+++ b/ipc.c
@@ -4,6 +4,7 @@
 #include <sys/ipc.h>
 #include <sys/shm.h>
 
+#define MAX_SEMOP_RETRIES 500
 
 int mutex_new(void)
 {
@@ -19,11 +20,13 @@ int mutex_destroy(int id)
 
 static void para_semop(int id, struct sembuf *sops, int num)
 {
-	if (semop(id, sops, num) >= 0)
-		return;
-	PARA_WARNING_LOG("semop failed (%s), retrying\n", strerror(errno));
-	while (semop(id, sops, num) < 0)
-		; /* nothing */
+	int i;
+
+	for (i = 0; i < MAX_SEMOP_RETRIES; i++)
+		if (semop(id, sops, num) >= 0)
+			return;
+	PARA_EMERG_LOG("semop failed %d times, aborting\n", MAX_SEMOP_RETRIES);
+	exit(EXIT_FAILURE);
 }
 
 /**