More SHM creation polishing

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@472 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/shmlog.c

@@ -129,6 +129,8 @@ VSL_Init(void)
 	    heritage.vsl_fd, 0);
 	assert(loghead != MAP_FAILED);
 
+	assert(loghead->magic == SHMLOGHEAD_MAGIC);
+	assert(loghead->hdrsize == sizeof *loghead);
 	/* XXX check sanity of loghead */
 	logstart = (unsigned char *)loghead + loghead->start;
 	AZ(pthread_mutex_init(&vsl_mutex, NULL));
@@ -151,8 +153,10 @@ VSL_MgtInit(const char *fn, unsigned size)
 	    slh.hdrsize != sizeof slh) {
 		/* XXX more checks */
 
-		if (heritage.vsl_fd >= 0);
+		fprintf(stderr, "Creating new SHMFILE\n");
+		if (heritage.vsl_fd >= 0); {
 			close(heritage.vsl_fd);
+		}
 		unlink(fn);
 		heritage.vsl_fd = open(fn, O_RDWR | O_CREAT, 0644);
 		if (heritage.vsl_fd < 0) {
@@ -160,8 +164,8 @@ VSL_MgtInit(const char *fn, unsigned size)
 			    fn, strerror(errno));
 			exit (1);
 		}
-		memset(&slh, 0, sizeof slh);
 
+		memset(&slh, 0, sizeof slh);
 		slh.magic = SHMLOGHEAD_MAGIC;
 		slh.hdrsize = sizeof slh;
 		slh.size = size;

include/shmlog.h

@@ -15,6 +15,8 @@ struct shmloghead {
 #define SHMLOGHEAD_MAGIC	4185512498U	/* From /dev/random */
 	unsigned		magic;
 
+	unsigned		hdrsize;
+
 	/*
 	 * Byte offset into the file where the fifolog starts
  	 * This allows the header to expand later.