Attachment 367 Details for Bug 1008 – mutex based on lock files

[patch] mutex based on lock files

mutex.diff (text/plain), 4.07 KB, created by Volker Lendecke on 2004-01-27 06:28:56 UTC

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Creator: Volker Lendecke

Created: 2004-01-27 06:28:56 UTC

Size: 4.07 KB

patch

obsolete

>Index: lib/server_mutex.c
>===================================================================
>RCS file: /data/vl/cvstree/samba/source/lib/server_mutex.c,v
>retrieving revision 1.1.2.4
>diff -u -r1.1.2.4 server_mutex.c
>--- lib/server_mutex.c	17 Mar 2003 23:06:12 -0000	1.1.2.4
>+++ lib/server_mutex.c	27 Jan 2004 13:43:34 -0000
>@@ -29,28 +29,109 @@
>    This locking allows smbd's mutlithread architecture to look
>    like the single-connection that NT makes. */
> 
>-static char *mutex_server_name;
>+static int  lock_file_fd = 0;
>+
>+static SIG_ATOMIC_T gotalarm;
>+
>+/***************************************************************
>+ Signal function to tell us we timed out.
>+ Shamelessly copied from tdbutil.c.
>+****************************************************************/
>+
>+static void gotalarm_sig(void)
>+{
>+	gotalarm = 1;
>+}
>+
>+/****************************************************************************
>+ fcntl lock with timeout (in seconds).
>+****************************************************************************/
>+
>+static int fcntl_getlkw_with_timeout(int fd, struct flock *lock,
>+				     unsigned int timeout)
>+{
>+	/* Allow fcntl to be interrupted by an alarm. */
>+	int ret;
>+	gotalarm = 0;
>+
>+	if (timeout) {
>+		CatchSignal(SIGALRM, SIGNAL_CAST gotalarm_sig);
>+		alarm(timeout);
>+	}
>+
>+	do {
>+		ret = fcntl(fd, F_SETLKW, lock);
>+		if (ret == -1 && errno == EINTR && gotalarm)
>+			break;
>+	} while (ret == -1 && errno == EINTR);
>+
>+	if (timeout) {
>+		alarm(0);
>+		CatchSignal(SIGALRM, SIGNAL_CAST SIG_IGN);
>+		if (gotalarm)
>+			return -1;
>+	}
>+
>+	return ret;
>+}
> 
> BOOL grab_server_mutex(const char *name)
> {
>-	mutex_server_name = strdup(name);
>-	if (!mutex_server_name) {
>+	pstring mutex_path;
>+	char *lock_file_name;
>+	int res;
>+
>+	if (lock_file_fd != 0) {
>+		DEBUG(0, ("Already got a lock file fd, name = %s\n", name));
>+		return False;
>+	}
>+
>+	pstrcpy(mutex_path, lock_path("mutex"));
>+	mkdir(mutex_path, 0700);
>+
>+	if (!directory_exist(mutex_path, NULL)) {
>+		DEBUG(0, ("Could not create mutex dir: %s\n", mutex_path));
>+		return False;
>+	}
>+	
>+	asprintf(&lock_file_name, "%s/%s", mutex_path, name);
>+
>+	if (!lock_file_name) {
> 		DEBUG(0,("grab_server_mutex: malloc failed for %s\n", name));
> 		return False;
> 	}
>-	if (!secrets_named_mutex(mutex_server_name, 10)) {
>-		DEBUG(10,("grab_server_mutex: failed for %s\n", name));
>-		SAFE_FREE(mutex_server_name);
>+
>+	lock_file_fd = open(lock_file_name, O_RDWR|O_CREAT, 0600);
>+
>+	if (lock_file_fd < 0) {
>+		DEBUG(0, ("Could not create lock file %s\n", lock_file_name));
>+		free(lock_file_name);
> 		return False;
> 	}
> 
>-	return True;
>+	free(lock_file_name);
>+
>+	{
>+		struct flock lock;
>+		lock.l_type   = F_WRLCK;
>+		lock.l_whence = SEEK_SET;
>+		lock.l_start  = 0;
>+		lock.l_len    = 1;
>+
>+		res = fcntl_getlkw_with_timeout(lock_file_fd, &lock, 10);
>+	}
>+
>+	if (res == -1) {
>+		close(lock_file_fd);
>+		lock_file_fd = 0;
>+	}
>+
>+	return res;
> }
> 
> void release_server_mutex(void)
> {
>-	if (mutex_server_name) {
>-		secrets_named_mutex_release(mutex_server_name);
>-		SAFE_FREE(mutex_server_name);
>+	if (lock_file_fd != 0) {
>+		close(lock_file_fd);
> 	}
> }
>Index: torture/torture.c
>===================================================================
>RCS file: /data/vl/cvstree/samba/source/torture/torture.c,v
>retrieving revision 1.63.2.21
>diff -u -r1.63.2.21 torture.c
>--- torture/torture.c	30 Dec 2003 15:18:25 -0000	1.63.2.21
>+++ torture/torture.c	27 Jan 2004 14:23:35 -0000
>@@ -4421,6 +4421,33 @@
> 	return True;
> }
> 
>+static BOOL run_one_mutex(int client)
>+{
>+	char *name;
>+
>+	asprintf(&name, "test%d", client%10);
>+
>+	printf("Trying to grab mutex %s\n", name);
>+
>+	if (grab_server_mutex(name) == 0)
>+		printf("success\n");
>+	else
>+		printf("failure\n");
>+
>+	sleep(1);
>+
>+	release_server_mutex();
>+	return True;
>+}
>+
>+static BOOL run_mutex(int dummy)
>+{
>+	BOOL correct = True;
>+
>+	create_procs(run_one_mutex, &correct);
>+	return correct;
>+}
>+
> static double create_procs(BOOL (*fn)(int), BOOL *result)
> {
> 	int i, status;
>@@ -4570,6 +4597,7 @@
> 	{"IOCTL",  torture_ioctl_test, 0},
> 	{"CHKPATH",  torture_chkpath_test, 0},
> 	{"FDSESS", run_fdsesstest, 0},
>+	{"MUTEX", run_mutex, 0},
> 	{NULL, NULL, 0}};
> 
>

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