Race condition prevents working completely

Binary package hint: xmms-alarm

There is a race condition at the start of alarm_start_thread() when the condition of the while loop is first evaluated, since the global start_tid may not yet have been initialized with the return value of alarm_thread_create(). This access to start_tid should be protected by a mutex.

Here comes the patch :

diff -ru xmms-alarm-0.3.7/src/alarm.c xmms-alarm-0.3.7-repaired/src/alarm.c
--- xmms-alarm-0.3.7/src/alarm.c 2005-04-09 02:20:12.000000000 +0200
+++ xmms-alarm-0.3.7-repaired/src/alarm.c 2007-10-30 07:50:54.000000000 +0100
@@ -57,6 +57,7 @@
 static pthread_t start_tid; /* thread id of alarm loop */
 static pthread_t stop_tid; /* thread id of stop loop */
 static pthread_mutex_t fader_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t start_lock = PTHREAD_MUTEX_INITIALIZER;

 static GeneralPlugin alarm_plugin;

@@ -880,6 +881,9 @@
    unsigned int play_start = 0;
    guint today;

+ pthread_mutex_lock(&start_lock);
+ pthread_mutex_unlock(&start_lock);
+
    while(start_tid != 0)
    {
      /* sit around and wait for the faders to not be doing anything */
@@ -1080,7 +1084,9 @@
    alarm_read_config();

    /* start the main thread running */
+ pthread_mutex_lock(&start_lock);
    start_tid = alarm_thread_create(alarm_start_thread, NULL, 1);
+ pthread_mutex_unlock(&start_lock);

Please apply and notify upstream (if any still alive).