Re: [AD] small bug in uthreads.c

[Peter Wang <tjaden@xxxxxxxxxx>]

Elias Pschernig wrote:

> As this thread http://www.allegro.cc/forums/view_thread.php?_id=433516
> shows, there is a bug in uthreads.c. It tries to close the background
> thread, even if it failed creating it. (I'm puzzled though how the
> creation of the thread can fail.)
>
>  

Your patch is incomplete and I don't think another variable is 
necessary.  Alternative attached.

Peter

Index: src/unix/uthreads.c
===================================================================
RCS file: /cvsroot/alleg/allegro/src/unix/uthreads.c,v
retrieving revision 1.18
diff -u -r1.18 uthreads.c
--- src/unix/uthreads.c	29 Jul 2004 08:27:35 -0000	1.18
+++ src/unix/uthreads.c	27 Nov 2004 05:57:05 -0000
@@ -37,7 +37,7 @@
 static bg_func funcs[MAX_FUNCS];
 static int max_func; /* highest+1 used entry */
 
-static pthread_t thread;
+static pthread_t thread = 0;
 static pthread_mutex_t cli_mutex;
 static pthread_cond_t cli_cond;
 static int cli_count;
@@ -122,6 +122,8 @@
 {
    int i;
 
+   ASSERT(thread == 0);
+
    for (i = 0; i < MAX_FUNCS; i++)
       funcs[i] = NULL;
 
@@ -134,6 +136,7 @@
    if (pthread_create(&thread, NULL, bg_man_pthreads_threadfunc, NULL)) {
       pthread_mutex_destroy(&cli_mutex);
       pthread_cond_destroy(&cli_cond);
+      thread = 0;
       return -1;
    }
 
@@ -147,10 +150,15 @@
  */
 static void bg_man_pthreads_exit(void)
 {
-   pthread_cancel(thread);
-   pthread_join(thread, NULL);
-   pthread_mutex_destroy(&cli_mutex);
-   pthread_cond_destroy(&cli_cond);
+   if (thread) {
+      pthread_cancel(thread);
+      pthread_join(thread, NULL);
+      pthread_mutex_destroy(&cli_mutex);
+      pthread_cond_destroy(&cli_cond);
+      thread = 0;
+   }
+
+   ASSERT(thread == 0);
 }
 
 
Index: src/x/xsystem.c
===================================================================
RCS file: /cvsroot/alleg/allegro/src/x/xsystem.c,v
retrieving revision 1.30
diff -u -r1.30 xsystem.c
--- src/x/xsystem.c	5 Nov 2004 17:08:15 -0000	1.30
+++ src/x/xsystem.c	27 Nov 2004 05:57:06 -0000
@@ -251,7 +251,10 @@
 #endif
 
 #ifdef ALLEGRO_MULTITHREADED
-   _unix_destroy_mutex (_xwin.mutex);
+   if (_xwin.mutex) {
+      _unix_destroy_mutex(_xwin.mutex);
+      _xwin.mutex = NULL;
+   }
 #endif
 }