+
+// standard barrier implementation using conds and mutexes
+// see: http://www.howforge.com/implementing-barrier-in-pthreads
+typedef struct {
+ unsigned int needed;
+ unsigned int called;
+ void *mutex;
+ void *cond;
+} barrier_t;
+
+void *_Thread_CreateBarrier(unsigned int count, const char *filename, int fileline)
+{
+ volatile barrier_t *b = (volatile barrier_t *) Z_Malloc(sizeof(barrier_t));
+#ifdef THREADDEBUG
+ Sys_PrintfToTerminal("%p barrier create(%d) %s:%i\n", b, count, filename, fileline);
+#endif
+ b->needed = count;
+ b->called = 0;
+ b->mutex = Thread_CreateMutex();
+ b->cond = Thread_CreateCond();
+ return (void *) b;
+}
+
+void _Thread_DestroyBarrier(void *barrier, const char *filename, int fileline)
+{
+ volatile barrier_t *b = (volatile barrier_t *) barrier;
+#ifdef THREADDEBUG
+ Sys_PrintfToTerminal("%p barrier destroy %s:%i\n", b, filename, fileline);
+#endif
+ Thread_DestroyMutex(b->mutex);
+ Thread_DestroyCond(b->cond);
+}
+
+void _Thread_WaitBarrier(void *barrier, const char *filename, int fileline)
+{
+ volatile barrier_t *b = (volatile barrier_t *) barrier;
+#ifdef THREADDEBUG
+ Sys_PrintfToTerminal("%p barrier wait %s:%i\n", b, filename, fileline);
+#endif
+ Thread_LockMutex(b->mutex);
+ b->called++;
+ if (b->called == b->needed) {
+ b->called = 0;
+ Thread_CondBroadcast(b->cond);
+ } else {
+ do {
+ Thread_CondWait(b->cond, b->mutex);
+ } while(b->called);
+ }
+ Thread_UnlockMutex(b->mutex);
+}