[project @ 2004-02-27 15:58:54 by simonmar]

redo the condition-cache hack

diff --git a/ghc/rts/Schedule.c b/ghc/rts/Schedule.c
index b73f530..869dd38 100644 (file)
--- a/ghc/rts/Schedule.c
+++ b/ghc/rts/Schedule.c
@@ -1,5 +1,5 @@
 /* ---------------------------------------------------------------------------
- * $Id: Schedule.c,v 1.190 2004/02/27 15:56:25 simonmar Exp $
+ * $Id: Schedule.c,v 1.191 2004/02/27 15:58:54 simonmar Exp $
  *
  * (c) The GHC Team, 1998-2003
  *
@@ -1965,9 +1965,11 @@ scheduleThread(StgTSO* tso)
 }
 
 #if defined(RTS_SUPPORTS_THREADS)
-static Condition *bound_cond_cache = NULL;
+static Condition bound_cond_cache;
+static int bound_cond_cache_full = 0;
 #endif
 
+
 SchedulerStatus
 scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret,
                   Capability *initialCapability)
@@ -1983,9 +1985,9 @@ scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret,
     // Allocating a new condition for each thread is expensive, so we
     // cache one.  This is a pretty feeble hack, but it helps speed up
     // consecutive call-ins quite a bit.
-    if (bound_cond_cache != NULL) {
-       m->bound_thread_cond = *bound_cond_cache;
-       bound_cond_cache = NULL;
+    if (bound_cond_cache_full) {
+       m->bound_thread_cond = bound_cond_cache;
+       bound_cond_cache_full = 0;
     } else {
        initCondition(&m->bound_thread_cond);
     }
@@ -2080,7 +2082,6 @@ initScheduler(void)
 #endif
 
   RELEASE_LOCK(&sched_mutex);
-
 }
 
 void
@@ -2125,8 +2126,9 @@ waitThread_(StgMainThread* m, Capability *initialCapability)
 
 #if defined(RTS_SUPPORTS_THREADS)
   // Free the condition variable, returning it to the cache if possible.
-  if (bound_cond_cache == NULL) {
-      *bound_cond_cache = m->bound_thread_cond;
+  if (!bound_cond_cache_full) {
+      bound_cond_cache = m->bound_thread_cond;
+      bound_cond_cache_full = 1;
   } else {
       closeCondition(&m->bound_thread_cond);
   }