fix haddock submodule pointer

[ghc-hetmet.git] / rts / Messages.c

diff --git a/rts/Messages.c b/rts/Messages.c
index 91ee9a6..5dec6c6 100644 (file)
--- a/rts/Messages.c
+++ b/rts/Messages.c
@@ -98,11 +98,13 @@ loop:
         r = throwToMsg(cap, t);
 
         switch (r) {
-        case THROWTO_SUCCESS:
+        case THROWTO_SUCCESS: {
             // this message is done
-            unlockClosure((StgClosure*)m, &stg_MSG_NULL_info);
-            tryWakeupThread(cap, t->source);
+            StgTSO *source = t->source;
+            doneWithMsgThrowTo(t);
+            tryWakeupThread(cap, source);
             break;
+        }
         case THROWTO_BLOCKED:
             // unlock the message
             unlockClosure((StgClosure*)m, &stg_MSG_THROWTO_info);
@@ -161,7 +163,7 @@ nat messageBlackHole(Capability *cap, MessageBlackHole *msg)
     const StgInfoTable *info;
     StgClosure *p;
     StgBlockingQueue *bq;
-    StgClosure *bh = msg->bh;
+    StgClosure *bh = UNTAG_CLOSURE(msg->bh);
     StgTSO *owner;
 
     debugTraceCap(DEBUG_sched, cap, "message: thread %d blocking on blackhole %p", 
@@ -175,6 +177,7 @@ nat messageBlackHole(Capability *cap, MessageBlackHole *msg)
     // all.
     if (info != &stg_BLACKHOLE_info && 
         info != &stg_CAF_BLACKHOLE_info && 
+        info != &__stg_EAGER_BLACKHOLE_info &&
         info != &stg_WHITEHOLE_info) {
         // if it is a WHITEHOLE, then a thread is in the process of
         // trying to BLACKHOLE it.  But we know that it was once a
@@ -186,7 +189,9 @@ nat messageBlackHole(Capability *cap, MessageBlackHole *msg)
     // The blackhole must indirect to a TSO, a BLOCKING_QUEUE, an IND,
     // or a value.
 loop:
-    p = UNTAG_CLOSURE(((StgInd*)bh)->indirectee);
+    // NB. VOLATILE_LOAD(), because otherwise gcc hoists the load
+    // and turns this into an infinite loop.
+    p = UNTAG_CLOSURE((StgClosure*)VOLATILE_LOAD(&((StgInd*)bh)->indirectee));
     info = p->header.info;
 
     if (info == &stg_IND_info)
@@ -200,7 +205,7 @@ loop:
 
     else if (info == &stg_TSO_info)
     {
-        owner = deRefTSO((StgTSO *)p);
+        owner = (StgTSO*)p;
 
 #ifdef THREADED_RTS
         if (owner->cap != cap) {
@@ -262,7 +267,7 @@ loop:
 
         ASSERT(bq->bh == bh);
 
-        owner = deRefTSO(bq->owner);
+        owner = bq->owner;
 
         ASSERT(owner != END_TSO_QUEUE);
 
@@ -298,3 +303,46 @@ loop:
     return 0; // not blocked
 }
 
+// A shorter version of messageBlackHole(), that just returns the
+// owner (or NULL if the owner cannot be found, because the blackhole
+// has been updated in the meantime).
+
+StgTSO * blackHoleOwner (StgClosure *bh)
+{
+    const StgInfoTable *info;
+    StgClosure *p;
+
+    info = bh->header.info;
+
+    if (info != &stg_BLACKHOLE_info &&
+        info != &stg_CAF_BLACKHOLE_info && 
+        info != &__stg_EAGER_BLACKHOLE_info &&
+        info != &stg_WHITEHOLE_info) {
+        return NULL;
+    }
+
+    // The blackhole must indirect to a TSO, a BLOCKING_QUEUE, an IND,
+    // or a value.
+loop:
+    // NB. VOLATILE_LOAD(), because otherwise gcc hoists the load
+    // and turns this into an infinite loop.
+    p = UNTAG_CLOSURE((StgClosure*)VOLATILE_LOAD(&((StgInd*)bh)->indirectee));
+    info = p->header.info;
+
+    if (info == &stg_IND_info) goto loop;
+
+    else if (info == &stg_TSO_info)
+    {
+        return (StgTSO*)p;
+    }
+    else if (info == &stg_BLOCKING_QUEUE_CLEAN_info || 
+             info == &stg_BLOCKING_QUEUE_DIRTY_info)
+    {
+        StgBlockingQueue *bq = (StgBlockingQueue *)p;
+        return bq->owner;
+    }
+    
+    return NULL; // not blocked
+}
+
+