[project @ 2001-03-14 15:01:04 by sewardj]

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

diff --git a/ghc/rts/Schedule.c b/ghc/rts/Schedule.c
index 665e60f..14be29b 100644 (file)
--- a/ghc/rts/Schedule.c
+++ b/ghc/rts/Schedule.c
@@ -1,5 +1,5 @@
 /* ---------------------------------------------------------------------------
- * $Id: Schedule.c,v 1.89 2001/02/09 13:09:16 simonmar Exp $
+ * $Id: Schedule.c,v 1.93 2001/03/02 16:15:53 simonmar Exp $
  *
  * (c) The GHC Team, 1998-2000
  *
@@ -877,25 +877,18 @@ schedule( void )
     switch (cap->rCurrentTSO->what_next) {
     case ThreadKilled:
     case ThreadComplete:
-      /* Thread already finished, return to scheduler. */
-      ret = ThreadFinished;
-      break;
+       /* Thread already finished, return to scheduler. */
+       ret = ThreadFinished;
+       break;
     case ThreadEnterGHC:
-      ret = StgRun((StgFunPtr) stg_enterStackTop, cap);
-      break;
+       ret = StgRun((StgFunPtr) stg_enterStackTop, cap);
+       break;
     case ThreadRunGHC:
-      ret = StgRun((StgFunPtr) stg_returnToStackTop, cap);
-      break;
+       ret = StgRun((StgFunPtr) stg_returnToStackTop, cap);
+       break;
     case ThreadEnterInterp:
-#ifdef GHCI
-      {
-        IF_DEBUG(scheduler,sched_belch("entering interpreter"));
-        ret = interpretBCO(cap);
-         break;
-      }
-#else
-      barf("Panic: entered a BCO but no bytecode interpreter in this build");
-#endif
+       ret = interpretBCO(cap);
+       break;
     default:
       barf("schedule: invalid what_next field");
     }
@@ -2497,6 +2490,12 @@ unblockThread(StgTSO *tso)
       StgTSO *target  = tso->block_info.tso;
 
       ASSERT(get_itbl(target)->type == TSO);
+
+      if (target->what_next == ThreadRelocated) {
+         target = target->link;
+         ASSERT(get_itbl(target)->type == TSO);
+      }
+
       ASSERT(target->blocked_exceptions != NULL);
 
       last = (StgBlockingQueueElement **)&target->blocked_exceptions;
@@ -2617,6 +2616,12 @@ unblockThread(StgTSO *tso)
       StgTSO *target  = tso->block_info.tso;
 
       ASSERT(get_itbl(target)->type == TSO);
+
+      while (target->what_next == ThreadRelocated) {
+         target = target->link;
+         ASSERT(get_itbl(target)->type == TSO);
+      }
+      
       ASSERT(target->blocked_exceptions != NULL);
 
       last = &target->blocked_exceptions;
@@ -2836,14 +2841,24 @@ raiseAsync(StgTSO *tso, StgClosure *exception)
        /* Replace the updatee with an indirection - happily
         * this will also wake up any threads currently
         * waiting on the result.
+        *
+        * Warning: if we're in a loop, more than one update frame on
+        * the stack may point to the same object.  Be careful not to
+        * overwrite an IND_OLDGEN in this case, because we'll screw
+        * up the mutable lists.  To be on the safe side, don't
+        * overwrite any kind of indirection at all.  See also
+        * threadSqueezeStack in GC.c, where we have to make a similar
+        * check.
         */
-       UPD_IND_NOLOCK(su->updatee,ap);  /* revert the black hole */
+       if (!closure_IND(su->updatee)) {
+           UPD_IND_NOLOCK(su->updatee,ap);  /* revert the black hole */
+       }
        su = su->link;
        sp += sizeofW(StgUpdateFrame) -1;
        sp[0] = (W_)ap; /* push onto stack */
        break;
       }
-      
+
     case CATCH_FRAME:
       {
        StgCatchFrame *cf = (StgCatchFrame *)su;
@@ -2973,6 +2988,11 @@ detectBlackHoles( void )
 
     for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
 
+       while (t->what_next == ThreadRelocated) {
+           t = t->link;
+           ASSERT(get_itbl(t)->type == TSO);
+       }
+      
        if (t->why_blocked != BlockedOnBlackHole) {
            continue;
        }