Fix a very rare crash in GHCi

[ghc-hetmet.git] / rts / sm / Scav.c

diff --git a/rts/sm/Scav.c b/rts/sm/Scav.c
index 75c186c..d01442b 100644 (file)
--- a/rts/sm/Scav.c
+++ b/rts/sm/Scav.c
@@ -69,10 +69,23 @@ scavengeTSO (StgTSO *tso)
     saved_eager = gct->eager_promotion;
     gct->eager_promotion = rtsFalse;
 
+
+    evacuate((StgClosure **)&tso->blocked_exceptions);
+    evacuate((StgClosure **)&tso->bq);
+    
+    // scavange current transaction record
+    evacuate((StgClosure **)&tso->trec);
+    
+    // scavenge this thread's stack 
+    scavenge_stack(tso->sp, &(tso->stack[tso->stack_size]));
+
+    tso->dirty = gct->failed_to_evac;
+
+    evacuate((StgClosure **)&tso->_link);
     if (   tso->why_blocked == BlockedOnMVar
        || tso->why_blocked == BlockedOnBlackHole
-       || tso->why_blocked == BlockedOnMsgWakeup
        || tso->why_blocked == BlockedOnMsgThrowTo
+        || tso->why_blocked == NotBlocked
        ) {
        evacuate(&tso->block_info.closure);
     }
@@ -86,26 +99,10 @@ scavengeTSO (StgTSO *tso)
     }
 #endif
 
-    evacuate((StgClosure **)&tso->blocked_exceptions);
-    evacuate((StgClosure **)&tso->bq);
-    
-    // scavange current transaction record
-    evacuate((StgClosure **)&tso->trec);
-    
-    // scavenge this thread's stack 
-    scavenge_stack(tso->sp, &(tso->stack[tso->stack_size]));
-
-    if (gct->failed_to_evac) {
-        tso->dirty = 1;
-        evacuate((StgClosure **)&tso->_link);
+    if (tso->dirty == 0 && gct->failed_to_evac) {
+        tso->flags |= TSO_LINK_DIRTY;
     } else {
-        tso->dirty = 0;
-        evacuate((StgClosure **)&tso->_link);
-        if (gct->failed_to_evac) {
-            tso->flags |= TSO_LINK_DIRTY;
-        } else {
-            tso->flags &= ~TSO_LINK_DIRTY;
-        }
+        tso->flags &= ~TSO_LINK_DIRTY;
     }
 
     gct->eager_promotion = saved_eager;
@@ -332,7 +329,7 @@ scavenge_srt (StgClosure **srt, nat srt_bitmap)
 
   while (bitmap != 0) {
       if ((bitmap & 1) != 0) {
-#if defined(__PIC__) && defined(mingw32_TARGET_OS)
+#if defined(__PIC__) && defined(mingw32_HOST_OS)
          // Special-case to handle references to closures hiding out in DLLs, since
          // double indirections required to get at those. The code generator knows
          // which is which when generating the SRT, so it stores the (indirect)
@@ -553,23 +550,6 @@ scavenge_block (bdescr *bd)
     }
 
     case IND_PERM:
-      if (bd->gen_no != 0) {
-#ifdef PROFILING
-        // @LDV profiling
-        // No need to call LDV_recordDead_FILL_SLOP_DYNAMIC() because an 
-        // IND_OLDGEN_PERM closure is larger than an IND_PERM closure.
-        LDV_recordDead((StgClosure *)p, sizeofW(StgInd));
-#endif        
-        // 
-        // Todo: maybe use SET_HDR() and remove LDV_RECORD_CREATE()?
-        //
-       SET_INFO(((StgClosure *)p), &stg_IND_OLDGEN_PERM_info);
-
-        // We pretend that p has just been created.
-        LDV_RECORD_CREATE((StgClosure *)p);
-      }
-       // fall through 
-    case IND_OLDGEN_PERM:
     case BLACKHOLE:
        evacuate(&((StgInd *)p)->indirectee);
        p += sizeofW(StgInd);
@@ -898,8 +878,7 @@ scavenge_mark_stack(void)
            // no "old" generation.
            break;
 
-       case IND_OLDGEN:
-       case IND_OLDGEN_PERM:
+       case IND:
         case BLACKHOLE:
            evacuate(&((StgInd *)p)->indirectee);
            break;
@@ -1286,8 +1265,6 @@ scavenge_one(StgPtr p)
         // IND can happen, for example, when the interpreter allocates
         // a gigantic AP closure (more than one block), which ends up
         // on the large-object list and then gets updated.  See #3424.
-    case IND_OLDGEN:
-    case IND_OLDGEN_PERM:
     case BLACKHOLE:
     case IND_STATIC:
        evacuate(&((StgInd *)p)->indirectee);
@@ -1407,6 +1384,13 @@ scavenge_mutable_list(bdescr *bd, generation *gen)
                     // ASSERT(tso->flags & TSO_LINK_DIRTY);
 
                     evacuate((StgClosure **)&tso->_link);
+                    if (   tso->why_blocked == BlockedOnMVar
+                        || tso->why_blocked == BlockedOnBlackHole
+                        || tso->why_blocked == BlockedOnMsgThrowTo
+                        || tso->why_blocked == NotBlocked
+                        ) {
+                        evacuate((StgClosure **)&tso->block_info.prev);
+                    }
                     if (gct->failed_to_evac) {
                         recordMutableGen_GC((StgClosure *)p,gen->no);
                         gct->failed_to_evac = rtsFalse;
@@ -1550,23 +1534,21 @@ scavenge_static(void)
 static void
 scavenge_large_bitmap( StgPtr p, StgLargeBitmap *large_bitmap, nat size )
 {
-    nat i, b;
+    nat i, j, b;
     StgWord bitmap;
     
     b = 0;
-    bitmap = large_bitmap->bitmap[b];
-    for (i = 0; i < size; ) {
-       if ((bitmap & 1) == 0) {
-           evacuate((StgClosure **)p);
-       }
-       i++;
-       p++;
-       if (i % BITS_IN(W_) == 0) {
-           b++;
-           bitmap = large_bitmap->bitmap[b];
-       } else {
+
+    for (i = 0; i < size; b++) {
+        bitmap = large_bitmap->bitmap[b];
+        j = stg_min(size-i, BITS_IN(W_));
+        i += j;
+        for (; j > 0; j--, p++) {
+            if ((bitmap & 1) == 0) {
+                evacuate((StgClosure **)p);
+            }
            bitmap = bitmap >> 1;
-       }
+        }            
     }
 }