Add a proper write barrier for MVars

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

diff --git a/rts/sm/Scav.c b/rts/sm/Scav.c
index f211401..54fe9a4 100644 (file)
--- a/rts/sm/Scav.c
+++ b/rts/sm/Scav.c
@@ -77,7 +77,7 @@ scavenge_srt (StgClosure **srt, nat srt_bitmap)
 
   while (bitmap != 0) {
       if ((bitmap & 1) != 0) {
-#ifdef ENABLE_WIN32_DLL_SUPPORT
+#if defined(__PIC__) && defined(mingw32_TARGET_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)
@@ -293,15 +293,23 @@ scavenge(step *stp)
     q = p;
     switch (info->type) {
 
-    case MVAR:
+    case MVAR_CLEAN:
+    case MVAR_DIRTY:
     { 
+       rtsBool saved_eager_promotion = eager_promotion;
+
        StgMVar *mvar = ((StgMVar *)p);
-       evac_gen = 0;
+       eager_promotion = rtsFalse;
        mvar->head = (StgTSO *)evacuate((StgClosure *)mvar->head);
        mvar->tail = (StgTSO *)evacuate((StgClosure *)mvar->tail);
        mvar->value = evacuate((StgClosure *)mvar->value);
-       evac_gen = saved_evac_gen;
-       failed_to_evac = rtsTrue; // mutable.
+       eager_promotion = saved_eager_promotion;
+
+       if (failed_to_evac) {
+           mvar->header.info = &stg_MVAR_DIRTY_info;
+       } else {
+           mvar->header.info = &stg_MVAR_CLEAN_info;
+       }
        p += sizeofW(StgMVar);
        break;
     }
@@ -696,17 +704,25 @@ linear_scan:
        q = p;
        switch (info->type) {
            
-       case MVAR:
-       {
-           StgMVar *mvar = ((StgMVar *)p);
-           evac_gen = 0;
-           mvar->head = (StgTSO *)evacuate((StgClosure *)mvar->head);
-           mvar->tail = (StgTSO *)evacuate((StgClosure *)mvar->tail);
-           mvar->value = evacuate((StgClosure *)mvar->value);
-           evac_gen = saved_evac_gen;
-           failed_to_evac = rtsTrue; // mutable.
-           break;
-       }
+        case MVAR_CLEAN:
+        case MVAR_DIRTY:
+        { 
+            rtsBool saved_eager_promotion = eager_promotion;
+            
+            StgMVar *mvar = ((StgMVar *)p);
+            eager_promotion = rtsFalse;
+            mvar->head = (StgTSO *)evacuate((StgClosure *)mvar->head);
+            mvar->tail = (StgTSO *)evacuate((StgClosure *)mvar->tail);
+            mvar->value = evacuate((StgClosure *)mvar->value);
+            eager_promotion = saved_eager_promotion;
+            
+            if (failed_to_evac) {
+                mvar->header.info = &stg_MVAR_DIRTY_info;
+            } else {
+                mvar->header.info = &stg_MVAR_CLEAN_info;
+            }
+            break;
+        }
 
        case FUN_2_0:
            scavenge_fun_srt(info);
@@ -1074,15 +1090,23 @@ scavenge_one(StgPtr p)
     
     switch (info->type) {
        
-    case MVAR:
+    case MVAR_CLEAN:
+    case MVAR_DIRTY:
     { 
+       rtsBool saved_eager_promotion = eager_promotion;
+
        StgMVar *mvar = ((StgMVar *)p);
-       evac_gen = 0;
+       eager_promotion = rtsFalse;
        mvar->head = (StgTSO *)evacuate((StgClosure *)mvar->head);
        mvar->tail = (StgTSO *)evacuate((StgClosure *)mvar->tail);
        mvar->value = evacuate((StgClosure *)mvar->value);
-       evac_gen = saved_evac_gen;
-       failed_to_evac = rtsTrue; // mutable.
+       eager_promotion = saved_eager_promotion;
+
+       if (failed_to_evac) {
+           mvar->header.info = &stg_MVAR_DIRTY_info;
+       } else {
+           mvar->header.info = &stg_MVAR_CLEAN_info;
+       }
        break;
     }
 
@@ -1409,6 +1433,10 @@ scavenge_mutable_list(generation *gen)
            case MUT_ARR_PTRS_FROZEN:
            case MUT_ARR_PTRS_FROZEN0:
                mutlist_MUTARRS++; break;
+           case MVAR_CLEAN:
+               barf("MVAR_CLEAN on mutable list");
+           case MVAR_DIRTY:
+               mutlist_MVARS++; break;
            default:
                mutlist_OTHERS++; break;
            }