[project @ 2001-03-02 16:15:53 by simonmar]

[ghc-hetmet.git] / ghc / rts / Storage.h

diff --git a/ghc/rts/Storage.h b/ghc/rts/Storage.h
index 6311084..f446c0a 100644 (file)
--- a/ghc/rts/Storage.h
+++ b/ghc/rts/Storage.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Storage.h,v 1.29 2001/02/11 17:51:08 simonmar Exp $
+ * $Id: Storage.h,v 1.31 2001/03/02 16:15:53 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -164,11 +164,17 @@ recordOldToNewPtrs(StgMutClosure *p)
 
 /* In the DEBUG case, we also zero out the slop of the old closure,
  * so that the sanity checker can tell where the next closure is.
+ *
+ * Two important invariants: we should never try to update a closure
+ * to point to itself, and the closure being updated should not
+ * already have been updated (the mutable list will get messed up
+ * otherwise).
  */
 #define updateWithIndirection(info, p1, p2)                            \
   {                                                                    \
     bdescr *bd;                                                                \
                                                                        \
+    ASSERT( p1 != p2 && !closure_IND(p1) );                            \
     bd = Bdescr((P_)p1);                                               \
     if (bd->gen->no == 0) {                                            \
       ((StgInd *)p1)->indirectee = p2;                                 \
@@ -176,14 +182,14 @@ recordOldToNewPtrs(StgMutClosure *p)
       TICK_UPD_NEW_IND();                                              \
     } else {                                                           \
       if (info != &stg_BLACKHOLE_BQ_info) {                            \
-       {                                                               \
+       {                                                               \
           StgInfoTable *inf = get_itbl(p1);                            \
          nat np = inf->layout.payload.ptrs,                            \
              nw = inf->layout.payload.nptrs, i;                        \
-          if (inf->type != THUNK_SELECTOR) {                            \
+          if (inf->type != THUNK_SELECTOR) {                           \
              for (i = np; i < np + nw; i++) {                          \
                ((StgClosure *)p1)->payload[i] = 0;                     \
-             }                                                          \
+             }                                                         \
           }                                                            \
         }                                                              \
         ACQUIRE_LOCK(&sm_mutex);                                       \
@@ -202,6 +208,7 @@ recordOldToNewPtrs(StgMutClosure *p)
  */
 #define updateWithStaticIndirection(info, p1, p2)                      \
   {                                                                    \
+    ASSERT( p1 != p2 && !closure_IND(p1) );                            \
     ASSERT( ((StgMutClosure*)p1)->mut_link == NULL );                  \
                                                                        \
     ACQUIRE_LOCK(&sm_mutex);                                           \
@@ -220,6 +227,7 @@ updateWithPermIndirection(const StgInfoTable *info, StgClosure *p1, StgClosure *
 {
   bdescr *bd;
 
+  ASSERT( p1 != p2 && !closure_IND(p1) );
   bd = Bdescr((P_)p1);
   if (bd->gen->no == 0) {
     ((StgInd *)p1)->indirectee = p2;