X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=ghc%2Frts%2FWeak.c;h=bc993ecf3b6b8889d2510d03d9b59368479362af;hb=fd23905bf703daa9df3a0d6858d32aa737b0516b;hp=48e7310112f08052752b52ca1b77d1c78665bf2c;hpb=ed4cd6d403d932026f38608f81c3a8872e38b2ce;p=ghc-hetmet.git

diff --git a/ghc/rts/Weak.c b/ghc/rts/Weak.c
index 48e7310..bc993ec 100644
--- a/ghc/rts/Weak.c
+++ b/ghc/rts/Weak.c
@@ -1,68 +1,98 @@
 /* -----------------------------------------------------------------------------
- * $Id: Weak.c,v 1.4 1999/01/26 11:12:53 simonm Exp $
+ * $Id: Weak.c,v 1.15 2000/06/20 15:18:40 simonmar Exp $
  *
- * Weak pointers / finalisers
+ * (c) The GHC Team, 1998-1999
+ *
+ * Weak pointers / finalizers
  *
  * ---------------------------------------------------------------------------*/
 
 #include "Rts.h"
 #include "RtsAPI.h"
+#include "SchedAPI.h"
 #include "RtsFlags.h"
 #include "Weak.h"
 #include "Storage.h"
+#include "Prelude.h"
 
 StgWeak *weak_ptr_list;
 
 /*
- * finaliseWeakPointersNow() is called just before the system is shut
- * down.  It runs the finaliser for each weak pointer still in the
+ * finalizeWeakPointersNow() is called just before the system is shut
+ * down.  It runs the finalizer for each weak pointer still in the
  * system.
+ *
+ * Careful here - rts_evalIO might cause a garbage collection, which
+ * might change weak_ptr_list.  Must re-load weak_ptr_list each time
+ * around the loop.
  */
 
 void
-finaliseWeakPointersNow(void)
+finalizeWeakPointersNow(void)
 {
   StgWeak *w;
-
-  for (w = weak_ptr_list; w; w = w->link) {
-    IF_DEBUG(weak,fprintf(stderr,"Finalising weak pointer at %p -> %p\n", w, w->key));
-    w->header.info = &DEAD_WEAK_info;
-    rts_evalIO(w->finaliser,NULL);
+  
+  while ((w = weak_ptr_list)) {
+    weak_ptr_list = w->link;
+    if (w->header.info != &DEAD_WEAK_info) {
+	w->header.info = &DEAD_WEAK_info;
+	IF_DEBUG(weak,fprintf(stderr,"Finalising weak pointer at %p -> %p\n", w, w->key));
+	if (w->finalizer != &NO_FINALIZER_closure) {
+	    rts_evalIO(w->finalizer,NULL);
+	}
+    }
   }
 } 
 
 /*
- * scheduleFinalisers() is called on the list of weak pointers found
+ * scheduleFinalizers() is called on the list of weak pointers found
  * to be dead after a garbage collection.  It overwrites each object
- * with DEAD_WEAK, and creates a new thread for the finaliser.
+ * with DEAD_WEAK, and creates a new thread to run the pending finalizers.
+ *
+ * This function is called just after GC.  The weak pointers on the
+ * argument list are those whose keys were found to be not reachable,
+ * however the value and finalizer fields have by now been marked live.
+ * The weak pointer object itself may not be alive - i.e. we may be
+ * looking at either an object in from-space or one in to-space.  It
+ * doesn't really matter either way.
  */
 
 void
-scheduleFinalisers(StgWeak *list)
+scheduleFinalizers(StgWeak *list)
 {
-  StgWeak *w;
-  
-  for (w = list; w; w = w->link) {
-    IF_DEBUG(weak,fprintf(stderr,"Finalising weak pointer at %p -> %p\n", w, w->key));
-#ifdef INTERPRETER
-    createGenThread(RtsFlags.GcFlags.initialStkSize, w->finaliser);
-#else
-    createIOThread(RtsFlags.GcFlags.initialStkSize, w->finaliser);
-#endif
-    w->header.info = &DEAD_WEAK_info;
-  }
-}
+    StgWeak *w;
+    StgTSO *t;
+    StgMutArrPtrs *arr;
+    nat n;
 
-void
-markWeakList(void)
-{
-  StgWeak *w, **last_w;
+    /* count number of finalizers first... */
+    for (n = 0, w = list; w; w = w->link) { 
+	if (w->finalizer != &NO_FINALIZER_closure)
+	    n++;
+    }
+	
+    if (n == 0) return;
 
-  last_w = &weak_ptr_list;
-  for (w = weak_ptr_list; w; w = w->link) {
-    w = (StgWeak *)MarkRoot((StgClosure *)w);
-    *last_w = w;
-    last_w = &(w->link);
-  }
-}
+    IF_DEBUG(weak,fprintf(stderr,"weak: batching %d finalizers\n", n));
+
+    arr = (StgMutArrPtrs *)allocate(sizeofW(StgMutArrPtrs) + n);
+    SET_HDR(arr, &MUT_ARR_PTRS_FROZEN_info, CCS_SYSTEM);
+    arr->ptrs = n;
 
+    for (n = 0, w = list; w; w = w->link) {
+	if (w->finalizer != &NO_FINALIZER_closure) {
+	    arr->payload[n] = w->finalizer;
+	    n++;
+	}
+	w->header.info = &DEAD_WEAK_info;
+    }
+
+    t = createIOThread(RtsFlags.GcFlags.initialStkSize, 
+		       rts_apply(
+			   rts_apply(
+			       (StgClosure *)runFinalizerBatch_closure,
+			       rts_mkInt(n)), 
+			   (StgClosure *)arr)
+	);
+    scheduleThread(t);
+}