[project @ 2004-08-13 13:04:50 by simonmar]

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

diff --git a/ghc/rts/Weak.c b/ghc/rts/Weak.c
index 7cbf989..ccb9eb2 100644 (file)
--- a/ghc/rts/Weak.c
+++ b/ghc/rts/Weak.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Weak.c,v 1.16 2000/11/13 14:40:37 simonmar Exp $
+ * $Id: Weak.c,v 1.32 2004/08/13 13:11:13 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -7,13 +7,16 @@
  *
  * ---------------------------------------------------------------------------*/
 
+#include "PosixSource.h"
+#define COMPILING_RTS_MAIN
 #include "Rts.h"
-#include "RtsAPI.h"
 #include "SchedAPI.h"
 #include "RtsFlags.h"
 #include "Weak.h"
 #include "Storage.h"
+#include "Schedule.h"
 #include "Prelude.h"
+#include "RtsAPI.h"
 
 StgWeak *weak_ptr_list;
 
@@ -32,16 +35,20 @@ finalizeWeakPointersNow(void)
 {
   StgWeak *w;
   
+  rts_lock();
   while ((w = weak_ptr_list)) {
     weak_ptr_list = w->link;
     if (w->header.info != &stg_DEAD_WEAK_info) {
-       w->header.info = &stg_DEAD_WEAK_info;
+       SET_HDR(w, &stg_DEAD_WEAK_info, w->header.prof.ccs);
        IF_DEBUG(weak,fprintf(stderr,"Finalising weak pointer at %p -> %p\n", w, w->key));
        if (w->finalizer != &stg_NO_FINALIZER_closure) {
-           rts_evalIO(w->finalizer,NULL);
+           rts_evalLazyIO(w->finalizer,NULL);
+           rts_unlock();
+           rts_lock();
        }
     }
   }
+  rts_unlock();
 } 
 
 /*
@@ -55,6 +62,8 @@ finalizeWeakPointersNow(void)
  * 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.
+ *
+ * Pre-condition: sched_mutex _not_ held.
  */
 
 void
@@ -65,26 +74,47 @@ scheduleFinalizers(StgWeak *list)
     StgMutArrPtrs *arr;
     nat n;
 
-    /* count number of finalizers first... */
-    for (n = 0, w = list; w; w = w->link) { 
-       if (w->finalizer != &stg_NO_FINALIZER_closure)
+    // count number of finalizers, and kill all the weak pointers first...
+    n = 0;
+    for (w = list; w; w = w->link) { 
+
+       // Better not be a DEAD_WEAK at this stage; the garbage
+       // collector removes DEAD_WEAKs from the weak pointer list.
+       ASSERT(w->header.info != &stg_DEAD_WEAK_info);
+
+       if (w->finalizer != &stg_NO_FINALIZER_closure) {
            n++;
+       }
+
+#ifdef PROFILING
+        // A weak pointer is inherently used, so we do not need to call
+        // LDV_recordDead().
+       //
+        // Furthermore, when PROFILING is turned on, dead weak
+        // pointers are exactly as large as weak pointers, so there is
+        // no need to fill the slop, either.  See stg_DEAD_WEAK_info
+        // in StgMiscClosures.hc.
+#endif
+       SET_HDR(w, &stg_DEAD_WEAK_info, w->header.prof.ccs);
     }
        
+    // No finalizers to run?
     if (n == 0) return;
 
     IF_DEBUG(weak,fprintf(stderr,"weak: batching %d finalizers\n", n));
 
     arr = (StgMutArrPtrs *)allocate(sizeofW(StgMutArrPtrs) + n);
+    TICK_ALLOC_PRIM(sizeofW(StgMutArrPtrs), n, 0);
     SET_HDR(arr, &stg_MUT_ARR_PTRS_FROZEN_info, CCS_SYSTEM);
+    arr->mut_link = NULL;
     arr->ptrs = n;
 
-    for (n = 0, w = list; w; w = w->link) {
+    n = 0;
+    for (w = list; w; w = w->link) {
        if (w->finalizer != &stg_NO_FINALIZER_closure) {
            arr->payload[n] = w->finalizer;
            n++;
        }
-       w->header.info = &stg_DEAD_WEAK_info;
     }
 
     t = createIOThread(RtsFlags.GcFlags.initialStkSize,