X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FWeak.c;h=f0103952212399ca567866428f27390ef0015430;hb=0372ac231bd18e993a2533f784805046876d5527;hp=db97eccedeacd54f058cb5dbbe0d78813d86de16;hpb=438596897ebbe25a07e1c82085cfbc5bdb00f09e;p=ghc-hetmet.git

diff --git a/ghc/rts/Weak.c b/ghc/rts/Weak.c
index db97ecc..f010395 100644
--- a/ghc/rts/Weak.c
+++ b/ghc/rts/Weak.c
@@ -1,68 +1,97 @@
 /* -----------------------------------------------------------------------------
- * $Id: Weak.c,v 1.2 1998/12/02 13:29:01 simonm Exp $
  *
- * Weak pointers / finalisers
+ * (c) The GHC Team, 1998-1999
+ *
+ * Weak pointers / finalizers
  *
  * ---------------------------------------------------------------------------*/
 
+#include "PosixSource.h"
+#define COMPILING_RTS_MAIN
 #include "Rts.h"
-#include "RtsAPI.h"
+#include "RtsUtils.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;
 
 /*
- * finaliseWeakPointersNow() is called just before the system is shut
- * down.  It runs the finaliser for each weak pointer still in the
- * system.
+ * 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 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.
+ *
+ * Pre-condition: sched_mutex _not_ held.
  */
 
 void
-finaliseWeakPointersNow(void)
+scheduleFinalizers(Capability *cap, StgWeak *list)
 {
-  StgWeak *w;
+    StgWeak *w;
+    StgTSO *t;
+    StgMutArrPtrs *arr;
+    nat n;
 
-  for (w = weak_ptr_list; w; w = w->link) {
-    IF_DEBUG(weak,fprintf(stderr,"Finalising weak pointer at %p\n", w));
-    w->header.info = &DEAD_WEAK_info;
-    rts_evalIO(w->finaliser,NULL);
-  }
-} 
+    // count number of finalizers, and kill all the weak pointers first...
+    n = 0;
+    for (w = list; w; w = w->link) { 
 
-/*
- * scheduleFinalisers() 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.
- */
+	// 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);
 
-void
-scheduleFinalisers(StgWeak *list)
-{
-  StgWeak *w;
-  
-  for (w = list; w; w = w->link) {
-    IF_DEBUG(weak,fprintf(stderr,"Finalising weak pointer at %p\n", w));
-#ifdef INTERPRETER
-    createGenThread(RtsFlags.GcFlags.initialStkSize, w->finaliser);
-#else
-    createIOThread(RtsFlags.GcFlags.initialStkSize, w->finaliser);
+	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
-    w->header.info = &DEAD_WEAK_info;
-  }
-}
+	SET_HDR(w, &stg_DEAD_WEAK_info, w->header.prof.ccs);
+    }
+	
+    // No finalizers to run?
+    if (n == 0) return;
 
-void
-markWeakList(void)
-{
-  StgWeak *w, **last_w;
+    IF_DEBUG(weak,debugBelch("weak: batching %d finalizers\n", n));
 
-  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);
-  }
-}
+    arr = (StgMutArrPtrs *)allocateLocal(cap, sizeofW(StgMutArrPtrs) + n);
+    TICK_ALLOC_PRIM(sizeofW(StgMutArrPtrs), n, 0);
+    SET_HDR(arr, &stg_MUT_ARR_PTRS_FROZEN_info, CCS_SYSTEM);
+    arr->ptrs = n;
 
+    n = 0;
+    for (w = list; w; w = w->link) {
+	if (w->finalizer != &stg_NO_FINALIZER_closure) {
+	    arr->payload[n] = w->finalizer;
+	    n++;
+	}
+    }
+
+    t = createIOThread(cap, 
+		       RtsFlags.GcFlags.initialStkSize, 
+		       rts_apply(cap,
+			   rts_apply(cap,
+			       (StgClosure *)runFinalizerBatch_closure,
+			       rts_mkInt(cap,n)), 
+			   (StgClosure *)arr)
+	);
+    scheduleThread(cap,t);
+}