Bug 672112 - Fix PICTable bug in tracer (r=dmandelin)

js/src/jstracer.cpp

@@ -1662,6 +1662,7 @@ TreeFragment::initialize(JSContext* cx, SlotList *globalSlots, bool speculate)
     this->shapes.clear();
     this->unstableExits = NULL;
     this->sideExits.clear();
+    this->picTables.clear();
 
     /* Determine the native frame layout at the entry point. */
     this->nativeStackBase = (nStackTypes - (cx->regs().sp - cx->fp()->base())) *
@@ -2890,23 +2891,61 @@ HasUnreachableGCThings(JSContext *cx, TreeFragment *f)
      */
     if (IsAboutToBeFinalized(cx, f->globalObj))
         return true;
-    Value* vp = f->gcthings.data();
+    Value* vs = f->gcthings.data();
-    for (unsigned len = f->gcthings.length(); len; --len) {
+    for (unsigned i = 0; i < f->gcthings.length(); ++i) {
-        Value &v = *vp++;
+        Value &v = vs[i];
         JS_ASSERT(v.isMarkable());
         if (IsAboutToBeFinalized(cx, v.toGCThing()))
             return true;
     }
-    const Shape** shapep = f->shapes.data();
+    const Shape** shapes = f->shapes.data();
-    for (unsigned len = f->shapes.length(); len; --len) {
+    for (unsigned i = 0; i < f->shapes.length(); ++i) {
-        const Shape* shape = *shapep++;
+        if (IsAboutToBeFinalized(cx, shapes[i]))
-        if (IsAboutToBeFinalized(cx, shape))
             return true;
     }
 
     return false;
 }
 
+static const size_t PIC_TABLE_ENTRY_COUNT = 32;
+
+struct PICTableEntry
+{
+    jsid    id;
+    uint32  shape;
+    uint32  slot;
+};
+
+struct PICTable
+{
+    PICTable() : entryCount(0) {}
+
+    PICTableEntry   entries[PIC_TABLE_ENTRY_COUNT];
+    uint32          entryCount;
+
+    bool scan(uint32 shape, jsid id, uint32 *slotOut) {
+        for (size_t i = 0; i < entryCount; ++i) {
+            PICTableEntry &entry = entries[i];
+            if (entry.shape == shape && entry.id == id) {
+                *slotOut = entry.slot;
+                return true;
+            }
+        }
+        return false;
+    }
+
+    void update(uint32 shape, jsid id, uint32 slot) {
+        if (entryCount >= PIC_TABLE_ENTRY_COUNT)
+            return;
+        PICTableEntry &newEntry = entries[entryCount++];
+        newEntry.shape = shape;
+        newEntry.id = id;
+        newEntry.slot = slot;
+    }
+
+    void clear() { entryCount = 0; }
+};
+
 static bool
 ContainsUnrechableGCThingImpl(JSContext *cx, TreeFragment *f)
 {
@@ -2975,7 +3014,7 @@ void
 TraceMonitor::sweep(JSContext *cx)
 {
     JS_ASSERT(!ontrace());
-    debug_only_print0(LC_TMTracer, "Purging fragments with dead things");
+    debug_only_print0(LC_TMTracer, "Purging fragments with dead things\n");
 
     bool shouldAbortRecording = false;
     TreeFragment *recorderTree = NULL;
@@ -2983,7 +3022,7 @@ TraceMonitor::sweep(JSContext *cx)
         recorderTree = recorder->getTree();
         shouldAbortRecording = HasUnreachableGCThings(cx, recorderTree);
     }
-        
+
     for (size_t i = 0; i < FRAGMENT_TABLE_SIZE; ++i) {
         TreeFragment** fragp = &vmfragments[i];
         while (TreeFragment* frag = *fragp) {
@@ -2997,9 +3036,9 @@ TraceMonitor::sweep(JSContext *cx)
                 fragp = &frag->next;
                 continue;
             }
-            
+
             debug_only_printf(LC_TMTracer,
-                              "TreeFragment peer %p has dead gc thing."
+                              "TreeFragment peer %p has dead gc thing. "
                               "Disconnecting tree %p with ip %p\n",
                               (void *) peer, (void *) frag, frag->ip);
             JS_ASSERT(frag->root == frag);
@@ -3014,17 +3053,21 @@ TraceMonitor::sweep(JSContext *cx)
         }
     }
 
-#ifdef DEBUG
+    /* These tables contain GC things, so they must be cleared on GC. */
     for (size_t i = 0; i < FRAGMENT_TABLE_SIZE; ++i) {
         for (TreeFragment* frag = vmfragments[i]; frag; frag = frag->next) {
             TreeFragment* peer = frag;
             do {
                 JS_ASSERT(!peer->visiting);
+
+                PICTable** tables = peer->picTables.data();
+                for (unsigned j = 0; j < peer->picTables.length(); ++j)
+                    tables[j]->clear();
+
                 peer = peer->peer;
             } while (peer);
         }
     }
-#endif
 
     if (shouldAbortRecording)
         recorder->finishAbort("dead GC things");
@@ -12562,43 +12605,6 @@ RootedStringToId(JSContext* cx, JSString** namep, jsid* idp)
     return true;
 }
 
-static const size_t PIC_TABLE_ENTRY_COUNT = 32;
-
-struct PICTableEntry
-{
-    jsid    id;
-    uint32  shape;
-    uint32  slot;
-};
-
-struct PICTable
-{
-    PICTable() : entryCount(0) {}
-
-    PICTableEntry   entries[PIC_TABLE_ENTRY_COUNT];
-    uint32          entryCount;
-
-    bool scan(uint32 shape, jsid id, uint32 *slotOut) {
-        for (size_t i = 0; i < entryCount; ++i) {
-            PICTableEntry &entry = entries[i];
-            if (entry.shape == shape && entry.id == id) {
-                *slotOut = entry.slot;
-                return true;
-            }
-        }
-        return false;
-    }
-
-    void update(uint32 shape, jsid id, uint32 slot) {
-        if (entryCount >= PIC_TABLE_ENTRY_COUNT)
-            return;
-        PICTableEntry &newEntry = entries[entryCount++];
-        newEntry.shape = shape;
-        newEntry.id = id;
-        newEntry.slot = slot;
-    }
-};
-
 static JSBool FASTCALL
 GetPropertyByName(JSContext* cx, JSObject* obj, JSString** namep, Value* vp, PICTable *picTable)
 {
@@ -12691,6 +12697,7 @@ TraceRecorder::getPropertyByName(LIns* obj_ins, Value* idvalp, Value* outp)
     LIns* vp_ins = w.name(w.allocp(sizeof(Value)), "vp");
     LIns* idvalp_ins = w.name(addr(idvalp), "idvalp");
     PICTable *picTable = new (traceAlloc()) PICTable();
+    tree->picTables.add(picTable);
     LIns* pic_ins = w.nameImmpNonGC(picTable);
     LIns* args[] = {pic_ins, vp_ins, idvalp_ins, obj_ins, cx_ins};
     LIns* ok_ins = w.call(&GetPropertyByName_ci, args);

js/src/jstracer.h

@@ -539,6 +539,8 @@ struct LinkableFragment : public VMFragment
     SlotList*               globalSlots;
 };
 
+struct PICTable;
+
 /*
  * argc is cx->fp->argc at the trace loop header, i.e., the number of arguments
  * pushed for the innermost JS frame. This is required as part of the fragment
@@ -564,6 +566,7 @@ struct TreeFragment : public LinkableFragment
         sideExits(alloc),
         gcthings(alloc),
         shapes(alloc),
+        picTables(alloc),
         visiting(false)
     { }
 
@@ -590,6 +593,7 @@ struct TreeFragment : public LinkableFragment
     /* All embedded GC things are registered here so the GC can scan them. */
     Queue<Value>            gcthings;
     Queue<const js::Shape*> shapes;
+    Queue<PICTable*>        picTables;
     unsigned                maxNativeStackSlots;
     /* Gives the number of times we have entered this trace. */
     uintN                   execs;