From 6d139a1da0b2d0c6dae379b55db8560327f2f655 Mon Sep 17 00:00:00 2001
From: Jon Coppeard <jcoppeard@mozilla.com>
Date: Mon, 18 Nov 2013 17:21:43 +0000
Subject: [PATCH] Bug 934442 - Defer finalization of object ID table until
 after minor GC r=terrence

---
 js/ipc/JavaScriptShared.cpp | 33 ++++++++++++++++++++++-----------
 js/ipc/JavaScriptShared.h   |  3 ++-
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/js/ipc/JavaScriptShared.cpp b/js/ipc/JavaScriptShared.cpp
index 27681aafccb..2262a0ea1cb 100644
--- a/js/ipc/JavaScriptShared.cpp
+++ b/js/ipc/JavaScriptShared.cpp
@@ -6,6 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "JavaScriptShared.h"
+#include "mozilla/dom/BindingUtils.h"
 #include "jsfriendapi.h"
 #include "xpcprivate.h"
 
@@ -57,20 +58,30 @@ ObjectStore::remove(ObjectId id)
 }
 
 ObjectIdCache::ObjectIdCache()
-  : table_(SystemAllocPolicy())
+  : table_(nullptr)
 {
 }
 
+ObjectIdCache::~ObjectIdCache()
+{
+    if (table_) {
+        dom::AddForDeferredFinalization<ObjectIdTable, nsAutoPtr>(table_);
+        table_ = nullptr;
+    }
+}
+
 bool
 ObjectIdCache::init()
 {
-    return table_.init(32);
+    MOZ_ASSERT(!table_);
+    table_ = new ObjectIdTable(SystemAllocPolicy());
+    return table_ && table_->init(32);
 }
 
 void
 ObjectIdCache::trace(JSTracer *trc)
 {
-    for (ObjectIdTable::Range r(table_.all()); !r.empty(); r.popFront()) {
+    for (ObjectIdTable::Range r(table_->all()); !r.empty(); r.popFront()) {
         JSObject *obj = r.front().key;
         JS_CallObjectTracer(trc, &obj, "ipc-id");
         MOZ_ASSERT(obj == r.front().key);
@@ -80,7 +91,7 @@ ObjectIdCache::trace(JSTracer *trc)
 ObjectId
 ObjectIdCache::find(JSObject *obj)
 {
-    ObjectIdTable::Ptr p = table_.lookup(obj);
+    ObjectIdTable::Ptr p = table_->lookup(obj);
     if (!p)
         return 0;
     return p->value;
@@ -89,9 +100,9 @@ ObjectIdCache::find(JSObject *obj)
 bool
 ObjectIdCache::add(JSContext *cx, JSObject *obj, ObjectId id)
 {
-    if (!table_.put(obj, id))
+    if (!table_->put(obj, id))
         return false;
-    JS_StoreObjectPostBarrierCallback(cx, keyMarkCallback, obj, this);
+    JS_StoreObjectPostBarrierCallback(cx, keyMarkCallback, obj, table_);
     return true;
 }
 
@@ -100,18 +111,18 @@ ObjectIdCache::add(JSContext *cx, JSObject *obj, ObjectId id)
  * been moved.
  */
 /* static */ void
-ObjectIdCache::keyMarkCallback(JSTracer *trc, void *k, void *d) {
-    JSObject *key = static_cast<JSObject*>(k);
-    ObjectIdCache* self = static_cast<ObjectIdCache*>(d);
+ObjectIdCache::keyMarkCallback(JSTracer *trc, void *keyArg, void *dataArg) {
+    JSObject *key = static_cast<JSObject*>(keyArg);
+    ObjectIdTable* table = static_cast<ObjectIdTable*>(dataArg);
     JSObject *prior = key;
     JS_CallObjectTracer(trc, &key, "ObjectIdCache::table_ key");
-    self->table_.rekeyIfMoved(prior, key);
+    table->rekeyIfMoved(prior, key);
 }
 
 void
 ObjectIdCache::remove(JSObject *obj)
 {
-    table_.remove(obj);
+    table_->remove(obj);
 }
 
 bool
diff --git a/js/ipc/JavaScriptShared.h b/js/ipc/JavaScriptShared.h
index 63b99c14182..0316be50ab8 100644
--- a/js/ipc/JavaScriptShared.h
+++ b/js/ipc/JavaScriptShared.h
@@ -65,6 +65,7 @@ class ObjectIdCache
 
   public:
     ObjectIdCache();
+    ~ObjectIdCache();
 
     bool init();
     void trace(JSTracer *trc);
@@ -76,7 +77,7 @@ class ObjectIdCache
   private:
     static void keyMarkCallback(JSTracer *trc, void *key, void *data);
 
-    ObjectIdTable table_;
+    ObjectIdTable *table_;
 };
 
 class JavaScriptShared