Bug 945813 - Paper over cycle collection problem in IndexedDB. r=mccr8, r=khuey

dom/indexedDB/test/unit/test_cursor_cycle.js

@@ -0,0 +1,46 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+var testGenerator = testSteps();
+
+function testSteps()
+{
+  const Bob = { ss: "237-23-7732", name: "Bob" };
+
+  let request = indexedDB.open(this.window ? window.location.pathname : "Splendid Test", 1);
+  request.onerror = errorHandler;
+  request.onupgradeneeded = grabEventAndContinueHandler;
+  let event = yield undefined;
+
+  let db = event.target.result;
+  event.target.onsuccess = continueToNextStep;
+
+  let objectStore = db.createObjectStore("foo", { keyPath: "ss" });
+  objectStore.createIndex("name", "name", { unique: true });
+  objectStore.add(Bob);
+  yield undefined;
+
+  // This direct eval causes locals to be aliased, and thus allocated on
+  // the scope chain.  Comment it out (and the workarounds below) and
+  // the test passes.  Bug 943409.
+  eval('');
+
+  db.transaction("foo", "readwrite").objectStore("foo")
+    .index("name").openCursor().onsuccess = function(event) {
+    event.target.transaction.oncomplete = continueToNextStep;
+    let cursor = event.target.result;
+    if (cursor) {
+      let objectStore = event.target.transaction.objectStore("foo");
+      objectStore.delete(Bob.ss)
+                 .onsuccess = function(event) { cursor.continue(); };
+    }
+  };
+  yield undefined;
+  finishTest();
+
+  objectStore = null; // Bug 943409 workaround.
+
+  yield undefined;
+}

dom/indexedDB/test/unit/test_cursor_mutation.js

@@ -35,6 +35,11 @@ function testSteps()
   let objectStore = db.createObjectStore("foo", { keyPath: "ss" });
   objectStore.createIndex("name", "name", { unique: true });
 
+  // This direct eval causes locals to be aliased, and thus allocated on
+  // the scope chain.  Comment it out (and the workarounds below) and
+  // the test passes.  Bug 943409.
+  eval('');
+
   for (let i = 0; i < objectStoreData.length - 1; i++) {
     objectStore.add(objectStoreData[i]);
   }
@@ -111,5 +116,8 @@ function testSteps()
   is(sawRemoved, false, "Didn't see item that was removed");
 
   finishTest();
+
+  objectStore = null; // Bug 943409 workaround.
+
   yield undefined;
 }

dom/indexedDB/test/unit/test_index_object_cursors.js

@@ -34,6 +34,9 @@ function testSteps()
 
   event.target.onsuccess = continueToNextStep;
 
+  // Bug 943409.
+  eval('');
+
   for (let objectStoreIndex in objectStoreData) {
     const objectStoreInfo = objectStoreData[objectStoreIndex];
     let objectStore = db.createObjectStore(objectStoreInfo.name,
@@ -137,6 +140,8 @@ function testSteps()
         .objectStore(objectStoreName).clear()
         .onsuccess = continueToNextStep;
       yield undefined;
+
+      objectStore = index = null; // Bug 943409 workaround.
     }
   }
 

dom/indexedDB/test/unit/test_index_update_delete.js

@@ -18,6 +18,9 @@ function testSteps()
   let db = event.target.result;
   db.onerror = errorHandler;
 
+  // Bug 943409.
+  eval('');
+
   for each (let autoIncrement in [false, true]) {
     let objectStore =
       db.createObjectStore(autoIncrement, { keyPath: "id",
@@ -159,9 +162,13 @@ function testSteps()
 
       is(event.target.result, indexCount,
          "Correct number of entries in index");
+
+      index = event = null; // Bug 943409 workaround.
     }
+    objectStore = event = null; // Bug 943409 workaround.
   }
 
   finishTest();
+  event = db = request = null; // Bug 943409 workaround.
   yield undefined;
 }

dom/indexedDB/test/unit/xpcshell.ini

@@ -21,6 +21,7 @@ support-files =
 [test_create_index.js]
 [test_create_index_with_integer_keys.js]
 [test_create_objectStore.js]
+[test_cursor_cycle.js]
 [test_cursor_mutation.js]
 [test_cursor_update_updates_indexes.js]
 [test_cursors.js]

xpcom/base/nsCycleCollector.cpp

@@ -2723,8 +2723,8 @@ void
 nsCycleCollector::ShutdownCollect()
 {
     SliceBudget unlimitedBudget;
-    for (uint32_t i = 0; i < DEFAULT_SHUTDOWN_COLLECTIONS; ++i) {
-        NS_ASSERTION(i < NORMAL_SHUTDOWN_COLLECTIONS, "Extra shutdown CC");
+    uint32_t i;
+    for (i = 0; i < DEFAULT_SHUTDOWN_COLLECTIONS; ++i) {
         if (!Collect(ShutdownCC, unlimitedBudget, nullptr)) {
             break;
         }