summaryrefslogtreecommitdiffstats
path: root/Source/JavaScriptCore/heap/HandleHeap.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'Source/JavaScriptCore/heap/HandleHeap.cpp')
-rw-r--r--Source/JavaScriptCore/heap/HandleHeap.cpp174
1 files changed, 174 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/heap/HandleHeap.cpp b/Source/JavaScriptCore/heap/HandleHeap.cpp
new file mode 100644
index 0000000..1a0051e
--- /dev/null
+++ b/Source/JavaScriptCore/heap/HandleHeap.cpp
@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2011 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "HandleHeap.h"
+
+#include "JSObject.h"
+
+namespace JSC {
+
+WeakHandleOwner::~WeakHandleOwner()
+{
+}
+
+bool WeakHandleOwner::isReachableFromOpaqueRoots(Handle<Unknown>, void*, MarkStack&)
+{
+ return false;
+}
+
+void WeakHandleOwner::finalize(Handle<Unknown>, void*)
+{
+}
+
+HandleHeap::HandleHeap(JSGlobalData* globalData)
+ : m_globalData(globalData)
+ , m_nextToFinalize(0)
+{
+ grow();
+}
+
+void HandleHeap::grow()
+{
+ Node* block = m_blockStack.grow();
+ for (int i = m_blockStack.blockLength - 1; i >= 0; --i) {
+ Node* node = &block[i];
+ new (node) Node(this);
+ m_freeList.push(node);
+ }
+}
+
+void HandleHeap::markStrongHandles(HeapRootMarker& heapRootMarker)
+{
+ Node* end = m_strongList.end();
+ for (Node* node = m_strongList.begin(); node != end; node = node->next())
+ heapRootMarker.mark(node->slot());
+}
+
+void HandleHeap::markWeakHandles(HeapRootMarker& heapRootMarker)
+{
+ MarkStack& markStack = heapRootMarker.markStack();
+
+ Node* end = m_weakList.end();
+ for (Node* node = m_weakList.begin(); node != end; node = node->next()) {
+ ASSERT(isValidWeakNode(node));
+ JSCell* cell = node->slot()->asCell();
+ if (Heap::isMarked(cell))
+ continue;
+
+ WeakHandleOwner* weakOwner = node->weakOwner();
+ if (!weakOwner)
+ continue;
+
+ if (!weakOwner->isReachableFromOpaqueRoots(Handle<Unknown>::wrapSlot(node->slot()), node->weakOwnerContext(), markStack))
+ continue;
+
+ heapRootMarker.mark(node->slot());
+ }
+}
+
+void HandleHeap::finalizeWeakHandles()
+{
+ Node* end = m_weakList.end();
+ for (Node* node = m_weakList.begin(); node != end; node = m_nextToFinalize) {
+ m_nextToFinalize = node->next();
+
+ ASSERT(isValidWeakNode(node));
+ JSCell* cell = node->slot()->asCell();
+ if (Heap::isMarked(cell))
+ continue;
+
+ if (WeakHandleOwner* weakOwner = node->weakOwner()) {
+ weakOwner->finalize(Handle<Unknown>::wrapSlot(node->slot()), node->weakOwnerContext());
+ if (m_nextToFinalize != node->next()) // Owner deallocated node.
+ continue;
+ }
+
+ *node->slot() = JSValue();
+ SentinelLinkedList<Node>::remove(node);
+ m_immediateList.push(node);
+ }
+
+ m_nextToFinalize = 0;
+}
+
+void HandleHeap::writeBarrier(HandleSlot slot, const JSValue& value)
+{
+ ASSERT(!m_nextToFinalize); // Forbid assignment to handles during the finalization phase, since it would violate many GC invariants.
+
+ if (!value == !*slot && slot->isCell() == value.isCell())
+ return;
+
+ Node* node = toNode(slot);
+ SentinelLinkedList<Node>::remove(node);
+ if (!value || !value.isCell()) {
+ m_immediateList.push(node);
+ return;
+ }
+
+ if (node->isWeak()) {
+ m_weakList.push(node);
+ return;
+ }
+
+ m_strongList.push(node);
+}
+
+unsigned HandleHeap::protectedGlobalObjectCount()
+{
+ unsigned count = 0;
+ Node* end = m_strongList.end();
+ for (Node* node = m_strongList.begin(); node != end; node = node->next()) {
+ JSValue value = *node->slot();
+ if (value.isObject() && asObject(value.asCell())->isGlobalObject())
+ count++;
+ }
+ return count;
+}
+
+#if !ASSERT_DISABLED
+bool HandleHeap::isValidWeakNode(Node* node)
+{
+ if (!node->isWeak())
+ return false;
+
+ JSValue value = *node->slot();
+ if (!value || !value.isCell())
+ return false;
+
+ JSCell* cell = value.asCell();
+ if (!cell || !cell->structure())
+ return false;
+
+#if ENABLE(JSC_ZOMBIES)
+ if (cell->isZombie())
+ return false;
+#endif
+
+ return true;
+}
+#endif
+
+} // namespace JSC