JavaScriptCore-903.tar.gz

[apple/javascriptcore.git] / heap / MarkedBlock.cpp

diff --git a/heap/MarkedBlock.cpp b/heap/MarkedBlock.cpp
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+/*
+ * 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 "MarkedBlock.h"
+
+#include "JSCell.h"
+#include "JSObject.h"
+#include "JSZombie.h"
+#include "ScopeChain.h"
+
+namespace JSC {
+
+MarkedBlock* MarkedBlock::create(JSGlobalData* globalData, size_t cellSize)
+{
+    PageAllocationAligned allocation = PageAllocationAligned::allocate(blockSize, blockSize, OSAllocator::JSGCHeapPages);
+    if (!static_cast<bool>(allocation))
+        CRASH();
+    return new (allocation.base()) MarkedBlock(allocation, globalData, cellSize);
+}
+
+void MarkedBlock::destroy(MarkedBlock* block)
+{
+    for (size_t i = block->firstAtom(); i < block->m_endAtom; i += block->m_atomsPerCell)
+        reinterpret_cast<JSCell*>(&block->atoms()[i])->~JSCell();
+    block->m_allocation.deallocate();
+}
+
+MarkedBlock::MarkedBlock(const PageAllocationAligned& allocation, JSGlobalData* globalData, size_t cellSize)
+    : m_nextAtom(firstAtom())
+    , m_allocation(allocation)
+    , m_heap(&globalData->heap)
+    , m_prev(0)
+    , m_next(0)
+{
+    m_atomsPerCell = (cellSize + atomSize - 1) / atomSize;
+    m_endAtom = atomsPerBlock - m_atomsPerCell + 1;
+
+    Structure* dummyMarkableCellStructure = globalData->dummyMarkableCellStructure.get();
+    for (size_t i = firstAtom(); i < m_endAtom; i += m_atomsPerCell)
+        new (&atoms()[i]) JSCell(*globalData, dummyMarkableCellStructure, JSCell::CreatingEarlyCell);
+}
+
+void MarkedBlock::sweep()
+{
+    Structure* dummyMarkableCellStructure = m_heap->globalData()->dummyMarkableCellStructure.get();
+
+    for (size_t i = firstAtom(); i < m_endAtom; i += m_atomsPerCell) {
+        if (m_marks.get(i))
+            continue;
+
+        JSCell* cell = reinterpret_cast<JSCell*>(&atoms()[i]);
+#if ENABLE(JSC_ZOMBIES)
+        if (cell->structure() && cell->structure() != dummyMarkableCellStructure && !cell->isZombie()) {
+            const ClassInfo* info = cell->classInfo();
+            cell->~JSCell();
+            new (cell) JSZombie(*m_heap->globalData(), info, m_heap->globalData()->zombieStructure.get());
+            m_marks.set(i);
+        }
+#else
+        cell->~JSCell();
+        new (cell) JSCell(*m_heap->globalData(), dummyMarkableCellStructure);
+#endif
+    }
+}
+
+} // namespace JSC