JavaScriptCore-903.tar.gz

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

diff --git a/heap/MarkedSpace.cpp b/heap/MarkedSpace.cpp
new file mode 100644 (file)
index 0000000..77f6e52
--- /dev/null
+++ b/heap/MarkedSpace.cpp
@@ -0,0 +1,167 @@
+/*
+ *  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
+ *  Copyright (C) 2007 Eric Seidel <eric@webkit.org>
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include "config.h"
+#include "MarkedSpace.h"
+
+#include "JSGlobalObject.h"
+#include "JSCell.h"
+#include "JSGlobalData.h"
+#include "JSLock.h"
+#include "JSObject.h"
+#include "ScopeChain.h"
+
+namespace JSC {
+
+class Structure;
+
+MarkedSpace::MarkedSpace(JSGlobalData* globalData)
+    : m_waterMark(0)
+    , m_highWaterMark(0)
+    , m_globalData(globalData)
+{
+    for (size_t cellSize = preciseStep; cellSize < preciseCutoff; cellSize += preciseStep)
+        sizeClassFor(cellSize).cellSize = cellSize;
+
+    for (size_t cellSize = impreciseStep; cellSize < impreciseCutoff; cellSize += impreciseStep)
+        sizeClassFor(cellSize).cellSize = cellSize;
+}
+
+void MarkedSpace::destroy()
+{
+    clearMarks();
+    shrink();
+    ASSERT(!size());
+}
+
+MarkedBlock* MarkedSpace::allocateBlock(SizeClass& sizeClass)
+{
+    MarkedBlock* block = MarkedBlock::create(globalData(), sizeClass.cellSize);
+    sizeClass.blockList.append(block);
+    sizeClass.nextBlock = block;
+    m_blocks.add(block);
+
+    return block;
+}
+
+void MarkedSpace::freeBlocks(DoublyLinkedList<MarkedBlock>& blocks)
+{
+    MarkedBlock* next;
+    for (MarkedBlock* block = blocks.head(); block; block = next) {
+        next = block->next();
+
+        blocks.remove(block);
+        m_blocks.remove(block);
+        MarkedBlock::destroy(block);
+    }
+}
+
+void* MarkedSpace::allocateFromSizeClass(SizeClass& sizeClass)
+{
+    for (MarkedBlock*& block = sizeClass.nextBlock ; block; block = block->next()) {
+        if (void* result = block->allocate())
+            return result;
+
+        m_waterMark += block->capacity();
+    }
+
+    if (m_waterMark < m_highWaterMark)
+        return allocateBlock(sizeClass)->allocate();
+
+    return 0;
+}
+
+void MarkedSpace::shrink()
+{
+    // We record a temporary list of empties to avoid modifying m_blocks while iterating it.
+    DoublyLinkedList<MarkedBlock> empties;
+
+    BlockIterator end = m_blocks.end();
+    for (BlockIterator it = m_blocks.begin(); it != end; ++it) {
+        MarkedBlock* block = *it;
+        if (block->isEmpty()) {
+            SizeClass& sizeClass = sizeClassFor(block->cellSize());
+            sizeClass.blockList.remove(block);
+            sizeClass.nextBlock = sizeClass.blockList.head();
+            empties.append(block);
+        }
+    }
+    
+    freeBlocks(empties);
+    ASSERT(empties.isEmpty());
+}
+
+void MarkedSpace::clearMarks()
+{
+    BlockIterator end = m_blocks.end();
+    for (BlockIterator it = m_blocks.begin(); it != end; ++it)
+        (*it)->clearMarks();
+}
+
+void MarkedSpace::sweep()
+{
+    BlockIterator end = m_blocks.end();
+    for (BlockIterator it = m_blocks.begin(); it != end; ++it)
+        (*it)->sweep();
+}
+
+size_t MarkedSpace::objectCount() const
+{
+    size_t result = 0;
+    BlockIterator end = m_blocks.end();
+    for (BlockIterator it = m_blocks.begin(); it != end; ++it)
+        result += (*it)->markCount();
+    return result;
+}
+
+size_t MarkedSpace::size() const
+{
+    size_t result = 0;
+    BlockIterator end = m_blocks.end();
+    for (BlockIterator it = m_blocks.begin(); it != end; ++it)
+        result += (*it)->size();
+    return result;
+}
+
+size_t MarkedSpace::capacity() const
+{
+    size_t result = 0;
+    BlockIterator end = m_blocks.end();
+    for (BlockIterator it = m_blocks.begin(); it != end; ++it)
+        result += (*it)->capacity();
+    return result;
+}
+
+void MarkedSpace::reset()
+{
+    m_waterMark = 0;
+
+    for (size_t cellSize = preciseStep; cellSize < preciseCutoff; cellSize += preciseStep)
+        sizeClassFor(cellSize).reset();
+
+    for (size_t cellSize = impreciseStep; cellSize < impreciseCutoff; cellSize += impreciseStep)
+        sizeClassFor(cellSize).reset();
+
+    BlockIterator end = m_blocks.end();
+    for (BlockIterator it = m_blocks.begin(); it != end; ++it)
+        (*it)->reset();
+}
+
+} // namespace JSC