JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / runtime / FunctionRareData.cpp

diff --git a/runtime/FunctionRareData.cpp b/runtime/FunctionRareData.cpp
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+/*
+ * Copyright (C) 2015 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. ``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
+ * 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 "FunctionRareData.h"
+
+#include "JSCInlines.h"
+
+namespace JSC {
+
+const ClassInfo FunctionRareData::s_info = { "FunctionRareData", 0, 0, CREATE_METHOD_TABLE(FunctionRareData) };
+
+FunctionRareData* FunctionRareData::create(VM& vm, JSObject* prototype, size_t inlineCapacity)
+{
+    FunctionRareData* rareData = new (NotNull, allocateCell<FunctionRareData>(vm.heap)) FunctionRareData(vm);
+    rareData->finishCreation(vm, prototype, inlineCapacity);
+    return rareData;
+}
+
+void FunctionRareData::destroy(JSCell* cell)
+{
+    FunctionRareData* rareData = static_cast<FunctionRareData*>(cell);
+    rareData->FunctionRareData::~FunctionRareData();
+}
+
+Structure* FunctionRareData::createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
+{
+    return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
+}
+
+void FunctionRareData::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    FunctionRareData* rareData = jsCast<FunctionRareData*>(cell);
+
+    rareData->m_allocationProfile.visitAggregate(visitor);
+}
+
+FunctionRareData::FunctionRareData(VM& vm)
+    : Base(vm, vm.functionRareDataStructure.get())
+    , m_allocationProfile()
+    // We initialize blind so that changes to the prototype after function creation but before
+    // the optimizer kicks in don't disable optimizations. Once the optimizer kicks in, the
+    // watchpoint will start watching and any changes will both force deoptimization and disable
+    // future attempts to optimize. This is necessary because we are guaranteed that the
+    // allocation profile is changed exactly once prior to optimizations kicking in. We could be
+    // smarter and count the number of times the prototype is clobbered and only optimize if it
+    // was clobbered exactly once, but that seems like overkill. In almost all cases it will be
+    // clobbered once, and if it's clobbered more than once, that will probably only occur
+    // before we started optimizing, anyway.
+    , m_allocationProfileWatchpoint(ClearWatchpoint)
+{
+}
+
+FunctionRareData::~FunctionRareData()
+{
+}
+
+void FunctionRareData::finishCreation(VM& vm, JSObject* prototype, size_t inlineCapacity)
+{
+    Base::finishCreation(vm);
+    initialize(vm, prototype, inlineCapacity);
+}
+
+void FunctionRareData::initialize(VM& vm, JSObject* prototype, size_t inlineCapacity)
+{
+    m_allocationProfile.initialize(vm, this, prototype, inlineCapacity);
+}
+
+void FunctionRareData::clear(const char* reason)
+{
+    m_allocationProfile.clear();
+    m_allocationProfileWatchpoint.fireAll(reason);
+}
+
+}