| /* |
| * Copyright (C) 2012 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. |
| */ |
| |
| #ifndef ExecutionCounter_h |
| #define ExecutionCounter_h |
| |
| #include "JSGlobalObject.h" |
| #include "Options.h" |
| #include <wtf/PrintStream.h> |
| #include <wtf/SimpleStats.h> |
| |
| namespace JSC { |
| |
| class CodeBlock; |
| |
| class ExecutionCounter { |
| public: |
| ExecutionCounter(); |
| bool checkIfThresholdCrossedAndSet(CodeBlock*); |
| void setNewThreshold(int32_t threshold, CodeBlock*); |
| void deferIndefinitely(); |
| double count() const { return static_cast<double>(m_totalCount) + m_counter; } |
| void dump(PrintStream&) const; |
| static double applyMemoryUsageHeuristics(int32_t value, CodeBlock*); |
| static int32_t applyMemoryUsageHeuristicsAndConvertToInt(int32_t value, CodeBlock*); |
| template<typename T> |
| static T clippedThreshold(JSGlobalObject* globalObject, T threshold) |
| { |
| int32_t maxThreshold; |
| if (Options::randomizeExecutionCountsBetweenCheckpoints()) |
| maxThreshold = globalObject->weakRandomInteger() % Options::maximumExecutionCountsBetweenCheckpoints(); |
| else |
| maxThreshold = Options::maximumExecutionCountsBetweenCheckpoints(); |
| if (threshold > maxThreshold) |
| threshold = maxThreshold; |
| return threshold; |
| } |
| |
| static int32_t formattedTotalCount(float value) |
| { |
| union { |
| int32_t i; |
| float f; |
| } u; |
| u.f = value; |
| return u.i; |
| } |
| |
| private: |
| bool hasCrossedThreshold(CodeBlock*) const; |
| bool setThreshold(CodeBlock*); |
| void reset(); |
| |
| public: |
| |
| // NB. These are intentionally public because it will be modified from machine code. |
| |
| // This counter is incremented by the JIT or LLInt. It starts out negative and is |
| // counted up until it becomes non-negative. At the start of a counting period, |
| // the threshold we wish to reach is m_totalCount + m_counter, in the sense that |
| // we will add X to m_totalCount and subtract X from m_counter. |
| int32_t m_counter; |
| |
| // Counts the total number of executions we have seen plus the ones we've set a |
| // threshold for in m_counter. Because m_counter's threshold is negative, the |
| // total number of actual executions can always be computed as m_totalCount + |
| // m_counter. |
| float m_totalCount; |
| |
| // This is the threshold we were originally targetting, without any correction for |
| // the memory usage heuristics. |
| int32_t m_activeThreshold; |
| }; |
| |
| } // namespace JSC |
| |
| #endif // ExecutionCounter_h |
| |