Imported WebKit commit 2ea9d364d0f6efa8fa64acf19f451504c59be0e4 (http://svn.webkit.org/repository/webkit/trunk@104285)

1 files changed, 480 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/bytecode/SamplingTool.cpp b/Source/JavaScriptCore/bytecode/SamplingTool.cpp
new file mode 100644
index 000000000..0dec25fb7
--- /dev/null
+++ b/Source/JavaScriptCore/bytecode/SamplingTool.cpp
@@ -0,0 +1,480 @@
+/*
+ * Copyright (C) 2008, 2009 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.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE 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 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 "SamplingTool.h"
+
+#include "CodeBlock.h"
+#include "Interpreter.h"
+#include "Opcode.h"
+
+#if !OS(WINDOWS)
+#include <unistd.h>
+#endif
+
+namespace JSC {
+
+#if ENABLE(SAMPLING_FLAGS)
+
+void SamplingFlags::sample()
+{
+    uint32_t mask = static_cast<uint32_t>(1 << 31);
+    unsigned index;
+
+    for (index = 0; index < 32; ++index) {
+        if (mask & s_flags)
+            break;
+        mask >>= 1;
+    }
+
+    s_flagCounts[32 - index]++;
+}
+
+void SamplingFlags::start()
+{
+    for (unsigned i = 0; i <= 32; ++i)
+        s_flagCounts[i] = 0;
+}
+void SamplingFlags::stop()
+{
+    uint64_t total = 0;
+    for (unsigned i = 0; i <= 32; ++i)
+        total += s_flagCounts[i];
+
+    if (total) {
+        printf("\nSamplingFlags: sample counts with flags set: (%lld total)\n", total);
+        for (unsigned i = 0; i <= 32; ++i) {
+            if (s_flagCounts[i])
+                printf("  [ %02d ] : %lld\t\t(%03.2f%%)\n", i, s_flagCounts[i], (100.0 * s_flagCounts[i]) / total);
+        }
+        printf("\n");
+    } else
+    printf("\nSamplingFlags: no samples.\n\n");
+}
+uint64_t SamplingFlags::s_flagCounts[33];
+
+#else
+void SamplingFlags::start() {}
+void SamplingFlags::stop() {}
+#endif
+
+#if ENABLE(SAMPLING_REGIONS)
+volatile uintptr_t SamplingRegion::s_currentOrReserved;
+Spectrum<const char*>* SamplingRegion::s_spectrum;
+unsigned long SamplingRegion::s_noneOfTheAbove;
+unsigned SamplingRegion::s_numberOfSamplesSinceDump;
+
+SamplingRegion::Locker::Locker()
+{
+    uintptr_t previous;
+    while (true) {
+        previous = s_currentOrReserved;
+        if (previous & 1) {
+#if OS(UNIX)
+            sched_yield();
+#endif
+            continue;
+        }
+        if (WTF::weakCompareAndSwap(&s_currentOrReserved, previous, previous | 1))
+            break;
+    }
+}
+
+SamplingRegion::Locker::~Locker()
+{
+    // We don't need the CAS, but we do it out of an
+    // abundance of caution (and because it gives us a memory fence, which is
+    // never bad).
+    uintptr_t previous;
+    do {
+        previous = s_currentOrReserved;
+    } while (!WTF::weakCompareAndSwap(&s_currentOrReserved, previous, previous & ~1));
+}
+
+void SamplingRegion::sample()
+{
+    // Make sure we lock s_current.
+    Locker locker;
+    
+    // Create a spectrum if we don't have one already.
+    if (!s_spectrum)
+        s_spectrum = new Spectrum<const char*>();
+    
+    ASSERT(s_currentOrReserved & 1);
+    
+    // Walk the region stack, and record each region we see.
+    SamplingRegion* region = bitwise_cast<SamplingRegion*>(s_currentOrReserved & ~1);
+    if (region) {
+        for (; region; region = region->m_previous)
+            s_spectrum->add(region->m_name);
+    } else
+        s_noneOfTheAbove++;
+    
+    if (s_numberOfSamplesSinceDump++ == SamplingThread::s_hertz) {
+        s_numberOfSamplesSinceDump = 0;
+        dumpInternal();
+    }
+}
+
+void SamplingRegion::dump()
+{
+    Locker locker;
+    
+    dumpInternal();
+}
+
+void SamplingRegion::dumpInternal()
+{
+    if (!s_spectrum) {
+        printf("\nSamplingRegion: was never sampled.\n\n");
+        return;
+    }
+    
+    Vector<Spectrum<const char*>::KeyAndCount> list = s_spectrum->buildList();
+    
+    unsigned long total = s_noneOfTheAbove;
+    for (unsigned i = list.size(); i--;)
+        total += list[i].count;
+    
+    printf("\nSamplingRegion: sample counts for regions: (%lu samples)\n", total);
+
+    for (unsigned i = list.size(); i--;)
+        printf("    %3.2lf%%  %s\n", (100.0 * list[i].count) / total, list[i].key);
+}
+#else // ENABLE(SAMPLING_REGIONS)
+void SamplingRegion::dump() { }
+#endif // ENABLE(SAMPLING_REGIONS)
+
+/*
+  Start with flag 16 set.
+  By doing this the monitoring of lower valued flags will be masked out
+  until flag 16 is explictly cleared.
+*/
+uint32_t SamplingFlags::s_flags = 1 << 15;
+
+
+#if OS(WINDOWS)
+
+static void sleepForMicroseconds(unsigned us)
+{
+    unsigned ms = us / 1000;
+    if (us && !ms)
+        ms = 1;
+    Sleep(ms);
+}
+
+#else 
+
+static void sleepForMicroseconds(unsigned us)
+{
+    usleep(us);
+}
+
+#endif
+
+static inline unsigned hertz2us(unsigned hertz)
+{
+    return 1000000 / hertz;
+}
+
+
+SamplingTool* SamplingTool::s_samplingTool = 0;
+
+
+bool SamplingThread::s_running = false;
+unsigned SamplingThread::s_hertz = 10000;
+ThreadIdentifier SamplingThread::s_samplingThread;
+
+void* SamplingThread::threadStartFunc(void*)
+{
+    while (s_running) {
+        sleepForMicroseconds(hertz2us(s_hertz));
+
+#if ENABLE(SAMPLING_FLAGS)
+        SamplingFlags::sample();
+#endif
+#if ENABLE(SAMPLING_REGIONS)
+        SamplingRegion::sample();
+#endif
+#if ENABLE(OPCODE_SAMPLING)
+        SamplingTool::sample();
+#endif
+    }
+
+    return 0;
+}
+
+
+void SamplingThread::start(unsigned hertz)
+{
+    ASSERT(!s_running);
+    s_running = true;
+    s_hertz = hertz;
+
+    s_samplingThread = createThread(threadStartFunc, 0, "JavaScriptCore::Sampler");
+}
+
+void SamplingThread::stop()
+{
+    ASSERT(s_running);
+    s_running = false;
+    waitForThreadCompletion(s_samplingThread, 0);
+}
+
+
+void ScriptSampleRecord::sample(CodeBlock* codeBlock, Instruction* vPC)
+{
+    if (!m_samples) {
+        m_size = codeBlock->instructions().size();
+        m_samples = static_cast<int*>(calloc(m_size, sizeof(int)));
+        m_codeBlock = codeBlock;
+    }
+
+    ++m_sampleCount;
+
+    unsigned offest = vPC - codeBlock->instructions().begin();
+    // Since we don't read and write codeBlock and vPC atomically, this check
+    // can fail if we sample mid op_call / op_ret.
+    if (offest < m_size) {
+        m_samples[offest]++;
+        m_opcodeSampleCount++;
+    }
+}
+
+void SamplingTool::doRun()
+{
+    Sample sample(m_sample, m_codeBlock);
+    ++m_sampleCount;
+
+    if (sample.isNull())
+        return;
+
+    if (!sample.inHostFunction()) {
+        unsigned opcodeID = m_interpreter->getOpcodeID(sample.vPC()[0].u.opcode);
+
+        ++m_opcodeSampleCount;
+        ++m_opcodeSamples[opcodeID];
+
+        if (sample.inCTIFunction())
+            m_opcodeSamplesInCTIFunctions[opcodeID]++;
+    }
+
+#if ENABLE(CODEBLOCK_SAMPLING)
+    if (CodeBlock* codeBlock = sample.codeBlock()) {
+        MutexLocker locker(m_scriptSampleMapMutex);
+        ScriptSampleRecord* record = m_scopeSampleMap->get(codeBlock->ownerExecutable());
+        ASSERT(record);
+        record->sample(codeBlock, sample.vPC());
+    }
+#endif
+}
+
+void SamplingTool::sample()
+{
+    s_samplingTool->doRun();
+}
+
+void SamplingTool::notifyOfScope(JSGlobalData& globalData, ScriptExecutable* script)
+{
+#if ENABLE(CODEBLOCK_SAMPLING)
+    MutexLocker locker(m_scriptSampleMapMutex);
+    m_scopeSampleMap->set(script, adoptPtr(new ScriptSampleRecord(globalData, script)));
+#else
+    UNUSED_PARAM(globalData);
+    UNUSED_PARAM(script);
+#endif
+}
+
+void SamplingTool::setup()
+{
+    s_samplingTool = this;
+}
+
+#if ENABLE(OPCODE_SAMPLING)
+
+struct OpcodeSampleInfo {
+    OpcodeID opcode;
+    long long count;
+    long long countInCTIFunctions;
+};
+
+struct LineCountInfo {
+    unsigned line;
+    unsigned count;
+};
+
+static int compareOpcodeIndicesSampling(const void* left, const void* right)
+{
+    const OpcodeSampleInfo* leftSampleInfo = reinterpret_cast<const OpcodeSampleInfo*>(left);
+    const OpcodeSampleInfo* rightSampleInfo = reinterpret_cast<const OpcodeSampleInfo*>(right);
+
+    return (leftSampleInfo->count < rightSampleInfo->count) ? 1 : (leftSampleInfo->count > rightSampleInfo->count) ? -1 : 0;
+}
+
+#if ENABLE(CODEBLOCK_SAMPLING)
+static int compareLineCountInfoSampling(const void* left, const void* right)
+{
+    const LineCountInfo* leftLineCount = reinterpret_cast<const LineCountInfo*>(left);
+    const LineCountInfo* rightLineCount = reinterpret_cast<const LineCountInfo*>(right);
+
+    return (leftLineCount->line > rightLineCount->line) ? 1 : (leftLineCount->line < rightLineCount->line) ? -1 : 0;
+}
+
+static int compareScriptSampleRecords(const void* left, const void* right)
+{
+    const ScriptSampleRecord* const leftValue = *static_cast<const ScriptSampleRecord* const *>(left);
+    const ScriptSampleRecord* const rightValue = *static_cast<const ScriptSampleRecord* const *>(right);
+
+    return (leftValue->m_sampleCount < rightValue->m_sampleCount) ? 1 : (leftValue->m_sampleCount > rightValue->m_sampleCount) ? -1 : 0;
+}
+#endif
+
+void SamplingTool::dump(ExecState* exec)
+{
+    // Tidies up SunSpider output by removing short scripts - such a small number of samples would likely not be useful anyhow.
+    if (m_sampleCount < 10)
+        return;
+    
+    // (1) Build and sort 'opcodeSampleInfo' array.
+
+    OpcodeSampleInfo opcodeSampleInfo[numOpcodeIDs];
+    for (int i = 0; i < numOpcodeIDs; ++i) {
+        opcodeSampleInfo[i].opcode = static_cast<OpcodeID>(i);
+        opcodeSampleInfo[i].count = m_opcodeSamples[i];
+        opcodeSampleInfo[i].countInCTIFunctions = m_opcodeSamplesInCTIFunctions[i];
+    }
+
+    qsort(opcodeSampleInfo, numOpcodeIDs, sizeof(OpcodeSampleInfo), compareOpcodeIndicesSampling);
+
+    // (2) Print Opcode sampling results.
+
+    printf("\nBytecode samples [*]\n");
+    printf("                             sample   %% of       %% of     |   cti     cti %%\n");
+    printf("opcode                       count     VM        total    |  count   of self\n");
+    printf("-------------------------------------------------------   |  ----------------\n");
+
+    for (int i = 0; i < numOpcodeIDs; ++i) {
+        long long count = opcodeSampleInfo[i].count;
+        if (!count)
+            continue;
+
+        OpcodeID opcodeID = opcodeSampleInfo[i].opcode;
+        
+        const char* opcodeName = opcodeNames[opcodeID];
+        const char* opcodePadding = padOpcodeName(opcodeID, 28);
+        double percentOfVM = (static_cast<double>(count) * 100) / m_opcodeSampleCount;
+        double percentOfTotal = (static_cast<double>(count) * 100) / m_sampleCount;
+        long long countInCTIFunctions = opcodeSampleInfo[i].countInCTIFunctions;
+        double percentInCTIFunctions = (static_cast<double>(countInCTIFunctions) * 100) / count;
+        fprintf(stdout, "%s:%s%-6lld %.3f%%\t%.3f%%\t  |   %-6lld %.3f%%\n", opcodeName, opcodePadding, count, percentOfVM, percentOfTotal, countInCTIFunctions, percentInCTIFunctions);
+    }
+    
+    printf("\n[*] Samples inside host code are not charged to any Bytecode.\n\n");
+    printf("\tSamples inside VM:\t\t%lld / %lld (%.3f%%)\n", m_opcodeSampleCount, m_sampleCount, (static_cast<double>(m_opcodeSampleCount) * 100) / m_sampleCount);
+    printf("\tSamples inside host code:\t%lld / %lld (%.3f%%)\n\n", m_sampleCount - m_opcodeSampleCount, m_sampleCount, (static_cast<double>(m_sampleCount - m_opcodeSampleCount) * 100) / m_sampleCount);
+    printf("\tsample count:\tsamples inside this opcode\n");
+    printf("\t%% of VM:\tsample count / all opcode samples\n");
+    printf("\t%% of total:\tsample count / all samples\n");
+    printf("\t--------------\n");
+    printf("\tcti count:\tsamples inside a CTI function called by this opcode\n");
+    printf("\tcti %% of self:\tcti count / sample count\n");
+    
+#if ENABLE(CODEBLOCK_SAMPLING)
+
+    // (3) Build and sort 'codeBlockSamples' array.
+
+    int scopeCount = m_scopeSampleMap->size();
+    Vector<ScriptSampleRecord*> codeBlockSamples(scopeCount);
+    ScriptSampleRecordMap::iterator iter = m_scopeSampleMap->begin();
+    for (int i = 0; i < scopeCount; ++i, ++iter)
+        codeBlockSamples[i] = iter->second.get();
+
+    qsort(codeBlockSamples.begin(), scopeCount, sizeof(ScriptSampleRecord*), compareScriptSampleRecords);
+
+    // (4) Print data from 'codeBlockSamples' array.
+
+    printf("\nCodeBlock samples\n\n"); 
+
+    for (int i = 0; i < scopeCount; ++i) {
+        ScriptSampleRecord* record = codeBlockSamples[i];
+        CodeBlock* codeBlock = record->m_codeBlock;
+
+        double blockPercent = (record->m_sampleCount * 100.0) / m_sampleCount;
+
+        if (blockPercent >= 1) {
+            //Instruction* code = codeBlock->instructions().begin();
+            printf("#%d: %s:%d: %d / %lld (%.3f%%)\n", i + 1, record->m_executable->sourceURL().utf8().data(), codeBlock->lineNumberForBytecodeOffset(0), record->m_sampleCount, m_sampleCount, blockPercent);
+            if (i < 10) {
+                HashMap<unsigned,unsigned> lineCounts;
+                codeBlock->dump(exec);
+
+                printf("    Opcode and line number samples [*]\n\n");
+                for (unsigned op = 0; op < record->m_size; ++op) {
+                    int count = record->m_samples[op];
+                    if (count) {
+                        printf("    [% 4d] has sample count: % 4d\n", op, count);
+                        unsigned line = codeBlock->lineNumberForBytecodeOffset(op);
+                        lineCounts.set(line, (lineCounts.contains(line) ? lineCounts.get(line) : 0) + count);
+                    }
+                }
+                printf("\n");
+
+                int linesCount = lineCounts.size();
+                Vector<LineCountInfo> lineCountInfo(linesCount);
+                int lineno = 0;
+                for (HashMap<unsigned,unsigned>::iterator iter = lineCounts.begin(); iter != lineCounts.end(); ++iter, ++lineno) {
+                    lineCountInfo[lineno].line = iter->first;
+                    lineCountInfo[lineno].count = iter->second;
+                }
+
+                qsort(lineCountInfo.begin(), linesCount, sizeof(LineCountInfo), compareLineCountInfoSampling);
+
+                for (lineno = 0; lineno < linesCount; ++lineno) {
+                    printf("    Line #%d has sample count %d.\n", lineCountInfo[lineno].line, lineCountInfo[lineno].count);
+                }
+                printf("\n");
+                printf("    [*] Samples inside host code are charged to the calling Bytecode.\n");
+                printf("        Samples on a call / return boundary are not charged to a specific opcode or line.\n\n");
+                printf("            Samples on a call / return boundary: %d / %d (%.3f%%)\n\n", record->m_sampleCount - record->m_opcodeSampleCount, record->m_sampleCount, (static_cast<double>(record->m_sampleCount - record->m_opcodeSampleCount) * 100) / record->m_sampleCount);
+            }
+        }
+    }
+#else
+    UNUSED_PARAM(exec);
+#endif
+}
+
+#else
+
+void SamplingTool::dump(ExecState*)
+{
+}
+
+#endif
+
+} // namespace JSC