bytecode/SamplingTool.cpp

   1 /*
   2  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "config.h"
  30 #include "SamplingTool.h"
  31
  32 #include "CodeBlock.h"
  33 #include "Interpreter.h"
  34 #include "Opcode.h"
  35
  36 #if !PLATFORM(WIN_OS)
  37 #include <unistd.h>
  38 #endif
  39
  40 namespace JSC {
  41
  42 void ScopeSampleRecord::sample(CodeBlock* codeBlock, Instruction* vPC)
  43 {
  44     if (!m_samples) {
  45         m_size = codeBlock->instructions().size();
  46         m_samples = static_cast<int*>(calloc(m_size, sizeof(int)));
  47         m_codeBlock = codeBlock;
  48     }
  49
  50     ++m_sampleCount;
  51
  52     unsigned offest = vPC - codeBlock->instructions().begin();
  53     // Since we don't read and write codeBlock and vPC atomically, this check
  54     // can fail if we sample mid op_call / op_ret.
  55     if (offest < m_size) {
  56         m_samples[offest]++;
  57         m_opcodeSampleCount++;
  58     }
  59 }
  60
  61 #if PLATFORM(WIN_OS)
  62
  63 static void sleepForMicroseconds(unsigned us)
  64 {
  65     unsigned ms = us / 1000;
  66     if (us && !ms)
  67         ms = 1;
  68     Sleep(ms);
  69 }
  70
  71 #else
  72
  73 static void sleepForMicroseconds(unsigned us)
  74 {
  75     usleep(us);
  76 }
  77
  78 #endif
  79
  80 static inline unsigned hertz2us(unsigned hertz)
  81 {
  82     return 1000000 / hertz;
  83 }
  84
  85 void SamplingTool::run()
  86 {
  87     while (m_running) {
  88         sleepForMicroseconds(hertz2us(m_hertz));
  89
  90         Sample sample(m_sample, m_codeBlock);
  91         ++m_sampleCount;
  92
  93         if (sample.isNull())
  94             continue;
  95
  96         if (!sample.inHostFunction()) {
  97             unsigned opcodeID = m_interpreter->getOpcodeID(sample.vPC()[0].u.opcode);
  98
  99             ++m_opcodeSampleCount;
 100             ++m_opcodeSamples[opcodeID];
 101
 102             if (sample.inCTIFunction())
 103                 m_opcodeSamplesInCTIFunctions[opcodeID]++;
 104         }
 105
 106 #if ENABLE(CODEBLOCK_SAMPLING)
 107         MutexLocker locker(m_scopeSampleMapMutex);
 108         ScopeSampleRecord* record = m_scopeSampleMap->get(sample.codeBlock()->ownerNode());
 109         ASSERT(record);
 110         record->sample(sample.codeBlock(), sample.vPC());
 111 #endif
 112     }
 113 }
 114
 115 void* SamplingTool::threadStartFunc(void* samplingTool)
 116 {
 117     reinterpret_cast<SamplingTool*>(samplingTool)->run();
 118     return 0;
 119 }
 120
 121 void SamplingTool::notifyOfScope(ScopeNode* scope)
 122 {
 123     MutexLocker locker(m_scopeSampleMapMutex);
 124     m_scopeSampleMap->set(scope, new ScopeSampleRecord(scope));
 125 }
 126
 127 void SamplingTool::start(unsigned hertz)
 128 {
 129     ASSERT(!m_running);
 130     m_running = true;
 131     m_hertz = hertz;
 132
 133     m_samplingThread = createThread(threadStartFunc, this, "JavaScriptCore::Sampler");
 134 }
 135
 136 void SamplingTool::stop()
 137 {
 138     ASSERT(m_running);
 139     m_running = false;
 140     waitForThreadCompletion(m_samplingThread, 0);
 141 }
 142
 143 #if ENABLE(OPCODE_SAMPLING)
 144
 145 struct OpcodeSampleInfo {
 146     OpcodeID opcode;
 147     long long count;
 148     long long countInCTIFunctions;
 149 };
 150
 151 struct LineCountInfo {
 152     unsigned line;
 153     unsigned count;
 154 };
 155
 156 static int compareLineCountInfoSampling(const void* left, const void* right)
 157 {
 158     const LineCountInfo* leftLineCount = reinterpret_cast<const LineCountInfo*>(left);
 159     const LineCountInfo* rightLineCount = reinterpret_cast<const LineCountInfo*>(right);
 160
 161     return (leftLineCount->line > rightLineCount->line) ? 1 : (leftLineCount->line < rightLineCount->line) ? -1 : 0;
 162 }
 163
 164 static int compareOpcodeIndicesSampling(const void* left, const void* right)
 165 {
 166     const OpcodeSampleInfo* leftSampleInfo = reinterpret_cast<const OpcodeSampleInfo*>(left);
 167     const OpcodeSampleInfo* rightSampleInfo = reinterpret_cast<const OpcodeSampleInfo*>(right);
 168
 169     return (leftSampleInfo->count < rightSampleInfo->count) ? 1 : (leftSampleInfo->count > rightSampleInfo->count) ? -1 : 0;
 170 }
 171
 172 static int compareScopeSampleRecords(const void* left, const void* right)
 173 {
 174     const ScopeSampleRecord* const leftValue = *static_cast<const ScopeSampleRecord* const *>(left);
 175     const ScopeSampleRecord* const rightValue = *static_cast<const ScopeSampleRecord* const *>(right);
 176
 177     return (leftValue->m_sampleCount < rightValue->m_sampleCount) ? 1 : (leftValue->m_sampleCount > rightValue->m_sampleCount) ? -1 : 0;
 178 }
 179
 180 void SamplingTool::dump(ExecState* exec)
 181 {
 182     // Tidies up SunSpider output by removing short scripts - such a small number of samples would likely not be useful anyhow.
 183     if (m_sampleCount < 10)
 184         return;
 185
 186     // (1) Build and sort 'opcodeSampleInfo' array.
 187
 188     OpcodeSampleInfo opcodeSampleInfo[numOpcodeIDs];
 189     for (int i = 0; i < numOpcodeIDs; ++i) {
 190         opcodeSampleInfo[i].opcode = static_cast<OpcodeID>(i);
 191         opcodeSampleInfo[i].count = m_opcodeSamples[i];
 192         opcodeSampleInfo[i].countInCTIFunctions = m_opcodeSamplesInCTIFunctions[i];
 193     }
 194
 195     qsort(opcodeSampleInfo, numOpcodeIDs, sizeof(OpcodeSampleInfo), compareOpcodeIndicesSampling);
 196
 197     // (2) Print Opcode sampling results.
 198
 199     printf("\nBytecode samples [*]\n");
 200     printf("                             sample   %% of       %% of     |   cti     cti %%\n");
 201     printf("opcode                       count     VM        total    |  count   of self\n");
 202     printf("-------------------------------------------------------   |  ----------------\n");
 203
 204     for (int i = 0; i < numOpcodeIDs; ++i) {
 205         long long count = opcodeSampleInfo[i].count;
 206         if (!count)
 207             continue;
 208
 209         OpcodeID opcodeID = opcodeSampleInfo[i].opcode;
 210
 211         const char* opcodeName = opcodeNames[opcodeID];
 212         const char* opcodePadding = padOpcodeName(opcodeID, 28);
 213         double percentOfVM = (static_cast<double>(count) * 100) / m_opcodeSampleCount;
 214         double percentOfTotal = (static_cast<double>(count) * 100) / m_sampleCount;
 215         long long countInCTIFunctions = opcodeSampleInfo[i].countInCTIFunctions;
 216         double percentInCTIFunctions = (static_cast<double>(countInCTIFunctions) * 100) / count;
 217         fprintf(stdout, "%s:%s%-6lld %.3f%%\t%.3f%%\t  |   %-6lld %.3f%%\n", opcodeName, opcodePadding, count, percentOfVM, percentOfTotal, countInCTIFunctions, percentInCTIFunctions);
 218     }
 219
 220     printf("\n[*] Samples inside host code are not charged to any Bytecode.\n\n");
 221     printf("\tSamples inside VM:\t\t%lld / %lld (%.3f%%)\n", m_opcodeSampleCount, m_sampleCount, (static_cast<double>(m_opcodeSampleCount) * 100) / m_sampleCount);
 222     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);
 223     printf("\tsample count:\tsamples inside this opcode\n");
 224     printf("\t%% of VM:\tsample count / all opcode samples\n");
 225     printf("\t%% of total:\tsample count / all samples\n");
 226     printf("\t--------------\n");
 227     printf("\tcti count:\tsamples inside a CTI function called by this opcode\n");
 228     printf("\tcti %% of self:\tcti count / sample count\n");
 229
 230     // (3) Build and sort 'codeBlockSamples' array.
 231
 232     int scopeCount = m_scopeSampleMap->size();
 233     Vector<ScopeSampleRecord*> codeBlockSamples(scopeCount);
 234     ScopeSampleRecordMap::iterator iter = m_scopeSampleMap->begin();
 235     for (int i = 0; i < scopeCount; ++i, ++iter)
 236         codeBlockSamples[i] = iter->second;
 237
 238     qsort(codeBlockSamples.begin(), scopeCount, sizeof(ScopeSampleRecord*), compareScopeSampleRecords);
 239
 240     // (4) Print data from 'codeBlockSamples' array.
 241
 242     printf("\nCodeBlock samples\n\n");
 243
 244     for (int i = 0; i < scopeCount; ++i) {
 245         ScopeSampleRecord* record = codeBlockSamples[i];
 246         CodeBlock* codeBlock = record->m_codeBlock;
 247
 248         double blockPercent = (record->m_sampleCount * 100.0) / m_sampleCount;
 249
 250         if (blockPercent >= 1) {
 251             //Instruction* code = codeBlock->instructions().begin();
 252             printf("#%d: %s:%d: %d / %lld (%.3f%%)\n", i + 1, record->m_scope->sourceURL().UTF8String().c_str(), codeBlock->lineNumberForBytecodeOffset(exec, 0), record->m_sampleCount, m_sampleCount, blockPercent);
 253             if (i < 10) {
 254                 HashMap<unsigned,unsigned> lineCounts;
 255                 codeBlock->dump(exec);
 256
 257                 printf("    Opcode and line number samples [*]\n\n");
 258                 for (unsigned op = 0; op < record->m_size; ++op) {
 259                     int count = record->m_samples[op];
 260                     if (count) {
 261                         printf("    [% 4d] has sample count: % 4d\n", op, count);
 262                         unsigned line = codeBlock->lineNumberForBytecodeOffset(exec, op);
 263                         lineCounts.set(line, (lineCounts.contains(line) ? lineCounts.get(line) : 0) + count);
 264                     }
 265                 }
 266                 printf("\n");
 267
 268                 int linesCount = lineCounts.size();
 269                 Vector<LineCountInfo> lineCountInfo(linesCount);
 270                 int lineno = 0;
 271                 for (HashMap<unsigned,unsigned>::iterator iter = lineCounts.begin(); iter != lineCounts.end(); ++iter, ++lineno) {
 272                     lineCountInfo[lineno].line = iter->first;
 273                     lineCountInfo[lineno].count = iter->second;
 274                 }
 275
 276                 qsort(lineCountInfo.begin(), linesCount, sizeof(LineCountInfo), compareLineCountInfoSampling);
 277
 278                 for (lineno = 0; lineno < linesCount; ++lineno) {
 279                     printf("    Line #%d has sample count %d.\n", lineCountInfo[lineno].line, lineCountInfo[lineno].count);
 280                 }
 281                 printf("\n");
 282                 printf("    [*] Samples inside host code are charged to the calling Bytecode.\n");
 283                 printf("        Samples on a call / return boundary are not charged to a specific opcode or line.\n\n");
 284                 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);
 285             }
 286         }
 287     }
 288 }
 289
 290 #else
 291
 292 void SamplingTool::dump(ExecState*)
 293 {
 294 }
 295
 296 #endif
 297
 298 } // namespace JSC