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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 !OS(WINDOWS)
37 #include <unistd.h>
38 #endif
39 
40 namespace JSC {
41 
42 #if ENABLE(SAMPLING_FLAGS)
43 
sample()44 void SamplingFlags::sample()
45 {
46     uint32_t mask = 1 << 31;
47     unsigned index;
48 
49     for (index = 0; index < 32; ++index) {
50         if (mask & s_flags)
51             break;
52         mask >>= 1;
53     }
54 
55     s_flagCounts[32 - index]++;
56 }
57 
start()58 void SamplingFlags::start()
59 {
60     for (unsigned i = 0; i <= 32; ++i)
61         s_flagCounts[i] = 0;
62 }
stop()63 void SamplingFlags::stop()
64 {
65     uint64_t total = 0;
66     for (unsigned i = 0; i <= 32; ++i)
67         total += s_flagCounts[i];
68 
69     if (total) {
70         printf("\nSamplingFlags: sample counts with flags set: (%lld total)\n", total);
71         for (unsigned i = 0; i <= 32; ++i) {
72             if (s_flagCounts[i])
73                 printf("  [ %02d ] : %lld\t\t(%03.2f%%)\n", i, s_flagCounts[i], (100.0 * s_flagCounts[i]) / total);
74         }
75         printf("\n");
76     } else
77     printf("\nSamplingFlags: no samples.\n\n");
78 }
79 uint64_t SamplingFlags::s_flagCounts[33];
80 
81 #else
82 void SamplingFlags::start() {}
83 void SamplingFlags::stop() {}
84 #endif
85 
86 /*
87   Start with flag 16 set.
88   By doing this the monitoring of lower valued flags will be masked out
89   until flag 16 is explictly cleared.
90 */
91 uint32_t SamplingFlags::s_flags = 1 << 15;
92 
93 
94 #if OS(WINDOWS)
95 
sleepForMicroseconds(unsigned us)96 static void sleepForMicroseconds(unsigned us)
97 {
98     unsigned ms = us / 1000;
99     if (us && !ms)
100         ms = 1;
101     Sleep(ms);
102 }
103 
104 #else
105 
sleepForMicroseconds(unsigned us)106 static void sleepForMicroseconds(unsigned us)
107 {
108     usleep(us);
109 }
110 
111 #endif
112 
hertz2us(unsigned hertz)113 static inline unsigned hertz2us(unsigned hertz)
114 {
115     return 1000000 / hertz;
116 }
117 
118 
119 SamplingTool* SamplingTool::s_samplingTool = 0;
120 
121 
122 bool SamplingThread::s_running = false;
123 unsigned SamplingThread::s_hertz = 10000;
124 ThreadIdentifier SamplingThread::s_samplingThread;
125 
threadStartFunc(void *)126 void* SamplingThread::threadStartFunc(void*)
127 {
128     while (s_running) {
129         sleepForMicroseconds(hertz2us(s_hertz));
130 
131 #if ENABLE(SAMPLING_FLAGS)
132         SamplingFlags::sample();
133 #endif
134 #if ENABLE(OPCODE_SAMPLING)
135         SamplingTool::sample();
136 #endif
137     }
138 
139     return 0;
140 }
141 
142 
start(unsigned hertz)143 void SamplingThread::start(unsigned hertz)
144 {
145     ASSERT(!s_running);
146     s_running = true;
147     s_hertz = hertz;
148 
149     s_samplingThread = createThread(threadStartFunc, 0, "JavaScriptCore::Sampler");
150 }
151 
stop()152 void SamplingThread::stop()
153 {
154     ASSERT(s_running);
155     s_running = false;
156     waitForThreadCompletion(s_samplingThread, 0);
157 }
158 
159 
sample(CodeBlock * codeBlock,Instruction * vPC)160 void ScriptSampleRecord::sample(CodeBlock* codeBlock, Instruction* vPC)
161 {
162     if (!m_samples) {
163         m_size = codeBlock->instructions().size();
164         m_samples = static_cast<int*>(calloc(m_size, sizeof(int)));
165         m_codeBlock = codeBlock;
166     }
167 
168     ++m_sampleCount;
169 
170     unsigned offest = vPC - codeBlock->instructions().begin();
171     // Since we don't read and write codeBlock and vPC atomically, this check
172     // can fail if we sample mid op_call / op_ret.
173     if (offest < m_size) {
174         m_samples[offest]++;
175         m_opcodeSampleCount++;
176     }
177 }
178 
doRun()179 void SamplingTool::doRun()
180 {
181     Sample sample(m_sample, m_codeBlock);
182     ++m_sampleCount;
183 
184     if (sample.isNull())
185         return;
186 
187     if (!sample.inHostFunction()) {
188         unsigned opcodeID = m_interpreter->getOpcodeID(sample.vPC()[0].u.opcode);
189 
190         ++m_opcodeSampleCount;
191         ++m_opcodeSamples[opcodeID];
192 
193         if (sample.inCTIFunction())
194             m_opcodeSamplesInCTIFunctions[opcodeID]++;
195     }
196 
197 #if ENABLE(CODEBLOCK_SAMPLING)
198     if (CodeBlock* codeBlock = sample.codeBlock()) {
199         MutexLocker locker(m_scriptSampleMapMutex);
200         ScriptSampleRecord* record = m_scopeSampleMap->get(codeBlock->ownerExecutable());
201         ASSERT(record);
202         record->sample(codeBlock, sample.vPC());
203     }
204 #endif
205 }
206 
sample()207 void SamplingTool::sample()
208 {
209     s_samplingTool->doRun();
210 }
211 
notifyOfScope(ScriptExecutable * script)212 void SamplingTool::notifyOfScope(ScriptExecutable* script)
213 {
214 #if ENABLE(CODEBLOCK_SAMPLING)
215     MutexLocker locker(m_scriptSampleMapMutex);
216     m_scopeSampleMap->set(script, new ScriptSampleRecord(script));
217 #else
218     UNUSED_PARAM(script);
219 #endif
220 }
221 
setup()222 void SamplingTool::setup()
223 {
224     s_samplingTool = this;
225 }
226 
227 #if ENABLE(OPCODE_SAMPLING)
228 
229 struct OpcodeSampleInfo {
230     OpcodeID opcode;
231     long long count;
232     long long countInCTIFunctions;
233 };
234 
235 struct LineCountInfo {
236     unsigned line;
237     unsigned count;
238 };
239 
compareOpcodeIndicesSampling(const void * left,const void * right)240 static int compareOpcodeIndicesSampling(const void* left, const void* right)
241 {
242     const OpcodeSampleInfo* leftSampleInfo = reinterpret_cast<const OpcodeSampleInfo*>(left);
243     const OpcodeSampleInfo* rightSampleInfo = reinterpret_cast<const OpcodeSampleInfo*>(right);
244 
245     return (leftSampleInfo->count < rightSampleInfo->count) ? 1 : (leftSampleInfo->count > rightSampleInfo->count) ? -1 : 0;
246 }
247 
248 #if ENABLE(CODEBLOCK_SAMPLING)
compareLineCountInfoSampling(const void * left,const void * right)249 static int compareLineCountInfoSampling(const void* left, const void* right)
250 {
251     const LineCountInfo* leftLineCount = reinterpret_cast<const LineCountInfo*>(left);
252     const LineCountInfo* rightLineCount = reinterpret_cast<const LineCountInfo*>(right);
253 
254     return (leftLineCount->line > rightLineCount->line) ? 1 : (leftLineCount->line < rightLineCount->line) ? -1 : 0;
255 }
256 
compareScriptSampleRecords(const void * left,const void * right)257 static int compareScriptSampleRecords(const void* left, const void* right)
258 {
259     const ScriptSampleRecord* const leftValue = *static_cast<const ScriptSampleRecord* const *>(left);
260     const ScriptSampleRecord* const rightValue = *static_cast<const ScriptSampleRecord* const *>(right);
261 
262     return (leftValue->m_sampleCount < rightValue->m_sampleCount) ? 1 : (leftValue->m_sampleCount > rightValue->m_sampleCount) ? -1 : 0;
263 }
264 #endif
265 
dump(ExecState * exec)266 void SamplingTool::dump(ExecState* exec)
267 {
268     // Tidies up SunSpider output by removing short scripts - such a small number of samples would likely not be useful anyhow.
269     if (m_sampleCount < 10)
270         return;
271 
272     // (1) Build and sort 'opcodeSampleInfo' array.
273 
274     OpcodeSampleInfo opcodeSampleInfo[numOpcodeIDs];
275     for (int i = 0; i < numOpcodeIDs; ++i) {
276         opcodeSampleInfo[i].opcode = static_cast<OpcodeID>(i);
277         opcodeSampleInfo[i].count = m_opcodeSamples[i];
278         opcodeSampleInfo[i].countInCTIFunctions = m_opcodeSamplesInCTIFunctions[i];
279     }
280 
281     qsort(opcodeSampleInfo, numOpcodeIDs, sizeof(OpcodeSampleInfo), compareOpcodeIndicesSampling);
282 
283     // (2) Print Opcode sampling results.
284 
285     printf("\nBytecode samples [*]\n");
286     printf("                             sample   %% of       %% of     |   cti     cti %%\n");
287     printf("opcode                       count     VM        total    |  count   of self\n");
288     printf("-------------------------------------------------------   |  ----------------\n");
289 
290     for (int i = 0; i < numOpcodeIDs; ++i) {
291         long long count = opcodeSampleInfo[i].count;
292         if (!count)
293             continue;
294 
295         OpcodeID opcodeID = opcodeSampleInfo[i].opcode;
296 
297         const char* opcodeName = opcodeNames[opcodeID];
298         const char* opcodePadding = padOpcodeName(opcodeID, 28);
299         double percentOfVM = (static_cast<double>(count) * 100) / m_opcodeSampleCount;
300         double percentOfTotal = (static_cast<double>(count) * 100) / m_sampleCount;
301         long long countInCTIFunctions = opcodeSampleInfo[i].countInCTIFunctions;
302         double percentInCTIFunctions = (static_cast<double>(countInCTIFunctions) * 100) / count;
303         fprintf(stdout, "%s:%s%-6lld %.3f%%\t%.3f%%\t  |   %-6lld %.3f%%\n", opcodeName, opcodePadding, count, percentOfVM, percentOfTotal, countInCTIFunctions, percentInCTIFunctions);
304     }
305 
306     printf("\n[*] Samples inside host code are not charged to any Bytecode.\n\n");
307     printf("\tSamples inside VM:\t\t%lld / %lld (%.3f%%)\n", m_opcodeSampleCount, m_sampleCount, (static_cast<double>(m_opcodeSampleCount) * 100) / m_sampleCount);
308     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);
309     printf("\tsample count:\tsamples inside this opcode\n");
310     printf("\t%% of VM:\tsample count / all opcode samples\n");
311     printf("\t%% of total:\tsample count / all samples\n");
312     printf("\t--------------\n");
313     printf("\tcti count:\tsamples inside a CTI function called by this opcode\n");
314     printf("\tcti %% of self:\tcti count / sample count\n");
315 
316 #if ENABLE(CODEBLOCK_SAMPLING)
317 
318     // (3) Build and sort 'codeBlockSamples' array.
319 
320     int scopeCount = m_scopeSampleMap->size();
321     Vector<ScriptSampleRecord*> codeBlockSamples(scopeCount);
322     ScriptSampleRecordMap::iterator iter = m_scopeSampleMap->begin();
323     for (int i = 0; i < scopeCount; ++i, ++iter)
324         codeBlockSamples[i] = iter->second;
325 
326     qsort(codeBlockSamples.begin(), scopeCount, sizeof(ScriptSampleRecord*), compareScriptSampleRecords);
327 
328     // (4) Print data from 'codeBlockSamples' array.
329 
330     printf("\nCodeBlock samples\n\n");
331 
332     for (int i = 0; i < scopeCount; ++i) {
333         ScriptSampleRecord* record = codeBlockSamples[i];
334         CodeBlock* codeBlock = record->m_codeBlock;
335 
336         double blockPercent = (record->m_sampleCount * 100.0) / m_sampleCount;
337 
338         if (blockPercent >= 1) {
339             //Instruction* code = codeBlock->instructions().begin();
340             printf("#%d: %s:%d: %d / %lld (%.3f%%)\n", i + 1, record->m_executable->sourceURL().UTF8String().c_str(), codeBlock->lineNumberForBytecodeOffset(exec, 0), record->m_sampleCount, m_sampleCount, blockPercent);
341             if (i < 10) {
342                 HashMap<unsigned,unsigned> lineCounts;
343                 codeBlock->dump(exec);
344 
345                 printf("    Opcode and line number samples [*]\n\n");
346                 for (unsigned op = 0; op < record->m_size; ++op) {
347                     int count = record->m_samples[op];
348                     if (count) {
349                         printf("    [% 4d] has sample count: % 4d\n", op, count);
350                         unsigned line = codeBlock->lineNumberForBytecodeOffset(exec, op);
351                         lineCounts.set(line, (lineCounts.contains(line) ? lineCounts.get(line) : 0) + count);
352                     }
353                 }
354                 printf("\n");
355 
356                 int linesCount = lineCounts.size();
357                 Vector<LineCountInfo> lineCountInfo(linesCount);
358                 int lineno = 0;
359                 for (HashMap<unsigned,unsigned>::iterator iter = lineCounts.begin(); iter != lineCounts.end(); ++iter, ++lineno) {
360                     lineCountInfo[lineno].line = iter->first;
361                     lineCountInfo[lineno].count = iter->second;
362                 }
363 
364                 qsort(lineCountInfo.begin(), linesCount, sizeof(LineCountInfo), compareLineCountInfoSampling);
365 
366                 for (lineno = 0; lineno < linesCount; ++lineno) {
367                     printf("    Line #%d has sample count %d.\n", lineCountInfo[lineno].line, lineCountInfo[lineno].count);
368                 }
369                 printf("\n");
370                 printf("    [*] Samples inside host code are charged to the calling Bytecode.\n");
371                 printf("        Samples on a call / return boundary are not charged to a specific opcode or line.\n\n");
372                 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);
373             }
374         }
375     }
376 #else
377     UNUSED_PARAM(exec);
378 #endif
379 }
380 
381 #else
382 
dump(ExecState *)383 void SamplingTool::dump(ExecState*)
384 {
385 }
386 
387 #endif
388 
dump()389 void AbstractSamplingCounter::dump()
390 {
391 #if ENABLE(SAMPLING_COUNTERS)
392     if (s_abstractSamplingCounterChain != &s_abstractSamplingCounterChainEnd) {
393         printf("\nSampling Counter Values:\n");
394         for (AbstractSamplingCounter* currCounter = s_abstractSamplingCounterChain; (currCounter != &s_abstractSamplingCounterChainEnd); currCounter = currCounter->m_next)
395             printf("\t%s\t: %lld\n", currCounter->m_name, currCounter->m_counter);
396         printf("\n\n");
397     }
398     s_completed = true;
399 #endif
400 }
401 
402 AbstractSamplingCounter AbstractSamplingCounter::s_abstractSamplingCounterChainEnd;
403 AbstractSamplingCounter* AbstractSamplingCounter::s_abstractSamplingCounterChain = &s_abstractSamplingCounterChainEnd;
404 bool AbstractSamplingCounter::s_completed = false;
405 
406 } // namespace JSC
407