1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "trace.h"
18
19 #include <sys/uio.h>
20
21 #include "base/stl_util.h"
22 #include "base/unix_file/fd_file.h"
23 #include "class_linker.h"
24 #include "common_throws.h"
25 #include "debugger.h"
26 #include "dex_file-inl.h"
27 #include "instrumentation.h"
28 #include "mirror/art_method-inl.h"
29 #include "mirror/class-inl.h"
30 #include "mirror/dex_cache.h"
31 #include "mirror/object_array-inl.h"
32 #include "mirror/object-inl.h"
33 #include "os.h"
34 #include "scoped_thread_state_change.h"
35 #include "ScopedLocalRef.h"
36 #include "thread.h"
37 #include "thread_list.h"
38 #if !defined(ART_USE_PORTABLE_COMPILER)
39 #include "entrypoints/quick/quick_entrypoints.h"
40 #endif
41
42 namespace art {
43
44 // File format:
45 // header
46 // record 0
47 // record 1
48 // ...
49 //
50 // Header format:
51 // u4 magic ('SLOW')
52 // u2 version
53 // u2 offset to data
54 // u8 start date/time in usec
55 // u2 record size in bytes (version >= 2 only)
56 // ... padding to 32 bytes
57 //
58 // Record format v1:
59 // u1 thread ID
60 // u4 method ID | method action
61 // u4 time delta since start, in usec
62 //
63 // Record format v2:
64 // u2 thread ID
65 // u4 method ID | method action
66 // u4 time delta since start, in usec
67 //
68 // Record format v3:
69 // u2 thread ID
70 // u4 method ID | method action
71 // u4 time delta since start, in usec
72 // u4 wall time since start, in usec (when clock == "dual" only)
73 //
74 // 32 bits of microseconds is 70 minutes.
75 //
76 // All values are stored in little-endian order.
77
78 enum TraceAction {
79 kTraceMethodEnter = 0x00, // method entry
80 kTraceMethodExit = 0x01, // method exit
81 kTraceUnroll = 0x02, // method exited by exception unrolling
82 // 0x03 currently unused
83 kTraceMethodActionMask = 0x03, // two bits
84 };
85
86 class BuildStackTraceVisitor : public StackVisitor {
87 public:
BuildStackTraceVisitor(Thread * thread)88 explicit BuildStackTraceVisitor(Thread* thread) : StackVisitor(thread, NULL),
89 method_trace_(Trace::AllocStackTrace()) {}
90
VisitFrame()91 bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
92 mirror::ArtMethod* m = GetMethod();
93 // Ignore runtime frames (in particular callee save).
94 if (!m->IsRuntimeMethod()) {
95 method_trace_->push_back(m);
96 }
97 return true;
98 }
99
100 // Returns a stack trace where the topmost frame corresponds with the first element of the vector.
GetStackTrace() const101 std::vector<mirror::ArtMethod*>* GetStackTrace() const {
102 return method_trace_;
103 }
104
105 private:
106 std::vector<mirror::ArtMethod*>* const method_trace_;
107 };
108
109 static const char kTraceTokenChar = '*';
110 static const uint16_t kTraceHeaderLength = 32;
111 static const uint32_t kTraceMagicValue = 0x574f4c53;
112 static const uint16_t kTraceVersionSingleClock = 2;
113 static const uint16_t kTraceVersionDualClock = 3;
114 static const uint16_t kTraceRecordSizeSingleClock = 10; // using v2
115 static const uint16_t kTraceRecordSizeDualClock = 14; // using v3 with two timestamps
116
117 TraceClockSource Trace::default_clock_source_ = kDefaultTraceClockSource;
118
119 Trace* volatile Trace::the_trace_ = NULL;
120 pthread_t Trace::sampling_pthread_ = 0U;
121 std::unique_ptr<std::vector<mirror::ArtMethod*>> Trace::temp_stack_trace_;
122
DecodeTraceMethodId(uint32_t tmid)123 static mirror::ArtMethod* DecodeTraceMethodId(uint32_t tmid) {
124 return reinterpret_cast<mirror::ArtMethod*>(tmid & ~kTraceMethodActionMask);
125 }
126
DecodeTraceAction(uint32_t tmid)127 static TraceAction DecodeTraceAction(uint32_t tmid) {
128 return static_cast<TraceAction>(tmid & kTraceMethodActionMask);
129 }
130
EncodeTraceMethodAndAction(mirror::ArtMethod * method,TraceAction action)131 static uint32_t EncodeTraceMethodAndAction(mirror::ArtMethod* method,
132 TraceAction action) {
133 uint32_t tmid = PointerToLowMemUInt32(method) | action;
134 DCHECK_EQ(method, DecodeTraceMethodId(tmid));
135 return tmid;
136 }
137
AllocStackTrace()138 std::vector<mirror::ArtMethod*>* Trace::AllocStackTrace() {
139 if (temp_stack_trace_.get() != NULL) {
140 return temp_stack_trace_.release();
141 } else {
142 return new std::vector<mirror::ArtMethod*>();
143 }
144 }
145
FreeStackTrace(std::vector<mirror::ArtMethod * > * stack_trace)146 void Trace::FreeStackTrace(std::vector<mirror::ArtMethod*>* stack_trace) {
147 stack_trace->clear();
148 temp_stack_trace_.reset(stack_trace);
149 }
150
SetDefaultClockSource(TraceClockSource clock_source)151 void Trace::SetDefaultClockSource(TraceClockSource clock_source) {
152 #if defined(HAVE_POSIX_CLOCKS)
153 default_clock_source_ = clock_source;
154 #else
155 if (clock_source != kTraceClockSourceWall) {
156 LOG(WARNING) << "Ignoring tracing request to use CPU time.";
157 }
158 #endif
159 }
160
GetTraceVersion(TraceClockSource clock_source)161 static uint16_t GetTraceVersion(TraceClockSource clock_source) {
162 return (clock_source == kTraceClockSourceDual) ? kTraceVersionDualClock
163 : kTraceVersionSingleClock;
164 }
165
GetRecordSize(TraceClockSource clock_source)166 static uint16_t GetRecordSize(TraceClockSource clock_source) {
167 return (clock_source == kTraceClockSourceDual) ? kTraceRecordSizeDualClock
168 : kTraceRecordSizeSingleClock;
169 }
170
UseThreadCpuClock()171 bool Trace::UseThreadCpuClock() {
172 return (clock_source_ == kTraceClockSourceThreadCpu) ||
173 (clock_source_ == kTraceClockSourceDual);
174 }
175
UseWallClock()176 bool Trace::UseWallClock() {
177 return (clock_source_ == kTraceClockSourceWall) ||
178 (clock_source_ == kTraceClockSourceDual);
179 }
180
MeasureClockOverhead()181 void Trace::MeasureClockOverhead() {
182 if (UseThreadCpuClock()) {
183 Thread::Current()->GetCpuMicroTime();
184 }
185 if (UseWallClock()) {
186 MicroTime();
187 }
188 }
189
190 // Compute an average time taken to measure clocks.
GetClockOverheadNanoSeconds()191 uint32_t Trace::GetClockOverheadNanoSeconds() {
192 Thread* self = Thread::Current();
193 uint64_t start = self->GetCpuMicroTime();
194
195 for (int i = 4000; i > 0; i--) {
196 MeasureClockOverhead();
197 MeasureClockOverhead();
198 MeasureClockOverhead();
199 MeasureClockOverhead();
200 MeasureClockOverhead();
201 MeasureClockOverhead();
202 MeasureClockOverhead();
203 MeasureClockOverhead();
204 }
205
206 uint64_t elapsed_us = self->GetCpuMicroTime() - start;
207 return static_cast<uint32_t>(elapsed_us / 32);
208 }
209
210 // TODO: put this somewhere with the big-endian equivalent used by JDWP.
Append2LE(uint8_t * buf,uint16_t val)211 static void Append2LE(uint8_t* buf, uint16_t val) {
212 *buf++ = static_cast<uint8_t>(val);
213 *buf++ = static_cast<uint8_t>(val >> 8);
214 }
215
216 // TODO: put this somewhere with the big-endian equivalent used by JDWP.
Append4LE(uint8_t * buf,uint32_t val)217 static void Append4LE(uint8_t* buf, uint32_t val) {
218 *buf++ = static_cast<uint8_t>(val);
219 *buf++ = static_cast<uint8_t>(val >> 8);
220 *buf++ = static_cast<uint8_t>(val >> 16);
221 *buf++ = static_cast<uint8_t>(val >> 24);
222 }
223
224 // TODO: put this somewhere with the big-endian equivalent used by JDWP.
Append8LE(uint8_t * buf,uint64_t val)225 static void Append8LE(uint8_t* buf, uint64_t val) {
226 *buf++ = static_cast<uint8_t>(val);
227 *buf++ = static_cast<uint8_t>(val >> 8);
228 *buf++ = static_cast<uint8_t>(val >> 16);
229 *buf++ = static_cast<uint8_t>(val >> 24);
230 *buf++ = static_cast<uint8_t>(val >> 32);
231 *buf++ = static_cast<uint8_t>(val >> 40);
232 *buf++ = static_cast<uint8_t>(val >> 48);
233 *buf++ = static_cast<uint8_t>(val >> 56);
234 }
235
GetSample(Thread * thread,void * arg)236 static void GetSample(Thread* thread, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
237 BuildStackTraceVisitor build_trace_visitor(thread);
238 build_trace_visitor.WalkStack();
239 std::vector<mirror::ArtMethod*>* stack_trace = build_trace_visitor.GetStackTrace();
240 Trace* the_trace = reinterpret_cast<Trace*>(arg);
241 the_trace->CompareAndUpdateStackTrace(thread, stack_trace);
242 }
243
ClearThreadStackTraceAndClockBase(Thread * thread,void * arg)244 static void ClearThreadStackTraceAndClockBase(Thread* thread, void* arg) {
245 thread->SetTraceClockBase(0);
246 std::vector<mirror::ArtMethod*>* stack_trace = thread->GetStackTraceSample();
247 thread->SetStackTraceSample(NULL);
248 delete stack_trace;
249 }
250
CompareAndUpdateStackTrace(Thread * thread,std::vector<mirror::ArtMethod * > * stack_trace)251 void Trace::CompareAndUpdateStackTrace(Thread* thread,
252 std::vector<mirror::ArtMethod*>* stack_trace) {
253 CHECK_EQ(pthread_self(), sampling_pthread_);
254 std::vector<mirror::ArtMethod*>* old_stack_trace = thread->GetStackTraceSample();
255 // Update the thread's stack trace sample.
256 thread->SetStackTraceSample(stack_trace);
257 // Read timer clocks to use for all events in this trace.
258 uint32_t thread_clock_diff = 0;
259 uint32_t wall_clock_diff = 0;
260 ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
261 if (old_stack_trace == NULL) {
262 // If there's no previous stack trace sample for this thread, log an entry event for all
263 // methods in the trace.
264 for (std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
265 rit != stack_trace->rend(); ++rit) {
266 LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
267 thread_clock_diff, wall_clock_diff);
268 }
269 } else {
270 // If there's a previous stack trace for this thread, diff the traces and emit entry and exit
271 // events accordingly.
272 std::vector<mirror::ArtMethod*>::reverse_iterator old_rit = old_stack_trace->rbegin();
273 std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
274 // Iterate bottom-up over both traces until there's a difference between them.
275 while (old_rit != old_stack_trace->rend() && rit != stack_trace->rend() && *old_rit == *rit) {
276 old_rit++;
277 rit++;
278 }
279 // Iterate top-down over the old trace until the point where they differ, emitting exit events.
280 for (std::vector<mirror::ArtMethod*>::iterator old_it = old_stack_trace->begin();
281 old_it != old_rit.base(); ++old_it) {
282 LogMethodTraceEvent(thread, *old_it, instrumentation::Instrumentation::kMethodExited,
283 thread_clock_diff, wall_clock_diff);
284 }
285 // Iterate bottom-up over the new trace from the point where they differ, emitting entry events.
286 for (; rit != stack_trace->rend(); ++rit) {
287 LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
288 thread_clock_diff, wall_clock_diff);
289 }
290 FreeStackTrace(old_stack_trace);
291 }
292 }
293
RunSamplingThread(void * arg)294 void* Trace::RunSamplingThread(void* arg) {
295 Runtime* runtime = Runtime::Current();
296 intptr_t interval_us = reinterpret_cast<intptr_t>(arg);
297 CHECK_GE(interval_us, 0);
298 CHECK(runtime->AttachCurrentThread("Sampling Profiler", true, runtime->GetSystemThreadGroup(),
299 !runtime->IsCompiler()));
300
301 while (true) {
302 usleep(interval_us);
303 ATRACE_BEGIN("Profile sampling");
304 Thread* self = Thread::Current();
305 Trace* the_trace;
306 {
307 MutexLock mu(self, *Locks::trace_lock_);
308 the_trace = the_trace_;
309 if (the_trace == NULL) {
310 break;
311 }
312 }
313
314 runtime->GetThreadList()->SuspendAll();
315 {
316 MutexLock mu(self, *Locks::thread_list_lock_);
317 runtime->GetThreadList()->ForEach(GetSample, the_trace);
318 }
319 runtime->GetThreadList()->ResumeAll();
320 ATRACE_END();
321 }
322
323 runtime->DetachCurrentThread();
324 return NULL;
325 }
326
Start(const char * trace_filename,int trace_fd,int buffer_size,int flags,bool direct_to_ddms,bool sampling_enabled,int interval_us)327 void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
328 bool direct_to_ddms, bool sampling_enabled, int interval_us) {
329 Thread* self = Thread::Current();
330 {
331 MutexLock mu(self, *Locks::trace_lock_);
332 if (the_trace_ != NULL) {
333 LOG(ERROR) << "Trace already in progress, ignoring this request";
334 return;
335 }
336 }
337
338 // Check interval if sampling is enabled
339 if (sampling_enabled && interval_us <= 0) {
340 LOG(ERROR) << "Invalid sampling interval: " << interval_us;
341 ScopedObjectAccess soa(self);
342 ThrowRuntimeException("Invalid sampling interval: %d", interval_us);
343 return;
344 }
345
346 // Open trace file if not going directly to ddms.
347 std::unique_ptr<File> trace_file;
348 if (!direct_to_ddms) {
349 if (trace_fd < 0) {
350 trace_file.reset(OS::CreateEmptyFile(trace_filename));
351 } else {
352 trace_file.reset(new File(trace_fd, "tracefile"));
353 trace_file->DisableAutoClose();
354 }
355 if (trace_file.get() == NULL) {
356 PLOG(ERROR) << "Unable to open trace file '" << trace_filename << "'";
357 ScopedObjectAccess soa(self);
358 ThrowRuntimeException("Unable to open trace file '%s'", trace_filename);
359 return;
360 }
361 }
362
363 Runtime* runtime = Runtime::Current();
364
365 // Enable count of allocs if specified in the flags.
366 bool enable_stats = false;
367
368 runtime->GetThreadList()->SuspendAll();
369
370 // Create Trace object.
371 {
372 MutexLock mu(self, *Locks::trace_lock_);
373 if (the_trace_ != NULL) {
374 LOG(ERROR) << "Trace already in progress, ignoring this request";
375 } else {
376 enable_stats = (flags && kTraceCountAllocs) != 0;
377 the_trace_ = new Trace(trace_file.release(), buffer_size, flags, sampling_enabled);
378 if (sampling_enabled) {
379 CHECK_PTHREAD_CALL(pthread_create, (&sampling_pthread_, NULL, &RunSamplingThread,
380 reinterpret_cast<void*>(interval_us)),
381 "Sampling profiler thread");
382 } else {
383 runtime->GetInstrumentation()->AddListener(the_trace_,
384 instrumentation::Instrumentation::kMethodEntered |
385 instrumentation::Instrumentation::kMethodExited |
386 instrumentation::Instrumentation::kMethodUnwind);
387 runtime->GetInstrumentation()->EnableMethodTracing();
388 }
389 }
390 }
391
392 runtime->GetThreadList()->ResumeAll();
393
394 // Can't call this when holding the mutator lock.
395 if (enable_stats) {
396 runtime->SetStatsEnabled(true);
397 }
398 }
399
Stop()400 void Trace::Stop() {
401 bool stop_alloc_counting = false;
402 Runtime* runtime = Runtime::Current();
403 runtime->GetThreadList()->SuspendAll();
404 Trace* the_trace = NULL;
405 pthread_t sampling_pthread = 0U;
406 {
407 MutexLock mu(Thread::Current(), *Locks::trace_lock_);
408 if (the_trace_ == NULL) {
409 LOG(ERROR) << "Trace stop requested, but no trace currently running";
410 } else {
411 the_trace = the_trace_;
412 the_trace_ = NULL;
413 sampling_pthread = sampling_pthread_;
414 }
415 }
416 if (the_trace != NULL) {
417 stop_alloc_counting = (the_trace->flags_ & kTraceCountAllocs) != 0;
418 the_trace->FinishTracing();
419
420 if (the_trace->sampling_enabled_) {
421 MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
422 runtime->GetThreadList()->ForEach(ClearThreadStackTraceAndClockBase, NULL);
423 } else {
424 runtime->GetInstrumentation()->DisableMethodTracing();
425 runtime->GetInstrumentation()->RemoveListener(the_trace,
426 instrumentation::Instrumentation::kMethodEntered |
427 instrumentation::Instrumentation::kMethodExited |
428 instrumentation::Instrumentation::kMethodUnwind);
429 }
430 if (the_trace->trace_file_.get() != nullptr) {
431 // Do not try to erase, so flush and close explicitly.
432 if (the_trace->trace_file_->Flush() != 0) {
433 PLOG(ERROR) << "Could not flush trace file.";
434 }
435 if (the_trace->trace_file_->Close() != 0) {
436 PLOG(ERROR) << "Could not close trace file.";
437 }
438 }
439 delete the_trace;
440 }
441 runtime->GetThreadList()->ResumeAll();
442
443 if (stop_alloc_counting) {
444 // Can be racy since SetStatsEnabled is not guarded by any locks.
445 Runtime::Current()->SetStatsEnabled(false);
446 }
447
448 if (sampling_pthread != 0U) {
449 CHECK_PTHREAD_CALL(pthread_join, (sampling_pthread, NULL), "sampling thread shutdown");
450 sampling_pthread_ = 0U;
451 }
452 }
453
Shutdown()454 void Trace::Shutdown() {
455 if (GetMethodTracingMode() != kTracingInactive) {
456 Stop();
457 }
458 }
459
GetMethodTracingMode()460 TracingMode Trace::GetMethodTracingMode() {
461 MutexLock mu(Thread::Current(), *Locks::trace_lock_);
462 if (the_trace_ == NULL) {
463 return kTracingInactive;
464 } else if (the_trace_->sampling_enabled_) {
465 return kSampleProfilingActive;
466 } else {
467 return kMethodTracingActive;
468 }
469 }
470
Trace(File * trace_file,int buffer_size,int flags,bool sampling_enabled)471 Trace::Trace(File* trace_file, int buffer_size, int flags, bool sampling_enabled)
472 : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
473 sampling_enabled_(sampling_enabled), clock_source_(default_clock_source_),
474 buffer_size_(buffer_size), start_time_(MicroTime()),
475 clock_overhead_ns_(GetClockOverheadNanoSeconds()), cur_offset_(0), overflow_(false) {
476 // Set up the beginning of the trace.
477 uint16_t trace_version = GetTraceVersion(clock_source_);
478 memset(buf_.get(), 0, kTraceHeaderLength);
479 Append4LE(buf_.get(), kTraceMagicValue);
480 Append2LE(buf_.get() + 4, trace_version);
481 Append2LE(buf_.get() + 6, kTraceHeaderLength);
482 Append8LE(buf_.get() + 8, start_time_);
483 if (trace_version >= kTraceVersionDualClock) {
484 uint16_t record_size = GetRecordSize(clock_source_);
485 Append2LE(buf_.get() + 16, record_size);
486 }
487
488 // Update current offset.
489 cur_offset_.StoreRelaxed(kTraceHeaderLength);
490 }
491
DumpBuf(uint8_t * buf,size_t buf_size,TraceClockSource clock_source)492 static void DumpBuf(uint8_t* buf, size_t buf_size, TraceClockSource clock_source)
493 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
494 uint8_t* ptr = buf + kTraceHeaderLength;
495 uint8_t* end = buf + buf_size;
496
497 while (ptr < end) {
498 uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
499 mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
500 TraceAction action = DecodeTraceAction(tmid);
501 LOG(INFO) << PrettyMethod(method) << " " << static_cast<int>(action);
502 ptr += GetRecordSize(clock_source);
503 }
504 }
505
FinishTracing()506 void Trace::FinishTracing() {
507 // Compute elapsed time.
508 uint64_t elapsed = MicroTime() - start_time_;
509
510 size_t final_offset = cur_offset_.LoadRelaxed();
511
512 std::set<mirror::ArtMethod*> visited_methods;
513 GetVisitedMethods(final_offset, &visited_methods);
514
515 std::ostringstream os;
516
517 os << StringPrintf("%cversion\n", kTraceTokenChar);
518 os << StringPrintf("%d\n", GetTraceVersion(clock_source_));
519 os << StringPrintf("data-file-overflow=%s\n", overflow_ ? "true" : "false");
520 if (UseThreadCpuClock()) {
521 if (UseWallClock()) {
522 os << StringPrintf("clock=dual\n");
523 } else {
524 os << StringPrintf("clock=thread-cpu\n");
525 }
526 } else {
527 os << StringPrintf("clock=wall\n");
528 }
529 os << StringPrintf("elapsed-time-usec=%" PRIu64 "\n", elapsed);
530 size_t num_records = (final_offset - kTraceHeaderLength) / GetRecordSize(clock_source_);
531 os << StringPrintf("num-method-calls=%zd\n", num_records);
532 os << StringPrintf("clock-call-overhead-nsec=%d\n", clock_overhead_ns_);
533 os << StringPrintf("vm=art\n");
534 if ((flags_ & kTraceCountAllocs) != 0) {
535 os << StringPrintf("alloc-count=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_OBJECTS));
536 os << StringPrintf("alloc-size=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_BYTES));
537 os << StringPrintf("gc-count=%d\n", Runtime::Current()->GetStat(KIND_GC_INVOCATIONS));
538 }
539 os << StringPrintf("%cthreads\n", kTraceTokenChar);
540 DumpThreadList(os);
541 os << StringPrintf("%cmethods\n", kTraceTokenChar);
542 DumpMethodList(os, visited_methods);
543 os << StringPrintf("%cend\n", kTraceTokenChar);
544
545 std::string header(os.str());
546 if (trace_file_.get() == NULL) {
547 iovec iov[2];
548 iov[0].iov_base = reinterpret_cast<void*>(const_cast<char*>(header.c_str()));
549 iov[0].iov_len = header.length();
550 iov[1].iov_base = buf_.get();
551 iov[1].iov_len = final_offset;
552 Dbg::DdmSendChunkV(CHUNK_TYPE("MPSE"), iov, 2);
553 const bool kDumpTraceInfo = false;
554 if (kDumpTraceInfo) {
555 LOG(INFO) << "Trace sent:\n" << header;
556 DumpBuf(buf_.get(), final_offset, clock_source_);
557 }
558 } else {
559 if (!trace_file_->WriteFully(header.c_str(), header.length()) ||
560 !trace_file_->WriteFully(buf_.get(), final_offset)) {
561 std::string detail(StringPrintf("Trace data write failed: %s", strerror(errno)));
562 PLOG(ERROR) << detail;
563 ThrowRuntimeException("%s", detail.c_str());
564 }
565 }
566 }
567
DexPcMoved(Thread * thread,mirror::Object * this_object,mirror::ArtMethod * method,uint32_t new_dex_pc)568 void Trace::DexPcMoved(Thread* thread, mirror::Object* this_object,
569 mirror::ArtMethod* method, uint32_t new_dex_pc) {
570 // We're not recorded to listen to this kind of event, so complain.
571 LOG(ERROR) << "Unexpected dex PC event in tracing " << PrettyMethod(method) << " " << new_dex_pc;
572 };
573
FieldRead(Thread *,mirror::Object * this_object,mirror::ArtMethod * method,uint32_t dex_pc,mirror::ArtField * field)574 void Trace::FieldRead(Thread* /*thread*/, mirror::Object* this_object,
575 mirror::ArtMethod* method, uint32_t dex_pc, mirror::ArtField* field)
576 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
577 // We're not recorded to listen to this kind of event, so complain.
578 LOG(ERROR) << "Unexpected field read event in tracing " << PrettyMethod(method) << " " << dex_pc;
579 }
580
FieldWritten(Thread *,mirror::Object * this_object,mirror::ArtMethod * method,uint32_t dex_pc,mirror::ArtField * field,const JValue & field_value)581 void Trace::FieldWritten(Thread* /*thread*/, mirror::Object* this_object,
582 mirror::ArtMethod* method, uint32_t dex_pc, mirror::ArtField* field,
583 const JValue& field_value)
584 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
585 // We're not recorded to listen to this kind of event, so complain.
586 LOG(ERROR) << "Unexpected field write event in tracing " << PrettyMethod(method) << " " << dex_pc;
587 }
588
MethodEntered(Thread * thread,mirror::Object * this_object,mirror::ArtMethod * method,uint32_t dex_pc)589 void Trace::MethodEntered(Thread* thread, mirror::Object* this_object,
590 mirror::ArtMethod* method, uint32_t dex_pc) {
591 uint32_t thread_clock_diff = 0;
592 uint32_t wall_clock_diff = 0;
593 ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
594 LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodEntered,
595 thread_clock_diff, wall_clock_diff);
596 }
597
MethodExited(Thread * thread,mirror::Object * this_object,mirror::ArtMethod * method,uint32_t dex_pc,const JValue & return_value)598 void Trace::MethodExited(Thread* thread, mirror::Object* this_object,
599 mirror::ArtMethod* method, uint32_t dex_pc,
600 const JValue& return_value) {
601 UNUSED(return_value);
602 uint32_t thread_clock_diff = 0;
603 uint32_t wall_clock_diff = 0;
604 ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
605 LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodExited,
606 thread_clock_diff, wall_clock_diff);
607 }
608
MethodUnwind(Thread * thread,mirror::Object * this_object,mirror::ArtMethod * method,uint32_t dex_pc)609 void Trace::MethodUnwind(Thread* thread, mirror::Object* this_object,
610 mirror::ArtMethod* method, uint32_t dex_pc) {
611 uint32_t thread_clock_diff = 0;
612 uint32_t wall_clock_diff = 0;
613 ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
614 LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodUnwind,
615 thread_clock_diff, wall_clock_diff);
616 }
617
ExceptionCaught(Thread * thread,const ThrowLocation & throw_location,mirror::ArtMethod * catch_method,uint32_t catch_dex_pc,mirror::Throwable * exception_object)618 void Trace::ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
619 mirror::ArtMethod* catch_method, uint32_t catch_dex_pc,
620 mirror::Throwable* exception_object)
621 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
622 LOG(ERROR) << "Unexpected exception caught event in tracing";
623 }
624
ReadClocks(Thread * thread,uint32_t * thread_clock_diff,uint32_t * wall_clock_diff)625 void Trace::ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff) {
626 if (UseThreadCpuClock()) {
627 uint64_t clock_base = thread->GetTraceClockBase();
628 if (UNLIKELY(clock_base == 0)) {
629 // First event, record the base time in the map.
630 uint64_t time = thread->GetCpuMicroTime();
631 thread->SetTraceClockBase(time);
632 } else {
633 *thread_clock_diff = thread->GetCpuMicroTime() - clock_base;
634 }
635 }
636 if (UseWallClock()) {
637 *wall_clock_diff = MicroTime() - start_time_;
638 }
639 }
640
LogMethodTraceEvent(Thread * thread,mirror::ArtMethod * method,instrumentation::Instrumentation::InstrumentationEvent event,uint32_t thread_clock_diff,uint32_t wall_clock_diff)641 void Trace::LogMethodTraceEvent(Thread* thread, mirror::ArtMethod* method,
642 instrumentation::Instrumentation::InstrumentationEvent event,
643 uint32_t thread_clock_diff, uint32_t wall_clock_diff) {
644 // Advance cur_offset_ atomically.
645 int32_t new_offset;
646 int32_t old_offset;
647 do {
648 old_offset = cur_offset_.LoadRelaxed();
649 new_offset = old_offset + GetRecordSize(clock_source_);
650 if (new_offset > buffer_size_) {
651 overflow_ = true;
652 return;
653 }
654 } while (!cur_offset_.CompareExchangeWeakSequentiallyConsistent(old_offset, new_offset));
655
656 TraceAction action = kTraceMethodEnter;
657 switch (event) {
658 case instrumentation::Instrumentation::kMethodEntered:
659 action = kTraceMethodEnter;
660 break;
661 case instrumentation::Instrumentation::kMethodExited:
662 action = kTraceMethodExit;
663 break;
664 case instrumentation::Instrumentation::kMethodUnwind:
665 action = kTraceUnroll;
666 break;
667 default:
668 UNIMPLEMENTED(FATAL) << "Unexpected event: " << event;
669 }
670
671 uint32_t method_value = EncodeTraceMethodAndAction(method, action);
672
673 // Write data
674 uint8_t* ptr = buf_.get() + old_offset;
675 Append2LE(ptr, thread->GetTid());
676 Append4LE(ptr + 2, method_value);
677 ptr += 6;
678
679 if (UseThreadCpuClock()) {
680 Append4LE(ptr, thread_clock_diff);
681 ptr += 4;
682 }
683 if (UseWallClock()) {
684 Append4LE(ptr, wall_clock_diff);
685 }
686 }
687
GetVisitedMethods(size_t buf_size,std::set<mirror::ArtMethod * > * visited_methods)688 void Trace::GetVisitedMethods(size_t buf_size,
689 std::set<mirror::ArtMethod*>* visited_methods) {
690 uint8_t* ptr = buf_.get() + kTraceHeaderLength;
691 uint8_t* end = buf_.get() + buf_size;
692
693 while (ptr < end) {
694 uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
695 mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
696 visited_methods->insert(method);
697 ptr += GetRecordSize(clock_source_);
698 }
699 }
700
DumpMethodList(std::ostream & os,const std::set<mirror::ArtMethod * > & visited_methods)701 void Trace::DumpMethodList(std::ostream& os, const std::set<mirror::ArtMethod*>& visited_methods) {
702 for (const auto& method : visited_methods) {
703 os << StringPrintf("%p\t%s\t%s\t%s\t%s\n", method,
704 PrettyDescriptor(method->GetDeclaringClassDescriptor()).c_str(), method->GetName(),
705 method->GetSignature().ToString().c_str(), method->GetDeclaringClassSourceFile());
706 }
707 }
708
DumpThread(Thread * t,void * arg)709 static void DumpThread(Thread* t, void* arg) {
710 std::ostream& os = *reinterpret_cast<std::ostream*>(arg);
711 std::string name;
712 t->GetThreadName(name);
713 os << t->GetTid() << "\t" << name << "\n";
714 }
715
DumpThreadList(std::ostream & os)716 void Trace::DumpThreadList(std::ostream& os) {
717 Thread* self = Thread::Current();
718 for (auto it : exited_threads_) {
719 os << it.first << "\t" << it.second << "\n";
720 }
721 Locks::thread_list_lock_->AssertNotHeld(self);
722 MutexLock mu(self, *Locks::thread_list_lock_);
723 Runtime::Current()->GetThreadList()->ForEach(DumpThread, &os);
724 }
725
StoreExitingThreadInfo(Thread * thread)726 void Trace::StoreExitingThreadInfo(Thread* thread) {
727 MutexLock mu(thread, *Locks::trace_lock_);
728 if (the_trace_ != nullptr) {
729 std::string name;
730 thread->GetThreadName(name);
731 the_trace_->exited_threads_.Put(thread->GetTid(), name);
732 }
733 }
734
735 } // namespace art
736