trace.cc revision c1ff4b79a5d81b849203cc1e1c4a91223e75cfd3 
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 "object_utils.h"
34#include "os.h"
35#include "scoped_thread_state_change.h"
36#include "ScopedLocalRef.h"
37#include "thread.h"
38#include "thread_list.h"
39#if !defined(ART_USE_PORTABLE_COMPILER)
40#include "entrypoints/quick/quick_entrypoints.h"
41#endif
42
43namespace art {
44
45// File format:
46//     header
47//     record 0
48//     record 1
49//     ...
50//
51// Header format:
52//     u4  magic ('SLOW')
53//     u2  version
54//     u2  offset to data
55//     u8  start date/time in usec
56//     u2  record size in bytes (version >= 2 only)
57//     ... padding to 32 bytes
58//
59// Record format v1:
60//     u1  thread ID
61//     u4  method ID | method action
62//     u4  time delta since start, in usec
63//
64// Record format v2:
65//     u2  thread ID
66//     u4  method ID | method action
67//     u4  time delta since start, in usec
68//
69// Record format v3:
70//     u2  thread ID
71//     u4  method ID | method action
72//     u4  time delta since start, in usec
73//     u4  wall time since start, in usec (when clock == "dual" only)
74//
75// 32 bits of microseconds is 70 minutes.
76//
77// All values are stored in little-endian order.
78
79enum TraceAction {
80    kTraceMethodEnter = 0x00,       // method entry
81    kTraceMethodExit = 0x01,        // method exit
82    kTraceUnroll = 0x02,            // method exited by exception unrolling
83    // 0x03 currently unused
84    kTraceMethodActionMask = 0x03,  // two bits
85};
86
87class BuildStackTraceVisitor : public StackVisitor {
88 public:
89  explicit BuildStackTraceVisitor(Thread* thread) : StackVisitor(thread, NULL),
90      method_trace_(Trace::AllocStackTrace()) {}
91
92  bool VisitFrame() {
93    mirror::ArtMethod* m = GetMethod();
94    // Ignore runtime frames (in particular callee save).
95    if (!m->IsRuntimeMethod()) {
96      method_trace_->push_back(m);
97    }
98    return true;
99  }
100
101  // Returns a stack trace where the topmost frame corresponds with the first element of the vector.
102  std::vector<mirror::ArtMethod*>* GetStackTrace() const {
103    return method_trace_;
104  }
105
106 private:
107  std::vector<mirror::ArtMethod*>* const method_trace_;
108};
109
110static const char     kTraceTokenChar             = '*';
111static const uint16_t kTraceHeaderLength          = 32;
112static const uint32_t kTraceMagicValue            = 0x574f4c53;
113static const uint16_t kTraceVersionSingleClock    = 2;
114static const uint16_t kTraceVersionDualClock      = 3;
115static const uint16_t kTraceRecordSizeSingleClock = 10;  // using v2
116static const uint16_t kTraceRecordSizeDualClock   = 14;  // using v3 with two timestamps
117
118#if defined(HAVE_POSIX_CLOCKS)
119ProfilerClockSource Trace::default_clock_source_ = kProfilerClockSourceDual;
120#else
121ProfilerClockSource Trace::default_clock_source_ = kProfilerClockSourceWall;
122#endif
123
124Trace* volatile Trace::the_trace_ = NULL;
125// TODO: Add way to enable sampling and set interval through gui.
126bool Trace::sampling_enabled_ = true;
127uint32_t Trace::sampling_interval_us_ = 10000;
128pthread_t Trace::sampling_pthread_ = 0U;
129UniquePtr<std::vector<mirror::ArtMethod*> > Trace::temp_stack_trace_;
130
131static mirror::ArtMethod* DecodeTraceMethodId(uint32_t tmid) {
132  return reinterpret_cast<mirror::ArtMethod*>(tmid & ~kTraceMethodActionMask);
133}
134
135static TraceAction DecodeTraceAction(uint32_t tmid) {
136  return static_cast<TraceAction>(tmid & kTraceMethodActionMask);
137}
138
139static uint32_t EncodeTraceMethodAndAction(const mirror::ArtMethod* method,
140                                           TraceAction action) {
141  uint32_t tmid = reinterpret_cast<uint32_t>(method) | action;
142  DCHECK_EQ(method, DecodeTraceMethodId(tmid));
143  return tmid;
144}
145
146std::vector<mirror::ArtMethod*>* Trace::AllocStackTrace() {
147  if (temp_stack_trace_.get() != NULL) {
148    return temp_stack_trace_.release();
149  } else {
150    return new std::vector<mirror::ArtMethod*>();
151  }
152}
153
154void Trace::FreeStackTrace(std::vector<mirror::ArtMethod*>* stack_trace) {
155  stack_trace->clear();
156  temp_stack_trace_.reset(stack_trace);
157}
158
159void Trace::SetDefaultClockSource(ProfilerClockSource clock_source) {
160#if defined(HAVE_POSIX_CLOCKS)
161  default_clock_source_ = clock_source;
162#else
163  if (clock_source != kProfilerClockSourceWall) {
164    LOG(WARNING) << "Ignoring tracing request to use CPU time.";
165  }
166#endif
167}
168
169static uint16_t GetTraceVersion(ProfilerClockSource clock_source) {
170  return (clock_source == kProfilerClockSourceDual) ? kTraceVersionDualClock
171                                                    : kTraceVersionSingleClock;
172}
173
174static uint16_t GetRecordSize(ProfilerClockSource clock_source) {
175  return (clock_source == kProfilerClockSourceDual) ? kTraceRecordSizeDualClock
176                                                    : kTraceRecordSizeSingleClock;
177}
178
179bool Trace::UseThreadCpuClock() {
180  return (clock_source_ == kProfilerClockSourceThreadCpu) ||
181      (clock_source_ == kProfilerClockSourceDual);
182}
183
184bool Trace::UseWallClock() {
185  return (clock_source_ == kProfilerClockSourceWall) ||
186      (clock_source_ == kProfilerClockSourceDual);
187}
188
189static void MeasureClockOverhead(Trace* trace) {
190  if (trace->UseThreadCpuClock()) {
191    Thread::Current()->GetCpuMicroTime();
192  }
193  if (trace->UseWallClock()) {
194    MicroTime();
195  }
196}
197
198// Compute an average time taken to measure clocks.
199static uint32_t GetClockOverheadNanoSeconds(Trace* trace) {
200  Thread* self = Thread::Current();
201  uint64_t start = self->GetCpuMicroTime();
202
203  for (int i = 4000; i > 0; i--) {
204    MeasureClockOverhead(trace);
205    MeasureClockOverhead(trace);
206    MeasureClockOverhead(trace);
207    MeasureClockOverhead(trace);
208    MeasureClockOverhead(trace);
209    MeasureClockOverhead(trace);
210    MeasureClockOverhead(trace);
211    MeasureClockOverhead(trace);
212  }
213
214  uint64_t elapsed_us = self->GetCpuMicroTime() - start;
215  return static_cast<uint32_t>(elapsed_us / 32);
216}
217
218// TODO: put this somewhere with the big-endian equivalent used by JDWP.
219static void Append2LE(uint8_t* buf, uint16_t val) {
220  *buf++ = static_cast<uint8_t>(val);
221  *buf++ = static_cast<uint8_t>(val >> 8);
222}
223
224// TODO: put this somewhere with the big-endian equivalent used by JDWP.
225static void Append4LE(uint8_t* buf, uint32_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}
231
232// TODO: put this somewhere with the big-endian equivalent used by JDWP.
233static void Append8LE(uint8_t* buf, uint64_t val) {
234  *buf++ = static_cast<uint8_t>(val);
235  *buf++ = static_cast<uint8_t>(val >> 8);
236  *buf++ = static_cast<uint8_t>(val >> 16);
237  *buf++ = static_cast<uint8_t>(val >> 24);
238  *buf++ = static_cast<uint8_t>(val >> 32);
239  *buf++ = static_cast<uint8_t>(val >> 40);
240  *buf++ = static_cast<uint8_t>(val >> 48);
241  *buf++ = static_cast<uint8_t>(val >> 56);
242}
243
244static void GetSample(Thread* thread, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
245  BuildStackTraceVisitor build_trace_visitor(thread);
246  build_trace_visitor.WalkStack();
247  std::vector<mirror::ArtMethod*>* stack_trace = build_trace_visitor.GetStackTrace();
248  Trace* the_trace = reinterpret_cast<Trace*>(arg);
249  the_trace->CompareAndUpdateStackTrace(thread, stack_trace);
250}
251
252static void ClearThreadStackTraceAndClockBase(Thread* thread, void* arg) {
253  thread->SetTraceClockBase(0);
254  std::vector<mirror::ArtMethod*>* stack_trace = thread->GetStackTraceSample();
255  thread->SetStackTraceSample(NULL);
256  delete stack_trace;
257}
258
259void Trace::CompareAndUpdateStackTrace(Thread* thread,
260                                       std::vector<mirror::ArtMethod*>* stack_trace) {
261  CHECK_EQ(pthread_self(), sampling_pthread_);
262  std::vector<mirror::ArtMethod*>* old_stack_trace = thread->GetStackTraceSample();
263  // Update the thread's stack trace sample.
264  thread->SetStackTraceSample(stack_trace);
265  // Read timer clocks to use for all events in this trace.
266  uint32_t thread_clock_diff = 0;
267  uint32_t wall_clock_diff = 0;
268  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
269  if (old_stack_trace == NULL) {
270    // If there's no previous stack trace sample for this thread, log an entry event for all
271    // methods in the trace.
272    for (std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
273         rit != stack_trace->rend(); ++rit) {
274      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
275                          thread_clock_diff, wall_clock_diff);
276    }
277  } else {
278    // If there's a previous stack trace for this thread, diff the traces and emit entry and exit
279    // events accordingly.
280    std::vector<mirror::ArtMethod*>::reverse_iterator old_rit = old_stack_trace->rbegin();
281    std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
282    // Iterate bottom-up over both traces until there's a difference between them.
283    while (old_rit != old_stack_trace->rend() && rit != stack_trace->rend() && *old_rit == *rit) {
284      old_rit++;
285      rit++;
286    }
287    // Iterate top-down over the old trace until the point where they differ, emitting exit events.
288    for (std::vector<mirror::ArtMethod*>::iterator old_it = old_stack_trace->begin();
289         old_it != old_rit.base(); ++old_it) {
290      LogMethodTraceEvent(thread, *old_it, instrumentation::Instrumentation::kMethodExited,
291                          thread_clock_diff, wall_clock_diff);
292    }
293    // Iterate bottom-up over the new trace from the point where they differ, emitting entry events.
294    for (; rit != stack_trace->rend(); ++rit) {
295      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
296                          thread_clock_diff, wall_clock_diff);
297    }
298    FreeStackTrace(old_stack_trace);
299  }
300}
301
302void* Trace::RunSamplingThread(void* arg) {
303  Runtime* runtime = Runtime::Current();
304  CHECK(runtime->AttachCurrentThread("Sampling Profiler", true, runtime->GetSystemThreadGroup(),
305                                     !runtime->IsCompiler()));
306
307  while (true) {
308    usleep(sampling_interval_us_);
309    ATRACE_BEGIN("Profile sampling");
310    Thread* self = Thread::Current();
311    Trace* the_trace;
312    {
313      MutexLock mu(self, *Locks::trace_lock_);
314      the_trace = the_trace_;
315      if (the_trace == NULL) {
316        break;
317      }
318    }
319
320    runtime->GetThreadList()->SuspendAll();
321    {
322      MutexLock mu(self, *Locks::thread_list_lock_);
323      runtime->GetThreadList()->ForEach(GetSample, the_trace);
324    }
325    runtime->GetThreadList()->ResumeAll();
326    ATRACE_END();
327  }
328
329  runtime->DetachCurrentThread();
330  return NULL;
331}
332
333void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
334                  bool direct_to_ddms) {
335  Thread* self = Thread::Current();
336  {
337    MutexLock mu(self, *Locks::trace_lock_);
338    if (the_trace_ != NULL) {
339      LOG(ERROR) << "Trace already in progress, ignoring this request";
340      return;
341    }
342  }
343  Runtime* runtime = Runtime::Current();
344  runtime->GetThreadList()->SuspendAll();
345
346  // Open trace file if not going directly to ddms.
347  UniquePtr<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      runtime->GetThreadList()->ResumeAll();
358      ScopedObjectAccess soa(self);
359      ThrowRuntimeException("Unable to open trace file '%s'", trace_filename);
360      return;
361    }
362  }
363
364  // Create Trace object.
365  {
366    MutexLock mu(self, *Locks::trace_lock_);
367    if (the_trace_ != NULL) {
368      LOG(ERROR) << "Trace already in progress, ignoring this request";
369    } else {
370      the_trace_ = new Trace(trace_file.release(), buffer_size, flags);
371
372      // Enable count of allocs if specified in the flags.
373      if ((flags && kTraceCountAllocs) != 0) {
374        runtime->SetStatsEnabled(true);
375      }
376
377      if (sampling_enabled_) {
378        CHECK_PTHREAD_CALL(pthread_create, (&sampling_pthread_, NULL, &RunSamplingThread, NULL),
379                           "Sampling profiler thread");
380      } else {
381        runtime->GetInstrumentation()->AddListener(the_trace_,
382                                                   instrumentation::Instrumentation::kMethodEntered |
383                                                   instrumentation::Instrumentation::kMethodExited |
384                                                   instrumentation::Instrumentation::kMethodUnwind);
385      }
386    }
387  }
388  runtime->GetThreadList()->ResumeAll();
389}
390
391void Trace::Stop() {
392  Runtime* runtime = Runtime::Current();
393  runtime->GetThreadList()->SuspendAll();
394  Trace* the_trace = NULL;
395  pthread_t sampling_pthread = 0U;
396  {
397    MutexLock mu(Thread::Current(), *Locks::trace_lock_);
398    if (the_trace_ == NULL) {
399      LOG(ERROR) << "Trace stop requested, but no trace currently running";
400    } else {
401      the_trace = the_trace_;
402      the_trace_ = NULL;
403      sampling_pthread = sampling_pthread_;
404      sampling_pthread_ = 0U;
405    }
406  }
407  if (the_trace != NULL) {
408    the_trace->FinishTracing();
409
410    if (sampling_enabled_) {
411      MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
412      runtime->GetThreadList()->ForEach(ClearThreadStackTraceAndClockBase, NULL);
413    } else {
414      runtime->GetInstrumentation()->RemoveListener(the_trace,
415                                                    instrumentation::Instrumentation::kMethodEntered |
416                                                    instrumentation::Instrumentation::kMethodExited |
417                                                    instrumentation::Instrumentation::kMethodUnwind);
418    }
419    delete the_trace;
420  }
421  runtime->GetThreadList()->ResumeAll();
422
423  if (sampling_enabled_ && sampling_pthread != 0U) {
424    CHECK_PTHREAD_CALL(pthread_join, (sampling_pthread, NULL), "sampling thread shutdown");
425  }
426}
427
428void Trace::Shutdown() {
429  if (IsMethodTracingActive()) {
430    Stop();
431  }
432}
433
434bool Trace::IsMethodTracingActive() {
435  MutexLock mu(Thread::Current(), *Locks::trace_lock_);
436  return the_trace_ != NULL;
437}
438
439Trace::Trace(File* trace_file, int buffer_size, int flags)
440    : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
441      clock_source_(default_clock_source_), buffer_size_(buffer_size), start_time_(MicroTime()),
442      cur_offset_(0),  overflow_(false) {
443  // Set up the beginning of the trace.
444  uint16_t trace_version = GetTraceVersion(clock_source_);
445  memset(buf_.get(), 0, kTraceHeaderLength);
446  Append4LE(buf_.get(), kTraceMagicValue);
447  Append2LE(buf_.get() + 4, trace_version);
448  Append2LE(buf_.get() + 6, kTraceHeaderLength);
449  Append8LE(buf_.get() + 8, start_time_);
450  if (trace_version >= kTraceVersionDualClock) {
451    uint16_t record_size = GetRecordSize(clock_source_);
452    Append2LE(buf_.get() + 16, record_size);
453  }
454
455  // Update current offset.
456  cur_offset_ = kTraceHeaderLength;
457}
458
459Trace::~Trace() {
460  CHECK_EQ(sampling_pthread_, static_cast<pthread_t>(0U));
461}
462
463static void DumpBuf(uint8_t* buf, size_t buf_size, ProfilerClockSource clock_source)
464    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
465  uint8_t* ptr = buf + kTraceHeaderLength;
466  uint8_t* end = buf + buf_size;
467
468  while (ptr < end) {
469    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
470    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
471    TraceAction action = DecodeTraceAction(tmid);
472    LOG(INFO) << PrettyMethod(method) << " " << static_cast<int>(action);
473    ptr += GetRecordSize(clock_source);
474  }
475}
476
477void Trace::FinishTracing() {
478  // Compute elapsed time.
479  uint64_t elapsed = MicroTime() - start_time_;
480
481  size_t final_offset = cur_offset_;
482  uint32_t clock_overhead_ns = GetClockOverheadNanoSeconds(this);
483
484  if ((flags_ & kTraceCountAllocs) != 0) {
485    Runtime::Current()->SetStatsEnabled(false);
486  }
487
488  std::set<mirror::ArtMethod*> visited_methods;
489  GetVisitedMethods(final_offset, &visited_methods);
490
491  std::ostringstream os;
492
493  os << StringPrintf("%cversion\n", kTraceTokenChar);
494  os << StringPrintf("%d\n", GetTraceVersion(clock_source_));
495  os << StringPrintf("data-file-overflow=%s\n", overflow_ ? "true" : "false");
496  if (UseThreadCpuClock()) {
497    if (UseWallClock()) {
498      os << StringPrintf("clock=dual\n");
499    } else {
500      os << StringPrintf("clock=thread-cpu\n");
501    }
502  } else {
503    os << StringPrintf("clock=wall\n");
504  }
505  os << StringPrintf("elapsed-time-usec=%llu\n", elapsed);
506  size_t num_records = (final_offset - kTraceHeaderLength) / GetRecordSize(clock_source_);
507  os << StringPrintf("num-method-calls=%zd\n", num_records);
508  os << StringPrintf("clock-call-overhead-nsec=%d\n", clock_overhead_ns);
509  os << StringPrintf("vm=art\n");
510  if ((flags_ & kTraceCountAllocs) != 0) {
511    os << StringPrintf("alloc-count=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_OBJECTS));
512    os << StringPrintf("alloc-size=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_BYTES));
513    os << StringPrintf("gc-count=%d\n", Runtime::Current()->GetStat(KIND_GC_INVOCATIONS));
514  }
515  os << StringPrintf("%cthreads\n", kTraceTokenChar);
516  DumpThreadList(os);
517  os << StringPrintf("%cmethods\n", kTraceTokenChar);
518  DumpMethodList(os, visited_methods);
519  os << StringPrintf("%cend\n", kTraceTokenChar);
520
521  std::string header(os.str());
522  if (trace_file_.get() == NULL) {
523    iovec iov[2];
524    iov[0].iov_base = reinterpret_cast<void*>(const_cast<char*>(header.c_str()));
525    iov[0].iov_len = header.length();
526    iov[1].iov_base = buf_.get();
527    iov[1].iov_len = final_offset;
528    Dbg::DdmSendChunkV(CHUNK_TYPE("MPSE"), iov, 2);
529    const bool kDumpTraceInfo = false;
530    if (kDumpTraceInfo) {
531      LOG(INFO) << "Trace sent:\n" << header;
532      DumpBuf(buf_.get(), final_offset, clock_source_);
533    }
534  } else {
535    if (!trace_file_->WriteFully(header.c_str(), header.length()) ||
536        !trace_file_->WriteFully(buf_.get(), final_offset)) {
537      std::string detail(StringPrintf("Trace data write failed: %s", strerror(errno)));
538      PLOG(ERROR) << detail;
539      ThrowRuntimeException("%s", detail.c_str());
540    }
541  }
542}
543
544void Trace::DexPcMoved(Thread* thread, mirror::Object* this_object,
545                       const mirror::ArtMethod* method, uint32_t new_dex_pc) {
546  // We're not recorded to listen to this kind of event, so complain.
547  LOG(ERROR) << "Unexpected dex PC event in tracing " << PrettyMethod(method) << " " << new_dex_pc;
548};
549
550void Trace::MethodEntered(Thread* thread, mirror::Object* this_object,
551                          const mirror::ArtMethod* method, uint32_t dex_pc) {
552  uint32_t thread_clock_diff = 0;
553  uint32_t wall_clock_diff = 0;
554  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
555  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodEntered,
556                      thread_clock_diff, wall_clock_diff);
557}
558
559void Trace::MethodExited(Thread* thread, mirror::Object* this_object,
560                         const mirror::ArtMethod* method, uint32_t dex_pc,
561                         const JValue& return_value) {
562  UNUSED(return_value);
563  uint32_t thread_clock_diff = 0;
564  uint32_t wall_clock_diff = 0;
565  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
566  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodExited,
567                      thread_clock_diff, wall_clock_diff);
568}
569
570void Trace::MethodUnwind(Thread* thread, const mirror::ArtMethod* method, uint32_t dex_pc) {
571  uint32_t thread_clock_diff = 0;
572  uint32_t wall_clock_diff = 0;
573  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
574  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodUnwind,
575                      thread_clock_diff, wall_clock_diff);
576}
577
578void Trace::ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
579                            mirror::ArtMethod* catch_method, uint32_t catch_dex_pc,
580                            mirror::Throwable* exception_object)
581    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
582  LOG(ERROR) << "Unexpected exception caught event in tracing";
583}
584
585void Trace::ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff) {
586  if (UseThreadCpuClock()) {
587    uint64_t clock_base = thread->GetTraceClockBase();
588    if (UNLIKELY(clock_base == 0)) {
589      // First event, record the base time in the map.
590      uint64_t time = thread->GetCpuMicroTime();
591      thread->SetTraceClockBase(time);
592    } else {
593      *thread_clock_diff = thread->GetCpuMicroTime() - clock_base;
594    }
595  }
596  if (UseWallClock()) {
597    *wall_clock_diff = MicroTime() - start_time_;
598  }
599}
600
601void Trace::LogMethodTraceEvent(Thread* thread, const mirror::ArtMethod* method,
602                                instrumentation::Instrumentation::InstrumentationEvent event,
603                                uint32_t thread_clock_diff, uint32_t wall_clock_diff) {
604  // Advance cur_offset_ atomically.
605  int32_t new_offset;
606  int32_t old_offset;
607  do {
608    old_offset = cur_offset_;
609    new_offset = old_offset + GetRecordSize(clock_source_);
610    if (new_offset > buffer_size_) {
611      overflow_ = true;
612      return;
613    }
614  } while (android_atomic_release_cas(old_offset, new_offset, &cur_offset_) != 0);
615
616  TraceAction action = kTraceMethodEnter;
617  switch (event) {
618    case instrumentation::Instrumentation::kMethodEntered:
619      action = kTraceMethodEnter;
620      break;
621    case instrumentation::Instrumentation::kMethodExited:
622      action = kTraceMethodExit;
623      break;
624    case instrumentation::Instrumentation::kMethodUnwind:
625      action = kTraceUnroll;
626      break;
627    default:
628      UNIMPLEMENTED(FATAL) << "Unexpected event: " << event;
629  }
630
631  uint32_t method_value = EncodeTraceMethodAndAction(method, action);
632
633  // Write data
634  uint8_t* ptr = buf_.get() + old_offset;
635  Append2LE(ptr, thread->GetTid());
636  Append4LE(ptr + 2, method_value);
637  ptr += 6;
638
639  if (UseThreadCpuClock()) {
640    Append4LE(ptr, thread_clock_diff);
641    ptr += 4;
642  }
643  if (UseWallClock()) {
644    Append4LE(ptr, wall_clock_diff);
645  }
646}
647
648void Trace::GetVisitedMethods(size_t buf_size,
649                              std::set<mirror::ArtMethod*>* visited_methods) {
650  uint8_t* ptr = buf_.get() + kTraceHeaderLength;
651  uint8_t* end = buf_.get() + buf_size;
652
653  while (ptr < end) {
654    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
655    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
656    visited_methods->insert(method);
657    ptr += GetRecordSize(clock_source_);
658  }
659}
660
661void Trace::DumpMethodList(std::ostream& os, const std::set<mirror::ArtMethod*>& visited_methods) {
662  MethodHelper mh;
663  for (const auto& method : visited_methods) {
664    mh.ChangeMethod(method);
665    os << StringPrintf("%p\t%s\t%s\t%s\t%s\n", method,
666        PrettyDescriptor(mh.GetDeclaringClassDescriptor()).c_str(), mh.GetName(),
667        mh.GetSignature().c_str(), mh.GetDeclaringClassSourceFile());
668  }
669}
670
671static void DumpThread(Thread* t, void* arg) {
672  std::ostream& os = *reinterpret_cast<std::ostream*>(arg);
673  std::string name;
674  t->GetThreadName(name);
675  os << t->GetTid() << "\t" << name << "\n";
676}
677
678void Trace::DumpThreadList(std::ostream& os) {
679  Thread* self = Thread::Current();
680  Locks::thread_list_lock_->AssertNotHeld(self);
681  MutexLock mu(self, *Locks::thread_list_lock_);
682  Runtime::Current()->GetThreadList()->ForEach(DumpThread, &os);
683}
684
685}  // namespace art
686