trace.cc revision 57dac6ed61a0a25c14d4e2fabc84435578d42360 
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_(new std::vector<mirror::ArtMethod*>) {}
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;
129
130static mirror::ArtMethod* DecodeTraceMethodId(uint32_t tmid) {
131  return reinterpret_cast<mirror::ArtMethod*>(tmid & ~kTraceMethodActionMask);
132}
133
134static TraceAction DecodeTraceAction(uint32_t tmid) {
135  return static_cast<TraceAction>(tmid & kTraceMethodActionMask);
136}
137
138static uint32_t EncodeTraceMethodAndAction(const mirror::ArtMethod* method,
139                                           TraceAction action) {
140  uint32_t tmid = reinterpret_cast<uint32_t>(method) | action;
141  DCHECK_EQ(method, DecodeTraceMethodId(tmid));
142  return tmid;
143}
144
145void Trace::SetDefaultClockSource(ProfilerClockSource clock_source) {
146#if defined(HAVE_POSIX_CLOCKS)
147  default_clock_source_ = clock_source;
148#else
149  if (clock_source != kProfilerClockSourceWall) {
150    LOG(WARNING) << "Ignoring tracing request to use ";
151  }
152#endif
153}
154
155static uint16_t GetTraceVersion(ProfilerClockSource clock_source) {
156  return (clock_source == kProfilerClockSourceDual) ? kTraceVersionDualClock
157                                                    : kTraceVersionSingleClock;
158}
159
160static uint16_t GetRecordSize(ProfilerClockSource clock_source) {
161  return (clock_source == kProfilerClockSourceDual) ? kTraceRecordSizeDualClock
162                                                    : kTraceRecordSizeSingleClock;
163}
164
165bool Trace::UseThreadCpuClock() {
166  return (clock_source_ == kProfilerClockSourceThreadCpu) ||
167      (clock_source_ == kProfilerClockSourceDual);
168}
169
170bool Trace::UseWallClock() {
171  return (clock_source_ == kProfilerClockSourceWall) ||
172      (clock_source_ == kProfilerClockSourceDual);
173}
174
175static void MeasureClockOverhead(Trace* trace) {
176  if (trace->UseThreadCpuClock()) {
177    Thread::Current()->GetCpuMicroTime();
178  }
179  if (trace->UseWallClock()) {
180    MicroTime();
181  }
182}
183
184static uint32_t GetClockOverhead(Trace* trace) {
185  Thread* self = Thread::Current();
186  uint64_t start = self->GetCpuMicroTime();
187
188  for (int i = 4000; i > 0; i--) {
189    MeasureClockOverhead(trace);
190    MeasureClockOverhead(trace);
191    MeasureClockOverhead(trace);
192    MeasureClockOverhead(trace);
193    MeasureClockOverhead(trace);
194    MeasureClockOverhead(trace);
195    MeasureClockOverhead(trace);
196    MeasureClockOverhead(trace);
197  }
198
199  uint64_t elapsed = self->GetCpuMicroTime() - start;
200  return uint32_t (elapsed / 32);
201}
202
203// TODO: put this somewhere with the big-endian equivalent used by JDWP.
204static void Append2LE(uint8_t* buf, uint16_t val) {
205  *buf++ = (uint8_t) val;
206  *buf++ = (uint8_t) (val >> 8);
207}
208
209// TODO: put this somewhere with the big-endian equivalent used by JDWP.
210static void Append4LE(uint8_t* buf, uint32_t val) {
211  *buf++ = (uint8_t) val;
212  *buf++ = (uint8_t) (val >> 8);
213  *buf++ = (uint8_t) (val >> 16);
214  *buf++ = (uint8_t) (val >> 24);
215}
216
217// TODO: put this somewhere with the big-endian equivalent used by JDWP.
218static void Append8LE(uint8_t* buf, uint64_t val) {
219  *buf++ = (uint8_t) val;
220  *buf++ = (uint8_t) (val >> 8);
221  *buf++ = (uint8_t) (val >> 16);
222  *buf++ = (uint8_t) (val >> 24);
223  *buf++ = (uint8_t) (val >> 32);
224  *buf++ = (uint8_t) (val >> 40);
225  *buf++ = (uint8_t) (val >> 48);
226  *buf++ = (uint8_t) (val >> 56);
227}
228
229static void GetSample(Thread* thread, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
230  BuildStackTraceVisitor build_trace_visitor(thread);
231  build_trace_visitor.WalkStack();
232  std::vector<mirror::ArtMethod*>* stack_trace = build_trace_visitor.GetStackTrace();
233  Trace* the_trace = reinterpret_cast<Trace*>(arg);
234  the_trace->CompareAndUpdateStackTrace(thread, stack_trace);
235}
236
237void Trace::CompareAndUpdateStackTrace(Thread* thread,
238                                       std::vector<mirror::ArtMethod*>* stack_trace) {
239  CHECK_EQ(pthread_self(), sampling_pthread_);
240  SafeMap<Thread*, std::vector<mirror::ArtMethod*>*>::iterator map_it = thread_stack_trace_map_.find(thread);
241  if (map_it == thread_stack_trace_map_.end()) {
242    // If there's no existing stack trace in the map for this thread, log an entry event for all
243    // methods in the trace.
244    thread_stack_trace_map_.Put(thread, stack_trace);
245    for (std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
246         rit != stack_trace->rend(); ++rit) {
247      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered);
248    }
249  } else {
250    // If there's a previous stack trace for this thread, diff the traces and emit entry and exit
251    // events accordingly.
252    std::vector<mirror::ArtMethod*>* old_stack_trace = map_it->second;
253    thread_stack_trace_map_.Overwrite(thread, stack_trace);
254    std::vector<mirror::ArtMethod*>::reverse_iterator old_rit = old_stack_trace->rbegin();
255    std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
256
257    // Iterate bottom-up over both traces until there's a difference between them.
258    while (old_rit != old_stack_trace->rend() && rit != stack_trace->rend() && *old_rit == *rit) {
259      old_rit++;
260      rit++;
261    }
262    // Iterate top-down over the old trace until the point where they differ, emitting exit events.
263    for (std::vector<mirror::ArtMethod*>::iterator old_it = old_stack_trace->begin();
264         old_it != old_rit.base(); ++old_it) {
265      LogMethodTraceEvent(thread, *old_it, instrumentation::Instrumentation::kMethodExited);
266    }
267    // Iterate bottom-up over the new trace from the point where they differ, emitting entry events.
268    for (; rit != stack_trace->rend(); ++rit) {
269      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered);
270    }
271    delete old_stack_trace;
272  }
273}
274
275void* Trace::RunSamplingThread(void* arg) {
276  Runtime* runtime = Runtime::Current();
277  CHECK(runtime->AttachCurrentThread("Sampling Profiler", true, runtime->GetSystemThreadGroup(),
278                                     !runtime->IsCompiler()));
279
280  while (true) {
281    usleep(sampling_interval_us_);
282
283    Thread* self = Thread::Current();
284    Trace* the_trace;
285    {
286      MutexLock mu(self, *Locks::trace_lock_);
287      the_trace = the_trace_;
288      if (the_trace == NULL) {
289        break;
290      }
291    }
292
293    runtime->GetThreadList()->SuspendAll();
294    {
295      MutexLock mu(self, *Locks::thread_list_lock_);
296      runtime->GetThreadList()->ForEach(GetSample, the_trace);
297    }
298    runtime->GetThreadList()->ResumeAll();
299  }
300
301  runtime->DetachCurrentThread();
302  return NULL;
303}
304
305void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
306                  bool direct_to_ddms) {
307  Thread* self = Thread::Current();
308  {
309    MutexLock mu(self, *Locks::trace_lock_);
310    if (the_trace_ != NULL) {
311      LOG(ERROR) << "Trace already in progress, ignoring this request";
312      return;
313    }
314  }
315  Runtime* runtime = Runtime::Current();
316  runtime->GetThreadList()->SuspendAll();
317
318  // Open trace file if not going directly to ddms.
319  UniquePtr<File> trace_file;
320  if (!direct_to_ddms) {
321    if (trace_fd < 0) {
322      trace_file.reset(OS::CreateEmptyFile(trace_filename));
323    } else {
324      trace_file.reset(new File(trace_fd, "tracefile"));
325      trace_file->DisableAutoClose();
326    }
327    if (trace_file.get() == NULL) {
328      PLOG(ERROR) << "Unable to open trace file '" << trace_filename << "'";
329      runtime->GetThreadList()->ResumeAll();
330      ScopedObjectAccess soa(self);
331      ThrowRuntimeException("Unable to open trace file '%s'", trace_filename);
332      return;
333    }
334  }
335
336  // Create Trace object.
337  {
338    MutexLock mu(self, *Locks::trace_lock_);
339    if (the_trace_ != NULL) {
340      LOG(ERROR) << "Trace already in progress, ignoring this request";
341    } else {
342      the_trace_ = new Trace(trace_file.release(), buffer_size, flags);
343
344      // Enable count of allocs if specified in the flags.
345      if ((flags && kTraceCountAllocs) != 0) {
346        runtime->SetStatsEnabled(true);
347      }
348
349      if (sampling_enabled_) {
350        CHECK_PTHREAD_CALL(pthread_create, (&sampling_pthread_, NULL, &RunSamplingThread, NULL),
351                           "Sampling profiler thread");
352      } else {
353        runtime->GetInstrumentation()->AddListener(the_trace_,
354                                                   instrumentation::Instrumentation::kMethodEntered |
355                                                   instrumentation::Instrumentation::kMethodExited |
356                                                   instrumentation::Instrumentation::kMethodUnwind);
357      }
358    }
359  }
360  runtime->GetThreadList()->ResumeAll();
361}
362
363void Trace::Stop() {
364  Runtime* runtime = Runtime::Current();
365  runtime->GetThreadList()->SuspendAll();
366  Trace* the_trace = NULL;
367  pthread_t sampling_pthread = 0U;
368  {
369    MutexLock mu(Thread::Current(), *Locks::trace_lock_);
370    if (the_trace_ == NULL) {
371      LOG(ERROR) << "Trace stop requested, but no trace currently running";
372    } else {
373      the_trace = the_trace_;
374      the_trace_ = NULL;
375      sampling_pthread = sampling_pthread_;
376      sampling_pthread_ = 0U;
377    }
378  }
379  if (the_trace != NULL) {
380    the_trace->FinishTracing();
381
382    if (!sampling_enabled_) {
383      runtime->GetInstrumentation()->RemoveListener(the_trace,
384                                                    instrumentation::Instrumentation::kMethodEntered |
385                                                    instrumentation::Instrumentation::kMethodExited |
386                                                    instrumentation::Instrumentation::kMethodUnwind);
387    }
388    delete the_trace;
389  }
390  runtime->GetThreadList()->ResumeAll();
391
392  if (sampling_enabled_ && sampling_pthread != 0U) {
393    CHECK_PTHREAD_CALL(pthread_join, (sampling_pthread, NULL), "sampling thread shutdown");
394  }
395}
396
397void Trace::Shutdown() {
398  if (IsMethodTracingActive()) {
399    Stop();
400  }
401}
402
403bool Trace::IsMethodTracingActive() {
404  MutexLock mu(Thread::Current(), *Locks::trace_lock_);
405  return the_trace_ != NULL;
406}
407
408Trace::Trace(File* trace_file, int buffer_size, int flags)
409    : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
410      clock_source_(default_clock_source_), buffer_size_(buffer_size), start_time_(MicroTime()),
411      cur_offset_(0),  overflow_(false) {
412  // Set up the beginning of the trace.
413  uint16_t trace_version = GetTraceVersion(clock_source_);
414  memset(buf_.get(), 0, kTraceHeaderLength);
415  Append4LE(buf_.get(), kTraceMagicValue);
416  Append2LE(buf_.get() + 4, trace_version);
417  Append2LE(buf_.get() + 6, kTraceHeaderLength);
418  Append8LE(buf_.get() + 8, start_time_);
419  if (trace_version >= kTraceVersionDualClock) {
420    uint16_t record_size = GetRecordSize(clock_source_);
421    Append2LE(buf_.get() + 16, record_size);
422  }
423
424  // Update current offset.
425  cur_offset_ = kTraceHeaderLength;
426}
427
428Trace::~Trace() {
429  CHECK_EQ(sampling_pthread_, static_cast<pthread_t>(0U));
430  STLDeleteValues(&thread_stack_trace_map_);
431}
432
433static void DumpBuf(uint8_t* buf, size_t buf_size, ProfilerClockSource clock_source)
434    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
435  uint8_t* ptr = buf + kTraceHeaderLength;
436  uint8_t* end = buf + buf_size;
437
438  while (ptr < end) {
439    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
440    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
441    TraceAction action = DecodeTraceAction(tmid);
442    LOG(INFO) << PrettyMethod(method) << " " << static_cast<int>(action);
443    ptr += GetRecordSize(clock_source);
444  }
445}
446
447void Trace::FinishTracing() {
448  // Compute elapsed time.
449  uint64_t elapsed = MicroTime() - start_time_;
450
451  size_t final_offset = cur_offset_;
452  uint32_t clock_overhead = GetClockOverhead(this);
453
454  if ((flags_ & kTraceCountAllocs) != 0) {
455    Runtime::Current()->SetStatsEnabled(false);
456  }
457
458  std::set<mirror::ArtMethod*> visited_methods;
459  GetVisitedMethods(final_offset, &visited_methods);
460
461  std::ostringstream os;
462
463  os << StringPrintf("%cversion\n", kTraceTokenChar);
464  os << StringPrintf("%d\n", GetTraceVersion(clock_source_));
465  os << StringPrintf("data-file-overflow=%s\n", overflow_ ? "true" : "false");
466  if (UseThreadCpuClock()) {
467    if (UseWallClock()) {
468      os << StringPrintf("clock=dual\n");
469    } else {
470      os << StringPrintf("clock=thread-cpu\n");
471    }
472  } else {
473    os << StringPrintf("clock=wall\n");
474  }
475  os << StringPrintf("elapsed-time-usec=%llu\n", elapsed);
476  size_t num_records = (final_offset - kTraceHeaderLength) / GetRecordSize(clock_source_);
477  os << StringPrintf("num-method-calls=%zd\n", num_records);
478  os << StringPrintf("clock-call-overhead-nsec=%d\n", clock_overhead);
479  os << StringPrintf("vm=art\n");
480  if ((flags_ & kTraceCountAllocs) != 0) {
481    os << StringPrintf("alloc-count=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_OBJECTS));
482    os << StringPrintf("alloc-size=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_BYTES));
483    os << StringPrintf("gc-count=%d\n", Runtime::Current()->GetStat(KIND_GC_INVOCATIONS));
484  }
485  os << StringPrintf("%cthreads\n", kTraceTokenChar);
486  DumpThreadList(os);
487  os << StringPrintf("%cmethods\n", kTraceTokenChar);
488  DumpMethodList(os, visited_methods);
489  os << StringPrintf("%cend\n", kTraceTokenChar);
490
491  std::string header(os.str());
492  if (trace_file_.get() == NULL) {
493    iovec iov[2];
494    iov[0].iov_base = reinterpret_cast<void*>(const_cast<char*>(header.c_str()));
495    iov[0].iov_len = header.length();
496    iov[1].iov_base = buf_.get();
497    iov[1].iov_len = final_offset;
498    Dbg::DdmSendChunkV(CHUNK_TYPE("MPSE"), iov, 2);
499    const bool kDumpTraceInfo = false;
500    if (kDumpTraceInfo) {
501      LOG(INFO) << "Trace sent:\n" << header;
502      DumpBuf(buf_.get(), final_offset, clock_source_);
503    }
504  } else {
505    if (!trace_file_->WriteFully(header.c_str(), header.length()) ||
506        !trace_file_->WriteFully(buf_.get(), final_offset)) {
507      std::string detail(StringPrintf("Trace data write failed: %s", strerror(errno)));
508      PLOG(ERROR) << detail;
509      ThrowRuntimeException("%s", detail.c_str());
510    }
511  }
512}
513
514void Trace::DexPcMoved(Thread* thread, mirror::Object* this_object,
515                       const mirror::ArtMethod* method, uint32_t new_dex_pc) {
516  // We're not recorded to listen to this kind of event, so complain.
517  LOG(ERROR) << "Unexpected dex PC event in tracing " << PrettyMethod(method) << " " << new_dex_pc;
518};
519
520void Trace::MethodEntered(Thread* thread, mirror::Object* this_object,
521                          const mirror::ArtMethod* method, uint32_t dex_pc) {
522  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodEntered);
523}
524
525void Trace::MethodExited(Thread* thread, mirror::Object* this_object,
526                         const mirror::ArtMethod* method, uint32_t dex_pc,
527                         const JValue& return_value) {
528  UNUSED(return_value);
529  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodExited);
530}
531
532void Trace::MethodUnwind(Thread* thread, const mirror::ArtMethod* method, uint32_t dex_pc) {
533  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodUnwind);
534}
535
536void Trace::ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
537                            mirror::ArtMethod* catch_method, uint32_t catch_dex_pc,
538                            mirror::Throwable* exception_object)
539    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
540  LOG(ERROR) << "Unexpected exception caught event in tracing";
541}
542
543void Trace::LogMethodTraceEvent(Thread* thread, const mirror::ArtMethod* method,
544                                instrumentation::Instrumentation::InstrumentationEvent event) {
545  // Advance cur_offset_ atomically.
546  int32_t new_offset;
547  int32_t old_offset;
548  do {
549    old_offset = cur_offset_;
550    new_offset = old_offset + GetRecordSize(clock_source_);
551    if (new_offset > buffer_size_) {
552      overflow_ = true;
553      return;
554    }
555  } while (android_atomic_release_cas(old_offset, new_offset, &cur_offset_) != 0);
556
557  TraceAction action = kTraceMethodEnter;
558  switch (event) {
559    case instrumentation::Instrumentation::kMethodEntered:
560      action = kTraceMethodEnter;
561      break;
562    case instrumentation::Instrumentation::kMethodExited:
563      action = kTraceMethodExit;
564      break;
565    case instrumentation::Instrumentation::kMethodUnwind:
566      action = kTraceUnroll;
567      break;
568    default:
569      UNIMPLEMENTED(FATAL) << "Unexpected event: " << event;
570  }
571
572  uint32_t method_value = EncodeTraceMethodAndAction(method, action);
573
574  // Write data
575  uint8_t* ptr = buf_.get() + old_offset;
576  Append2LE(ptr, thread->GetTid());
577  Append4LE(ptr + 2, method_value);
578  ptr += 6;
579
580  if (UseThreadCpuClock()) {
581    // TODO: this isn't vaguely thread safe.
582    SafeMap<Thread*, uint64_t>::iterator it = thread_clock_base_map_.find(thread);
583    uint32_t thread_clock_diff = 0;
584    if (UNLIKELY(it == thread_clock_base_map_.end())) {
585      // First event, the diff is 0, record the base time in the map.
586      uint64_t time = thread->GetCpuMicroTime();
587      thread_clock_base_map_.Put(thread, time);
588    } else {
589      uint64_t thread_clock_base = it->second;
590      thread_clock_diff = thread->GetCpuMicroTime() - thread_clock_base;
591    }
592    Append4LE(ptr, thread_clock_diff);
593    ptr += 4;
594  }
595  if (UseWallClock()) {
596    uint32_t wall_clock_diff = MicroTime() - start_time_;
597    Append4LE(ptr, wall_clock_diff);
598  }
599}
600
601void Trace::GetVisitedMethods(size_t buf_size,
602                              std::set<mirror::ArtMethod*>* visited_methods) {
603  uint8_t* ptr = buf_.get() + kTraceHeaderLength;
604  uint8_t* end = buf_.get() + buf_size;
605
606  while (ptr < end) {
607    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
608    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
609    visited_methods->insert(method);
610    ptr += GetRecordSize(clock_source_);
611  }
612}
613
614void Trace::DumpMethodList(std::ostream& os,
615                           const std::set<mirror::ArtMethod*>& visited_methods) {
616  typedef std::set<mirror::ArtMethod*>::const_iterator It;  // TODO: C++0x auto
617  MethodHelper mh;
618  for (It it = visited_methods.begin(); it != visited_methods.end(); ++it) {
619    mirror::ArtMethod* method = *it;
620    mh.ChangeMethod(method);
621    os << StringPrintf("%p\t%s\t%s\t%s\t%s\n", method,
622        PrettyDescriptor(mh.GetDeclaringClassDescriptor()).c_str(), mh.GetName(),
623        mh.GetSignature().c_str(), mh.GetDeclaringClassSourceFile());
624  }
625}
626
627static void DumpThread(Thread* t, void* arg) {
628  std::ostream& os = *reinterpret_cast<std::ostream*>(arg);
629  std::string name;
630  t->GetThreadName(name);
631  os << t->GetTid() << "\t" << name << "\n";
632}
633
634void Trace::DumpThreadList(std::ostream& os) {
635  Thread* self = Thread::Current();
636  Locks::thread_list_lock_->AssertNotHeld(self);
637  MutexLock mu(self, *Locks::thread_list_lock_);
638  Runtime::Current()->GetThreadList()->ForEach(DumpThread, &os);
639}
640
641}  // namespace art
642