trace.cc revision cf2fb8e6430059cc7fe0a6f931555bb717988393 
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;
125pthread_t Trace::sampling_pthread_ = 0U;
126UniquePtr<std::vector<mirror::ArtMethod*> > Trace::temp_stack_trace_;
127
128static mirror::ArtMethod* DecodeTraceMethodId(uint32_t tmid) {
129  return reinterpret_cast<mirror::ArtMethod*>(tmid & ~kTraceMethodActionMask);
130}
131
132static TraceAction DecodeTraceAction(uint32_t tmid) {
133  return static_cast<TraceAction>(tmid & kTraceMethodActionMask);
134}
135
136static uint32_t EncodeTraceMethodAndAction(const mirror::ArtMethod* method,
137                                           TraceAction action) {
138  uint32_t tmid = reinterpret_cast<uint32_t>(method) | action;
139  DCHECK_EQ(method, DecodeTraceMethodId(tmid));
140  return tmid;
141}
142
143std::vector<mirror::ArtMethod*>* Trace::AllocStackTrace() {
144  if (temp_stack_trace_.get() != NULL) {
145    return temp_stack_trace_.release();
146  } else {
147    return new std::vector<mirror::ArtMethod*>();
148  }
149}
150
151void Trace::FreeStackTrace(std::vector<mirror::ArtMethod*>* stack_trace) {
152  stack_trace->clear();
153  temp_stack_trace_.reset(stack_trace);
154}
155
156void Trace::SetDefaultClockSource(ProfilerClockSource clock_source) {
157#if defined(HAVE_POSIX_CLOCKS)
158  default_clock_source_ = clock_source;
159#else
160  if (clock_source != kProfilerClockSourceWall) {
161    LOG(WARNING) << "Ignoring tracing request to use CPU time.";
162  }
163#endif
164}
165
166static uint16_t GetTraceVersion(ProfilerClockSource clock_source) {
167  return (clock_source == kProfilerClockSourceDual) ? kTraceVersionDualClock
168                                                    : kTraceVersionSingleClock;
169}
170
171static uint16_t GetRecordSize(ProfilerClockSource clock_source) {
172  return (clock_source == kProfilerClockSourceDual) ? kTraceRecordSizeDualClock
173                                                    : kTraceRecordSizeSingleClock;
174}
175
176bool Trace::UseThreadCpuClock() {
177  return (clock_source_ == kProfilerClockSourceThreadCpu) ||
178      (clock_source_ == kProfilerClockSourceDual);
179}
180
181bool Trace::UseWallClock() {
182  return (clock_source_ == kProfilerClockSourceWall) ||
183      (clock_source_ == kProfilerClockSourceDual);
184}
185
186static void MeasureClockOverhead(Trace* trace) {
187  if (trace->UseThreadCpuClock()) {
188    Thread::Current()->GetCpuMicroTime();
189  }
190  if (trace->UseWallClock()) {
191    MicroTime();
192  }
193}
194
195// Compute an average time taken to measure clocks.
196static uint32_t GetClockOverheadNanoSeconds(Trace* trace) {
197  Thread* self = Thread::Current();
198  uint64_t start = self->GetCpuMicroTime();
199
200  for (int i = 4000; i > 0; i--) {
201    MeasureClockOverhead(trace);
202    MeasureClockOverhead(trace);
203    MeasureClockOverhead(trace);
204    MeasureClockOverhead(trace);
205    MeasureClockOverhead(trace);
206    MeasureClockOverhead(trace);
207    MeasureClockOverhead(trace);
208    MeasureClockOverhead(trace);
209  }
210
211  uint64_t elapsed_us = self->GetCpuMicroTime() - start;
212  return static_cast<uint32_t>(elapsed_us / 32);
213}
214
215// TODO: put this somewhere with the big-endian equivalent used by JDWP.
216static void Append2LE(uint8_t* buf, uint16_t val) {
217  *buf++ = static_cast<uint8_t>(val);
218  *buf++ = static_cast<uint8_t>(val >> 8);
219}
220
221// TODO: put this somewhere with the big-endian equivalent used by JDWP.
222static void Append4LE(uint8_t* buf, uint32_t val) {
223  *buf++ = static_cast<uint8_t>(val);
224  *buf++ = static_cast<uint8_t>(val >> 8);
225  *buf++ = static_cast<uint8_t>(val >> 16);
226  *buf++ = static_cast<uint8_t>(val >> 24);
227}
228
229// TODO: put this somewhere with the big-endian equivalent used by JDWP.
230static void Append8LE(uint8_t* buf, uint64_t val) {
231  *buf++ = static_cast<uint8_t>(val);
232  *buf++ = static_cast<uint8_t>(val >> 8);
233  *buf++ = static_cast<uint8_t>(val >> 16);
234  *buf++ = static_cast<uint8_t>(val >> 24);
235  *buf++ = static_cast<uint8_t>(val >> 32);
236  *buf++ = static_cast<uint8_t>(val >> 40);
237  *buf++ = static_cast<uint8_t>(val >> 48);
238  *buf++ = static_cast<uint8_t>(val >> 56);
239}
240
241static void GetSample(Thread* thread, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
242  BuildStackTraceVisitor build_trace_visitor(thread);
243  build_trace_visitor.WalkStack();
244  std::vector<mirror::ArtMethod*>* stack_trace = build_trace_visitor.GetStackTrace();
245  Trace* the_trace = reinterpret_cast<Trace*>(arg);
246  the_trace->CompareAndUpdateStackTrace(thread, stack_trace);
247}
248
249static void ClearThreadStackTraceAndClockBase(Thread* thread, void* arg) {
250  thread->SetTraceClockBase(0);
251  std::vector<mirror::ArtMethod*>* stack_trace = thread->GetStackTraceSample();
252  thread->SetStackTraceSample(NULL);
253  delete stack_trace;
254}
255
256void Trace::CompareAndUpdateStackTrace(Thread* thread,
257                                       std::vector<mirror::ArtMethod*>* stack_trace) {
258  CHECK_EQ(pthread_self(), sampling_pthread_);
259  std::vector<mirror::ArtMethod*>* old_stack_trace = thread->GetStackTraceSample();
260  // Update the thread's stack trace sample.
261  thread->SetStackTraceSample(stack_trace);
262  // Read timer clocks to use for all events in this trace.
263  uint32_t thread_clock_diff = 0;
264  uint32_t wall_clock_diff = 0;
265  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
266  if (old_stack_trace == NULL) {
267    // If there's no previous stack trace sample for this thread, log an entry event for all
268    // methods in the trace.
269    for (std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
270         rit != stack_trace->rend(); ++rit) {
271      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
272                          thread_clock_diff, wall_clock_diff);
273    }
274  } else {
275    // If there's a previous stack trace for this thread, diff the traces and emit entry and exit
276    // events accordingly.
277    std::vector<mirror::ArtMethod*>::reverse_iterator old_rit = old_stack_trace->rbegin();
278    std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
279    // Iterate bottom-up over both traces until there's a difference between them.
280    while (old_rit != old_stack_trace->rend() && rit != stack_trace->rend() && *old_rit == *rit) {
281      old_rit++;
282      rit++;
283    }
284    // Iterate top-down over the old trace until the point where they differ, emitting exit events.
285    for (std::vector<mirror::ArtMethod*>::iterator old_it = old_stack_trace->begin();
286         old_it != old_rit.base(); ++old_it) {
287      LogMethodTraceEvent(thread, *old_it, instrumentation::Instrumentation::kMethodExited,
288                          thread_clock_diff, wall_clock_diff);
289    }
290    // Iterate bottom-up over the new trace from the point where they differ, emitting entry events.
291    for (; rit != stack_trace->rend(); ++rit) {
292      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
293                          thread_clock_diff, wall_clock_diff);
294    }
295    FreeStackTrace(old_stack_trace);
296  }
297}
298
299void* Trace::RunSamplingThread(void* arg) {
300  Runtime* runtime = Runtime::Current();
301  int interval_us = reinterpret_cast<int>(arg);
302  CHECK(runtime->AttachCurrentThread("Sampling Profiler", true, runtime->GetSystemThreadGroup(),
303                                     !runtime->IsCompiler()));
304
305  while (true) {
306    usleep(interval_us);
307    ATRACE_BEGIN("Profile sampling");
308    Thread* self = Thread::Current();
309    Trace* the_trace;
310    {
311      MutexLock mu(self, *Locks::trace_lock_);
312      the_trace = the_trace_;
313      if (the_trace == NULL) {
314        break;
315      }
316    }
317
318    runtime->GetThreadList()->SuspendAll();
319    {
320      MutexLock mu(self, *Locks::thread_list_lock_);
321      runtime->GetThreadList()->ForEach(GetSample, the_trace);
322    }
323    runtime->GetThreadList()->ResumeAll();
324    ATRACE_END();
325  }
326
327  runtime->DetachCurrentThread();
328  return NULL;
329}
330
331void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
332                  bool direct_to_ddms, bool sampling_enabled, int interval_us) {
333  Thread* self = Thread::Current();
334  {
335    MutexLock mu(self, *Locks::trace_lock_);
336    if (the_trace_ != NULL) {
337      LOG(ERROR) << "Trace already in progress, ignoring this request";
338      return;
339    }
340  }
341  Runtime* runtime = Runtime::Current();
342  runtime->GetThreadList()->SuspendAll();
343
344  // Open trace file if not going directly to ddms.
345  UniquePtr<File> trace_file;
346  if (!direct_to_ddms) {
347    if (trace_fd < 0) {
348      trace_file.reset(OS::CreateEmptyFile(trace_filename));
349    } else {
350      trace_file.reset(new File(trace_fd, "tracefile"));
351      trace_file->DisableAutoClose();
352    }
353    if (trace_file.get() == NULL) {
354      PLOG(ERROR) << "Unable to open trace file '" << trace_filename << "'";
355      runtime->GetThreadList()->ResumeAll();
356      ScopedObjectAccess soa(self);
357      ThrowRuntimeException("Unable to open trace file '%s'", trace_filename);
358      return;
359    }
360  }
361
362  // Create Trace object.
363  {
364    MutexLock mu(self, *Locks::trace_lock_);
365    if (the_trace_ != NULL) {
366      LOG(ERROR) << "Trace already in progress, ignoring this request";
367    } else {
368      the_trace_ = new Trace(trace_file.release(), buffer_size, flags, sampling_enabled);
369
370      // Enable count of allocs if specified in the flags.
371      if ((flags && kTraceCountAllocs) != 0) {
372        runtime->SetStatsEnabled(true);
373      }
374
375
376
377      if (sampling_enabled) {
378        CHECK_PTHREAD_CALL(pthread_create, (&sampling_pthread_, NULL, &RunSamplingThread,
379                                            reinterpret_cast<void*>(interval_us)),
380                                            "Sampling profiler thread");
381      } else {
382        runtime->GetInstrumentation()->AddListener(the_trace_,
383                                                   instrumentation::Instrumentation::kMethodEntered |
384                                                   instrumentation::Instrumentation::kMethodExited |
385                                                   instrumentation::Instrumentation::kMethodUnwind);
386      }
387    }
388  }
389  runtime->GetThreadList()->ResumeAll();
390}
391
392void Trace::Stop() {
393  Runtime* runtime = Runtime::Current();
394  runtime->GetThreadList()->SuspendAll();
395  Trace* the_trace = NULL;
396  pthread_t sampling_pthread = 0U;
397  {
398    MutexLock mu(Thread::Current(), *Locks::trace_lock_);
399    if (the_trace_ == NULL) {
400      LOG(ERROR) << "Trace stop requested, but no trace currently running";
401    } else {
402      the_trace = the_trace_;
403      the_trace_ = NULL;
404      sampling_pthread = sampling_pthread_;
405      sampling_pthread_ = 0U;
406    }
407  }
408  if (the_trace != NULL) {
409    the_trace->FinishTracing();
410
411    if (the_trace->sampling_enabled_) {
412      MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
413      runtime->GetThreadList()->ForEach(ClearThreadStackTraceAndClockBase, NULL);
414    } else {
415      runtime->GetInstrumentation()->RemoveListener(the_trace,
416                                                    instrumentation::Instrumentation::kMethodEntered |
417                                                    instrumentation::Instrumentation::kMethodExited |
418                                                    instrumentation::Instrumentation::kMethodUnwind);
419    }
420    delete the_trace;
421  }
422  runtime->GetThreadList()->ResumeAll();
423
424  if (sampling_pthread != 0U) {
425    CHECK_PTHREAD_CALL(pthread_join, (sampling_pthread, NULL), "sampling thread shutdown");
426  }
427}
428
429void Trace::Shutdown() {
430  if (IsMethodTracingActive()) {
431    Stop();
432  }
433}
434
435bool Trace::IsMethodTracingActive() {
436  MutexLock mu(Thread::Current(), *Locks::trace_lock_);
437  return the_trace_ != NULL;
438}
439
440Trace::Trace(File* trace_file, int buffer_size, int flags, bool sampling_enabled)
441    : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
442      sampling_enabled_(sampling_enabled), clock_source_(default_clock_source_),
443      buffer_size_(buffer_size), start_time_(MicroTime()), cur_offset_(0),  overflow_(false) {
444  // Set up the beginning of the trace.
445  uint16_t trace_version = GetTraceVersion(clock_source_);
446  memset(buf_.get(), 0, kTraceHeaderLength);
447  Append4LE(buf_.get(), kTraceMagicValue);
448  Append2LE(buf_.get() + 4, trace_version);
449  Append2LE(buf_.get() + 6, kTraceHeaderLength);
450  Append8LE(buf_.get() + 8, start_time_);
451  if (trace_version >= kTraceVersionDualClock) {
452    uint16_t record_size = GetRecordSize(clock_source_);
453    Append2LE(buf_.get() + 16, record_size);
454  }
455
456  // Update current offset.
457  cur_offset_ = kTraceHeaderLength;
458}
459
460static void DumpBuf(uint8_t* buf, size_t buf_size, ProfilerClockSource clock_source)
461    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
462  uint8_t* ptr = buf + kTraceHeaderLength;
463  uint8_t* end = buf + buf_size;
464
465  while (ptr < end) {
466    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
467    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
468    TraceAction action = DecodeTraceAction(tmid);
469    LOG(INFO) << PrettyMethod(method) << " " << static_cast<int>(action);
470    ptr += GetRecordSize(clock_source);
471  }
472}
473
474void Trace::FinishTracing() {
475  // Compute elapsed time.
476  uint64_t elapsed = MicroTime() - start_time_;
477
478  size_t final_offset = cur_offset_;
479  uint32_t clock_overhead_ns = GetClockOverheadNanoSeconds(this);
480
481  if ((flags_ & kTraceCountAllocs) != 0) {
482    Runtime::Current()->SetStatsEnabled(false);
483  }
484
485  std::set<mirror::ArtMethod*> visited_methods;
486  GetVisitedMethods(final_offset, &visited_methods);
487
488  std::ostringstream os;
489
490  os << StringPrintf("%cversion\n", kTraceTokenChar);
491  os << StringPrintf("%d\n", GetTraceVersion(clock_source_));
492  os << StringPrintf("data-file-overflow=%s\n", overflow_ ? "true" : "false");
493  if (UseThreadCpuClock()) {
494    if (UseWallClock()) {
495      os << StringPrintf("clock=dual\n");
496    } else {
497      os << StringPrintf("clock=thread-cpu\n");
498    }
499  } else {
500    os << StringPrintf("clock=wall\n");
501  }
502  os << StringPrintf("elapsed-time-usec=%llu\n", elapsed);
503  size_t num_records = (final_offset - kTraceHeaderLength) / GetRecordSize(clock_source_);
504  os << StringPrintf("num-method-calls=%zd\n", num_records);
505  os << StringPrintf("clock-call-overhead-nsec=%d\n", clock_overhead_ns);
506  os << StringPrintf("vm=art\n");
507  if ((flags_ & kTraceCountAllocs) != 0) {
508    os << StringPrintf("alloc-count=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_OBJECTS));
509    os << StringPrintf("alloc-size=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_BYTES));
510    os << StringPrintf("gc-count=%d\n", Runtime::Current()->GetStat(KIND_GC_INVOCATIONS));
511  }
512  os << StringPrintf("%cthreads\n", kTraceTokenChar);
513  DumpThreadList(os);
514  os << StringPrintf("%cmethods\n", kTraceTokenChar);
515  DumpMethodList(os, visited_methods);
516  os << StringPrintf("%cend\n", kTraceTokenChar);
517
518  std::string header(os.str());
519  if (trace_file_.get() == NULL) {
520    iovec iov[2];
521    iov[0].iov_base = reinterpret_cast<void*>(const_cast<char*>(header.c_str()));
522    iov[0].iov_len = header.length();
523    iov[1].iov_base = buf_.get();
524    iov[1].iov_len = final_offset;
525    Dbg::DdmSendChunkV(CHUNK_TYPE("MPSE"), iov, 2);
526    const bool kDumpTraceInfo = false;
527    if (kDumpTraceInfo) {
528      LOG(INFO) << "Trace sent:\n" << header;
529      DumpBuf(buf_.get(), final_offset, clock_source_);
530    }
531  } else {
532    if (!trace_file_->WriteFully(header.c_str(), header.length()) ||
533        !trace_file_->WriteFully(buf_.get(), final_offset)) {
534      std::string detail(StringPrintf("Trace data write failed: %s", strerror(errno)));
535      PLOG(ERROR) << detail;
536      ThrowRuntimeException("%s", detail.c_str());
537    }
538  }
539}
540
541void Trace::DexPcMoved(Thread* thread, mirror::Object* this_object,
542                       const mirror::ArtMethod* method, uint32_t new_dex_pc) {
543  // We're not recorded to listen to this kind of event, so complain.
544  LOG(ERROR) << "Unexpected dex PC event in tracing " << PrettyMethod(method) << " " << new_dex_pc;
545};
546
547void Trace::MethodEntered(Thread* thread, mirror::Object* this_object,
548                          const mirror::ArtMethod* method, uint32_t dex_pc) {
549  uint32_t thread_clock_diff = 0;
550  uint32_t wall_clock_diff = 0;
551  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
552  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodEntered,
553                      thread_clock_diff, wall_clock_diff);
554}
555
556void Trace::MethodExited(Thread* thread, mirror::Object* this_object,
557                         const mirror::ArtMethod* method, uint32_t dex_pc,
558                         const JValue& return_value) {
559  UNUSED(return_value);
560  uint32_t thread_clock_diff = 0;
561  uint32_t wall_clock_diff = 0;
562  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
563  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodExited,
564                      thread_clock_diff, wall_clock_diff);
565}
566
567void Trace::MethodUnwind(Thread* thread, const mirror::ArtMethod* method, uint32_t dex_pc) {
568  uint32_t thread_clock_diff = 0;
569  uint32_t wall_clock_diff = 0;
570  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
571  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodUnwind,
572                      thread_clock_diff, wall_clock_diff);
573}
574
575void Trace::ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
576                            mirror::ArtMethod* catch_method, uint32_t catch_dex_pc,
577                            mirror::Throwable* exception_object)
578    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
579  LOG(ERROR) << "Unexpected exception caught event in tracing";
580}
581
582void Trace::ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff) {
583  if (UseThreadCpuClock()) {
584    uint64_t clock_base = thread->GetTraceClockBase();
585    if (UNLIKELY(clock_base == 0)) {
586      // First event, record the base time in the map.
587      uint64_t time = thread->GetCpuMicroTime();
588      thread->SetTraceClockBase(time);
589    } else {
590      *thread_clock_diff = thread->GetCpuMicroTime() - clock_base;
591    }
592  }
593  if (UseWallClock()) {
594    *wall_clock_diff = MicroTime() - start_time_;
595  }
596}
597
598void Trace::LogMethodTraceEvent(Thread* thread, const mirror::ArtMethod* method,
599                                instrumentation::Instrumentation::InstrumentationEvent event,
600                                uint32_t thread_clock_diff, uint32_t wall_clock_diff) {
601  // Advance cur_offset_ atomically.
602  int32_t new_offset;
603  int32_t old_offset;
604  do {
605    old_offset = cur_offset_;
606    new_offset = old_offset + GetRecordSize(clock_source_);
607    if (new_offset > buffer_size_) {
608      overflow_ = true;
609      return;
610    }
611  } while (android_atomic_release_cas(old_offset, new_offset, &cur_offset_) != 0);
612
613  TraceAction action = kTraceMethodEnter;
614  switch (event) {
615    case instrumentation::Instrumentation::kMethodEntered:
616      action = kTraceMethodEnter;
617      break;
618    case instrumentation::Instrumentation::kMethodExited:
619      action = kTraceMethodExit;
620      break;
621    case instrumentation::Instrumentation::kMethodUnwind:
622      action = kTraceUnroll;
623      break;
624    default:
625      UNIMPLEMENTED(FATAL) << "Unexpected event: " << event;
626  }
627
628  uint32_t method_value = EncodeTraceMethodAndAction(method, action);
629
630  // Write data
631  uint8_t* ptr = buf_.get() + old_offset;
632  Append2LE(ptr, thread->GetTid());
633  Append4LE(ptr + 2, method_value);
634  ptr += 6;
635
636  if (UseThreadCpuClock()) {
637    Append4LE(ptr, thread_clock_diff);
638    ptr += 4;
639  }
640  if (UseWallClock()) {
641    Append4LE(ptr, wall_clock_diff);
642  }
643}
644
645void Trace::GetVisitedMethods(size_t buf_size,
646                              std::set<mirror::ArtMethod*>* visited_methods) {
647  uint8_t* ptr = buf_.get() + kTraceHeaderLength;
648  uint8_t* end = buf_.get() + buf_size;
649
650  while (ptr < end) {
651    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
652    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
653    visited_methods->insert(method);
654    ptr += GetRecordSize(clock_source_);
655  }
656}
657
658void Trace::DumpMethodList(std::ostream& os, const std::set<mirror::ArtMethod*>& visited_methods) {
659  MethodHelper mh;
660  for (const auto& method : visited_methods) {
661    mh.ChangeMethod(method);
662    os << StringPrintf("%p\t%s\t%s\t%s\t%s\n", method,
663        PrettyDescriptor(mh.GetDeclaringClassDescriptor()).c_str(), mh.GetName(),
664        mh.GetSignature().c_str(), mh.GetDeclaringClassSourceFile());
665  }
666}
667
668static void DumpThread(Thread* t, void* arg) {
669  std::ostream& os = *reinterpret_cast<std::ostream*>(arg);
670  std::string name;
671  t->GetThreadName(name);
672  os << t->GetTid() << "\t" << name << "\n";
673}
674
675void Trace::DumpThreadList(std::ostream& os) {
676  Thread* self = Thread::Current();
677  Locks::thread_list_lock_->AssertNotHeld(self);
678  MutexLock mu(self, *Locks::thread_list_lock_);
679  Runtime::Current()->GetThreadList()->ForEach(DumpThread, &os);
680}
681
682}  // namespace art
683