trace.cc revision 6a3c1fcb4ba42ad4d5d142c17a3712a6ddd3866f 
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#define ATRACE_TAG ATRACE_TAG_DALVIK
22#include "cutils/trace.h"
23
24#include "base/stl_util.h"
25#include "base/unix_file/fd_file.h"
26#include "class_linker.h"
27#include "common_throws.h"
28#include "debugger.h"
29#include "dex_file-inl.h"
30#include "instrumentation.h"
31#include "mirror/art_method-inl.h"
32#include "mirror/class-inl.h"
33#include "mirror/dex_cache.h"
34#include "mirror/object_array-inl.h"
35#include "mirror/object-inl.h"
36#include "os.h"
37#include "scoped_thread_state_change.h"
38#include "ScopedLocalRef.h"
39#include "thread.h"
40#include "thread_list.h"
41#if !defined(ART_USE_PORTABLE_COMPILER)
42#include "entrypoints/quick/quick_entrypoints.h"
43#endif
44
45namespace art {
46
47// File format:
48//     header
49//     record 0
50//     record 1
51//     ...
52//
53// Header format:
54//     u4  magic ('SLOW')
55//     u2  version
56//     u2  offset to data
57//     u8  start date/time in usec
58//     u2  record size in bytes (version >= 2 only)
59//     ... padding to 32 bytes
60//
61// Record format v1:
62//     u1  thread ID
63//     u4  method ID | method action
64//     u4  time delta since start, in usec
65//
66// Record format v2:
67//     u2  thread ID
68//     u4  method ID | method action
69//     u4  time delta since start, in usec
70//
71// Record format v3:
72//     u2  thread ID
73//     u4  method ID | method action
74//     u4  time delta since start, in usec
75//     u4  wall time since start, in usec (when clock == "dual" only)
76//
77// 32 bits of microseconds is 70 minutes.
78//
79// All values are stored in little-endian order.
80
81enum TraceAction {
82    kTraceMethodEnter = 0x00,       // method entry
83    kTraceMethodExit = 0x01,        // method exit
84    kTraceUnroll = 0x02,            // method exited by exception unrolling
85    // 0x03 currently unused
86    kTraceMethodActionMask = 0x03,  // two bits
87};
88
89class BuildStackTraceVisitor : public StackVisitor {
90 public:
91  explicit BuildStackTraceVisitor(Thread* thread) : StackVisitor(thread, NULL),
92      method_trace_(Trace::AllocStackTrace()) {}
93
94  bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
95    mirror::ArtMethod* m = GetMethod();
96    // Ignore runtime frames (in particular callee save).
97    if (!m->IsRuntimeMethod()) {
98      method_trace_->push_back(m);
99    }
100    return true;
101  }
102
103  // Returns a stack trace where the topmost frame corresponds with the first element of the vector.
104  std::vector<mirror::ArtMethod*>* GetStackTrace() const {
105    return method_trace_;
106  }
107
108 private:
109  std::vector<mirror::ArtMethod*>* const method_trace_;
110};
111
112static const char     kTraceTokenChar             = '*';
113static const uint16_t kTraceHeaderLength          = 32;
114static const uint32_t kTraceMagicValue            = 0x574f4c53;
115static const uint16_t kTraceVersionSingleClock    = 2;
116static const uint16_t kTraceVersionDualClock      = 3;
117static const uint16_t kTraceRecordSizeSingleClock = 10;  // using v2
118static const uint16_t kTraceRecordSizeDualClock   = 14;  // using v3 with two timestamps
119
120TraceClockSource Trace::default_clock_source_ = kDefaultTraceClockSource;
121
122Trace* volatile Trace::the_trace_ = NULL;
123pthread_t Trace::sampling_pthread_ = 0U;
124std::unique_ptr<std::vector<mirror::ArtMethod*>> Trace::temp_stack_trace_;
125
126static mirror::ArtMethod* DecodeTraceMethodId(uint32_t tmid) {
127  return reinterpret_cast<mirror::ArtMethod*>(tmid & ~kTraceMethodActionMask);
128}
129
130static TraceAction DecodeTraceAction(uint32_t tmid) {
131  return static_cast<TraceAction>(tmid & kTraceMethodActionMask);
132}
133
134static uint32_t EncodeTraceMethodAndAction(mirror::ArtMethod* method,
135                                           TraceAction action) {
136  uint32_t tmid = PointerToLowMemUInt32(method) | action;
137  DCHECK_EQ(method, DecodeTraceMethodId(tmid));
138  return tmid;
139}
140
141std::vector<mirror::ArtMethod*>* Trace::AllocStackTrace() {
142  if (temp_stack_trace_.get() != NULL) {
143    return temp_stack_trace_.release();
144  } else {
145    return new std::vector<mirror::ArtMethod*>();
146  }
147}
148
149void Trace::FreeStackTrace(std::vector<mirror::ArtMethod*>* stack_trace) {
150  stack_trace->clear();
151  temp_stack_trace_.reset(stack_trace);
152}
153
154void Trace::SetDefaultClockSource(TraceClockSource clock_source) {
155#if defined(HAVE_POSIX_CLOCKS)
156  default_clock_source_ = clock_source;
157#else
158  if (clock_source != kTraceClockSourceWall) {
159    LOG(WARNING) << "Ignoring tracing request to use CPU time.";
160  }
161#endif
162}
163
164static uint16_t GetTraceVersion(TraceClockSource clock_source) {
165  return (clock_source == kTraceClockSourceDual) ? kTraceVersionDualClock
166                                                    : kTraceVersionSingleClock;
167}
168
169static uint16_t GetRecordSize(TraceClockSource clock_source) {
170  return (clock_source == kTraceClockSourceDual) ? kTraceRecordSizeDualClock
171                                                    : kTraceRecordSizeSingleClock;
172}
173
174bool Trace::UseThreadCpuClock() {
175  return (clock_source_ == kTraceClockSourceThreadCpu) ||
176      (clock_source_ == kTraceClockSourceDual);
177}
178
179bool Trace::UseWallClock() {
180  return (clock_source_ == kTraceClockSourceWall) ||
181      (clock_source_ == kTraceClockSourceDual);
182}
183
184void Trace::MeasureClockOverhead() {
185  if (UseThreadCpuClock()) {
186    Thread::Current()->GetCpuMicroTime();
187  }
188  if (UseWallClock()) {
189    MicroTime();
190  }
191}
192
193// Compute an average time taken to measure clocks.
194uint32_t Trace::GetClockOverheadNanoSeconds() {
195  Thread* self = Thread::Current();
196  uint64_t start = self->GetCpuMicroTime();
197
198  for (int i = 4000; i > 0; i--) {
199    MeasureClockOverhead();
200    MeasureClockOverhead();
201    MeasureClockOverhead();
202    MeasureClockOverhead();
203    MeasureClockOverhead();
204    MeasureClockOverhead();
205    MeasureClockOverhead();
206    MeasureClockOverhead();
207  }
208
209  uint64_t elapsed_us = self->GetCpuMicroTime() - start;
210  return static_cast<uint32_t>(elapsed_us / 32);
211}
212
213// TODO: put this somewhere with the big-endian equivalent used by JDWP.
214static void Append2LE(uint8_t* buf, uint16_t val) {
215  *buf++ = static_cast<uint8_t>(val);
216  *buf++ = static_cast<uint8_t>(val >> 8);
217}
218
219// TODO: put this somewhere with the big-endian equivalent used by JDWP.
220static void Append4LE(uint8_t* buf, uint32_t val) {
221  *buf++ = static_cast<uint8_t>(val);
222  *buf++ = static_cast<uint8_t>(val >> 8);
223  *buf++ = static_cast<uint8_t>(val >> 16);
224  *buf++ = static_cast<uint8_t>(val >> 24);
225}
226
227// TODO: put this somewhere with the big-endian equivalent used by JDWP.
228static void Append8LE(uint8_t* buf, uint64_t val) {
229  *buf++ = static_cast<uint8_t>(val);
230  *buf++ = static_cast<uint8_t>(val >> 8);
231  *buf++ = static_cast<uint8_t>(val >> 16);
232  *buf++ = static_cast<uint8_t>(val >> 24);
233  *buf++ = static_cast<uint8_t>(val >> 32);
234  *buf++ = static_cast<uint8_t>(val >> 40);
235  *buf++ = static_cast<uint8_t>(val >> 48);
236  *buf++ = static_cast<uint8_t>(val >> 56);
237}
238
239static void GetSample(Thread* thread, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
240  BuildStackTraceVisitor build_trace_visitor(thread);
241  build_trace_visitor.WalkStack();
242  std::vector<mirror::ArtMethod*>* stack_trace = build_trace_visitor.GetStackTrace();
243  Trace* the_trace = reinterpret_cast<Trace*>(arg);
244  the_trace->CompareAndUpdateStackTrace(thread, stack_trace);
245}
246
247static void ClearThreadStackTraceAndClockBase(Thread* thread ATTRIBUTE_UNUSED,
248                                              void* arg ATTRIBUTE_UNUSED) {
249  thread->SetTraceClockBase(0);
250  std::vector<mirror::ArtMethod*>* stack_trace = thread->GetStackTraceSample();
251  thread->SetStackTraceSample(NULL);
252  delete stack_trace;
253}
254
255void Trace::CompareAndUpdateStackTrace(Thread* thread,
256                                       std::vector<mirror::ArtMethod*>* stack_trace) {
257  CHECK_EQ(pthread_self(), sampling_pthread_);
258  std::vector<mirror::ArtMethod*>* old_stack_trace = thread->GetStackTraceSample();
259  // Update the thread's stack trace sample.
260  thread->SetStackTraceSample(stack_trace);
261  // Read timer clocks to use for all events in this trace.
262  uint32_t thread_clock_diff = 0;
263  uint32_t wall_clock_diff = 0;
264  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
265  if (old_stack_trace == NULL) {
266    // If there's no previous stack trace sample for this thread, log an entry event for all
267    // methods in the trace.
268    for (std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
269         rit != stack_trace->rend(); ++rit) {
270      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
271                          thread_clock_diff, wall_clock_diff);
272    }
273  } else {
274    // If there's a previous stack trace for this thread, diff the traces and emit entry and exit
275    // events accordingly.
276    std::vector<mirror::ArtMethod*>::reverse_iterator old_rit = old_stack_trace->rbegin();
277    std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
278    // Iterate bottom-up over both traces until there's a difference between them.
279    while (old_rit != old_stack_trace->rend() && rit != stack_trace->rend() && *old_rit == *rit) {
280      old_rit++;
281      rit++;
282    }
283    // Iterate top-down over the old trace until the point where they differ, emitting exit events.
284    for (std::vector<mirror::ArtMethod*>::iterator old_it = old_stack_trace->begin();
285         old_it != old_rit.base(); ++old_it) {
286      LogMethodTraceEvent(thread, *old_it, instrumentation::Instrumentation::kMethodExited,
287                          thread_clock_diff, wall_clock_diff);
288    }
289    // Iterate bottom-up over the new trace from the point where they differ, emitting entry events.
290    for (; rit != stack_trace->rend(); ++rit) {
291      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
292                          thread_clock_diff, wall_clock_diff);
293    }
294    FreeStackTrace(old_stack_trace);
295  }
296}
297
298void* Trace::RunSamplingThread(void* arg) {
299  Runtime* runtime = Runtime::Current();
300  intptr_t interval_us = reinterpret_cast<intptr_t>(arg);
301  CHECK_GE(interval_us, 0);
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
342  // Check interval if sampling is enabled
343  if (sampling_enabled && interval_us <= 0) {
344    LOG(ERROR) << "Invalid sampling interval: " << interval_us;
345    ScopedObjectAccess soa(self);
346    ThrowRuntimeException("Invalid sampling interval: %d", interval_us);
347    return;
348  }
349
350  // Open trace file if not going directly to ddms.
351  std::unique_ptr<File> trace_file;
352  if (!direct_to_ddms) {
353    if (trace_fd < 0) {
354      trace_file.reset(OS::CreateEmptyFile(trace_filename));
355    } else {
356      trace_file.reset(new File(trace_fd, "tracefile"));
357      trace_file->DisableAutoClose();
358    }
359    if (trace_file.get() == NULL) {
360      PLOG(ERROR) << "Unable to open trace file '" << trace_filename << "'";
361      ScopedObjectAccess soa(self);
362      ThrowRuntimeException("Unable to open trace file '%s'", trace_filename);
363      return;
364    }
365  }
366
367  Runtime* runtime = Runtime::Current();
368
369  // Enable count of allocs if specified in the flags.
370  bool enable_stats = false;
371
372  runtime->GetThreadList()->SuspendAll();
373
374  // Create Trace object.
375  {
376    MutexLock mu(self, *Locks::trace_lock_);
377    if (the_trace_ != NULL) {
378      LOG(ERROR) << "Trace already in progress, ignoring this request";
379    } else {
380      enable_stats = (flags && kTraceCountAllocs) != 0;
381      the_trace_ = new Trace(trace_file.release(), buffer_size, flags, sampling_enabled);
382      if (sampling_enabled) {
383        CHECK_PTHREAD_CALL(pthread_create, (&sampling_pthread_, NULL, &RunSamplingThread,
384                                            reinterpret_cast<void*>(interval_us)),
385                                            "Sampling profiler thread");
386      } else {
387        runtime->GetInstrumentation()->AddListener(the_trace_,
388                                                   instrumentation::Instrumentation::kMethodEntered |
389                                                   instrumentation::Instrumentation::kMethodExited |
390                                                   instrumentation::Instrumentation::kMethodUnwind);
391        runtime->GetInstrumentation()->EnableMethodTracing();
392      }
393    }
394  }
395
396  runtime->GetThreadList()->ResumeAll();
397
398  // Can't call this when holding the mutator lock.
399  if (enable_stats) {
400    runtime->SetStatsEnabled(true);
401  }
402}
403
404void Trace::Stop() {
405  bool stop_alloc_counting = false;
406  Runtime* runtime = Runtime::Current();
407  runtime->GetThreadList()->SuspendAll();
408  Trace* the_trace = NULL;
409  pthread_t sampling_pthread = 0U;
410  {
411    MutexLock mu(Thread::Current(), *Locks::trace_lock_);
412    if (the_trace_ == NULL) {
413      LOG(ERROR) << "Trace stop requested, but no trace currently running";
414    } else {
415      the_trace = the_trace_;
416      the_trace_ = NULL;
417      sampling_pthread = sampling_pthread_;
418    }
419  }
420  if (the_trace != NULL) {
421    stop_alloc_counting = (the_trace->flags_ & kTraceCountAllocs) != 0;
422    the_trace->FinishTracing();
423
424    if (the_trace->sampling_enabled_) {
425      MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
426      runtime->GetThreadList()->ForEach(ClearThreadStackTraceAndClockBase, NULL);
427    } else {
428      runtime->GetInstrumentation()->DisableMethodTracing();
429      runtime->GetInstrumentation()->RemoveListener(the_trace,
430                                                    instrumentation::Instrumentation::kMethodEntered |
431                                                    instrumentation::Instrumentation::kMethodExited |
432                                                    instrumentation::Instrumentation::kMethodUnwind);
433    }
434    delete the_trace;
435  }
436  runtime->GetThreadList()->ResumeAll();
437
438  if (stop_alloc_counting) {
439    // Can be racy since SetStatsEnabled is not guarded by any locks.
440    Runtime::Current()->SetStatsEnabled(false);
441  }
442
443  if (sampling_pthread != 0U) {
444    CHECK_PTHREAD_CALL(pthread_join, (sampling_pthread, NULL), "sampling thread shutdown");
445    sampling_pthread_ = 0U;
446  }
447}
448
449void Trace::Shutdown() {
450  if (GetMethodTracingMode() != kTracingInactive) {
451    Stop();
452  }
453}
454
455TracingMode Trace::GetMethodTracingMode() {
456  MutexLock mu(Thread::Current(), *Locks::trace_lock_);
457  if (the_trace_ == NULL) {
458    return kTracingInactive;
459  } else if (the_trace_->sampling_enabled_) {
460    return kSampleProfilingActive;
461  } else {
462    return kMethodTracingActive;
463  }
464}
465
466Trace::Trace(File* trace_file, int buffer_size, int flags, bool sampling_enabled)
467    : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
468      sampling_enabled_(sampling_enabled), clock_source_(default_clock_source_),
469      buffer_size_(buffer_size), start_time_(MicroTime()),
470      clock_overhead_ns_(GetClockOverheadNanoSeconds()), cur_offset_(0), overflow_(false) {
471  // Set up the beginning of the trace.
472  uint16_t trace_version = GetTraceVersion(clock_source_);
473  memset(buf_.get(), 0, kTraceHeaderLength);
474  Append4LE(buf_.get(), kTraceMagicValue);
475  Append2LE(buf_.get() + 4, trace_version);
476  Append2LE(buf_.get() + 6, kTraceHeaderLength);
477  Append8LE(buf_.get() + 8, start_time_);
478  if (trace_version >= kTraceVersionDualClock) {
479    uint16_t record_size = GetRecordSize(clock_source_);
480    Append2LE(buf_.get() + 16, record_size);
481  }
482
483  // Update current offset.
484  cur_offset_.StoreRelaxed(kTraceHeaderLength);
485}
486
487static void DumpBuf(uint8_t* buf, size_t buf_size, TraceClockSource clock_source)
488    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
489  uint8_t* ptr = buf + kTraceHeaderLength;
490  uint8_t* end = buf + buf_size;
491
492  while (ptr < end) {
493    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
494    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
495    TraceAction action = DecodeTraceAction(tmid);
496    LOG(INFO) << PrettyMethod(method) << " " << static_cast<int>(action);
497    ptr += GetRecordSize(clock_source);
498  }
499}
500
501void Trace::FinishTracing() {
502  // Compute elapsed time.
503  uint64_t elapsed = MicroTime() - start_time_;
504
505  size_t final_offset = cur_offset_.LoadRelaxed();
506
507  std::set<mirror::ArtMethod*> visited_methods;
508  GetVisitedMethods(final_offset, &visited_methods);
509
510  std::ostringstream os;
511
512  os << StringPrintf("%cversion\n", kTraceTokenChar);
513  os << StringPrintf("%d\n", GetTraceVersion(clock_source_));
514  os << StringPrintf("data-file-overflow=%s\n", overflow_ ? "true" : "false");
515  if (UseThreadCpuClock()) {
516    if (UseWallClock()) {
517      os << StringPrintf("clock=dual\n");
518    } else {
519      os << StringPrintf("clock=thread-cpu\n");
520    }
521  } else {
522    os << StringPrintf("clock=wall\n");
523  }
524  os << StringPrintf("elapsed-time-usec=%" PRIu64 "\n", elapsed);
525  size_t num_records = (final_offset - kTraceHeaderLength) / GetRecordSize(clock_source_);
526  os << StringPrintf("num-method-calls=%zd\n", num_records);
527  os << StringPrintf("clock-call-overhead-nsec=%d\n", clock_overhead_ns_);
528  os << StringPrintf("vm=art\n");
529  if ((flags_ & kTraceCountAllocs) != 0) {
530    os << StringPrintf("alloc-count=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_OBJECTS));
531    os << StringPrintf("alloc-size=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_BYTES));
532    os << StringPrintf("gc-count=%d\n", Runtime::Current()->GetStat(KIND_GC_INVOCATIONS));
533  }
534  os << StringPrintf("%cthreads\n", kTraceTokenChar);
535  DumpThreadList(os);
536  os << StringPrintf("%cmethods\n", kTraceTokenChar);
537  DumpMethodList(os, visited_methods);
538  os << StringPrintf("%cend\n", kTraceTokenChar);
539
540  std::string header(os.str());
541  if (trace_file_.get() == NULL) {
542    iovec iov[2];
543    iov[0].iov_base = reinterpret_cast<void*>(const_cast<char*>(header.c_str()));
544    iov[0].iov_len = header.length();
545    iov[1].iov_base = buf_.get();
546    iov[1].iov_len = final_offset;
547    Dbg::DdmSendChunkV(CHUNK_TYPE("MPSE"), iov, 2);
548    const bool kDumpTraceInfo = false;
549    if (kDumpTraceInfo) {
550      LOG(INFO) << "Trace sent:\n" << header;
551      DumpBuf(buf_.get(), final_offset, clock_source_);
552    }
553  } else {
554    if (!trace_file_->WriteFully(header.c_str(), header.length()) ||
555        !trace_file_->WriteFully(buf_.get(), final_offset)) {
556      std::string detail(StringPrintf("Trace data write failed: %s", strerror(errno)));
557      PLOG(ERROR) << detail;
558      ThrowRuntimeException("%s", detail.c_str());
559    }
560  }
561}
562
563void Trace::DexPcMoved(Thread* thread, mirror::Object* this_object,
564                       mirror::ArtMethod* method, uint32_t new_dex_pc) {
565  UNUSED(thread, this_object, method, new_dex_pc);
566  // We're not recorded to listen to this kind of event, so complain.
567  LOG(ERROR) << "Unexpected dex PC event in tracing " << PrettyMethod(method) << " " << new_dex_pc;
568}
569
570void Trace::FieldRead(Thread* thread, mirror::Object* this_object,
571                       mirror::ArtMethod* method, uint32_t dex_pc, mirror::ArtField* field)
572    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
573  UNUSED(thread, this_object, method, dex_pc, field);
574  // We're not recorded to listen to this kind of event, so complain.
575  LOG(ERROR) << "Unexpected field read event in tracing " << PrettyMethod(method) << " " << dex_pc;
576}
577
578void Trace::FieldWritten(Thread* thread, mirror::Object* this_object,
579                          mirror::ArtMethod* method, uint32_t dex_pc, mirror::ArtField* field,
580                          const JValue& field_value)
581    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
582  UNUSED(thread, this_object, method, dex_pc, field, field_value);
583  // We're not recorded to listen to this kind of event, so complain.
584  LOG(ERROR) << "Unexpected field write event in tracing " << PrettyMethod(method) << " " << dex_pc;
585}
586
587void Trace::MethodEntered(Thread* thread, mirror::Object* this_object ATTRIBUTE_UNUSED,
588                          mirror::ArtMethod* method, uint32_t dex_pc ATTRIBUTE_UNUSED) {
589  uint32_t thread_clock_diff = 0;
590  uint32_t wall_clock_diff = 0;
591  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
592  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodEntered,
593                      thread_clock_diff, wall_clock_diff);
594}
595
596void Trace::MethodExited(Thread* thread, mirror::Object* this_object ATTRIBUTE_UNUSED,
597                         mirror::ArtMethod* method, uint32_t dex_pc ATTRIBUTE_UNUSED,
598                         const JValue& return_value ATTRIBUTE_UNUSED) {
599  uint32_t thread_clock_diff = 0;
600  uint32_t wall_clock_diff = 0;
601  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
602  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodExited,
603                      thread_clock_diff, wall_clock_diff);
604}
605
606void Trace::MethodUnwind(Thread* thread, mirror::Object* this_object ATTRIBUTE_UNUSED,
607                         mirror::ArtMethod* method, uint32_t dex_pc ATTRIBUTE_UNUSED) {
608  uint32_t thread_clock_diff = 0;
609  uint32_t wall_clock_diff = 0;
610  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
611  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodUnwind,
612                      thread_clock_diff, wall_clock_diff);
613}
614
615void Trace::ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
616                            mirror::ArtMethod* catch_method, uint32_t catch_dex_pc,
617                            mirror::Throwable* exception_object)
618    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
619  UNUSED(thread, throw_location, catch_method, catch_dex_pc, exception_object);
620  LOG(ERROR) << "Unexpected exception caught event in tracing";
621}
622
623void Trace::ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff) {
624  if (UseThreadCpuClock()) {
625    uint64_t clock_base = thread->GetTraceClockBase();
626    if (UNLIKELY(clock_base == 0)) {
627      // First event, record the base time in the map.
628      uint64_t time = thread->GetCpuMicroTime();
629      thread->SetTraceClockBase(time);
630    } else {
631      *thread_clock_diff = thread->GetCpuMicroTime() - clock_base;
632    }
633  }
634  if (UseWallClock()) {
635    *wall_clock_diff = MicroTime() - start_time_;
636  }
637}
638
639void Trace::LogMethodTraceEvent(Thread* thread, mirror::ArtMethod* method,
640                                instrumentation::Instrumentation::InstrumentationEvent event,
641                                uint32_t thread_clock_diff, uint32_t wall_clock_diff) {
642  // Advance cur_offset_ atomically.
643  int32_t new_offset;
644  int32_t old_offset;
645  do {
646    old_offset = cur_offset_.LoadRelaxed();
647    new_offset = old_offset + GetRecordSize(clock_source_);
648    if (new_offset > buffer_size_) {
649      overflow_ = true;
650      return;
651    }
652  } while (!cur_offset_.CompareExchangeWeakSequentiallyConsistent(old_offset, new_offset));
653
654  TraceAction action = kTraceMethodEnter;
655  switch (event) {
656    case instrumentation::Instrumentation::kMethodEntered:
657      action = kTraceMethodEnter;
658      break;
659    case instrumentation::Instrumentation::kMethodExited:
660      action = kTraceMethodExit;
661      break;
662    case instrumentation::Instrumentation::kMethodUnwind:
663      action = kTraceUnroll;
664      break;
665    default:
666      UNIMPLEMENTED(FATAL) << "Unexpected event: " << event;
667  }
668
669  uint32_t method_value = EncodeTraceMethodAndAction(method, action);
670
671  // Write data
672  uint8_t* ptr = buf_.get() + old_offset;
673  Append2LE(ptr, thread->GetTid());
674  Append4LE(ptr + 2, method_value);
675  ptr += 6;
676
677  if (UseThreadCpuClock()) {
678    Append4LE(ptr, thread_clock_diff);
679    ptr += 4;
680  }
681  if (UseWallClock()) {
682    Append4LE(ptr, wall_clock_diff);
683  }
684}
685
686void Trace::GetVisitedMethods(size_t buf_size,
687                              std::set<mirror::ArtMethod*>* visited_methods) {
688  uint8_t* ptr = buf_.get() + kTraceHeaderLength;
689  uint8_t* end = buf_.get() + buf_size;
690
691  while (ptr < end) {
692    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
693    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
694    visited_methods->insert(method);
695    ptr += GetRecordSize(clock_source_);
696  }
697}
698
699void Trace::DumpMethodList(std::ostream& os, const std::set<mirror::ArtMethod*>& visited_methods) {
700  for (const auto& method : visited_methods) {
701    os << StringPrintf("%p\t%s\t%s\t%s\t%s\n", method,
702        PrettyDescriptor(method->GetDeclaringClassDescriptor()).c_str(), method->GetName(),
703        method->GetSignature().ToString().c_str(), method->GetDeclaringClassSourceFile());
704  }
705}
706
707static void DumpThread(Thread* t, void* arg) {
708  std::ostream& os = *reinterpret_cast<std::ostream*>(arg);
709  std::string name;
710  t->GetThreadName(name);
711  os << t->GetTid() << "\t" << name << "\n";
712}
713
714void Trace::DumpThreadList(std::ostream& os) {
715  Thread* self = Thread::Current();
716  for (auto it : exited_threads_) {
717    os << it.first << "\t" << it.second << "\n";
718  }
719  Locks::thread_list_lock_->AssertNotHeld(self);
720  MutexLock mu(self, *Locks::thread_list_lock_);
721  Runtime::Current()->GetThreadList()->ForEach(DumpThread, &os);
722}
723
724void Trace::StoreExitingThreadInfo(Thread* thread) {
725  MutexLock mu(thread, *Locks::trace_lock_);
726  if (the_trace_ != nullptr) {
727    std::string name;
728    thread->GetThreadName(name);
729    the_trace_->exited_threads_.Put(thread->GetTid(), name);
730  }
731}
732
733}  // namespace art
734