trace.cc revision c785344b87221f5e4e6473e5b762e4e61fe65dcf 
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#include <unistd.h>
21
22#define ATRACE_TAG ATRACE_TAG_DALVIK
23#include "cutils/trace.h"
24
25#include "base/stl_util.h"
26#include "base/unix_file/fd_file.h"
27#include "class_linker.h"
28#include "common_throws.h"
29#include "debugger.h"
30#include "dex_file-inl.h"
31#include "instrumentation.h"
32#include "mirror/art_method-inl.h"
33#include "mirror/class-inl.h"
34#include "mirror/dex_cache.h"
35#include "mirror/object_array-inl.h"
36#include "mirror/object-inl.h"
37#include "os.h"
38#include "scoped_thread_state_change.h"
39#include "ScopedLocalRef.h"
40#include "thread.h"
41#include "thread_list.h"
42#include "entrypoints/quick/quick_entrypoints.h"
43
44namespace art {
45
46// File format:
47//     header
48//     record 0
49//     record 1
50//     ...
51//
52// Header format:
53//     u4  magic ('SLOW')
54//     u2  version
55//     u2  offset to data
56//     u8  start date/time in usec
57//     u2  record size in bytes (version >= 2 only)
58//     ... padding to 32 bytes
59//
60// Record format v1:
61//     u1  thread ID
62//     u4  method ID | method action
63//     u4  time delta since start, in usec
64//
65// Record format v2:
66//     u2  thread ID
67//     u4  method ID | method action
68//     u4  time delta since start, in usec
69//
70// Record format v3:
71//     u2  thread ID
72//     u4  method ID | method action
73//     u4  time delta since start, in usec
74//     u4  wall time since start, in usec (when clock == "dual" only)
75//
76// 32 bits of microseconds is 70 minutes.
77//
78// All values are stored in little-endian order.
79
80enum TraceAction {
81    kTraceMethodEnter = 0x00,       // method entry
82    kTraceMethodExit = 0x01,        // method exit
83    kTraceUnroll = 0x02,            // method exited by exception unrolling
84    // 0x03 currently unused
85    kTraceMethodActionMask = 0x03,  // two bits
86};
87
88class BuildStackTraceVisitor : public StackVisitor {
89 public:
90  explicit BuildStackTraceVisitor(Thread* thread) : StackVisitor(thread, NULL),
91      method_trace_(Trace::AllocStackTrace()) {}
92
93  bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
94    mirror::ArtMethod* m = GetMethod();
95    // Ignore runtime frames (in particular callee save).
96    if (!m->IsRuntimeMethod()) {
97      method_trace_->push_back(m);
98    }
99    return true;
100  }
101
102  // Returns a stack trace where the topmost frame corresponds with the first element of the vector.
103  std::vector<mirror::ArtMethod*>* GetStackTrace() const {
104    return method_trace_;
105  }
106
107 private:
108  std::vector<mirror::ArtMethod*>* const method_trace_;
109};
110
111static const char     kTraceTokenChar             = '*';
112static const uint16_t kTraceHeaderLength          = 32;
113static const uint32_t kTraceMagicValue            = 0x574f4c53;
114static const uint16_t kTraceVersionSingleClock    = 2;
115static const uint16_t kTraceVersionDualClock      = 3;
116static const uint16_t kTraceRecordSizeSingleClock = 10;  // using v2
117static const uint16_t kTraceRecordSizeDualClock   = 14;  // using v3 with two timestamps
118
119TraceClockSource Trace::default_clock_source_ = kDefaultTraceClockSource;
120
121Trace* volatile Trace::the_trace_ = NULL;
122pthread_t Trace::sampling_pthread_ = 0U;
123std::unique_ptr<std::vector<mirror::ArtMethod*>> Trace::temp_stack_trace_;
124
125static mirror::ArtMethod* DecodeTraceMethodId(uint32_t tmid) {
126  return reinterpret_cast<mirror::ArtMethod*>(tmid & ~kTraceMethodActionMask);
127}
128
129static TraceAction DecodeTraceAction(uint32_t tmid) {
130  return static_cast<TraceAction>(tmid & kTraceMethodActionMask);
131}
132
133static uint32_t EncodeTraceMethodAndAction(mirror::ArtMethod* method,
134                                           TraceAction action) {
135  uint32_t tmid = PointerToLowMemUInt32(method) | action;
136  DCHECK_EQ(method, DecodeTraceMethodId(tmid));
137  return tmid;
138}
139
140std::vector<mirror::ArtMethod*>* Trace::AllocStackTrace() {
141  if (temp_stack_trace_.get() != NULL) {
142    return temp_stack_trace_.release();
143  } else {
144    return new std::vector<mirror::ArtMethod*>();
145  }
146}
147
148void Trace::FreeStackTrace(std::vector<mirror::ArtMethod*>* stack_trace) {
149  stack_trace->clear();
150  temp_stack_trace_.reset(stack_trace);
151}
152
153void Trace::SetDefaultClockSource(TraceClockSource clock_source) {
154#if defined(__linux__)
155  default_clock_source_ = clock_source;
156#else
157  if (clock_source != TraceClockSource::kWall) {
158    LOG(WARNING) << "Ignoring tracing request to use CPU time.";
159  }
160#endif
161}
162
163static uint16_t GetTraceVersion(TraceClockSource clock_source) {
164  return (clock_source == TraceClockSource::kDual) ? kTraceVersionDualClock
165                                                    : kTraceVersionSingleClock;
166}
167
168static uint16_t GetRecordSize(TraceClockSource clock_source) {
169  return (clock_source == TraceClockSource::kDual) ? kTraceRecordSizeDualClock
170                                                    : kTraceRecordSizeSingleClock;
171}
172
173bool Trace::UseThreadCpuClock() {
174  return (clock_source_ == TraceClockSource::kThreadCpu) ||
175      (clock_source_ == TraceClockSource::kDual);
176}
177
178bool Trace::UseWallClock() {
179  return (clock_source_ == TraceClockSource::kWall) ||
180      (clock_source_ == TraceClockSource::kDual);
181}
182
183void Trace::MeasureClockOverhead() {
184  if (UseThreadCpuClock()) {
185    Thread::Current()->GetCpuMicroTime();
186  }
187  if (UseWallClock()) {
188    MicroTime();
189  }
190}
191
192// Compute an average time taken to measure clocks.
193uint32_t Trace::GetClockOverheadNanoSeconds() {
194  Thread* self = Thread::Current();
195  uint64_t start = self->GetCpuMicroTime();
196
197  for (int i = 4000; i > 0; i--) {
198    MeasureClockOverhead();
199    MeasureClockOverhead();
200    MeasureClockOverhead();
201    MeasureClockOverhead();
202    MeasureClockOverhead();
203    MeasureClockOverhead();
204    MeasureClockOverhead();
205    MeasureClockOverhead();
206  }
207
208  uint64_t elapsed_us = self->GetCpuMicroTime() - start;
209  return static_cast<uint32_t>(elapsed_us / 32);
210}
211
212// TODO: put this somewhere with the big-endian equivalent used by JDWP.
213static void Append2LE(uint8_t* buf, uint16_t val) {
214  *buf++ = static_cast<uint8_t>(val);
215  *buf++ = static_cast<uint8_t>(val >> 8);
216}
217
218// TODO: put this somewhere with the big-endian equivalent used by JDWP.
219static void Append4LE(uint8_t* buf, uint32_t val) {
220  *buf++ = static_cast<uint8_t>(val);
221  *buf++ = static_cast<uint8_t>(val >> 8);
222  *buf++ = static_cast<uint8_t>(val >> 16);
223  *buf++ = static_cast<uint8_t>(val >> 24);
224}
225
226// TODO: put this somewhere with the big-endian equivalent used by JDWP.
227static void Append8LE(uint8_t* buf, uint64_t val) {
228  *buf++ = static_cast<uint8_t>(val);
229  *buf++ = static_cast<uint8_t>(val >> 8);
230  *buf++ = static_cast<uint8_t>(val >> 16);
231  *buf++ = static_cast<uint8_t>(val >> 24);
232  *buf++ = static_cast<uint8_t>(val >> 32);
233  *buf++ = static_cast<uint8_t>(val >> 40);
234  *buf++ = static_cast<uint8_t>(val >> 48);
235  *buf++ = static_cast<uint8_t>(val >> 56);
236}
237
238static void GetSample(Thread* thread, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
239  BuildStackTraceVisitor build_trace_visitor(thread);
240  build_trace_visitor.WalkStack();
241  std::vector<mirror::ArtMethod*>* stack_trace = build_trace_visitor.GetStackTrace();
242  Trace* the_trace = reinterpret_cast<Trace*>(arg);
243  the_trace->CompareAndUpdateStackTrace(thread, stack_trace);
244}
245
246static void ClearThreadStackTraceAndClockBase(Thread* thread, void* arg ATTRIBUTE_UNUSED) {
247  thread->SetTraceClockBase(0);
248  std::vector<mirror::ArtMethod*>* stack_trace = thread->GetStackTraceSample();
249  thread->SetStackTraceSample(NULL);
250  delete stack_trace;
251}
252
253void Trace::CompareAndUpdateStackTrace(Thread* thread,
254                                       std::vector<mirror::ArtMethod*>* stack_trace) {
255  CHECK_EQ(pthread_self(), sampling_pthread_);
256  std::vector<mirror::ArtMethod*>* old_stack_trace = thread->GetStackTraceSample();
257  // Update the thread's stack trace sample.
258  thread->SetStackTraceSample(stack_trace);
259  // Read timer clocks to use for all events in this trace.
260  uint32_t thread_clock_diff = 0;
261  uint32_t wall_clock_diff = 0;
262  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
263  if (old_stack_trace == NULL) {
264    // If there's no previous stack trace sample for this thread, log an entry event for all
265    // methods in the trace.
266    for (std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
267         rit != stack_trace->rend(); ++rit) {
268      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
269                          thread_clock_diff, wall_clock_diff);
270    }
271  } else {
272    // If there's a previous stack trace for this thread, diff the traces and emit entry and exit
273    // events accordingly.
274    std::vector<mirror::ArtMethod*>::reverse_iterator old_rit = old_stack_trace->rbegin();
275    std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
276    // Iterate bottom-up over both traces until there's a difference between them.
277    while (old_rit != old_stack_trace->rend() && rit != stack_trace->rend() && *old_rit == *rit) {
278      old_rit++;
279      rit++;
280    }
281    // Iterate top-down over the old trace until the point where they differ, emitting exit events.
282    for (std::vector<mirror::ArtMethod*>::iterator old_it = old_stack_trace->begin();
283         old_it != old_rit.base(); ++old_it) {
284      LogMethodTraceEvent(thread, *old_it, instrumentation::Instrumentation::kMethodExited,
285                          thread_clock_diff, wall_clock_diff);
286    }
287    // Iterate bottom-up over the new trace from the point where they differ, emitting entry events.
288    for (; rit != stack_trace->rend(); ++rit) {
289      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
290                          thread_clock_diff, wall_clock_diff);
291    }
292    FreeStackTrace(old_stack_trace);
293  }
294}
295
296void* Trace::RunSamplingThread(void* arg) {
297  Runtime* runtime = Runtime::Current();
298  intptr_t interval_us = reinterpret_cast<intptr_t>(arg);
299  CHECK_GE(interval_us, 0);
300  CHECK(runtime->AttachCurrentThread("Sampling Profiler", true, runtime->GetSystemThreadGroup(),
301                                     !runtime->IsAotCompiler()));
302
303  while (true) {
304    usleep(interval_us);
305    ATRACE_BEGIN("Profile sampling");
306    Thread* self = Thread::Current();
307    Trace* the_trace;
308    {
309      MutexLock mu(self, *Locks::trace_lock_);
310      the_trace = the_trace_;
311      if (the_trace == NULL) {
312        break;
313      }
314    }
315
316    runtime->GetThreadList()->SuspendAll(__FUNCTION__);
317    {
318      MutexLock mu(self, *Locks::thread_list_lock_);
319      runtime->GetThreadList()->ForEach(GetSample, the_trace);
320    }
321    runtime->GetThreadList()->ResumeAll();
322    ATRACE_END();
323  }
324
325  runtime->DetachCurrentThread();
326  return NULL;
327}
328
329void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
330                  TraceOutputMode output_mode, TraceMode trace_mode, int interval_us) {
331  Thread* self = Thread::Current();
332  {
333    MutexLock mu(self, *Locks::trace_lock_);
334    if (the_trace_ != NULL) {
335      LOG(ERROR) << "Trace already in progress, ignoring this request";
336      return;
337    }
338  }
339
340  // Check interval if sampling is enabled
341  if (trace_mode == TraceMode::kSampling && interval_us <= 0) {
342    LOG(ERROR) << "Invalid sampling interval: " << interval_us;
343    ScopedObjectAccess soa(self);
344    ThrowRuntimeException("Invalid sampling interval: %d", interval_us);
345    return;
346  }
347
348  // Open trace file if not going directly to ddms.
349  std::unique_ptr<File> trace_file;
350  if (output_mode != TraceOutputMode::kDDMS) {
351    if (trace_fd < 0) {
352      trace_file.reset(OS::CreateEmptyFile(trace_filename));
353    } else {
354      trace_file.reset(new File(trace_fd, "tracefile"));
355      trace_file->DisableAutoClose();
356    }
357    if (trace_file.get() == NULL) {
358      PLOG(ERROR) << "Unable to open trace file '" << trace_filename << "'";
359      ScopedObjectAccess soa(self);
360      ThrowRuntimeException("Unable to open trace file '%s'", trace_filename);
361      return;
362    }
363  }
364
365  Runtime* runtime = Runtime::Current();
366
367  // Enable count of allocs if specified in the flags.
368  bool enable_stats = false;
369
370  runtime->GetThreadList()->SuspendAll(__FUNCTION__);
371
372  // Create Trace object.
373  {
374    MutexLock mu(self, *Locks::trace_lock_);
375    if (the_trace_ != NULL) {
376      LOG(ERROR) << "Trace already in progress, ignoring this request";
377    } else {
378      enable_stats = (flags && kTraceCountAllocs) != 0;
379      the_trace_ = new Trace(trace_file.release(), buffer_size, flags, trace_mode);
380      if (trace_mode == TraceMode::kSampling) {
381        CHECK_PTHREAD_CALL(pthread_create, (&sampling_pthread_, NULL, &RunSamplingThread,
382                                            reinterpret_cast<void*>(interval_us)),
383                                            "Sampling profiler thread");
384      } else {
385        runtime->GetInstrumentation()->AddListener(the_trace_,
386                                                   instrumentation::Instrumentation::kMethodEntered |
387                                                   instrumentation::Instrumentation::kMethodExited |
388                                                   instrumentation::Instrumentation::kMethodUnwind);
389        runtime->GetInstrumentation()->EnableMethodTracing();
390      }
391    }
392  }
393
394  runtime->GetThreadList()->ResumeAll();
395
396  // Can't call this when holding the mutator lock.
397  if (enable_stats) {
398    runtime->SetStatsEnabled(true);
399  }
400}
401
402void Trace::Stop() {
403  bool stop_alloc_counting = false;
404  Runtime* const runtime = Runtime::Current();
405  Trace* the_trace = nullptr;
406  pthread_t sampling_pthread = 0U;
407  {
408    MutexLock mu(Thread::Current(), *Locks::trace_lock_);
409    if (the_trace_ == NULL) {
410      LOG(ERROR) << "Trace stop requested, but no trace currently running";
411    } else {
412      the_trace = the_trace_;
413      the_trace_ = NULL;
414      sampling_pthread = sampling_pthread_;
415    }
416  }
417  // Make sure that we join before we delete the trace since we don't want to have
418  // the sampling thread access a stale pointer. This finishes since the sampling thread exits when
419  // the_trace_ is null.
420  if (sampling_pthread != 0U) {
421    CHECK_PTHREAD_CALL(pthread_join, (sampling_pthread, NULL), "sampling thread shutdown");
422    sampling_pthread_ = 0U;
423  }
424  runtime->GetThreadList()->SuspendAll(__FUNCTION__);
425  if (the_trace != nullptr) {
426    stop_alloc_counting = (the_trace->flags_ & kTraceCountAllocs) != 0;
427    the_trace->FinishTracing();
428
429    if (the_trace->trace_mode_ == TraceMode::kSampling) {
430      MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
431      runtime->GetThreadList()->ForEach(ClearThreadStackTraceAndClockBase, nullptr);
432    } else {
433      runtime->GetInstrumentation()->DisableMethodTracing();
434      runtime->GetInstrumentation()->RemoveListener(
435          the_trace, instrumentation::Instrumentation::kMethodEntered |
436          instrumentation::Instrumentation::kMethodExited |
437          instrumentation::Instrumentation::kMethodUnwind);
438    }
439    if (the_trace->trace_file_.get() != nullptr) {
440      // Do not try to erase, so flush and close explicitly.
441      if (the_trace->trace_file_->Flush() != 0) {
442        PLOG(ERROR) << "Could not flush trace file.";
443      }
444      if (the_trace->trace_file_->Close() != 0) {
445        PLOG(ERROR) << "Could not close trace file.";
446      }
447    }
448    delete the_trace;
449  }
450  runtime->GetThreadList()->ResumeAll();
451  if (stop_alloc_counting) {
452    // Can be racy since SetStatsEnabled is not guarded by any locks.
453    runtime->SetStatsEnabled(false);
454  }
455}
456
457void Trace::Shutdown() {
458  if (GetMethodTracingMode() != kTracingInactive) {
459    Stop();
460  }
461}
462
463TracingMode Trace::GetMethodTracingMode() {
464  MutexLock mu(Thread::Current(), *Locks::trace_lock_);
465  if (the_trace_ == NULL) {
466    return kTracingInactive;
467  } else {
468    switch (the_trace_->trace_mode_) {
469      case TraceMode::kSampling:
470        return kSampleProfilingActive;
471      case TraceMode::kMethodTracing:
472        return kMethodTracingActive;
473    }
474    LOG(FATAL) << "Unreachable";
475    UNREACHABLE();
476  }
477}
478
479Trace::Trace(File* trace_file, int buffer_size, int flags, TraceMode trace_mode)
480    : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
481      trace_mode_(trace_mode), clock_source_(default_clock_source_),
482      buffer_size_(buffer_size), start_time_(MicroTime()),
483      clock_overhead_ns_(GetClockOverheadNanoSeconds()), cur_offset_(0), overflow_(false) {
484  // Set up the beginning of the trace.
485  uint16_t trace_version = GetTraceVersion(clock_source_);
486  memset(buf_.get(), 0, kTraceHeaderLength);
487  Append4LE(buf_.get(), kTraceMagicValue);
488  Append2LE(buf_.get() + 4, trace_version);
489  Append2LE(buf_.get() + 6, kTraceHeaderLength);
490  Append8LE(buf_.get() + 8, start_time_);
491  if (trace_version >= kTraceVersionDualClock) {
492    uint16_t record_size = GetRecordSize(clock_source_);
493    Append2LE(buf_.get() + 16, record_size);
494  }
495
496  // Update current offset.
497  cur_offset_.StoreRelaxed(kTraceHeaderLength);
498}
499
500static void DumpBuf(uint8_t* buf, size_t buf_size, TraceClockSource clock_source)
501    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
502  uint8_t* ptr = buf + kTraceHeaderLength;
503  uint8_t* end = buf + buf_size;
504
505  while (ptr < end) {
506    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
507    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
508    TraceAction action = DecodeTraceAction(tmid);
509    LOG(INFO) << PrettyMethod(method) << " " << static_cast<int>(action);
510    ptr += GetRecordSize(clock_source);
511  }
512}
513
514void Trace::FinishTracing() {
515  // Compute elapsed time.
516  uint64_t elapsed = MicroTime() - start_time_;
517
518  size_t final_offset = cur_offset_.LoadRelaxed();
519
520  std::set<mirror::ArtMethod*> visited_methods;
521  GetVisitedMethods(final_offset, &visited_methods);
522
523  std::ostringstream os;
524
525  os << StringPrintf("%cversion\n", kTraceTokenChar);
526  os << StringPrintf("%d\n", GetTraceVersion(clock_source_));
527  os << StringPrintf("data-file-overflow=%s\n", overflow_ ? "true" : "false");
528  if (UseThreadCpuClock()) {
529    if (UseWallClock()) {
530      os << StringPrintf("clock=dual\n");
531    } else {
532      os << StringPrintf("clock=thread-cpu\n");
533    }
534  } else {
535    os << StringPrintf("clock=wall\n");
536  }
537  os << StringPrintf("elapsed-time-usec=%" PRIu64 "\n", elapsed);
538  size_t num_records = (final_offset - kTraceHeaderLength) / GetRecordSize(clock_source_);
539  os << StringPrintf("num-method-calls=%zd\n", num_records);
540  os << StringPrintf("clock-call-overhead-nsec=%d\n", clock_overhead_ns_);
541  os << StringPrintf("vm=art\n");
542  os << StringPrintf("pid=%d\n", getpid());
543  if ((flags_ & kTraceCountAllocs) != 0) {
544    os << StringPrintf("alloc-count=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_OBJECTS));
545    os << StringPrintf("alloc-size=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_BYTES));
546    os << StringPrintf("gc-count=%d\n", Runtime::Current()->GetStat(KIND_GC_INVOCATIONS));
547  }
548  os << StringPrintf("%cthreads\n", kTraceTokenChar);
549  DumpThreadList(os);
550  os << StringPrintf("%cmethods\n", kTraceTokenChar);
551  DumpMethodList(os, visited_methods);
552  os << StringPrintf("%cend\n", kTraceTokenChar);
553
554  std::string header(os.str());
555  if (trace_file_.get() == NULL) {
556    iovec iov[2];
557    iov[0].iov_base = reinterpret_cast<void*>(const_cast<char*>(header.c_str()));
558    iov[0].iov_len = header.length();
559    iov[1].iov_base = buf_.get();
560    iov[1].iov_len = final_offset;
561    Dbg::DdmSendChunkV(CHUNK_TYPE("MPSE"), iov, 2);
562    const bool kDumpTraceInfo = false;
563    if (kDumpTraceInfo) {
564      LOG(INFO) << "Trace sent:\n" << header;
565      DumpBuf(buf_.get(), final_offset, clock_source_);
566    }
567  } else {
568    if (!trace_file_->WriteFully(header.c_str(), header.length()) ||
569        !trace_file_->WriteFully(buf_.get(), final_offset)) {
570      std::string detail(StringPrintf("Trace data write failed: %s", strerror(errno)));
571      PLOG(ERROR) << detail;
572      ThrowRuntimeException("%s", detail.c_str());
573    }
574  }
575}
576
577void Trace::DexPcMoved(Thread* thread, mirror::Object* this_object,
578                       mirror::ArtMethod* method, uint32_t new_dex_pc) {
579  UNUSED(thread, this_object, method, new_dex_pc);
580  // We're not recorded to listen to this kind of event, so complain.
581  LOG(ERROR) << "Unexpected dex PC event in tracing " << PrettyMethod(method) << " " << new_dex_pc;
582}
583
584void Trace::FieldRead(Thread* thread, mirror::Object* this_object,
585                       mirror::ArtMethod* method, uint32_t dex_pc, ArtField* field)
586    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
587  UNUSED(thread, this_object, method, dex_pc, field);
588  // We're not recorded to listen to this kind of event, so complain.
589  LOG(ERROR) << "Unexpected field read event in tracing " << PrettyMethod(method) << " " << dex_pc;
590}
591
592void Trace::FieldWritten(Thread* thread, mirror::Object* this_object,
593                          mirror::ArtMethod* method, uint32_t dex_pc, ArtField* field,
594                          const JValue& field_value)
595    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
596  UNUSED(thread, this_object, method, dex_pc, field, field_value);
597  // We're not recorded to listen to this kind of event, so complain.
598  LOG(ERROR) << "Unexpected field write event in tracing " << PrettyMethod(method) << " " << dex_pc;
599}
600
601void Trace::MethodEntered(Thread* thread, mirror::Object* this_object ATTRIBUTE_UNUSED,
602                          mirror::ArtMethod* method, uint32_t dex_pc ATTRIBUTE_UNUSED) {
603  uint32_t thread_clock_diff = 0;
604  uint32_t wall_clock_diff = 0;
605  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
606  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodEntered,
607                      thread_clock_diff, wall_clock_diff);
608}
609
610void Trace::MethodExited(Thread* thread, mirror::Object* this_object ATTRIBUTE_UNUSED,
611                         mirror::ArtMethod* method, uint32_t dex_pc ATTRIBUTE_UNUSED,
612                         const JValue& return_value ATTRIBUTE_UNUSED) {
613  uint32_t thread_clock_diff = 0;
614  uint32_t wall_clock_diff = 0;
615  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
616  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodExited,
617                      thread_clock_diff, wall_clock_diff);
618}
619
620void Trace::MethodUnwind(Thread* thread, mirror::Object* this_object ATTRIBUTE_UNUSED,
621                         mirror::ArtMethod* method, uint32_t dex_pc ATTRIBUTE_UNUSED) {
622  uint32_t thread_clock_diff = 0;
623  uint32_t wall_clock_diff = 0;
624  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
625  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodUnwind,
626                      thread_clock_diff, wall_clock_diff);
627}
628
629void Trace::ExceptionCaught(Thread* thread, mirror::Throwable* exception_object)
630    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
631  UNUSED(thread, exception_object);
632  LOG(ERROR) << "Unexpected exception caught event in tracing";
633}
634
635void Trace::BackwardBranch(Thread* /*thread*/, mirror::ArtMethod* method,
636                           int32_t /*dex_pc_offset*/)
637      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
638  LOG(ERROR) << "Unexpected backward branch event in tracing" << PrettyMethod(method);
639}
640
641void Trace::ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff) {
642  if (UseThreadCpuClock()) {
643    uint64_t clock_base = thread->GetTraceClockBase();
644    if (UNLIKELY(clock_base == 0)) {
645      // First event, record the base time in the map.
646      uint64_t time = thread->GetCpuMicroTime();
647      thread->SetTraceClockBase(time);
648    } else {
649      *thread_clock_diff = thread->GetCpuMicroTime() - clock_base;
650    }
651  }
652  if (UseWallClock()) {
653    *wall_clock_diff = MicroTime() - start_time_;
654  }
655}
656
657void Trace::LogMethodTraceEvent(Thread* thread, mirror::ArtMethod* method,
658                                instrumentation::Instrumentation::InstrumentationEvent event,
659                                uint32_t thread_clock_diff, uint32_t wall_clock_diff) {
660  // Advance cur_offset_ atomically.
661  int32_t new_offset;
662  int32_t old_offset;
663  do {
664    old_offset = cur_offset_.LoadRelaxed();
665    new_offset = old_offset + GetRecordSize(clock_source_);
666    if (new_offset > buffer_size_) {
667      overflow_ = true;
668      return;
669    }
670  } while (!cur_offset_.CompareExchangeWeakSequentiallyConsistent(old_offset, new_offset));
671
672  TraceAction action = kTraceMethodEnter;
673  switch (event) {
674    case instrumentation::Instrumentation::kMethodEntered:
675      action = kTraceMethodEnter;
676      break;
677    case instrumentation::Instrumentation::kMethodExited:
678      action = kTraceMethodExit;
679      break;
680    case instrumentation::Instrumentation::kMethodUnwind:
681      action = kTraceUnroll;
682      break;
683    default:
684      UNIMPLEMENTED(FATAL) << "Unexpected event: " << event;
685  }
686
687  uint32_t method_value = EncodeTraceMethodAndAction(method, action);
688
689  // Write data
690  uint8_t* ptr = buf_.get() + old_offset;
691  Append2LE(ptr, thread->GetTid());
692  Append4LE(ptr + 2, method_value);
693  ptr += 6;
694
695  if (UseThreadCpuClock()) {
696    Append4LE(ptr, thread_clock_diff);
697    ptr += 4;
698  }
699  if (UseWallClock()) {
700    Append4LE(ptr, wall_clock_diff);
701  }
702}
703
704void Trace::GetVisitedMethods(size_t buf_size,
705                              std::set<mirror::ArtMethod*>* visited_methods) {
706  uint8_t* ptr = buf_.get() + kTraceHeaderLength;
707  uint8_t* end = buf_.get() + buf_size;
708
709  while (ptr < end) {
710    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
711    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
712    visited_methods->insert(method);
713    ptr += GetRecordSize(clock_source_);
714  }
715}
716
717void Trace::DumpMethodList(std::ostream& os, const std::set<mirror::ArtMethod*>& visited_methods) {
718  for (const auto& method : visited_methods) {
719    os << StringPrintf("%p\t%s\t%s\t%s\t%s\n", method,
720        PrettyDescriptor(method->GetDeclaringClassDescriptor()).c_str(), method->GetName(),
721        method->GetSignature().ToString().c_str(), method->GetDeclaringClassSourceFile());
722  }
723}
724
725static void DumpThread(Thread* t, void* arg) {
726  std::ostream& os = *reinterpret_cast<std::ostream*>(arg);
727  std::string name;
728  t->GetThreadName(name);
729  os << t->GetTid() << "\t" << name << "\n";
730}
731
732void Trace::DumpThreadList(std::ostream& os) {
733  Thread* self = Thread::Current();
734  for (auto it : exited_threads_) {
735    os << it.first << "\t" << it.second << "\n";
736  }
737  Locks::thread_list_lock_->AssertNotHeld(self);
738  MutexLock mu(self, *Locks::thread_list_lock_);
739  Runtime::Current()->GetThreadList()->ForEach(DumpThread, &os);
740}
741
742void Trace::StoreExitingThreadInfo(Thread* thread) {
743  MutexLock mu(thread, *Locks::trace_lock_);
744  if (the_trace_ != nullptr) {
745    std::string name;
746    thread->GetThreadName(name);
747    // The same thread/tid may be used multiple times. As SafeMap::Put does not allow to override
748    // a previous mapping, use SafeMap::Overwrite.
749    the_trace_->exited_threads_.Overwrite(thread->GetTid(), name);
750  }
751}
752
753}  // namespace art
754