trace.cc revision cf7f19135f0e273f7b0136315633c2abfc715343 
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, void* arg) {
248  thread->SetTraceClockBase(0);
249  std::vector<mirror::ArtMethod*>* stack_trace = thread->GetStackTraceSample();
250  thread->SetStackTraceSample(NULL);
251  delete stack_trace;
252}
253
254void Trace::CompareAndUpdateStackTrace(Thread* thread,
255                                       std::vector<mirror::ArtMethod*>* stack_trace) {
256  CHECK_EQ(pthread_self(), sampling_pthread_);
257  std::vector<mirror::ArtMethod*>* old_stack_trace = thread->GetStackTraceSample();
258  // Update the thread's stack trace sample.
259  thread->SetStackTraceSample(stack_trace);
260  // Read timer clocks to use for all events in this trace.
261  uint32_t thread_clock_diff = 0;
262  uint32_t wall_clock_diff = 0;
263  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
264  if (old_stack_trace == NULL) {
265    // If there's no previous stack trace sample for this thread, log an entry event for all
266    // methods in the trace.
267    for (std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
268         rit != stack_trace->rend(); ++rit) {
269      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
270                          thread_clock_diff, wall_clock_diff);
271    }
272  } else {
273    // If there's a previous stack trace for this thread, diff the traces and emit entry and exit
274    // events accordingly.
275    std::vector<mirror::ArtMethod*>::reverse_iterator old_rit = old_stack_trace->rbegin();
276    std::vector<mirror::ArtMethod*>::reverse_iterator rit = stack_trace->rbegin();
277    // Iterate bottom-up over both traces until there's a difference between them.
278    while (old_rit != old_stack_trace->rend() && rit != stack_trace->rend() && *old_rit == *rit) {
279      old_rit++;
280      rit++;
281    }
282    // Iterate top-down over the old trace until the point where they differ, emitting exit events.
283    for (std::vector<mirror::ArtMethod*>::iterator old_it = old_stack_trace->begin();
284         old_it != old_rit.base(); ++old_it) {
285      LogMethodTraceEvent(thread, *old_it, instrumentation::Instrumentation::kMethodExited,
286                          thread_clock_diff, wall_clock_diff);
287    }
288    // Iterate bottom-up over the new trace from the point where they differ, emitting entry events.
289    for (; rit != stack_trace->rend(); ++rit) {
290      LogMethodTraceEvent(thread, *rit, instrumentation::Instrumentation::kMethodEntered,
291                          thread_clock_diff, wall_clock_diff);
292    }
293    FreeStackTrace(old_stack_trace);
294  }
295}
296
297void* Trace::RunSamplingThread(void* arg) {
298  Runtime* runtime = Runtime::Current();
299  intptr_t interval_us = reinterpret_cast<intptr_t>(arg);
300  CHECK_GE(interval_us, 0);
301  CHECK(runtime->AttachCurrentThread("Sampling Profiler", true, runtime->GetSystemThreadGroup(),
302                                     !runtime->IsCompiler()));
303
304  while (true) {
305    usleep(interval_us);
306    ATRACE_BEGIN("Profile sampling");
307    Thread* self = Thread::Current();
308    Trace* the_trace;
309    {
310      MutexLock mu(self, *Locks::trace_lock_);
311      the_trace = the_trace_;
312      if (the_trace == NULL) {
313        break;
314      }
315    }
316
317    runtime->GetThreadList()->SuspendAll();
318    {
319      MutexLock mu(self, *Locks::thread_list_lock_);
320      runtime->GetThreadList()->ForEach(GetSample, the_trace);
321    }
322    runtime->GetThreadList()->ResumeAll();
323    ATRACE_END();
324  }
325
326  runtime->DetachCurrentThread();
327  return NULL;
328}
329
330void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
331                  bool direct_to_ddms, bool sampling_enabled, int interval_us) {
332  Thread* self = Thread::Current();
333  {
334    MutexLock mu(self, *Locks::trace_lock_);
335    if (the_trace_ != NULL) {
336      LOG(ERROR) << "Trace already in progress, ignoring this request";
337      return;
338    }
339  }
340
341  // Check interval if sampling is enabled
342  if (sampling_enabled && interval_us <= 0) {
343    LOG(ERROR) << "Invalid sampling interval: " << interval_us;
344    ScopedObjectAccess soa(self);
345    ThrowRuntimeException("Invalid sampling interval: %d", interval_us);
346    return;
347  }
348
349  // Open trace file if not going directly to ddms.
350  std::unique_ptr<File> trace_file;
351  if (!direct_to_ddms) {
352    if (trace_fd < 0) {
353      trace_file.reset(OS::CreateEmptyFile(trace_filename));
354    } else {
355      trace_file.reset(new File(trace_fd, "tracefile"));
356      trace_file->DisableAutoClose();
357    }
358    if (trace_file.get() == NULL) {
359      PLOG(ERROR) << "Unable to open trace file '" << trace_filename << "'";
360      ScopedObjectAccess soa(self);
361      ThrowRuntimeException("Unable to open trace file '%s'", trace_filename);
362      return;
363    }
364  }
365
366  Runtime* runtime = Runtime::Current();
367
368  // Enable count of allocs if specified in the flags.
369  bool enable_stats = false;
370
371  runtime->GetThreadList()->SuspendAll();
372
373  // Create Trace object.
374  {
375    MutexLock mu(self, *Locks::trace_lock_);
376    if (the_trace_ != NULL) {
377      LOG(ERROR) << "Trace already in progress, ignoring this request";
378    } else {
379      enable_stats = (flags && kTraceCountAllocs) != 0;
380      the_trace_ = new Trace(trace_file.release(), buffer_size, flags, sampling_enabled);
381      if (sampling_enabled) {
382        CHECK_PTHREAD_CALL(pthread_create, (&sampling_pthread_, NULL, &RunSamplingThread,
383                                            reinterpret_cast<void*>(interval_us)),
384                                            "Sampling profiler thread");
385      } else {
386        runtime->GetInstrumentation()->AddListener(the_trace_,
387                                                   instrumentation::Instrumentation::kMethodEntered |
388                                                   instrumentation::Instrumentation::kMethodExited |
389                                                   instrumentation::Instrumentation::kMethodUnwind);
390        runtime->GetInstrumentation()->EnableMethodTracing();
391      }
392    }
393  }
394
395  runtime->GetThreadList()->ResumeAll();
396
397  // Can't call this when holding the mutator lock.
398  if (enable_stats) {
399    runtime->SetStatsEnabled(true);
400  }
401}
402
403void Trace::Stop() {
404  bool stop_alloc_counting = false;
405  Runtime* runtime = Runtime::Current();
406  runtime->GetThreadList()->SuspendAll();
407  Trace* the_trace = NULL;
408  pthread_t sampling_pthread = 0U;
409  {
410    MutexLock mu(Thread::Current(), *Locks::trace_lock_);
411    if (the_trace_ == NULL) {
412      LOG(ERROR) << "Trace stop requested, but no trace currently running";
413    } else {
414      the_trace = the_trace_;
415      the_trace_ = NULL;
416      sampling_pthread = sampling_pthread_;
417    }
418  }
419  if (the_trace != NULL) {
420    stop_alloc_counting = (the_trace->flags_ & kTraceCountAllocs) != 0;
421    the_trace->FinishTracing();
422
423    if (the_trace->sampling_enabled_) {
424      MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
425      runtime->GetThreadList()->ForEach(ClearThreadStackTraceAndClockBase, NULL);
426    } else {
427      runtime->GetInstrumentation()->DisableMethodTracing();
428      runtime->GetInstrumentation()->RemoveListener(the_trace,
429                                                    instrumentation::Instrumentation::kMethodEntered |
430                                                    instrumentation::Instrumentation::kMethodExited |
431                                                    instrumentation::Instrumentation::kMethodUnwind);
432    }
433    delete the_trace;
434  }
435  runtime->GetThreadList()->ResumeAll();
436
437  if (stop_alloc_counting) {
438    // Can be racy since SetStatsEnabled is not guarded by any locks.
439    Runtime::Current()->SetStatsEnabled(false);
440  }
441
442  if (sampling_pthread != 0U) {
443    CHECK_PTHREAD_CALL(pthread_join, (sampling_pthread, NULL), "sampling thread shutdown");
444    sampling_pthread_ = 0U;
445  }
446}
447
448void Trace::Shutdown() {
449  if (GetMethodTracingMode() != kTracingInactive) {
450    Stop();
451  }
452}
453
454TracingMode Trace::GetMethodTracingMode() {
455  MutexLock mu(Thread::Current(), *Locks::trace_lock_);
456  if (the_trace_ == NULL) {
457    return kTracingInactive;
458  } else if (the_trace_->sampling_enabled_) {
459    return kSampleProfilingActive;
460  } else {
461    return kMethodTracingActive;
462  }
463}
464
465Trace::Trace(File* trace_file, int buffer_size, int flags, bool sampling_enabled)
466    : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
467      sampling_enabled_(sampling_enabled), clock_source_(default_clock_source_),
468      buffer_size_(buffer_size), start_time_(MicroTime()),
469      clock_overhead_ns_(GetClockOverheadNanoSeconds()), cur_offset_(0), overflow_(false) {
470  // Set up the beginning of the trace.
471  uint16_t trace_version = GetTraceVersion(clock_source_);
472  memset(buf_.get(), 0, kTraceHeaderLength);
473  Append4LE(buf_.get(), kTraceMagicValue);
474  Append2LE(buf_.get() + 4, trace_version);
475  Append2LE(buf_.get() + 6, kTraceHeaderLength);
476  Append8LE(buf_.get() + 8, start_time_);
477  if (trace_version >= kTraceVersionDualClock) {
478    uint16_t record_size = GetRecordSize(clock_source_);
479    Append2LE(buf_.get() + 16, record_size);
480  }
481
482  // Update current offset.
483  cur_offset_.StoreRelaxed(kTraceHeaderLength);
484}
485
486static void DumpBuf(uint8_t* buf, size_t buf_size, TraceClockSource clock_source)
487    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
488  uint8_t* ptr = buf + kTraceHeaderLength;
489  uint8_t* end = buf + buf_size;
490
491  while (ptr < end) {
492    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
493    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
494    TraceAction action = DecodeTraceAction(tmid);
495    LOG(INFO) << PrettyMethod(method) << " " << static_cast<int>(action);
496    ptr += GetRecordSize(clock_source);
497  }
498}
499
500void Trace::FinishTracing() {
501  // Compute elapsed time.
502  uint64_t elapsed = MicroTime() - start_time_;
503
504  size_t final_offset = cur_offset_.LoadRelaxed();
505
506  std::set<mirror::ArtMethod*> visited_methods;
507  GetVisitedMethods(final_offset, &visited_methods);
508
509  std::ostringstream os;
510
511  os << StringPrintf("%cversion\n", kTraceTokenChar);
512  os << StringPrintf("%d\n", GetTraceVersion(clock_source_));
513  os << StringPrintf("data-file-overflow=%s\n", overflow_ ? "true" : "false");
514  if (UseThreadCpuClock()) {
515    if (UseWallClock()) {
516      os << StringPrintf("clock=dual\n");
517    } else {
518      os << StringPrintf("clock=thread-cpu\n");
519    }
520  } else {
521    os << StringPrintf("clock=wall\n");
522  }
523  os << StringPrintf("elapsed-time-usec=%" PRIu64 "\n", elapsed);
524  size_t num_records = (final_offset - kTraceHeaderLength) / GetRecordSize(clock_source_);
525  os << StringPrintf("num-method-calls=%zd\n", num_records);
526  os << StringPrintf("clock-call-overhead-nsec=%d\n", clock_overhead_ns_);
527  os << StringPrintf("vm=art\n");
528  if ((flags_ & kTraceCountAllocs) != 0) {
529    os << StringPrintf("alloc-count=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_OBJECTS));
530    os << StringPrintf("alloc-size=%d\n", Runtime::Current()->GetStat(KIND_ALLOCATED_BYTES));
531    os << StringPrintf("gc-count=%d\n", Runtime::Current()->GetStat(KIND_GC_INVOCATIONS));
532  }
533  os << StringPrintf("%cthreads\n", kTraceTokenChar);
534  DumpThreadList(os);
535  os << StringPrintf("%cmethods\n", kTraceTokenChar);
536  DumpMethodList(os, visited_methods);
537  os << StringPrintf("%cend\n", kTraceTokenChar);
538
539  std::string header(os.str());
540  if (trace_file_.get() == NULL) {
541    iovec iov[2];
542    iov[0].iov_base = reinterpret_cast<void*>(const_cast<char*>(header.c_str()));
543    iov[0].iov_len = header.length();
544    iov[1].iov_base = buf_.get();
545    iov[1].iov_len = final_offset;
546    Dbg::DdmSendChunkV(CHUNK_TYPE("MPSE"), iov, 2);
547    const bool kDumpTraceInfo = false;
548    if (kDumpTraceInfo) {
549      LOG(INFO) << "Trace sent:\n" << header;
550      DumpBuf(buf_.get(), final_offset, clock_source_);
551    }
552  } else {
553    if (!trace_file_->WriteFully(header.c_str(), header.length()) ||
554        !trace_file_->WriteFully(buf_.get(), final_offset)) {
555      std::string detail(StringPrintf("Trace data write failed: %s", strerror(errno)));
556      PLOG(ERROR) << detail;
557      ThrowRuntimeException("%s", detail.c_str());
558    }
559  }
560}
561
562void Trace::DexPcMoved(Thread* thread, mirror::Object* this_object,
563                       mirror::ArtMethod* method, uint32_t new_dex_pc) {
564  // We're not recorded to listen to this kind of event, so complain.
565  LOG(ERROR) << "Unexpected dex PC event in tracing " << PrettyMethod(method) << " " << new_dex_pc;
566}
567
568void Trace::FieldRead(Thread* /*thread*/, mirror::Object* this_object,
569                       mirror::ArtMethod* method, uint32_t dex_pc, mirror::ArtField* field)
570    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
571  // We're not recorded to listen to this kind of event, so complain.
572  LOG(ERROR) << "Unexpected field read event in tracing " << PrettyMethod(method) << " " << dex_pc;
573}
574
575void Trace::FieldWritten(Thread* /*thread*/, mirror::Object* this_object,
576                          mirror::ArtMethod* method, uint32_t dex_pc, mirror::ArtField* field,
577                          const JValue& field_value)
578    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
579  // We're not recorded to listen to this kind of event, so complain.
580  LOG(ERROR) << "Unexpected field write event in tracing " << PrettyMethod(method) << " " << dex_pc;
581}
582
583void Trace::MethodEntered(Thread* thread, mirror::Object* this_object,
584                          mirror::ArtMethod* method, uint32_t dex_pc) {
585  uint32_t thread_clock_diff = 0;
586  uint32_t wall_clock_diff = 0;
587  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
588  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodEntered,
589                      thread_clock_diff, wall_clock_diff);
590}
591
592void Trace::MethodExited(Thread* thread, mirror::Object* this_object,
593                         mirror::ArtMethod* method, uint32_t dex_pc,
594                         const JValue& return_value) {
595  UNUSED(return_value);
596  uint32_t thread_clock_diff = 0;
597  uint32_t wall_clock_diff = 0;
598  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
599  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodExited,
600                      thread_clock_diff, wall_clock_diff);
601}
602
603void Trace::MethodUnwind(Thread* thread, mirror::Object* this_object,
604                         mirror::ArtMethod* method, uint32_t dex_pc) {
605  uint32_t thread_clock_diff = 0;
606  uint32_t wall_clock_diff = 0;
607  ReadClocks(thread, &thread_clock_diff, &wall_clock_diff);
608  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodUnwind,
609                      thread_clock_diff, wall_clock_diff);
610}
611
612void Trace::ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
613                            mirror::ArtMethod* catch_method, uint32_t catch_dex_pc,
614                            mirror::Throwable* exception_object)
615    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
616  LOG(ERROR) << "Unexpected exception caught event in tracing";
617}
618
619void Trace::ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff) {
620  if (UseThreadCpuClock()) {
621    uint64_t clock_base = thread->GetTraceClockBase();
622    if (UNLIKELY(clock_base == 0)) {
623      // First event, record the base time in the map.
624      uint64_t time = thread->GetCpuMicroTime();
625      thread->SetTraceClockBase(time);
626    } else {
627      *thread_clock_diff = thread->GetCpuMicroTime() - clock_base;
628    }
629  }
630  if (UseWallClock()) {
631    *wall_clock_diff = MicroTime() - start_time_;
632  }
633}
634
635void Trace::LogMethodTraceEvent(Thread* thread, mirror::ArtMethod* method,
636                                instrumentation::Instrumentation::InstrumentationEvent event,
637                                uint32_t thread_clock_diff, uint32_t wall_clock_diff) {
638  // Advance cur_offset_ atomically.
639  int32_t new_offset;
640  int32_t old_offset;
641  do {
642    old_offset = cur_offset_.LoadRelaxed();
643    new_offset = old_offset + GetRecordSize(clock_source_);
644    if (new_offset > buffer_size_) {
645      overflow_ = true;
646      return;
647    }
648  } while (!cur_offset_.CompareExchangeWeakSequentiallyConsistent(old_offset, new_offset));
649
650  TraceAction action = kTraceMethodEnter;
651  switch (event) {
652    case instrumentation::Instrumentation::kMethodEntered:
653      action = kTraceMethodEnter;
654      break;
655    case instrumentation::Instrumentation::kMethodExited:
656      action = kTraceMethodExit;
657      break;
658    case instrumentation::Instrumentation::kMethodUnwind:
659      action = kTraceUnroll;
660      break;
661    default:
662      UNIMPLEMENTED(FATAL) << "Unexpected event: " << event;
663  }
664
665  uint32_t method_value = EncodeTraceMethodAndAction(method, action);
666
667  // Write data
668  uint8_t* ptr = buf_.get() + old_offset;
669  Append2LE(ptr, thread->GetTid());
670  Append4LE(ptr + 2, method_value);
671  ptr += 6;
672
673  if (UseThreadCpuClock()) {
674    Append4LE(ptr, thread_clock_diff);
675    ptr += 4;
676  }
677  if (UseWallClock()) {
678    Append4LE(ptr, wall_clock_diff);
679  }
680}
681
682void Trace::GetVisitedMethods(size_t buf_size,
683                              std::set<mirror::ArtMethod*>* visited_methods) {
684  uint8_t* ptr = buf_.get() + kTraceHeaderLength;
685  uint8_t* end = buf_.get() + buf_size;
686
687  while (ptr < end) {
688    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
689    mirror::ArtMethod* method = DecodeTraceMethodId(tmid);
690    visited_methods->insert(method);
691    ptr += GetRecordSize(clock_source_);
692  }
693}
694
695void Trace::DumpMethodList(std::ostream& os, const std::set<mirror::ArtMethod*>& visited_methods) {
696  for (const auto& method : visited_methods) {
697    os << StringPrintf("%p\t%s\t%s\t%s\t%s\n", method,
698        PrettyDescriptor(method->GetDeclaringClassDescriptor()).c_str(), method->GetName(),
699        method->GetSignature().ToString().c_str(), method->GetDeclaringClassSourceFile());
700  }
701}
702
703static void DumpThread(Thread* t, void* arg) {
704  std::ostream& os = *reinterpret_cast<std::ostream*>(arg);
705  std::string name;
706  t->GetThreadName(name);
707  os << t->GetTid() << "\t" << name << "\n";
708}
709
710void Trace::DumpThreadList(std::ostream& os) {
711  Thread* self = Thread::Current();
712  for (auto it : exited_threads_) {
713    os << it.first << "\t" << it.second << "\n";
714  }
715  Locks::thread_list_lock_->AssertNotHeld(self);
716  MutexLock mu(self, *Locks::thread_list_lock_);
717  Runtime::Current()->GetThreadList()->ForEach(DumpThread, &os);
718}
719
720void Trace::StoreExitingThreadInfo(Thread* thread) {
721  MutexLock mu(thread, *Locks::trace_lock_);
722  if (the_trace_ != nullptr) {
723    std::string name;
724    thread->GetThreadName(name);
725    the_trace_->exited_threads_.Put(thread->GetTid(), name);
726  }
727}
728
729}  // namespace art
730