trace.h revision c7c6d18a90079b67a7592d3f2cb3d4c6f0081512 
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#ifndef ART_RUNTIME_TRACE_H_
18#define ART_RUNTIME_TRACE_H_
19
20#include <memory>
21#include <ostream>
22#include <set>
23#include <string>
24#include <vector>
25
26#include "atomic.h"
27#include "base/macros.h"
28#include "globals.h"
29#include "instrumentation.h"
30#include "os.h"
31#include "safe_map.h"
32
33namespace art {
34
35namespace mirror {
36  class ArtField;
37  class ArtMethod;
38}  // namespace mirror
39class Thread;
40
41enum ProfilerClockSource {
42  kProfilerClockSourceThreadCpu,
43  kProfilerClockSourceWall,
44  kProfilerClockSourceDual,  // Both wall and thread CPU clocks.
45};
46
47#if defined(HAVE_POSIX_CLOCKS)
48const ProfilerClockSource kDefaultProfilerClockSource = kProfilerClockSourceDual;
49#else
50const ProfilerClockSource kDefaultProfilerClockSource = kProfilerClockSourceWall;
51#endif
52
53enum TracingMode {
54  kTracingInactive,
55  kMethodTracingActive,
56  kSampleProfilingActive,
57};
58
59class Trace FINAL : public instrumentation::InstrumentationListener {
60 public:
61  enum TraceFlag {
62    kTraceCountAllocs = 1,
63  };
64
65  static void SetDefaultClockSource(ProfilerClockSource clock_source);
66
67  static void Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
68                    bool direct_to_ddms, bool sampling_enabled, int interval_us)
69      LOCKS_EXCLUDED(Locks::mutator_lock_,
70                     Locks::thread_list_lock_,
71                     Locks::thread_suspend_count_lock_,
72                     Locks::trace_lock_);
73  static void Stop()
74      LOCKS_EXCLUDED(Locks::mutator_lock_,
75                     Locks::thread_list_lock_,
76                     Locks::trace_lock_);
77  static void Shutdown() LOCKS_EXCLUDED(Locks::trace_lock_);
78  static TracingMode GetMethodTracingMode() LOCKS_EXCLUDED(Locks::trace_lock_);
79
80  bool UseWallClock();
81  bool UseThreadCpuClock();
82  void MeasureClockOverhead();
83  uint32_t GetClockOverheadNanoSeconds();
84
85  void CompareAndUpdateStackTrace(Thread* thread, std::vector<mirror::ArtMethod*>* stack_trace)
86      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
87
88  // InstrumentationListener implementation.
89  void MethodEntered(Thread* thread, mirror::Object* this_object,
90                     mirror::ArtMethod* method, uint32_t dex_pc)
91      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
92  void MethodExited(Thread* thread, mirror::Object* this_object,
93                    mirror::ArtMethod* method, uint32_t dex_pc,
94                    const JValue& return_value)
95      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
96  void MethodUnwind(Thread* thread, mirror::Object* this_object,
97                    mirror::ArtMethod* method, uint32_t dex_pc)
98      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
99  void DexPcMoved(Thread* thread, mirror::Object* this_object,
100                  mirror::ArtMethod* method, uint32_t new_dex_pc)
101      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
102  void FieldRead(Thread* thread, mirror::Object* this_object,
103                 mirror::ArtMethod* method, uint32_t dex_pc, mirror::ArtField* field)
104      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
105  void FieldWritten(Thread* thread, mirror::Object* this_object,
106                    mirror::ArtMethod* method, uint32_t dex_pc, mirror::ArtField* field,
107                    const JValue& field_value)
108      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
109  void ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
110                       mirror::ArtMethod* catch_method, uint32_t catch_dex_pc,
111                       mirror::Throwable* exception_object)
112      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) OVERRIDE;
113
114  // Reuse an old stack trace if it exists, otherwise allocate a new one.
115  static std::vector<mirror::ArtMethod*>* AllocStackTrace();
116  // Clear and store an old stack trace for later use.
117  static void FreeStackTrace(std::vector<mirror::ArtMethod*>* stack_trace);
118
119 private:
120  explicit Trace(File* trace_file, int buffer_size, int flags, bool sampling_enabled);
121
122  // The sampling interval in microseconds is passed as an argument.
123  static void* RunSamplingThread(void* arg) LOCKS_EXCLUDED(Locks::trace_lock_);
124
125  void FinishTracing() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
126
127  void ReadClocks(Thread* thread, uint32_t* thread_clock_diff, uint32_t* wall_clock_diff);
128
129  void LogMethodTraceEvent(Thread* thread, mirror::ArtMethod* method,
130                           instrumentation::Instrumentation::InstrumentationEvent event,
131                           uint32_t thread_clock_diff, uint32_t wall_clock_diff);
132
133  // Methods to output traced methods and threads.
134  void GetVisitedMethods(size_t end_offset, std::set<mirror::ArtMethod*>* visited_methods);
135  void DumpMethodList(std::ostream& os, const std::set<mirror::ArtMethod*>& visited_methods)
136      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
137  void DumpThreadList(std::ostream& os) LOCKS_EXCLUDED(Locks::thread_list_lock_);
138
139  // Singleton instance of the Trace or NULL when no method tracing is active.
140  static Trace* volatile the_trace_ GUARDED_BY(Locks::trace_lock_);
141
142  // The default profiler clock source.
143  static ProfilerClockSource default_clock_source_;
144
145  // Sampling thread, non-zero when sampling.
146  static pthread_t sampling_pthread_;
147
148  // Used to remember an unused stack trace to avoid re-allocation during sampling.
149  static std::unique_ptr<std::vector<mirror::ArtMethod*>> temp_stack_trace_;
150
151  // File to write trace data out to, NULL if direct to ddms.
152  std::unique_ptr<File> trace_file_;
153
154  // Buffer to store trace data.
155  std::unique_ptr<uint8_t> buf_;
156
157  // Flags enabling extra tracing of things such as alloc counts.
158  const int flags_;
159
160  // True if traceview should sample instead of instrumenting method entry/exit.
161  const bool sampling_enabled_;
162
163  const ProfilerClockSource clock_source_;
164
165  // Size of buf_.
166  const int buffer_size_;
167
168  // Time trace was created.
169  const uint64_t start_time_;
170
171  // Clock overhead.
172  const uint32_t clock_overhead_ns_;
173
174  // Offset into buf_.
175  AtomicInteger cur_offset_;
176
177  // Did we overflow the buffer recording traces?
178  bool overflow_;
179
180  DISALLOW_COPY_AND_ASSIGN(Trace);
181};
182
183}  // namespace art
184
185#endif  // ART_RUNTIME_TRACE_H_
186