base/trace_event/trace_event_impl.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5
   6 #ifndef BASE_TRACE_EVENT_TRACE_EVENT_IMPL_H_
   7 #define BASE_TRACE_EVENT_TRACE_EVENT_IMPL_H_
   8
   9 #include <stack>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "base/atomicops.h"
  14 #include "base/base_export.h"
  15 #include "base/callback.h"
  16 #include "base/containers/hash_tables.h"
  17 #include "base/gtest_prod_util.h"
  18 #include "base/memory/ref_counted_memory.h"
  19 #include "base/observer_list.h"
  20 #include "base/single_thread_task_runner.h"
  21 #include "base/strings/string_util.h"
  22 #include "base/synchronization/condition_variable.h"
  23 #include "base/synchronization/lock.h"
  24 #include "base/threading/thread.h"
  25 #include "base/threading/thread_local.h"
  26 #include "base/trace_event/trace_event_memory_overhead.h"
  27
  28 namespace base {
  29
  30 class WaitableEvent;
  31 class MessageLoop;
  32
  33 namespace trace_event {
  34
  35 typedef base::Callback<bool(const char* category_group_name,
  36                             const char* event_name)> ArgumentFilterPredicate;
  37
  38 // For any argument of type TRACE_VALUE_TYPE_CONVERTABLE the provided
  39 // class must implement this interface.
  40 class BASE_EXPORT ConvertableToTraceFormat
  41     : public RefCounted<ConvertableToTraceFormat> {
  42  public:
  43   // Append the class info to the provided |out| string. The appended
  44   // data must be a valid JSON object. Strings must be properly quoted, and
  45   // escaped. There is no processing applied to the content after it is
  46   // appended.
  47   virtual void AppendAsTraceFormat(std::string* out) const = 0;
  48
  49   virtual void EstimateTraceMemoryOverhead(TraceEventMemoryOverhead* overhead);
  50
  51   std::string ToString() const {
  52     std::string result;
  53     AppendAsTraceFormat(&result);
  54     return result;
  55   }
  56
  57  protected:
  58   virtual ~ConvertableToTraceFormat() {}
  59
  60  private:
  61   friend class RefCounted<ConvertableToTraceFormat>;
  62 };
  63
  64 const int kTraceMaxNumArgs = 2;
  65
  66 struct TraceEventHandle {
  67   uint32 chunk_seq;
  68   // These numbers of bits must be kept consistent with
  69   // TraceBufferChunk::kMaxTrunkIndex and
  70   // TraceBufferChunk::kTraceBufferChunkSize (in trace_buffer.h).
  71   unsigned chunk_index : 26;
  72   unsigned event_index : 6;
  73 };
  74
  75 class BASE_EXPORT TraceEvent {
  76  public:
  77   union TraceValue {
  78     bool as_bool;
  79     unsigned long long as_uint;
  80     long long as_int;
  81     double as_double;
  82     const void* as_pointer;
  83     const char* as_string;
  84   };
  85
  86   TraceEvent();
  87   ~TraceEvent();
  88
  89   // We don't need to copy TraceEvent except when TraceEventBuffer is cloned.
  90   // Use explicit copy method to avoid accidentally misuse of copy.
  91   void CopyFrom(const TraceEvent& other);
  92
  93   void Initialize(
  94       int thread_id,
  95       TraceTicks timestamp,
  96       ThreadTicks thread_timestamp,
  97       char phase,
  98       const unsigned char* category_group_enabled,
  99       const char* name,
 100       unsigned long long id,
 101       unsigned long long context_id,
 102       unsigned long long bind_id,
 103       int num_args,
 104       const char** arg_names,
 105       const unsigned char* arg_types,
 106       const unsigned long long* arg_values,
 107       const scoped_refptr<ConvertableToTraceFormat>* convertable_values,
 108       unsigned int flags);
 109
 110   void Reset();
 111
 112   void UpdateDuration(const TraceTicks& now, const ThreadTicks& thread_now);
 113
 114   void EstimateTraceMemoryOverhead(TraceEventMemoryOverhead*);
 115
 116   // Serialize event data to JSON
 117   void AppendAsJSON(
 118       std::string* out,
 119       const ArgumentFilterPredicate& argument_filter_predicate) const;
 120   void AppendPrettyPrinted(std::ostringstream* out) const;
 121
 122   static void AppendValueAsJSON(unsigned char type,
 123                                 TraceValue value,
 124                                 std::string* out);
 125
 126   TraceTicks timestamp() const { return timestamp_; }
 127   ThreadTicks thread_timestamp() const { return thread_timestamp_; }
 128   char phase() const { return phase_; }
 129   int thread_id() const { return thread_id_; }
 130   TimeDelta duration() const { return duration_; }
 131   TimeDelta thread_duration() const { return thread_duration_; }
 132   unsigned long long id() const { return id_; }
 133   unsigned long long context_id() const { return context_id_; }
 134   unsigned int flags() const { return flags_; }
 135
 136   // Exposed for unittesting:
 137
 138   const base::RefCountedString* parameter_copy_storage() const {
 139     return parameter_copy_storage_.get();
 140   }
 141
 142   const unsigned char* category_group_enabled() const {
 143     return category_group_enabled_;
 144   }
 145
 146   const char* name() const { return name_; }
 147
 148 #if defined(OS_ANDROID)
 149   void SendToATrace();
 150 #endif
 151
 152  private:
 153   // Note: these are ordered by size (largest first) for optimal packing.
 154   TraceTicks timestamp_;
 155   ThreadTicks thread_timestamp_;
 156   TimeDelta duration_;
 157   TimeDelta thread_duration_;
 158   // id_ can be used to store phase-specific data.
 159   unsigned long long id_;
 160   // context_id_ is used to store context information.
 161   unsigned long long context_id_;
 162   TraceValue arg_values_[kTraceMaxNumArgs];
 163   const char* arg_names_[kTraceMaxNumArgs];
 164   scoped_refptr<ConvertableToTraceFormat> convertable_values_[kTraceMaxNumArgs];
 165   const unsigned char* category_group_enabled_;
 166   const char* name_;
 167   scoped_refptr<base::RefCountedString> parameter_copy_storage_;
 168   int thread_id_;
 169   char phase_;
 170   unsigned int flags_;
 171   unsigned long long bind_id_;
 172   unsigned char arg_types_[kTraceMaxNumArgs];
 173
 174   DISALLOW_COPY_AND_ASSIGN(TraceEvent);
 175 };
 176
 177 }  // namespace trace_event
 178 }  // namespace base
 179
 180 #endif  // BASE_TRACE_EVENT_TRACE_EVENT_IMPL_H_