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      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 <stdint.h>
     10 
     11 #include <memory>
     12 #include <stack>
     13 #include <string>
     14 #include <vector>
     15 
     16 #include "base/atomicops.h"
     17 #include "base/base_export.h"
     18 #include "base/callback.h"
     19 #include "base/containers/hash_tables.h"
     20 #include "base/macros.h"
     21 #include "base/observer_list.h"
     22 #include "base/single_thread_task_runner.h"
     23 #include "base/strings/string_util.h"
     24 #include "base/synchronization/condition_variable.h"
     25 #include "base/synchronization/lock.h"
     26 #include "base/threading/thread.h"
     27 #include "base/threading/thread_local.h"
     28 #include "base/trace_event/trace_event_memory_overhead.h"
     29 #include "build/build_config.h"
     30 
     31 namespace base {
     32 
     33 class WaitableEvent;
     34 class MessageLoop;
     35 
     36 namespace trace_event {
     37 
     38 typedef base::Callback<bool(const char* arg_name)> ArgumentNameFilterPredicate;
     39 
     40 typedef base::Callback<bool(const char* category_group_name,
     41                             const char* event_name,
     42                             ArgumentNameFilterPredicate*)>
     43     ArgumentFilterPredicate;
     44 
     45 // For any argument of type TRACE_VALUE_TYPE_CONVERTABLE the provided
     46 // class must implement this interface.
     47 class BASE_EXPORT ConvertableToTraceFormat {
     48  public:
     49   ConvertableToTraceFormat() {}
     50   virtual ~ConvertableToTraceFormat() {}
     51 
     52   // Append the class info to the provided |out| string. The appended
     53   // data must be a valid JSON object. Strings must be properly quoted, and
     54   // escaped. There is no processing applied to the content after it is
     55   // appended.
     56   virtual void AppendAsTraceFormat(std::string* out) const = 0;
     57 
     58   virtual void EstimateTraceMemoryOverhead(TraceEventMemoryOverhead* overhead);
     59 
     60   std::string ToString() const {
     61     std::string result;
     62     AppendAsTraceFormat(&result);
     63     return result;
     64   }
     65 
     66  private:
     67   DISALLOW_COPY_AND_ASSIGN(ConvertableToTraceFormat);
     68 };
     69 
     70 const int kTraceMaxNumArgs = 2;
     71 
     72 struct TraceEventHandle {
     73   uint32_t chunk_seq;
     74   // These numbers of bits must be kept consistent with
     75   // TraceBufferChunk::kMaxTrunkIndex and
     76   // TraceBufferChunk::kTraceBufferChunkSize (in trace_buffer.h).
     77   unsigned chunk_index : 26;
     78   unsigned event_index : 6;
     79 };
     80 
     81 class BASE_EXPORT TraceEvent {
     82  public:
     83   union TraceValue {
     84     bool as_bool;
     85     unsigned long long as_uint;
     86     long long as_int;
     87     double as_double;
     88     const void* as_pointer;
     89     const char* as_string;
     90   };
     91 
     92   TraceEvent();
     93   ~TraceEvent();
     94 
     95   void MoveFrom(std::unique_ptr<TraceEvent> other);
     96 
     97   void Initialize(int thread_id,
     98                   TimeTicks timestamp,
     99                   ThreadTicks thread_timestamp,
    100                   char phase,
    101                   const unsigned char* category_group_enabled,
    102                   const char* name,
    103                   const char* scope,
    104                   unsigned long long id,
    105                   unsigned long long bind_id,
    106                   int num_args,
    107                   const char** arg_names,
    108                   const unsigned char* arg_types,
    109                   const unsigned long long* arg_values,
    110                   std::unique_ptr<ConvertableToTraceFormat>* convertable_values,
    111                   unsigned int flags);
    112 
    113   void Reset();
    114 
    115   void UpdateDuration(const TimeTicks& now, const ThreadTicks& thread_now);
    116 
    117   void EstimateTraceMemoryOverhead(TraceEventMemoryOverhead* overhead);
    118 
    119   // Serialize event data to JSON
    120   void AppendAsJSON(
    121       std::string* out,
    122       const ArgumentFilterPredicate& argument_filter_predicate) const;
    123   void AppendPrettyPrinted(std::ostringstream* out) const;
    124 
    125   static void AppendValueAsJSON(unsigned char type,
    126                                 TraceValue value,
    127                                 std::string* out);
    128 
    129   TimeTicks timestamp() const { return timestamp_; }
    130   ThreadTicks thread_timestamp() const { return thread_timestamp_; }
    131   char phase() const { return phase_; }
    132   int thread_id() const { return thread_id_; }
    133   TimeDelta duration() const { return duration_; }
    134   TimeDelta thread_duration() const { return thread_duration_; }
    135   const char* scope() const { return scope_; }
    136   unsigned long long id() const { return id_; }
    137   unsigned int flags() const { return flags_; }
    138 
    139   // Exposed for unittesting:
    140 
    141   const std::string* parameter_copy_storage() const {
    142     return parameter_copy_storage_.get();
    143   }
    144 
    145   const unsigned char* category_group_enabled() const {
    146     return category_group_enabled_;
    147   }
    148 
    149   const char* name() const { return name_; }
    150 
    151 #if defined(OS_ANDROID)
    152   void SendToATrace();
    153 #endif
    154 
    155  private:
    156   // Note: these are ordered by size (largest first) for optimal packing.
    157   TimeTicks timestamp_;
    158   ThreadTicks thread_timestamp_;
    159   TimeDelta duration_;
    160   TimeDelta thread_duration_;
    161   // scope_ and id_ can be used to store phase-specific data.
    162   const char* scope_;
    163   unsigned long long id_;
    164   TraceValue arg_values_[kTraceMaxNumArgs];
    165   const char* arg_names_[kTraceMaxNumArgs];
    166   std::unique_ptr<ConvertableToTraceFormat>
    167       convertable_values_[kTraceMaxNumArgs];
    168   const unsigned char* category_group_enabled_;
    169   const char* name_;
    170   std::unique_ptr<std::string> parameter_copy_storage_;
    171   // Depending on TRACE_EVENT_FLAG_HAS_PROCESS_ID the event will have either:
    172   //  tid: thread_id_, pid: current_process_id (default case).
    173   //  tid: -1, pid: process_id_ (when flags_ & TRACE_EVENT_FLAG_HAS_PROCESS_ID).
    174   union {
    175     int thread_id_;
    176     int process_id_;
    177   };
    178   unsigned int flags_;
    179   unsigned long long bind_id_;
    180   unsigned char arg_types_[kTraceMaxNumArgs];
    181   char phase_;
    182 
    183   DISALLOW_COPY_AND_ASSIGN(TraceEvent);
    184 };
    185 
    186 }  // namespace trace_event
    187 }  // namespace base
    188 
    189 #endif  // BASE_TRACE_EVENT_TRACE_EVENT_IMPL_H_
    190