Merge gpu_trace_event back into base/debug/trace_event

gpu/common/gpu_trace_event.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Trace events are for tracking application performance.
-//
-// Events are issued against categories. Whereas LOG's
-// categories are statically defined, TRACE categories are created
-// implicitly with a string. For example:
-//   GPU_TRACE_EVENT_INSTANT0("MY_SUBSYSTEM", "SomeImportantEvent")
-//
-// Events can be INSTANT, or can be pairs of BEGIN and END:
-//   GPU_TRACE_EVENT_BEGIN0("MY_SUBSYSTEM", "SomethingCostly")
-//   doSomethingCostly()
-//   GPU_TRACE_EVENT_END0("MY_SUBSYSTEM", "SomethingCostly")
-//
-// A common use case is to trace entire function scopes. This
-// issues a trace BEGIN and END automatically:
-//   void doSomethingCostly() {
-//     GPU_TRACE_EVENT0("MY_SUBSYSTEM", "doSomethingCostly");
-//     ...
-//   }
-//
-// Additional parameters can be associated with an event:
-//   void doSomethingCostly2(int howMuch) {
-//     GPU_TRACE_EVENT1("MY_SUBSYSTEM", "doSomethingCostly",
-//         "howMuch", StringPrintf("%i", howMuch).c_str());
-//     ...
-//   }
-//
-// The trace system will automatically add to this information the
-// current process id, thread id, a timestamp down to the
-// microsecond, as well as the file and line number of the calling location.
-//
-// By default, trace collection is compiled in, but turned off at runtime.
-// Collecting trace data is the responsibility of the embedding
-// application. In Chrome's case, navigating to about:gpu will turn on
-// tracing and display data collected across all active processes.
-//
-
-#ifndef GPU_TRACE_EVENT_H_
-#define GPU_TRACE_EVENT_H_
-#pragma once
-
-#include "build/build_config.h"
-
-#include <string>
-
-#include "base/memory/scoped_ptr.h"
-#include "base/atomicops.h"
-#include "base/memory/scoped_vector.h"
-#include "base/memory/singleton.h"
-#include "base/time.h"
-#include "base/timer.h"
-#include "base/callback.h"
-#include <vector>
-
-
-// Implementation detail: trace event macros create temporary variables
-// to keep instrumentation overhead low. These macros give each temporary
-// variable a unique name based on the line number to prevent name collissions.
-#define GPU_TRACE_EVENT_UNIQUE_IDENTIFIER3(a,b) a##b
-#define GPU_TRACE_EVENT_UNIQUE_IDENTIFIER2(a,b) \
-  GPU_TRACE_EVENT_UNIQUE_IDENTIFIER3(a,b)
-#define GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(name_prefix) \
-  GPU_TRACE_EVENT_UNIQUE_IDENTIFIER2(name_prefix, __LINE__)
-
-// Records a pair of begin and end events called "name" for the current
-// scope, with 0, 1 or 2 associated arguments. If the category is not
-// enabled, then this does nothing.
-#define GPU_TRACE_EVENT0(category, name) \
-  GPU_TRACE_EVENT1(category, name, NULL, NULL)
-#define GPU_TRACE_EVENT1(category, name, arg1name, arg1val) \
-  GPU_TRACE_EVENT2(category, name, arg1name, arg1val, NULL, NULL)
-#define GPU_TRACE_EVENT2(category, name, arg1name, arg1val, arg2name, arg2val) \
-  static gpu::TraceCategory* \
-      GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic) = \
-      gpu::TraceLog::GetInstance()->GetCategory(category); \
-  if (base::subtle::Acquire_Load(\
-      &(GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic))->enabled_)) { \
-    gpu::TraceLog::GetInstance()->AddTraceEvent( \
-        gpu::GPU_TRACE_EVENT_PHASE_BEGIN, \
-        __FILE__, __LINE__, \
-        GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic), \
-        name, \
-        arg1name, arg1val, \
-        arg2name, arg2val); \
-  } \
-  gpu::internal::TraceEndOnScopeClose __profileScope ## __LINE ( \
-      __FILE__, __LINE__, \
-      GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic), name);
-
-// Records a single event called "name" immediately, with 0, 1 or 2
-// associated arguments. If the category is not enabled, then this
-// does nothing.
-#define GPU_TRACE_EVENT_INSTANT0(category, name) \
-  GPU_TRACE_EVENT_INSTANT1(category, name, NULL, NULL)
-#define GPU_TRACE_EVENT_INSTANT1(category, name, arg1name, arg1val) \
-  GPU_TRACE_EVENT_INSTANT2(category, name, arg1name, arg1val, NULL, NULL)
-#define GPU_TRACE_EVENT_INSTANT2(category, name, arg1name, arg1val, \
-    arg2name, arg2val) \
-  static gpu::TraceCategory* \
-      GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic) = \
-      gpu::TraceLog::GetInstance()->GetCategory(category); \
-  if (base::subtle::Acquire_Load( \
-      &(GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic))->enabled_)) { \
-    gpu::TraceLog::GetInstance()->AddTraceEvent( \
-        gpu::GPU_TRACE_EVENT_PHASE_INSTANT, \
-        __FILE__, __LINE__, \
-        GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic), \
-        name, \
-        arg1name, arg1val, \
-        arg2name, arg2val); \
-  }
-
-// Records a single BEGIN event called "name" immediately, with 0, 1 or 2
-// associated arguments. If the category is not enabled, then this
-// does nothing.
-#define GPU_TRACE_EVENT_BEGIN0(category, name) \
-  GPU_TRACE_EVENT_BEGIN1(category, name, NULL, NULL)
-#define GPU_TRACE_EVENT_BEGIN1(category, name, arg1name, arg1val) \
-  GPU_TRACE_EVENT_BEGIN2(category, name, arg1name, arg1val, NULL, NULL)
-#define GPU_TRACE_EVENT_BEGIN2(category, name, arg1name, arg1val, \
-    arg2name, arg2val) \
-  static gpu::TraceCategory* \
-      GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic) = \
-      gpu::TraceLog::GetInstance()->GetCategory(category); \
-  if (base::subtle::Acquire_Load( \
-      &(GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic))->enabled_)) { \
-    gpu::TraceLog::GetInstance()->AddTraceEvent( \
-        gpu::GPU_TRACE_EVENT_PHASE_BEGIN, \
-        __FILE__, __LINE__, \
-        GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic), \
-        name, \
-        arg1name, arg1val, \
-        arg2name, arg2val); \
-  }
-
-// Records a single END event for "name" immediately. If the category
-// is not enabled, then this does nothing.
-#define GPU_TRACE_EVENT_END0(category, name) \
-  static gpu::TraceCategory* \
-      GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic) = \
-      gpu::TraceLog::GetInstance()->GetCategory(category); \
-  if (base::subtle::Acquire_Load( \
-      &(GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic))->enabled_)) {  \
-    gpu::TraceLog::GetInstance()->AddTraceEvent( \
-        gpu::GPU_TRACE_EVENT_PHASE_END, \
-        __FILE__, __LINE__, \
-        GPU_TRACE_EVENT_UNIQUE_IDENTIFIER(catstatic), \
-        name, \
-        NULL, NULL, \
-        NULL, NULL); \
-  }
-
-
-namespace gpu {
-
-// Categories allow enabling/disabling of streams of trace events
-// Don't manipulate the category object directly, as this may lead
-// to threading issues. Use the TraceLog methods instead.
-class TraceCategory {
- public:
-  TraceCategory(const char* name, bool enabled);
-  ~TraceCategory();
-
-  const char* name() const { return name_; }
-
-  // NEVER read these directly, let the macros do it for you
-  volatile base::subtle::Atomic32 enabled_;
- protected:
-  const char* name_;
-};
-
-#define TRACE_MAX_NUM_ARGS 2
-
-enum TraceEventPhase {
-  GPU_TRACE_EVENT_PHASE_BEGIN,
-  GPU_TRACE_EVENT_PHASE_END,
-  GPU_TRACE_EVENT_PHASE_INSTANT
-};
-
-// Output records are "Events" and can be obtained via the
-// OutputCallback whenever the logging system decides to flush. This
-// can happen at any time, on any thread, or you can programatically
-// force it to happen.
-struct TraceEvent {
-  static void AppendAsJSON(std::string* out,
-      const std::vector<TraceEvent>& events,
-      size_t start,
-      size_t count);
-  TraceEvent();
-  ~TraceEvent();
-  void AppendAsJSON(std::string* out) const;
-
-
-  unsigned long processId;
-  unsigned long threadId;
-  base::TimeTicks timestamp;
-  TraceEventPhase phase;
-  TraceCategory* category;
-  const char* name;
-  const char* argNames[TRACE_MAX_NUM_ARGS];
-  std::string argValues[TRACE_MAX_NUM_ARGS];
-};
-
-
-class TraceLog {
- public:
-  static TraceLog* GetInstance();
-
-  // Global enable of tracing. Currently enables all categories or not.
-  // TODO(nduca) Replaced with an Enable/DisableCategory() that
-  // implicitly controls the global logging state.
-  void SetEnabled(bool enabled);
-
-  // When enough events are collected, they are handed (in bulk) to
-  // the output callback. If no callback is set, the output will be
-  // silently dropped.
-  typedef Callback1<const std::string& /* json_events */>::Type OutputCallback;
-  void SetOutputCallback(OutputCallback* cb);
-
-  // Forwards data collected by a child process to the registered
-  //  output callback.
-  void AddRemotelyCollectedData(const std::string& json_events);
-
-  // Flushes all logged data to the callback.
-  void Flush();
-
-  // Called by GPU_TRACE_EVENT* macros, don't call this directly.
-  TraceCategory* GetCategory(const char* name);
-
-  // Called by GPU_TRACE_EVENT* macros, don't call this directly.
-  void AddTraceEvent(TraceEventPhase phase,
-      const char* file, int line,
-      TraceCategory* category,
-      const char* name,
-      const char* arg1name, const char* arg1val,
-      const char* arg2name, const char* arg2val);
-
- private:
-  // This allows constructor and destructor to be private and usable only
-  // by the Singleton class.
-  friend struct StaticMemorySingletonTraits<TraceLog>;
-
-  TraceLog();
-  ~TraceLog();
-  void FlushWithLockAlreadyHeld();
-
-  // TODO(nduca): switch to per-thread trace buffers to reduce thread
-  // synchronization.
-  base::Lock lock_;
-  bool enabled_;
-  ScopedVector<TraceCategory> categories_;
-  scoped_ptr<OutputCallback> output_callback_;
-  std::vector<TraceEvent> logged_events_;
-
-  DISALLOW_COPY_AND_ASSIGN(TraceLog);
-};
-
-namespace internal {
-
-// Used by GPU_TRACE_EVENTx macro. Do not use directly.
-class TraceEndOnScopeClose {
- public:
-  TraceEndOnScopeClose(const char* file, int line,
-                       TraceCategory* category,
-                       const char* name)
-      : file_(file)
-      , line_(line)
-      , category_(category)
-      , name_(name) { }
-
-  ~TraceEndOnScopeClose() {
-    if (base::subtle::Acquire_Load(&category_->enabled_))
-      gpu::TraceLog::GetInstance()->AddTraceEvent(
-          gpu::GPU_TRACE_EVENT_PHASE_END,
-          file_, line_,
-          category_,
-          name_,
-          NULL, NULL, NULL, NULL);
-  }
-
- private:
-  const char* file_;
-  int line_;
-  TraceCategory* category_;
-  const char* name_;
-};
-
-}  // namespace internal
-
-}  // namespace gpu
-
-#endif  // GPU_TRACE_EVENT_H_