WIP: The tracing service prototype

services/resource_coordinator/tracing/coordinator_impl.h

+// Copyright 2017 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.
+
+#ifndef SERVICES_RESOURCE_COORDINATOR_TRACING_COORDINATOR_IMPL_H_
+#define SERVICES_RESOURCE_COORDINATOR_TRACING_COORDINATOR_IMPL_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner.h"
+#include "mojo/public/cpp/system/data_pipe.h"
+#include "services/resource_coordinator/public/interfaces/tracing/tracing.mojom.h"
+#include "services/resource_coordinator/tracing/agent_set_impl.h"
+#include "services/resource_coordinator/tracing/recorder_impl.h"
+
+namespace resource_coordinator {
+namespace tracing {
+
+class CoordinatorImpl : public mojom::Coordinator {
+ public:
+  // The getter of the unique instance.
+  static CoordinatorImpl* GetInstance();
+
+  CoordinatorImpl();
+
+  void BindCoordinatorRequest(mojom::CoordinatorRequest request);
+  AgentSetImpl* agent_set() { return agent_set_.get(); }
+
+ private:
+  friend std::default_delete<CoordinatorImpl>;
+  friend class Service;
+
+  ~CoordinatorImpl() override;
+
+  // mojom::Coordinator
+  void IsTracing(const IsTracingCallback& callback) override;
+  void GetCategories(const GetCategoriesCallback& callback) override;
+  void RequestBufferUsage(const RequestBufferUsageCallback& callback) override;
+  void StartTracing(mojo::ScopedDataPipeProducerHandle stream,
+                    const std::string& config) override;
+  void StopAndFlush() override;
+
+  bool IsTracing();
+
+  void SendStartTracingToAgent(AgentSetImpl::Entry* entry);
+  void OnRecorderUpdated(const std::string& label);
+  bool ReadFromRecorders();
+  void OnFlushDone();
+  void OnRequestBufferStatusResponse(AgentSetImpl::Entry* entry,
+                                     uint32_t capacity,
+                                     uint32_t count);
+
+  // Type of closures that may be run when an agent connection is closed.
+  static const char kRequestBufferUsageType[];
+
+  mojo::Binding<mojom::Coordinator> binding_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_refptr<base::SequencedTaskRunner> background_task_runner_;
+  std::unique_ptr<AgentSetImpl> agent_set_;
+  std::string config_;
+  mojo::ScopedDataPipeProducerHandle stream_;
+  std::unordered_map<std::string, std::set<std::unique_ptr<RecorderImpl>>>
+      recorders_;
+  std::string recording_label_;
+  bool first_recorder_update_;
+  bool write_label_;
+
+  // For computing trace buffer usage.
+  float maximum_trace_buffer_usage_;
+  uint32_t approximate_event_count_;
+  size_t pending_request_buffer_status_count_;
+  RequestBufferUsageCallback request_buffer_usage_callback_;
+
+  GetCategoriesCallback get_categories_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(CoordinatorImpl);
+};
+
+}  // namespace tracing
+}  // namespace resource_coordinator
+#endif  // SERVICES_RESOURCE_COORDINATOR_TRACING_COORDINATOR_IMPL_H_