services/resource_coordinator/public/cpp/memory_instrumentation/tracing_observer.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_PUBLIC_CPP_MEMORY_INSTRUMENTATION_TRACING_OBSERVER_H
#define SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_MEMORY_INSTRUMENTATION_TRACING_OBSERVER_H

#include "base/macros.h"
#include "base/trace_event/memory_dump_manager.h"
#include "base/trace_event/trace_event.h"
#include "services/resource_coordinator/public/cpp/resource_coordinator_export.h"
#include "services/resource_coordinator/public/mojom/memory_instrumentation/memory_instrumentation.mojom.h"

namespace memory_instrumentation {

// Observes TraceLog for Enable/Disable events and when they occur Enables and
// Disables the MemoryDumpManager with the correct state based on reading the
// trace log. Also provides a method for adding a dump to the trace.
class SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_EXPORT TracingObserver
    : public base::trace_event::TraceLog::EnabledStateObserver {
 public:
  TracingObserver(base::trace_event::TraceLog*,
                  base::trace_event::MemoryDumpManager*);
  ~TracingObserver() override;

  // TraceLog::EnabledStateObserver implementation.
  void OnTraceLogEnabled() override;
  void OnTraceLogDisabled() override;

  bool AddChromeDumpToTraceIfEnabled(
      const base::trace_event::MemoryDumpRequestArgs&,
      const base::ProcessId pid,
      const base::trace_event::ProcessMemoryDump*);
  bool AddOsDumpToTraceIfEnabled(
      const base::trace_event::MemoryDumpRequestArgs&,
      const base::ProcessId,
      const mojom::OSMemDump*,
      const std::vector<mojom::VmRegionPtr>*);

  static void MemoryMapsAsValueInto(
      const std::vector<mojom::VmRegionPtr>& memory_maps,
      base::trace_event::TracedValue* value,
      bool is_argument_filtering_enabled);

  // TODO(lalitm): make these private again after TracingObserver is moved
  // to private space.
  bool ShouldAddToTrace(const base::trace_event::MemoryDumpRequestArgs&);
  void AddToTrace(const base::trace_event::MemoryDumpRequestArgs&,
                  const base::ProcessId,
                  std::unique_ptr<base::trace_event::TracedValue>);

 private:
  // Returns true if the dump mode is allowed for current tracing session.
  bool IsDumpModeAllowed(base::trace_event::MemoryDumpLevelOfDetail) const;

  base::trace_event::MemoryDumpManager* const memory_dump_manager_;
  base::trace_event::TraceLog* const trace_log_;
  std::unique_ptr<base::trace_event::TraceConfig::MemoryDumpConfig>
      memory_dump_config_;

  DISALLOW_COPY_AND_ASSIGN(TracingObserver);
};

}  // namespace memory_instrumentation

#endif  // SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_MEMORY_INSTRUMENTATION_TRACING_OBSERVER_H