components/tracing/child_memory_dump_manager_delegate_impl.h

   1 // Copyright 2015 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 #ifndef COMPONENTS_TRACING_CHILD_MEMORY_DUMP_MANAGER_DELEGATE_IMPL_H_
   6 #define COMPONENTS_TRACING_CHILD_MEMORY_DUMP_MANAGER_DELEGATE_IMPL_H_
   7
   8 #include "base/trace_event/memory_dump_manager.h"
   9
  10 #include "base/memory/ref_counted.h"
  11 #include "base/memory/singleton.h"
  12
  13 namespace base {
  14 class SingleThreadTaskRunner;
  15 }  // namespace base
  16
  17 namespace tracing {
  18
  19 class ChildTraceMessageFilter;
  20
  21 // This class is a simple proxy class between the MemoryDumpManager and the
  22 // ChildTraceMessageFilter. It's only purpose is to adapt the lifetime of
  23 // CTMF to the demands of MDM, which expects the delegate to be thread-safe
  24 // and long lived. CTMF, instead, can be torn down during browser shutdown.
  25 // This class is registered as MDM delegate in child processes and handles
  26 // gracefully (and thread-safely) failures in the case of a lack of the CTMF.
  27 class ChildMemoryDumpManagerDelegateImpl
  28     : public base::trace_event::MemoryDumpManagerDelegate {
  29  public:
  30   static ChildMemoryDumpManagerDelegateImpl* GetInstance();
  31
  32   // base::trace_event::MemoryDumpManagerDelegate implementation.
  33   void RequestGlobalMemoryDump(
  34       const base::trace_event::MemoryDumpRequestArgs& args,
  35       const base::trace_event::MemoryDumpCallback& callback) override;
  36   uint64 GetTracingProcessId() const override;
  37
  38   void SetChildTraceMessageFilter(ChildTraceMessageFilter* ctmf);
  39
  40   // Pass kInvalidTracingProcessId to invalidate the id.
  41   void set_tracing_process_id(uint64 id) {
  42     DCHECK_IMPLIES(
  43         tracing_process_id_ !=
  44             base::trace_event::MemoryDumpManager::kInvalidTracingProcessId,
  45         id == base::trace_event::MemoryDumpManager::kInvalidTracingProcessId ||
  46             id == tracing_process_id_);
  47     tracing_process_id_ = id;
  48   }
  49
  50  protected:
  51   // Make CreateProcessDump() visible to ChildTraceMessageFilter.
  52   friend class ChildTraceMessageFilter;
  53
  54  private:
  55   friend struct base::DefaultSingletonTraits<
  56       ChildMemoryDumpManagerDelegateImpl>;
  57
  58   ChildMemoryDumpManagerDelegateImpl();
  59   ~ChildMemoryDumpManagerDelegateImpl() override;
  60
  61   ChildTraceMessageFilter* ctmf_;  // Not owned.
  62
  63   // The SingleThreadTaskRunner where the |ctmf_| lives.
  64   // It is NULL iff |cmtf_| is NULL.
  65   scoped_refptr<base::SingleThreadTaskRunner> ctmf_task_runner_;
  66
  67   // The unique id of the child process, created for tracing and is expected to
  68   // be valid only when tracing is enabled.
  69   uint64 tracing_process_id_;
  70
  71   DISALLOW_COPY_AND_ASSIGN(ChildMemoryDumpManagerDelegateImpl);
  72 };
  73
  74 }  // namespace tracing
  75
  76 #endif  // COMPONENTS_TRACING_CHILD_MEMORY_DUMP_MANAGER_DELEGATE_IMPL_H_