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 #include "base/synchronization/lock.h"
  13
  14 namespace base {
  15 class SingleThreadTaskRunner;
  16 }  // namespace base
  17
  18 namespace tracing {
  19
  20 class ChildTraceMessageFilter;
  21
  22 // This class is a simple proxy class between the MemoryDumpManager and the
  23 // ChildTraceMessageFilter. It's only purpose is to adapt the lifetime of
  24 // CTMF to the demands of MDM, which expects the delegate to be thread-safe
  25 // and long lived. CTMF, instead, can be torn down during browser shutdown.
  26 // This class is registered as MDM delegate in child processes and handles
  27 // gracefully (and thread-safely) failures in the case of a lack of the CTMF.
  28 class ChildMemoryDumpManagerDelegateImpl
  29     : public base::trace_event::MemoryDumpManagerDelegate {
  30  public:
  31   static ChildMemoryDumpManagerDelegateImpl* GetInstance();
  32
  33   // base::trace_event::MemoryDumpManagerDelegate implementation.
  34   void RequestGlobalMemoryDump(
  35       const base::trace_event::MemoryDumpRequestArgs& args,
  36       const base::trace_event::MemoryDumpCallback& callback) override;
  37   uint64 GetTracingProcessId() const override;
  38
  39   void SetChildTraceMessageFilter(ChildTraceMessageFilter* ctmf);
  40
  41   // Pass kInvalidTracingProcessId to invalidate the id.
  42   void set_tracing_process_id(uint64 id) {
  43     DCHECK_IMPLIES(
  44         tracing_process_id_ !=
  45             base::trace_event::MemoryDumpManager::kInvalidTracingProcessId,
  46         id == base::trace_event::MemoryDumpManager::kInvalidTracingProcessId ||
  47             id == tracing_process_id_);
  48     tracing_process_id_ = id;
  49   }
  50
  51  protected:
  52   // Make CreateProcessDump() visible to ChildTraceMessageFilter.
  53   friend class ChildTraceMessageFilter;
  54
  55  private:
  56   friend struct base::DefaultSingletonTraits<
  57       ChildMemoryDumpManagerDelegateImpl>;
  58
  59   ChildMemoryDumpManagerDelegateImpl();
  60   ~ChildMemoryDumpManagerDelegateImpl() override;
  61
  62   ChildTraceMessageFilter* ctmf_;  // Not owned.
  63
  64   // The SingleThreadTaskRunner where the |ctmf_| lives.
  65   // It is NULL iff |cmtf_| is NULL.
  66   scoped_refptr<base::SingleThreadTaskRunner> ctmf_task_runner_;
  67
  68   // Protects from concurrent access to |ctmf_task_runner_| to allow
  69   // RequestGlobalMemoryDump to be called from arbitrary threads.
  70   base::Lock lock_;
  71
  72   // The unique id of the child process, created for tracing and is expected to
  73   // be valid only when tracing is enabled.
  74   uint64 tracing_process_id_;
  75
  76   DISALLOW_COPY_AND_ASSIGN(ChildMemoryDumpManagerDelegateImpl);
  77 };
  78
  79 }  // namespace tracing
  80
  81 #endif  // COMPONENTS_TRACING_CHILD_MEMORY_DUMP_MANAGER_DELEGATE_IMPL_H_