[tracing] Implement polling in MemoryDumpManager

base/trace_event/memory_dump_manager.h

 // Copyright 2015 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 BASE_TRACE_EVENT_MEMORY_DUMP_MANAGER_H_
 #define BASE_TRACE_EVENT_MEMORY_DUMP_MANAGER_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <set>
 #include <vector>
 
 #include "base/atomicops.h"
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/singleton.h"
 #include "base/synchronization/lock.h"
-#include "base/timer/timer.h"
 #include "base/trace_event/memory_dump_request_args.h"
 #include "base/trace_event/process_memory_dump.h"
 #include "base/trace_event/trace_event.h"
 
 namespace base {
 
 class SingleThreadTaskRunner;
 class Thread;
 
 namespace trace_event {
 
 class MemoryDumpManagerDelegate;
 class MemoryDumpProvider;
 class MemoryDumpSessionState;
+class MemoryDumpTrigger;
 
 // This is the interface exposed to the rest of the codebase to deal with
 // memory tracing. The main entry point for clients is represented by
 // RequestDumpPoint(). The extension by Un(RegisterDumpProvider).
 class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
  public:
   static const char* const kTraceCategory;
   static const char* const kLogPrefix;
 
   // This value is returned as the tracing id of the child processes by
@@ skipping 99 matching lines @@
   // When set to true, calling |RegisterMemoryDumpProvider| is a no-op.
   void set_dumper_registrations_ignored_for_testing(bool ignored) {
     dumper_registrations_ignored_for_testing_ = ignored;
   }
 
  private:
   friend std::default_delete<MemoryDumpManager>;  // For the testing instance.
   friend struct DefaultSingletonTraits<MemoryDumpManager>;
   friend class MemoryDumpManagerDelegate;
   friend class MemoryDumpManagerTest;
+  friend class MemoryDumpTrigger;
 
   // Descriptor used to hold information about registered MDPs.
   // Some important considerations about lifetime of this object:
   // - In nominal conditions, all the MemoryDumpProviderInfo instances live in
   //   the |dump_providers_| collection (% unregistration while dumping).
   // - Upon each dump they (actually their scoped_refptr-s) are copied into
   //   the ProcessMemoryDumpAsyncState. This is to allow removal (see below).
   // - When the MDP.OnMemoryDump() is invoked, the corresponding MDPInfo copy
   //   inside ProcessMemoryDumpAsyncState is removed.
   // - In most cases, the MDPInfo is destroyed within UnregisterDumpProvider().
@@ skipping 102 matching lines @@
     // This is essentially |dump_thread_|.task_runner() but needs to be kept
     // as a separate variable as it needs to be accessed by arbitrary dumpers'
     // threads outside of the lock_ to avoid races when disabling tracing.
     // It is immutable for all the duration of a tracing session.
     const scoped_refptr<SingleThreadTaskRunner> dump_thread_task_runner;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(ProcessMemoryDumpAsyncState);
   };
 
-  // Sets up periodic memory dump timers to start global dump requests based on
-  // the dump triggers from trace config.
-  class BASE_EXPORT PeriodicGlobalDumpTimer {
-   public:
-    PeriodicGlobalDumpTimer();
-    ~PeriodicGlobalDumpTimer();
-
-    void Start(const std::vector<TraceConfig::MemoryDumpConfig::Trigger>&
-                   triggers_list);
-    void Stop();
-
-    bool IsRunning();
-
-   private:
-    // Periodically called by the timer.
-    void RequestPeriodicGlobalDump();
-
-    RepeatingTimer timer_;
-    uint32_t periodic_dumps_count_;
-    uint32_t light_dump_rate_;
-    uint32_t heavy_dump_rate_;
-
-    DISALLOW_COPY_AND_ASSIGN(PeriodicGlobalDumpTimer);
-  };
-
   static const int kMaxConsecutiveFailuresCount;
   static const char* const kSystemAllocatorPoolName;
 
   MemoryDumpManager();
   ~MemoryDumpManager() override;
 
   static void SetInstanceForTesting(MemoryDumpManager* instance);
   static void FinalizeDumpAndAddToTrace(
       std::unique_ptr<ProcessMemoryDumpAsyncState> pmd_async_state);
 
@@ skipping 16 matching lines @@
   // Invokes OnMemoryDump() of the next MDP and calls SetupNextMemoryDump() at
   // the end to continue the ProcessMemoryDump. Should be called on the MDP task
   // runner.
   void InvokeOnMemoryDump(ProcessMemoryDumpAsyncState* owned_pmd_async_state);
 
   // Records a quick total memory usage in |memory_total|. This is used to track
   // and detect peaks in the memory usage of the process without having to
   // record all data from dump providers. This value is approximate to trade-off
   // speed, and not consistent with the rest of the memory-infra metrics. Must
   // be called on the dump thread.
-  void PollFastMemoryTotal(uint64_t* memory_total);
+  // Returns true if |memory_total| was updated by polling at least 1 MDP.
+  bool PollFastMemoryTotal(uint64_t* memory_total);
 
   // Helper for RegierDumpProvider* functions.
   void RegisterDumpProviderInternal(
       MemoryDumpProvider* mdp,
       const char* name,
       scoped_refptr<SequencedTaskRunner> task_runner,
       const MemoryDumpProvider::Options& options);
 
   // Helper for the public UnregisterDumpProvider* functions.
   void UnregisterDumpProviderInternal(MemoryDumpProvider* mdp,
@@ skipping 12 matching lines @@
 
   // A copy of mdpinfo list that support polling. It must be accessed only on
   // the dump thread if dump thread exists.
   MemoryDumpProviderInfo::OrderedSet dump_providers_for_polling_;
 
   // Shared among all the PMDs to keep state scoped to the tracing session.
   scoped_refptr<MemoryDumpSessionState> session_state_;
 
   MemoryDumpManagerDelegate* delegate_;  // Not owned.
 
-  // When true, this instance is in charge of coordinating periodic dumps.
-  bool is_coordinator_;
-
   // Protects from concurrent accesses to the |dump_providers_*| and |delegate_|
   // to guard against disabling logging while dumping on another thread.
   Lock lock_;
 
   // Optimization to avoid attempting any memory dump (i.e. to not walk an empty
   // dump_providers_enabled_ list) when tracing is not enabled.
   subtle::AtomicWord memory_tracing_enabled_;
 
-  // For time-triggered periodic dumps.
-  PeriodicGlobalDumpTimer periodic_dump_timer_;
+  // For triggering memory dumps.
+  std::unique_ptr<MemoryDumpTrigger> dump_trigger_;
 
   // Thread used for MemoryDumpProviders which don't specify a task runner
   // affinity.
   std::unique_ptr<Thread> dump_thread_;
 
   // The unique id of the child process. This is created only for tracing and is
   // expected to be valid only when tracing is enabled.
   uint64_t tracing_process_id_;
 
   // When true, calling |RegisterMemoryDumpProvider| is a no-op.
@@ skipping 26 matching lines @@
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MemoryDumpManagerDelegate);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_MEMORY_DUMP_MANAGER_H_