ipc/glue/IdleSchedulerParent.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_ipc_IdleSchedulerParent_h__
   8 #define mozilla_ipc_IdleSchedulerParent_h__
   9
  10 #include "mozilla/Assertions.h"
  11 #include "mozilla/Atomics.h"
  12 #include "mozilla/Attributes.h"
  13 #include "mozilla/LinkedList.h"
  14 #include "mozilla/ipc/PIdleSchedulerParent.h"
  15 #include "base/shared_memory.h"
  16 #include <bitset>
  17
  18 #define NS_IDLE_SCHEDULER_COUNTER_ARRAY_LENGHT 1024
  19 #define NS_IDLE_SCHEDULER_INDEX_OF_ACTIVITY_COUNTER 0
  20 #define NS_IDLE_SCHEDULER_INDEX_OF_CPU_COUNTER 1
  21
  22 class nsITimer;
  23
  24 namespace mozilla {
  25
  26 namespace ipc {
  27
  28 class BackgroundParentImpl;
  29
  30 class IdleSchedulerParent final
  31     : public PIdleSchedulerParent,
  32       public LinkedListElement<IdleSchedulerParent> {
  33  public:
  34   NS_INLINE_DECL_REFCOUNTING(IdleSchedulerParent)
  35
  36   IPCResult RecvInitForIdleUse(InitForIdleUseResolver&& aResolve);
  37   IPCResult RecvRequestIdleTime(uint64_t aId, TimeDuration aBudget);
  38   IPCResult RecvIdleTimeUsed(uint64_t aId);
  39   IPCResult RecvSchedule();
  40   IPCResult RecvRunningPrioritizedOperation();
  41   IPCResult RecvPrioritizedOperationDone();
  42   IPCResult RecvRequestGC(RequestGCResolver&& aResolve);
  43   IPCResult RecvStartedGC();
  44   IPCResult RecvDoneGC();
  45
  46  private:
  47   friend class BackgroundParentImpl;
  48   IdleSchedulerParent();
  49   ~IdleSchedulerParent();
  50
  51   static void CalculateNumIdleTasks();
  52
  53   static int32_t ActiveCount();
  54   static void Schedule(IdleSchedulerParent* aRequester);
  55   static bool HasSpareCycles(int32_t aActiveCount);
  56   static bool HasSpareGCCycles();
  57   using PIdleSchedulerParent::SendIdleTime;
  58   void SendIdleTime();
  59   void SendMayGC();
  60
  61   static void EnsureStarvationTimer();
  62   static void StarvationCallback(nsITimer* aTimer, void* aData);
  63
  64   uint64_t mCurrentRequestId = 0;
  65   // For now we don't really use idle budget for scheduling.  Zero if the
  66   // process isn't requestiong or running an idle task.
  67   TimeDuration mRequestedIdleBudget;
  68
  69   // Counting all the prioritized operations the process is doing.
  70   uint32_t mRunningPrioritizedOperation = 0;
  71
  72   // Only one of these may be true at a time, giving three states:
  73   // No active GC request, A pending GC request, or a granted GC request.
  74   Maybe<RequestGCResolver> mRequestingGC;
  75   bool mDoingGC = false;
  76
  77   uint32_t mChildId = 0;
  78
  79   // Current state, only one of these may be true at a time.
  80   bool IsWaitingForIdle() const { return isInList() && mRequestedIdleBudget; }
  81   bool IsDoingIdleTask() const { return !isInList() && mRequestedIdleBudget; }
  82   bool IsNotDoingIdleTask() const { return !mRequestedIdleBudget; }
  83
  84   // Shared memory for counting how many child processes are running
  85   // tasks. This memory is shared across all the child processes.
  86   // The [0] is used for counting all the processes and
  87   // [childId] is for counting per process activity.
  88   // This way the global activity can be checked in a fast way by just looking
  89   // at [0] value.
  90   // [1] is used for cpu count for child processes.
  91   static base::SharedMemory* sActiveChildCounter;
  92   // A bit is set if there is a child with child Id as the offset.
  93   // The bit is used to check per child specific activity counters in
  94   // sActiveChildCounter.
  95   static std::bitset<NS_IDLE_SCHEDULER_COUNTER_ARRAY_LENGHT>
  96       sInUseChildCounters;
  97
  98   // Processes on this list have requested (but the request hasn't yet been
  99   // granted) idle time or to start a GC or both.
 100   //
 101   // Either or both their mRequestedIdleBudget or mRequestingGC fields are
 102   // non-zero.  Child processes not on this list have either been granted all
 103   // their requests not made a request ever or since they last finished an idle
 104   // or GC task.
 105   //
 106   // Use the methods above to determine a process' idle time state, or check the
 107   // mRequestingGC and mDoingGC fields for the GC state.
 108   static LinkedList<IdleSchedulerParent> sIdleAndGCRequests;
 109
 110   static int32_t sMaxConcurrentIdleTasksInChildProcesses;
 111   static uint32_t sMaxConcurrentGCs;
 112   static uint32_t sActiveGCs;
 113
 114   // Counting all the child processes which have at least one prioritized
 115   // operation.
 116   static uint32_t sChildProcessesRunningPrioritizedOperation;
 117
 118   // When this hits zero, it's time to free the shared memory and pack up.
 119   static uint32_t sChildProcessesAlive;
 120
 121   static nsITimer* sStarvationPreventer;
 122
 123   static uint32_t sNumCPUs;
 124   static uint32_t sPrefConcurrentGCsMax;
 125   static uint32_t sPrefConcurrentGCsCPUDivisor;
 126 };
 127
 128 }  // namespace ipc
 129 }  // namespace mozilla
 130
 131 #endif  // mozilla_ipc_IdleSchedulerParent_h__