base/memory/memory_pressure_monitor_mac.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 BASE_MEMORY_MEMORY_PRESSURE_MONITOR_MAC_H_
   6 #define BASE_MEMORY_MEMORY_PRESSURE_MONITOR_MAC_H_
   7
   8 #include <dispatch/dispatch.h>
   9
  10 #include "base/base_export.h"
  11 #include "base/memory/memory_pressure_listener.h"
  12 #include "base/memory/memory_pressure_monitor.h"
  13
  14 // The following was added to <dispatch/source.h> after 10.8.
  15 // TODO(shrike): Remove the DISPATCH_MEMORYPRESSURE_NORMAL ifndef once builders
  16 // reach 10.9 or higher.
  17 #ifndef DISPATCH_MEMORYPRESSURE_NORMAL
  18
  19 #define DISPATCH_MEMORYPRESSURE_NORMAL    0x01
  20 #define DISPATCH_MEMORYPRESSURE_WARN      0x02
  21 #define DISPATCH_MEMORYPRESSURE_CRITICAL  0x04
  22
  23 #endif  // DISPATCH_MEMORYPRESSURE_NORMAL
  24
  25 namespace base {
  26 namespace mac {
  27
  28 class TestMemoryPressureMonitor;
  29
  30 struct DispatchSourceSDeleter {
  31   void operator()(dispatch_source_s* ptr) {
  32     dispatch_source_cancel(ptr);
  33     dispatch_release(ptr);
  34   }
  35 };
  36
  37 // Declares the interface for the Mac MemoryPressureMonitor, which reports
  38 // memory pressure events and status.
  39 class BASE_EXPORT MemoryPressureMonitor : public base::MemoryPressureMonitor {
  40  public:
  41   MemoryPressureMonitor();
  42   ~MemoryPressureMonitor() override;
  43
  44   // Returns the currently-observed memory pressure.
  45   MemoryPressureLevel GetCurrentPressureLevel() const override;
  46
  47  private:
  48   friend TestMemoryPressureMonitor;
  49
  50   static MemoryPressureLevel
  51       MemoryPressureLevelForMacMemoryPressure(int mac_memory_pressure);
  52   static void NotifyMemoryPressureChanged(dispatch_source_s* event_source);
  53
  54   scoped_ptr<dispatch_source_s, DispatchSourceSDeleter>
  55       memory_level_event_source_;
  56
  57   DISALLOW_COPY_AND_ASSIGN(MemoryPressureMonitor);
  58 };
  59
  60 }  // namespace mac
  61 }  // namespace base
  62
  63 #endif  // BASE_MEMORY_MEMORY_PRESSURE_MONITOR_MAC_H_