| // Copyright (c) 2016 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 CONTENT_BROWSER_MEMORY_BROWSER_MEMORY_MONITOR_WIN_H_ |
| #define CONTENT_BROWSER_MEMORY_BROWSER_MEMORY_MONITOR_WIN_H_ |
| |
| #include "content/browser/memory/memory_monitor.h" |
| |
| namespace base { |
| struct SystemMemoryInfoKB; |
| } // namespace base |
| |
| namespace content { |
| |
| // A memory monitor for the Windows platform. After much experimentation this |
| // class uses a very simple heuristic to anticipate paging (critical memory |
| // pressure). When the amount of memory available dips below a provided |
| // threshold, it is assumed that paging is inevitable. |
| class CONTENT_EXPORT MemoryMonitorWin : public MemoryMonitor { |
| public: |
| // Default constants governing the amount of free memory that the memory |
| // manager attempts to maintain. |
| static const int kLargeMemoryThresholdMB; |
| static const int kSmallMemoryTargetFreeMB; |
| static const int kLargeMemoryTargetFreeMB; |
| |
| MemoryMonitorWin(MemoryMonitorDelegate* delegate, int target_free_mb); |
| ~MemoryMonitorWin() override {} |
| |
| // MemoryMonitor: |
| int GetFreeMemoryUntilCriticalMB() override; |
| |
| // Returns the current free memory target. |
| int target_free_mb() const { return target_free_mb_; } |
| |
| // Factory function. Automatically sizes |target_free_mb| based on the |
| // system. |
| static std::unique_ptr<MemoryMonitorWin> Create( |
| MemoryMonitorDelegate* delegate); |
| |
| protected: |
| // Determines if the system is in large memory mode. Exposed so that this |
| // function can be tested. |
| static bool IsLargeMemory(MemoryMonitorDelegate* delegate); |
| |
| // Determines the default target free MB value. Exposed so that this function |
| // can be tested. |
| static int GetTargetFreeMB(MemoryMonitorDelegate* delegate); |
| |
| private: |
| // The delegate to be used for retrieving system memory information. Used as a |
| // testing seam. |
| MemoryMonitorDelegate* delegate_; |
| |
| // The amount of memory that the memory manager (MM) attempts to keep in a |
| // free state. When less than this amount of physical memory is free, it is |
| // assumed that the MM will start paging things out. |
| int target_free_mb_; |
| }; |
| |
| // A delegate that wraps functions used by MemoryMonitorWin. Used as a testing |
| // seam. |
| class CONTENT_EXPORT MemoryMonitorWinDelegate { |
| public: |
| MemoryMonitorWinDelegate() {} |
| virtual ~MemoryMonitorWinDelegate() {} |
| |
| // Returns system memory information. |
| virtual void GetSystemMemoryInfo(base::SystemMemoryInfoKB* mem_info) = 0; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(MemoryMonitorWinDelegate); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_BROWSER_MEMORY_BROWSER_MEMORY_MONITOR_WIN_H_ |