1 // Copyright 2019 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_MADV_FREE_DISCARDABLE_MEMORY_ALLOCATOR_POSIX_H_ 6 #define BASE_MEMORY_MADV_FREE_DISCARDABLE_MEMORY_ALLOCATOR_POSIX_H_ 7 8 #include <stddef.h> 9 10 #include <atomic> 11 #include <memory> 12 13 #include "base/base_export.h" 14 #include "base/bind.h" 15 #include "base/callback.h" 16 #include "base/macros.h" 17 #include "base/memory/discardable_memory.h" 18 #include "base/memory/discardable_memory_allocator.h" 19 #include "base/memory/madv_free_discardable_memory_posix.h" 20 #include "base/trace_event/base_tracing.h" 21 #include "build/build_config.h" 22 23 namespace base { 24 class BASE_EXPORT MadvFreeDiscardableMemoryAllocatorPosix 25 : public DiscardableMemoryAllocator, 26 public base::trace_event::MemoryDumpProvider { 27 public: 28 MadvFreeDiscardableMemoryAllocatorPosix(); 29 ~MadvFreeDiscardableMemoryAllocatorPosix() override; 30 31 std::unique_ptr<DiscardableMemory> AllocateLockedDiscardableMemory( 32 size_t size) override; 33 34 size_t GetBytesAllocated() const override; 35 ReleaseFreeMemory()36 void ReleaseFreeMemory() override { 37 // Do nothing, since MADV_FREE discardable memory does not keep any memory 38 // overhead that can be released. 39 } 40 41 bool OnMemoryDump(const trace_event::MemoryDumpArgs& args, 42 trace_event::ProcessMemoryDump* pmd) override; 43 44 private: 45 std::atomic<size_t> bytes_allocated_{0}; 46 47 DISALLOW_COPY_AND_ASSIGN(MadvFreeDiscardableMemoryAllocatorPosix); 48 }; 49 } // namespace base 50 51 #endif // BASE_MEMORY_MADV_FREE_DISCARDABLE_MEMORY_ALLOCATOR_POSIX_H_ 52