src/base/memory/discardable_memory_android.cc

   1 // Copyright (c) 2013 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 #include "base/memory/discardable_memory.h"
   6
   7 #include "base/android/sys_utils.h"
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/logging.h"
  12 #include "base/memory/discardable_memory_ashmem.h"
  13 #include "base/memory/discardable_memory_ashmem_allocator.h"
  14 #include "base/memory/discardable_memory_emulated.h"
  15 #include "base/memory/discardable_memory_malloc.h"
  16
  17 namespace base {
  18 namespace {
  19
  20 const char kAshmemAllocatorName[] = "DiscardableMemoryAshmemAllocator";
  21
  22 // For Ashmem, have the DiscardableMemoryManager trigger userspace eviction
  23 // when address space usage gets too high (e.g. 512 MBytes).
  24 const size_t kAshmemMemoryLimit = 512 * 1024 * 1024;
  25
  26 size_t GetOptimalAshmemRegionSizeForAllocator() {
  27   // Note that this may do some I/O (without hitting the disk though) so it
  28   // should not be called on the critical path.
  29   return base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8;
  30 }
  31
  32 // Holds the shared state used for allocations.
  33 struct SharedState {
  34   SharedState()
  35       : manager(kAshmemMemoryLimit, kAshmemMemoryLimit),
  36         allocator(kAshmemAllocatorName,
  37                   GetOptimalAshmemRegionSizeForAllocator()) {}
  38
  39   internal::DiscardableMemoryManager manager;
  40   internal::DiscardableMemoryAshmemAllocator allocator;
  41 };
  42 LazyInstance<SharedState>::Leaky g_shared_state = LAZY_INSTANCE_INITIALIZER;
  43
  44 }  // namespace
  45
  46 // static
  47 void DiscardableMemory::RegisterMemoryPressureListeners() {
  48   internal::DiscardableMemoryEmulated::RegisterMemoryPressureListeners();
  49 }
  50
  51 // static
  52 void DiscardableMemory::UnregisterMemoryPressureListeners() {
  53   internal::DiscardableMemoryEmulated::UnregisterMemoryPressureListeners();
  54 }
  55
  56 // static
  57 void DiscardableMemory::GetSupportedTypes(
  58     std::vector<DiscardableMemoryType>* types) {
  59   const DiscardableMemoryType supported_types[] = {
  60     DISCARDABLE_MEMORY_TYPE_ASHMEM,
  61     DISCARDABLE_MEMORY_TYPE_EMULATED,
  62     DISCARDABLE_MEMORY_TYPE_MALLOC
  63   };
  64   types->assign(supported_types, supported_types + arraysize(supported_types));
  65 }
  66
  67 // static
  68 scoped_ptr<DiscardableMemory> DiscardableMemory::CreateLockedMemoryWithType(
  69     DiscardableMemoryType type, size_t size) {
  70   switch (type) {
  71     case DISCARDABLE_MEMORY_TYPE_NONE:
  72     case DISCARDABLE_MEMORY_TYPE_MAC:
  73       return scoped_ptr<DiscardableMemory>();
  74     case DISCARDABLE_MEMORY_TYPE_ASHMEM: {
  75       SharedState* const shared_state = g_shared_state.Pointer();
  76       scoped_ptr<internal::DiscardableMemoryAshmem> memory(
  77           new internal::DiscardableMemoryAshmem(
  78               size, &shared_state->allocator, &shared_state->manager));
  79       if (!memory->Initialize())
  80         return scoped_ptr<DiscardableMemory>();
  81
  82       return memory.PassAs<DiscardableMemory>();
  83     }
  84     case DISCARDABLE_MEMORY_TYPE_EMULATED: {
  85       scoped_ptr<internal::DiscardableMemoryEmulated> memory(
  86           new internal::DiscardableMemoryEmulated(size));
  87       if (!memory->Initialize())
  88         return scoped_ptr<DiscardableMemory>();
  89
  90       return memory.PassAs<DiscardableMemory>();
  91     }
  92     case DISCARDABLE_MEMORY_TYPE_MALLOC: {
  93       scoped_ptr<internal::DiscardableMemoryMalloc> memory(
  94           new internal::DiscardableMemoryMalloc(size));
  95       if (!memory->Initialize())
  96         return scoped_ptr<DiscardableMemory>();
  97
  98       return memory.PassAs<DiscardableMemory>();
  99     }
 100   }
 101
 102   NOTREACHED();
 103   return scoped_ptr<DiscardableMemory>();
 104 }
 105
 106 // static
 107 void DiscardableMemory::PurgeForTesting() {
 108   g_shared_state.Pointer()->manager.PurgeAll();
 109   internal::DiscardableMemoryEmulated::PurgeForTesting();
 110 }
 111
 112 }  // namespace base