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 // When ashmem is used, have the DiscardableMemoryManager trigger userspace
  23 // eviction when address space usage gets too high (e.g. 512 MBytes).
  24 const size_t kAshmemMaxAddressSpaceUsage = 512 * 1024 * 1024;
  25
  26 // Holds the state used for ashmem allocations.
  27 struct AshmemGlobalContext {
  28   AshmemGlobalContext()
  29       : allocator(kAshmemAllocatorName,
  30                   GetOptimalAshmemRegionSizeForAllocator()) {
  31     manager.SetMemoryLimit(kAshmemMaxAddressSpaceUsage);
  32   }
  33
  34   internal::DiscardableMemoryAshmemAllocator allocator;
  35   internal::DiscardableMemoryManager manager;
  36
  37  private:
  38   // Returns 64 MBytes for a 512 MBytes device, 128 MBytes for 1024 MBytes...
  39   static size_t GetOptimalAshmemRegionSizeForAllocator() {
  40     // Note that this may do some I/O (without hitting the disk though) so it
  41     // should not be called on the critical path.
  42     return base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8;
  43   }
  44 };
  45
  46 LazyInstance<AshmemGlobalContext>::Leaky g_context = LAZY_INSTANCE_INITIALIZER;
  47
  48 }  // namespace
  49
  50 // static
  51 void DiscardableMemory::RegisterMemoryPressureListeners() {
  52   internal::DiscardableMemoryEmulated::RegisterMemoryPressureListeners();
  53 }
  54
  55 // static
  56 void DiscardableMemory::UnregisterMemoryPressureListeners() {
  57   internal::DiscardableMemoryEmulated::UnregisterMemoryPressureListeners();
  58 }
  59
  60 // static
  61 void DiscardableMemory::GetSupportedTypes(
  62     std::vector<DiscardableMemoryType>* types) {
  63   const DiscardableMemoryType supported_types[] = {
  64     DISCARDABLE_MEMORY_TYPE_ASHMEM,
  65     DISCARDABLE_MEMORY_TYPE_EMULATED,
  66     DISCARDABLE_MEMORY_TYPE_MALLOC
  67   };
  68   types->assign(supported_types, supported_types + arraysize(supported_types));
  69 }
  70
  71 // static
  72 scoped_ptr<DiscardableMemory> DiscardableMemory::CreateLockedMemoryWithType(
  73     DiscardableMemoryType type, size_t size) {
  74   switch (type) {
  75     case DISCARDABLE_MEMORY_TYPE_NONE:
  76     case DISCARDABLE_MEMORY_TYPE_MAC:
  77       return scoped_ptr<DiscardableMemory>();
  78     case DISCARDABLE_MEMORY_TYPE_ASHMEM: {
  79       AshmemGlobalContext* const global_context = g_context.Pointer();
  80       scoped_ptr<internal::DiscardableMemoryAshmem> memory(
  81           new internal::DiscardableMemoryAshmem(
  82               size, &global_context->allocator, &global_context->manager));
  83       if (!memory->Initialize())
  84         return scoped_ptr<DiscardableMemory>();
  85
  86       return memory.PassAs<DiscardableMemory>();
  87     }
  88     case DISCARDABLE_MEMORY_TYPE_EMULATED: {
  89       scoped_ptr<internal::DiscardableMemoryEmulated> memory(
  90           new internal::DiscardableMemoryEmulated(size));
  91       if (!memory->Initialize())
  92         return scoped_ptr<DiscardableMemory>();
  93
  94       return memory.PassAs<DiscardableMemory>();
  95     }
  96     case DISCARDABLE_MEMORY_TYPE_MALLOC: {
  97       scoped_ptr<internal::DiscardableMemoryMalloc> memory(
  98           new internal::DiscardableMemoryMalloc(size));
  99       if (!memory->Initialize())
 100         return scoped_ptr<DiscardableMemory>();
 101
 102       return memory.PassAs<DiscardableMemory>();
 103     }
 104   }
 105
 106   NOTREACHED();
 107   return scoped_ptr<DiscardableMemory>();
 108 }
 109
 110 // static
 111 void DiscardableMemory::PurgeForTesting() {
 112   g_context.Pointer()->manager.PurgeAll();
 113   internal::DiscardableMemoryEmulated::PurgeForTesting();
 114 }
 115
 116 }  // namespace base