base: Add soft memory limit to DiscardableMemoryManager.

base/memory/discardable_memory_mac.cc

 // Copyright (c) 2013 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.
 
 #include "base/memory/discardable_memory.h"
 
 #include <mach/mach.h>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/mac/mach_logging.h"
 #include "base/mac/scoped_mach_vm.h"
 #include "base/memory/discardable_memory_emulated.h"
 #include "base/memory/discardable_memory_malloc.h"
 #include "base/memory/discardable_memory_manager.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace base {
 namespace {
 
 // For Mac, have the DiscardableMemoryManager trigger userspace eviction when
 // address space usage gets too high (e.g. 512 MBytes).
 const size_t kMacMemoryLimit = 512 * 1024 * 1024;
 
 struct SharedState {
-  SharedState() : manager(kMacMemoryLimit, kMacMemoryLimit) {}
+  SharedState()
+      : manager(kMacMemoryLimit,
+                kMacMemoryLimit,
+                kMacMemoryLimit,
+                TimeDelta::Max()) {}
 
   internal::DiscardableMemoryManager manager;
 };
 LazyInstance<SharedState>::Leaky g_shared_state = LAZY_INSTANCE_INITIALIZER;
 
 // The VM subsystem allows tagging of memory and 240-255 is reserved for
 // application use (see mach/vm_statistics.h). Pick 252 (after chromium's atomic
 // weight of ~52).
 const int kDiscardableMemoryTag = VM_MAKE_TAG(252);
 
@@ skipping 120 matching lines @@
 void DiscardableMemory::RegisterMemoryPressureListeners() {
   internal::DiscardableMemoryEmulated::RegisterMemoryPressureListeners();
 }
 
 // static
 void DiscardableMemory::UnregisterMemoryPressureListeners() {
   internal::DiscardableMemoryEmulated::UnregisterMemoryPressureListeners();
 }
 
 // static
+bool DiscardableMemory::ReduceMemoryUsage() {
+  return internal::DiscardableMemoryEmulated::ReduceMemoryUsage();
+}
+
+// static
 void DiscardableMemory::GetSupportedTypes(
     std::vector<DiscardableMemoryType>* types) {
   const DiscardableMemoryType supported_types[] = {
     DISCARDABLE_MEMORY_TYPE_MAC,
     DISCARDABLE_MEMORY_TYPE_EMULATED,
     DISCARDABLE_MEMORY_TYPE_MALLOC
   };
   types->assign(supported_types, supported_types + arraysize(supported_types));
 }
 
@@ skipping 34 matching lines @@
 }
 
 // static
 void DiscardableMemory::PurgeForTesting() {
   int state = 0;
   vm_purgable_control(mach_task_self(), 0, VM_PURGABLE_PURGE_ALL, &state);
   internal::DiscardableMemoryEmulated::PurgeForTesting();
 }
 
 }  // namespace base