Android should be able to discard CachedResources

Source/core/platform/mac/PurgeableBufferMac.cpp

Index: Source/core/platform/mac/PurgeableBufferMac.cpp
diff --git a/Source/core/platform/mac/PurgeableBufferMac.cpp b/Source/core/platform/mac/PurgeableBufferMac.cpp
deleted file mode 100644
index 597f70f250a6248ecbd29c5d8ad63aa3d73652b0..0000000000000000000000000000000000000000
--- a/Source/core/platform/mac/PurgeableBufferMac.cpp
+++ /dev/null
@@ -1,150 +0,0 @@
-/*
- * Copyright (C) 2008 Apple Inc. All Rights Reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
- */
-
-#include "config.h"
-
-#if ENABLE(PURGEABLE_MEMORY)
-
-#include "core/platform/PurgeableBuffer.h"
-
-#include <mach/mach.h>
-#include <wtf/Assertions.h>
-#include <wtf/VMTags.h>
-
-namespace WebCore {
-
-// Purgeable buffers are allocated in multiples of the page size (4KB in common CPUs) so
-// it does not make sense for very small buffers. Set our minimum size to 16KB.
-static const size_t minPurgeableBufferSize = 4 * 4096;
-
-PurgeableBuffer::PurgeableBuffer(char* data, size_t size)
-    : m_data(data)
-    , m_size(size)
-    , m_purgePriority(PurgeDefault)
-    , m_state(NonVolatile)
-{
-}
-
-PurgeableBuffer::~PurgeableBuffer()
-{
-    vm_deallocate(mach_task_self(), reinterpret_cast<vm_address_t>(m_data), m_size);
-}
-
-PassOwnPtr<PurgeableBuffer> PurgeableBuffer::create(const char* data, size_t size)
-{
-    if (size < minPurgeableBufferSize)
-        return nullptr;
-
-    vm_address_t buffer = 0;
-    kern_return_t ret = vm_allocate(mach_task_self(), &buffer, size, VM_FLAGS_PURGABLE | VM_FLAGS_ANYWHERE | VM_TAG_FOR_WEBCORE_PURGEABLE_MEMORY);
-
-    ASSERT(ret == KERN_SUCCESS);
-    if (ret != KERN_SUCCESS)
-        return nullptr;
-
-    memcpy(reinterpret_cast<char*>(buffer), data, size);
-
-    return adoptPtr(new PurgeableBuffer(reinterpret_cast<char*>(buffer), size));
-}
-
-bool PurgeableBuffer::makePurgeable(bool purgeable)
-{
-    if (purgeable) {
-        if (m_state != NonVolatile)
-            return true;
-
-        int volatileGroup;
-        if (m_purgePriority == PurgeFirst)
-            volatileGroup = VM_VOLATILE_GROUP_0;
-        else if (m_purgePriority == PurgeMiddle)
-            volatileGroup = VM_VOLATILE_GROUP_4;
-        else
-            volatileGroup = VM_VOLATILE_GROUP_7;
-        
-        int state = VM_PURGABLE_VOLATILE | volatileGroup;
-        // So apparently "purgeable" is the correct spelling and the API here is misspelled.
-        kern_return_t ret = vm_purgable_control(mach_task_self(), reinterpret_cast<vm_address_t>(m_data), VM_PURGABLE_SET_STATE, &state);
-        
-        if (ret != KERN_SUCCESS) {
-            // If that failed we have no clue what state we are in so assume purged.
-            m_state = Purged;
-            return true;
-        }
-        
-        m_state = Volatile;
-        return true;
-    }
-
-    if (m_state == NonVolatile)
-        return true;
-    if (m_state == Purged)
-        return false;
-    
-    int state = VM_PURGABLE_NONVOLATILE;
-    kern_return_t ret = vm_purgable_control(mach_task_self(), reinterpret_cast<vm_address_t>(m_data), VM_PURGABLE_SET_STATE, &state);
-
-    if (ret != KERN_SUCCESS) {
-        // If that failed we have no clue what state we are in so assume purged.
-        m_state = Purged;
-        return false;
-    }
-
-    m_state = state & VM_PURGABLE_EMPTY ? Purged : NonVolatile;
-    return m_state == NonVolatile;
-}
-    
-bool PurgeableBuffer::wasPurged() const
-{
-    if (m_state == NonVolatile)
-        return false;
-    if (m_state == Purged)
-        return true;
-
-    int state;
-    kern_return_t ret = vm_purgable_control(mach_task_self(), reinterpret_cast<vm_address_t>(m_data), VM_PURGABLE_GET_STATE, &state);
-
-    if (ret != KERN_SUCCESS) {
-        // If that failed we have no clue what state we are in so assume purged.
-        m_state = Purged;
-        return true;        
-    }
-
-    if (state & VM_PURGABLE_EMPTY) {
-        m_state = Purged;
-        return true;
-    }
-        
-    return false;
-}
-
-const char* PurgeableBuffer::data() const
-{
-    ASSERT(m_state == NonVolatile);
-    return m_data;
-}
-    
-}
-
-#endif