Purge SkPurgeableMemoryBlock.

src/ports/SkPurgeableMemoryBlock_mac.cpp

-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkPurgeableMemoryBlock.h"
-
-#include <mach/mach.h>
-
-bool SkPurgeableMemoryBlock::IsSupported() {
-    return true;
-}
-
-#ifdef SK_DEBUG
-bool SkPurgeableMemoryBlock::PlatformSupportsPurgingAllUnpinnedBlocks() {
-    return true;
-}
-
-bool SkPurgeableMemoryBlock::PurgeAllUnpinnedBlocks() {
-    // Unused.
-    int state = 0;
-    kern_return_t ret = vm_purgable_control(mach_task_self(), 0, VM_PURGABLE_PURGE_ALL, &state);
-    return ret == KERN_SUCCESS;
-}
-
-bool SkPurgeableMemoryBlock::purge() {
-    return false;
-}
-#endif
-
-static size_t round_to_page_size(size_t size) {
-    const size_t mask = 4096 - 1;
-    return (size + mask) & ~mask;
-}
-
-SkPurgeableMemoryBlock::SkPurgeableMemoryBlock(size_t size)
-    : fAddr(NULL)
-    , fSize(round_to_page_size(size))
-    , fPinned(false) {
-}
-
-SkPurgeableMemoryBlock::~SkPurgeableMemoryBlock() {
-    SkDEBUGCODE(kern_return_t ret =) vm_deallocate(mach_task_self(),
-                                                   reinterpret_cast<vm_address_t>(fAddr),
-                                                   static_cast<vm_size_t>(fSize));
-#ifdef SK_DEBUG
-    if (ret != KERN_SUCCESS) {
-        SkDebugf("SkPurgeableMemoryBlock destructor failed to deallocate.\n");
-    }
-#endif
-}
-
-void* SkPurgeableMemoryBlock::pin(SkPurgeableMemoryBlock::PinResult* pinResult) {
-    SkASSERT(!fPinned);
-    SkASSERT(pinResult != NULL);
-    if (NULL == fAddr) {
-        vm_address_t addr = 0;
-        kern_return_t ret = vm_allocate(mach_task_self(), &addr, static_cast<vm_size_t>(fSize),
-                                        VM_FLAGS_PURGABLE | VM_FLAGS_ANYWHERE);
-        if (KERN_SUCCESS == ret) {
-            fAddr = reinterpret_cast<void*>(addr);
-            *pinResult = kUninitialized_PinResult;
-            fPinned = true;
-        } else {
-            fAddr = NULL;
-        }
-    } else {
-        int state = VM_PURGABLE_NONVOLATILE;
-        kern_return_t ret = vm_purgable_control(mach_task_self(),
-                                                reinterpret_cast<vm_address_t>(fAddr),
-                                                VM_PURGABLE_SET_STATE, &state);
-        if (ret != KERN_SUCCESS) {
-            fAddr = NULL;
-            fPinned = false;
-            return NULL;
-        }
-
-        fPinned = true;
-
-        if (state & VM_PURGABLE_EMPTY) {
-            *pinResult = kUninitialized_PinResult;
-        } else {
-            *pinResult = kRetained_PinResult;
-        }
-    }
-    return fAddr;
-}
-
-void SkPurgeableMemoryBlock::unpin() {
-    SkASSERT(fPinned);
-    int state = VM_PURGABLE_VOLATILE | VM_VOLATILE_GROUP_DEFAULT;
-    SkDEBUGCODE(kern_return_t ret =) vm_purgable_control(mach_task_self(),
-                                                         reinterpret_cast<vm_address_t>(fAddr),
-                                                         VM_PURGABLE_SET_STATE, &state);
-    fPinned = false;
-
-#ifdef SK_DEBUG
-    if (ret != KERN_SUCCESS) {
-        SkDebugf("SkPurgeableMemoryBlock::unpin() failed.\n");
-    }
-#endif
-}