1 /*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SkPurgeableMemoryBlock.h"
9
10 #include <mach/mach.h>
11
IsSupported()12 bool SkPurgeableMemoryBlock::IsSupported() {
13 return true;
14 }
15
16 #ifdef SK_DEBUG
PlatformSupportsPurgingAllUnpinnedBlocks()17 bool SkPurgeableMemoryBlock::PlatformSupportsPurgingAllUnpinnedBlocks() {
18 return true;
19 }
20
PurgeAllUnpinnedBlocks()21 bool SkPurgeableMemoryBlock::PurgeAllUnpinnedBlocks() {
22 // Unused.
23 int state = 0;
24 kern_return_t ret = vm_purgable_control(mach_task_self(), 0, VM_PURGABLE_PURGE_ALL, &state);
25 return ret == KERN_SUCCESS;
26 }
27
purge()28 bool SkPurgeableMemoryBlock::purge() {
29 return false;
30 }
31 #endif
32
round_to_page_size(size_t size)33 static size_t round_to_page_size(size_t size) {
34 const size_t mask = 4096 - 1;
35 return (size + mask) & ~mask;
36 }
37
SkPurgeableMemoryBlock(size_t size)38 SkPurgeableMemoryBlock::SkPurgeableMemoryBlock(size_t size)
39 : fAddr(NULL)
40 , fSize(round_to_page_size(size))
41 , fPinned(false) {
42 }
43
~SkPurgeableMemoryBlock()44 SkPurgeableMemoryBlock::~SkPurgeableMemoryBlock() {
45 SkDEBUGCODE(kern_return_t ret =) vm_deallocate(mach_task_self(),
46 reinterpret_cast<vm_address_t>(fAddr),
47 static_cast<vm_size_t>(fSize));
48 #ifdef SK_DEBUG
49 if (ret != KERN_SUCCESS) {
50 SkDebugf("SkPurgeableMemoryBlock destructor failed to deallocate.\n");
51 }
52 #endif
53 }
54
pin(SkPurgeableMemoryBlock::PinResult * pinResult)55 void* SkPurgeableMemoryBlock::pin(SkPurgeableMemoryBlock::PinResult* pinResult) {
56 SkASSERT(!fPinned);
57 SkASSERT(pinResult != NULL);
58 if (NULL == fAddr) {
59 vm_address_t addr = 0;
60 kern_return_t ret = vm_allocate(mach_task_self(), &addr, static_cast<vm_size_t>(fSize),
61 VM_FLAGS_PURGABLE | VM_FLAGS_ANYWHERE);
62 if (KERN_SUCCESS == ret) {
63 fAddr = reinterpret_cast<void*>(addr);
64 *pinResult = kUninitialized_PinResult;
65 fPinned = true;
66 } else {
67 fAddr = NULL;
68 }
69 } else {
70 int state = VM_PURGABLE_NONVOLATILE;
71 kern_return_t ret = vm_purgable_control(mach_task_self(),
72 reinterpret_cast<vm_address_t>(fAddr),
73 VM_PURGABLE_SET_STATE, &state);
74 if (ret != KERN_SUCCESS) {
75 fAddr = NULL;
76 fPinned = false;
77 return NULL;
78 }
79
80 fPinned = true;
81
82 if (state & VM_PURGABLE_EMPTY) {
83 *pinResult = kUninitialized_PinResult;
84 } else {
85 *pinResult = kRetained_PinResult;
86 }
87 }
88 return fAddr;
89 }
90
unpin()91 void SkPurgeableMemoryBlock::unpin() {
92 SkASSERT(fPinned);
93 int state = VM_PURGABLE_VOLATILE | VM_VOLATILE_GROUP_DEFAULT;
94 SkDEBUGCODE(kern_return_t ret =) vm_purgable_control(mach_task_self(),
95 reinterpret_cast<vm_address_t>(fAddr),
96 VM_PURGABLE_SET_STATE, &state);
97 fPinned = false;
98
99 #ifdef SK_DEBUG
100 if (ret != KERN_SUCCESS) {
101 SkDebugf("SkPurgeableMemoryBlock::unpin() failed.\n");
102 }
103 #endif
104 }
105