reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2014 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 "SkCachedData.h" |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 9 | #include "SkDiscardableMemory.h" |
Herb Derby | b549cc3 | 2017-03-27 13:35:15 -0400 | [diff] [blame^] | 10 | #include "SkMalloc.h" |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 11 | |
| 12 | //#define TRACK_CACHEDDATA_LIFETIME |
| 13 | |
| 14 | #ifdef TRACK_CACHEDDATA_LIFETIME |
| 15 | static int32_t gCachedDataCounter; |
| 16 | |
| 17 | static void inc() { |
| 18 | int32_t oldCount = sk_atomic_inc(&gCachedDataCounter); |
| 19 | SkDebugf("SkCachedData inc %d\n", oldCount + 1); |
| 20 | } |
| 21 | |
| 22 | static void dec() { |
| 23 | int32_t oldCount = sk_atomic_dec(&gCachedDataCounter); |
| 24 | SkDebugf("SkCachedData dec %d\n", oldCount - 1); |
| 25 | } |
| 26 | #else |
| 27 | static void inc() {} |
| 28 | static void dec() {} |
| 29 | #endif |
| 30 | |
| 31 | SkCachedData::SkCachedData(void* data, size_t size) |
| 32 | : fData(data) |
| 33 | , fSize(size) |
| 34 | , fRefCnt(1) |
| 35 | , fStorageType(kMalloc_StorageType) |
| 36 | , fInCache(false) |
| 37 | , fIsLocked(true) |
| 38 | { |
| 39 | fStorage.fMalloc = data; |
| 40 | inc(); |
| 41 | } |
| 42 | |
| 43 | SkCachedData::SkCachedData(size_t size, SkDiscardableMemory* dm) |
| 44 | : fData(dm->data()) |
| 45 | , fSize(size) |
| 46 | , fRefCnt(1) |
| 47 | , fStorageType(kDiscardableMemory_StorageType) |
| 48 | , fInCache(false) |
| 49 | , fIsLocked(true) |
| 50 | { |
| 51 | fStorage.fDM = dm; |
| 52 | inc(); |
| 53 | } |
| 54 | |
| 55 | SkCachedData::~SkCachedData() { |
| 56 | switch (fStorageType) { |
| 57 | case kMalloc_StorageType: |
| 58 | sk_free(fStorage.fMalloc); |
| 59 | break; |
| 60 | case kDiscardableMemory_StorageType: |
halcanary | 385fe4d | 2015-08-26 13:07:48 -0700 | [diff] [blame] | 61 | delete fStorage.fDM; |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 62 | break; |
| 63 | } |
| 64 | dec(); |
| 65 | } |
| 66 | |
| 67 | class SkCachedData::AutoMutexWritable { |
| 68 | public: |
| 69 | AutoMutexWritable(const SkCachedData* cd) : fCD(const_cast<SkCachedData*>(cd)) { |
| 70 | fCD->fMutex.acquire(); |
| 71 | fCD->validate(); |
| 72 | } |
| 73 | ~AutoMutexWritable() { |
| 74 | fCD->validate(); |
| 75 | fCD->fMutex.release(); |
| 76 | } |
| 77 | |
| 78 | SkCachedData* get() { return fCD; } |
| 79 | SkCachedData* operator->() { return fCD; } |
| 80 | |
| 81 | private: |
| 82 | SkCachedData* fCD; |
| 83 | }; |
| 84 | |
| 85 | void SkCachedData::internalRef(bool fromCache) const { |
| 86 | AutoMutexWritable(this)->inMutexRef(fromCache); |
| 87 | } |
| 88 | |
| 89 | void SkCachedData::internalUnref(bool fromCache) const { |
| 90 | if (AutoMutexWritable(this)->inMutexUnref(fromCache)) { |
| 91 | // can't delete inside doInternalUnref, since it is locking a mutex (which we own) |
halcanary | 385fe4d | 2015-08-26 13:07:48 -0700 | [diff] [blame] | 92 | delete this; |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 93 | } |
| 94 | } |
| 95 | |
| 96 | /////////////////////////////////////////////////////////////////////////////////////////////////// |
| 97 | |
| 98 | void SkCachedData::inMutexRef(bool fromCache) { |
| 99 | if ((1 == fRefCnt) && fInCache) { |
| 100 | this->inMutexLock(); |
| 101 | } |
halcanary | 9d524f2 | 2016-03-29 09:03:52 -0700 | [diff] [blame] | 102 | |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 103 | fRefCnt += 1; |
| 104 | if (fromCache) { |
| 105 | SkASSERT(!fInCache); |
| 106 | fInCache = true; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | bool SkCachedData::inMutexUnref(bool fromCache) { |
| 111 | switch (--fRefCnt) { |
| 112 | case 0: |
| 113 | // we're going to be deleted, so we need to be unlocked (for DiscardableMemory) |
| 114 | if (fIsLocked) { |
| 115 | this->inMutexUnlock(); |
| 116 | } |
| 117 | break; |
| 118 | case 1: |
| 119 | if (fInCache && !fromCache) { |
| 120 | // If we're down to 1 owner, and that owner is the cache, this it is safe |
| 121 | // to unlock (and mutate fData) even if the cache is in a different thread, |
| 122 | // as the cache is NOT allowed to inspect or use fData. |
| 123 | this->inMutexUnlock(); |
| 124 | } |
| 125 | break; |
| 126 | default: |
| 127 | break; |
| 128 | } |
halcanary | 9d524f2 | 2016-03-29 09:03:52 -0700 | [diff] [blame] | 129 | |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 130 | if (fromCache) { |
| 131 | SkASSERT(fInCache); |
| 132 | fInCache = false; |
| 133 | } |
halcanary | 9d524f2 | 2016-03-29 09:03:52 -0700 | [diff] [blame] | 134 | |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 135 | // return true when we need to be deleted |
| 136 | return 0 == fRefCnt; |
| 137 | } |
| 138 | |
| 139 | void SkCachedData::inMutexLock() { |
| 140 | fMutex.assertHeld(); |
halcanary | 9d524f2 | 2016-03-29 09:03:52 -0700 | [diff] [blame] | 141 | |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 142 | SkASSERT(!fIsLocked); |
| 143 | fIsLocked = true; |
halcanary | 9d524f2 | 2016-03-29 09:03:52 -0700 | [diff] [blame] | 144 | |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 145 | switch (fStorageType) { |
| 146 | case kMalloc_StorageType: |
| 147 | this->setData(fStorage.fMalloc); |
| 148 | break; |
| 149 | case kDiscardableMemory_StorageType: |
| 150 | if (fStorage.fDM->lock()) { |
| 151 | void* ptr = fStorage.fDM->data(); |
| 152 | SkASSERT(ptr); |
| 153 | this->setData(ptr); |
| 154 | } else { |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 155 | this->setData(nullptr); // signal failure to lock, contents are gone |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 156 | } |
| 157 | break; |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | void SkCachedData::inMutexUnlock() { |
| 162 | fMutex.assertHeld(); |
halcanary | 9d524f2 | 2016-03-29 09:03:52 -0700 | [diff] [blame] | 163 | |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 164 | SkASSERT(fIsLocked); |
| 165 | fIsLocked = false; |
halcanary | 9d524f2 | 2016-03-29 09:03:52 -0700 | [diff] [blame] | 166 | |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 167 | switch (fStorageType) { |
| 168 | case kMalloc_StorageType: |
| 169 | // nothing to do/check |
| 170 | break; |
| 171 | case kDiscardableMemory_StorageType: |
| 172 | if (fData) { // did the previous lock succeed? |
| 173 | fStorage.fDM->unlock(); |
| 174 | } |
| 175 | break; |
| 176 | } |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 177 | this->setData(nullptr); // signal that we're in an unlocked state |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 178 | } |
| 179 | |
| 180 | /////////////////////////////////////////////////////////////////////////////////////////////////// |
| 181 | |
| 182 | #ifdef SK_DEBUG |
| 183 | void SkCachedData::validate() const { |
| 184 | if (fIsLocked) { |
| 185 | SkASSERT((fInCache && fRefCnt > 1) || !fInCache); |
| 186 | switch (fStorageType) { |
| 187 | case kMalloc_StorageType: |
| 188 | SkASSERT(fData == fStorage.fMalloc); |
| 189 | break; |
| 190 | case kDiscardableMemory_StorageType: |
| 191 | // fData can be null or the actual value, depending if DM's lock succeeded |
| 192 | break; |
| 193 | } |
| 194 | } else { |
| 195 | SkASSERT((fInCache && 1 == fRefCnt) || (0 == fRefCnt)); |
halcanary | 96fcdcc | 2015-08-27 07:41:13 -0700 | [diff] [blame] | 196 | SkASSERT(nullptr == fData); |
reed | 9d93c2e | 2014-10-08 05:17:12 -0700 | [diff] [blame] | 197 | } |
| 198 | } |
| 199 | #endif |