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comparison: gfx/skia/trunk/src/ports/SkDiscardableMemory_ashmem.cpp
gfx/skia/trunk/src/ports/SkDiscardableMemory_ashmem.cpp
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:4c4edd52393f |
|---|---|
| 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 <unistd.h> | |
| 9 #include <sys/mman.h> | |
| 10 #include "SkDiscardableMemory.h" | |
| 11 #include "SkTypes.h" | |
| 12 #include "android/ashmem.h" | |
| 13 | |
| 14 //////////////////////////////////////////////////////////////////////////////// | |
| 15 namespace { | |
| 16 /** | |
| 17 * DiscardableMemory implementation that uses the Android kernel's | |
| 18 * ashmem (Android shared memory). | |
| 19 */ | |
| 20 class SkAshmemDiscardableMemory : public SkDiscardableMemory { | |
| 21 public: | |
| 22 SkAshmemDiscardableMemory(int fd, void* address, size_t size); | |
| 23 virtual ~SkAshmemDiscardableMemory(); | |
| 24 virtual bool lock() SK_OVERRIDE; | |
| 25 virtual void* data() SK_OVERRIDE; | |
| 26 virtual void unlock() SK_OVERRIDE; | |
| 27 private: | |
| 28 bool fLocked; | |
| 29 int fFd; | |
| 30 void* fMemory; | |
| 31 const size_t fSize; | |
| 32 }; | |
| 33 | |
| 34 SkAshmemDiscardableMemory::SkAshmemDiscardableMemory(int fd, | |
| 35 void* address, | |
| 36 size_t size) | |
| 37 : fLocked(true) // Ashmem pages are pinned by default. | |
| 38 , fFd(fd) | |
| 39 , fMemory(address) | |
| 40 , fSize(size) { | |
| 41 SkASSERT(fFd >= 0); | |
| 42 SkASSERT(fMemory != NULL); | |
| 43 SkASSERT(fSize > 0); | |
| 44 } | |
| 45 | |
| 46 SkAshmemDiscardableMemory::~SkAshmemDiscardableMemory() { | |
| 47 SkASSERT(!fLocked); | |
| 48 if (NULL != fMemory) { | |
| 49 munmap(fMemory, fSize); | |
| 50 } | |
| 51 if (fFd != -1) { | |
| 52 close(fFd); | |
| 53 } | |
| 54 } | |
| 55 | |
| 56 bool SkAshmemDiscardableMemory::lock() { | |
| 57 SkASSERT(!fLocked); | |
| 58 if (-1 == fFd) { | |
| 59 fLocked = false; | |
| 60 return false; | |
| 61 } | |
| 62 SkASSERT(fMemory != NULL); | |
| 63 if (fLocked || (ASHMEM_NOT_PURGED == ashmem_pin_region(fFd, 0, 0))) { | |
| 64 fLocked = true; | |
| 65 return true; | |
| 66 } else { | |
| 67 munmap(fMemory, fSize); | |
| 68 fMemory = NULL; | |
| 69 | |
| 70 close(fFd); | |
| 71 fFd = -1; | |
| 72 fLocked = false; | |
| 73 return false; | |
| 74 } | |
| 75 } | |
| 76 | |
| 77 void* SkAshmemDiscardableMemory::data() { | |
| 78 SkASSERT(fLocked); | |
| 79 return fLocked ? fMemory : NULL; | |
| 80 } | |
| 81 | |
| 82 void SkAshmemDiscardableMemory::unlock() { | |
| 83 SkASSERT(fLocked); | |
| 84 if (fLocked && (fFd != -1)) { | |
| 85 ashmem_unpin_region(fFd, 0, 0); | |
| 86 } | |
| 87 fLocked = false; | |
| 88 } | |
| 89 } // namespace | |
| 90 //////////////////////////////////////////////////////////////////////////////// | |
| 91 | |
| 92 SkDiscardableMemory* SkDiscardableMemory::Create(size_t bytes) { | |
| 93 // ashmem likes lengths on page boundaries. | |
| 94 const size_t mask = getpagesize() - 1; | |
| 95 size_t size = (bytes + mask) & ~mask; | |
| 96 | |
| 97 static const char name[] = "Skia_Ashmem_Discardable_Memory"; | |
| 98 int fd = ashmem_create_region(name, size); | |
| 99 if (fd < 0) { | |
| 100 return NULL; | |
| 101 } | |
| 102 if (0 != ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE)) { | |
| 103 close(fd); | |
| 104 return NULL; | |
| 105 } | |
| 106 void* addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); | |
| 107 if ((MAP_FAILED == addr) || (NULL == addr)) { | |
| 108 close(fd); | |
| 109 return NULL; | |
| 110 } | |
| 111 | |
| 112 return SkNEW_ARGS(SkAshmemDiscardableMemory, (fd, addr, size)); | |
| 113 } |
