1 2 /* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 #include "SkImageRef_ashmem.h" 9 #include "SkImageDecoder.h" 10 #include "SkFlattenable.h" 11 #include "SkThread.h" 12 13 #include <sys/mman.h> 14 #include <unistd.h> 15 #include <cutils/ashmem.h> 16 17 //#define TRACE_ASH_PURGE // just trace purges 18 19 #ifdef DUMP_IMAGEREF_LIFECYCLE 20 #define DUMP_ASHMEM_LIFECYCLE 21 #else 22 // #define DUMP_ASHMEM_LIFECYCLE 23 #endif 24 25 // ashmem likes lengths on page boundaries 26 static size_t roundToPageSize(size_t size) { 27 const size_t mask = getpagesize() - 1; 28 size_t newsize = (size + mask) & ~mask; 29 // SkDebugf("---- oldsize %d newsize %d\n", size, newsize); 30 return newsize; 31 } 32 33 SkImageRef_ashmem::SkImageRef_ashmem(SkStream* stream, 34 SkBitmap::Config config, 35 int sampleSize) 36 : SkImageRef(stream, config, sampleSize) { 37 38 fRec.fFD = -1; 39 fRec.fAddr = NULL; 40 fRec.fSize = 0; 41 fRec.fPinned = false; 42 43 fCT = NULL; 44 } 45 46 SkImageRef_ashmem::~SkImageRef_ashmem() { 47 SkSafeUnref(fCT); 48 this->closeFD(); 49 } 50 51 void SkImageRef_ashmem::closeFD() { 52 if (-1 != fRec.fFD) { 53 #ifdef DUMP_ASHMEM_LIFECYCLE 54 SkDebugf("=== ashmem close %d\n", fRec.fFD); 55 #endif 56 SkASSERT(fRec.fAddr); 57 SkASSERT(fRec.fSize); 58 munmap(fRec.fAddr, fRec.fSize); 59 close(fRec.fFD); 60 fRec.fFD = -1; 61 } 62 } 63 64 /////////////////////////////////////////////////////////////////////////////// 65 66 class AshmemAllocator : public SkBitmap::Allocator { 67 public: 68 AshmemAllocator(SkAshmemRec* rec, const char name[]) 69 : fRec(rec), fName(name) {} 70 71 virtual bool allocPixelRef(SkBitmap* bm, SkColorTable* ct) { 72 const size_t size = roundToPageSize(bm->getSize()); 73 int fd = fRec->fFD; 74 void* addr = fRec->fAddr; 75 76 SkASSERT(!fRec->fPinned); 77 78 if (-1 == fd) { 79 SkASSERT(NULL == addr); 80 SkASSERT(0 == fRec->fSize); 81 82 fd = ashmem_create_region(fName, size); 83 #ifdef DUMP_ASHMEM_LIFECYCLE 84 SkDebugf("=== ashmem_create_region %s size=%d fd=%d\n", fName, size, fd); 85 #endif 86 if (-1 == fd) { 87 SkDebugf("------- imageref_ashmem create failed <%s> %d\n", 88 fName, size); 89 return false; 90 } 91 92 int err = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE); 93 if (err) { 94 SkDebugf("------ ashmem_set_prot_region(%d) failed %d\n", 95 fd, err); 96 close(fd); 97 return false; 98 } 99 100 addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); 101 if (-1 == (long)addr) { 102 SkDebugf("---------- mmap failed for imageref_ashmem size=%d\n", 103 size); 104 close(fd); 105 return false; 106 } 107 108 fRec->fFD = fd; 109 fRec->fAddr = addr; 110 fRec->fSize = size; 111 } else { 112 SkASSERT(addr); 113 SkASSERT(size == fRec->fSize); 114 (void)ashmem_pin_region(fd, 0, 0); 115 } 116 117 bm->setPixels(addr, ct); 118 fRec->fPinned = true; 119 return true; 120 } 121 122 private: 123 // we just point to our caller's memory, these are not copies 124 SkAshmemRec* fRec; 125 const char* fName; 126 }; 127 128 bool SkImageRef_ashmem::onDecode(SkImageDecoder* codec, SkStream* stream, 129 SkBitmap* bitmap, SkBitmap::Config config, 130 SkImageDecoder::Mode mode) { 131 132 if (SkImageDecoder::kDecodeBounds_Mode == mode) { 133 return this->INHERITED::onDecode(codec, stream, bitmap, config, mode); 134 } 135 136 AshmemAllocator alloc(&fRec, this->getURI()); 137 138 codec->setAllocator(&alloc); 139 bool success = this->INHERITED::onDecode(codec, stream, bitmap, config, 140 mode); 141 // remove the allocator, since its on the stack 142 codec->setAllocator(NULL); 143 144 if (success) { 145 // remember the colortable (if any) 146 SkRefCnt_SafeAssign(fCT, bitmap->getColorTable()); 147 return true; 148 } else { 149 if (fRec.fPinned) { 150 ashmem_unpin_region(fRec.fFD, 0, 0); 151 fRec.fPinned = false; 152 } 153 this->closeFD(); 154 return false; 155 } 156 } 157 158 void* SkImageRef_ashmem::onLockPixels(SkColorTable** ct) { 159 SkASSERT(fBitmap.getPixels() == NULL); 160 SkASSERT(fBitmap.getColorTable() == NULL); 161 162 // fast case: check if we can just pin and get the cached data 163 if (-1 != fRec.fFD) { 164 SkASSERT(fRec.fAddr); 165 SkASSERT(!fRec.fPinned); 166 int pin = ashmem_pin_region(fRec.fFD, 0, 0); 167 168 if (ASHMEM_NOT_PURGED == pin) { // yea, fast case! 169 fBitmap.setPixels(fRec.fAddr, fCT); 170 fRec.fPinned = true; 171 } else if (ASHMEM_WAS_PURGED == pin) { 172 ashmem_unpin_region(fRec.fFD, 0, 0); 173 // let go of our colortable if we lost the pixels. Well get it back 174 // again when we re-decode 175 if (fCT) { 176 fCT->unref(); 177 fCT = NULL; 178 } 179 #if defined(DUMP_ASHMEM_LIFECYCLE) || defined(TRACE_ASH_PURGE) 180 SkDebugf("===== ashmem purged %d\n", fBitmap.getSize()); 181 #endif 182 } else { 183 SkDebugf("===== ashmem pin_region(%d) returned %d\n", fRec.fFD, pin); 184 // return null result for failure 185 if (ct) { 186 *ct = NULL; 187 } 188 return NULL; 189 } 190 } else { 191 // no FD, will create an ashmem region in allocator 192 } 193 194 return this->INHERITED::onLockPixels(ct); 195 } 196 197 void SkImageRef_ashmem::onUnlockPixels() { 198 this->INHERITED::onUnlockPixels(); 199 200 if (-1 != fRec.fFD) { 201 SkASSERT(fRec.fAddr); 202 SkASSERT(fRec.fPinned); 203 204 ashmem_unpin_region(fRec.fFD, 0, 0); 205 fRec.fPinned = false; 206 } 207 208 // we clear this with or without an error, since we've either closed or 209 // unpinned the region 210 fBitmap.setPixels(NULL, NULL); 211 } 212 213 void SkImageRef_ashmem::flatten(SkFlattenableWriteBuffer& buffer) const { 214 this->INHERITED::flatten(buffer); 215 const char* uri = getURI(); 216 if (uri) { 217 size_t len = strlen(uri); 218 buffer.write32(len); 219 buffer.writePad(uri, len); 220 } else { 221 buffer.write32(0); 222 } 223 } 224 225 SkImageRef_ashmem::SkImageRef_ashmem(SkFlattenableReadBuffer& buffer) 226 : INHERITED(buffer) { 227 fRec.fFD = -1; 228 fRec.fAddr = NULL; 229 fRec.fSize = 0; 230 fRec.fPinned = false; 231 fCT = NULL; 232 size_t length = buffer.readU32(); 233 if (length) { 234 char* buf = (char*) malloc(length); 235 buffer.read(buf, length); 236 setURI(buf, length); 237 } 238 } 239 240 SkPixelRef* SkImageRef_ashmem::Create(SkFlattenableReadBuffer& buffer) { 241 return SkNEW_ARGS(SkImageRef_ashmem, (buffer)); 242 } 243 244 SK_DEFINE_PIXEL_REF_REGISTRAR(SkImageRef_ashmem) 245
