2 * Copyright 2011 Google Inc.
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
8 #include "SkImageRef_ashmem.h"
9 #include "SkImageDecoder.h"
10 #include "SkReadBuffer.h"
11 #include "SkWriteBuffer.h"
14 #include "android/ashmem.h"
19 //#define TRACE_ASH_PURGE // just trace purges
21 #ifdef DUMP_IMAGEREF_LIFECYCLE
22 #define DUMP_ASHMEM_LIFECYCLE
24 // #define DUMP_ASHMEM_LIFECYCLE
27 // ashmem likes lengths on page boundaries
28 static size_t roundToPageSize(size_t size) {
29 const size_t mask = getpagesize() - 1;
30 size_t newsize = (size + mask) & ~mask;
31 // SkDebugf("---- oldsize %d newsize %d\n", size, newsize);
35 SkImageRef_ashmem::SkImageRef_ashmem(const SkImageInfo& info,
36 SkStreamRewindable* stream,
38 : SkImageRef(info, stream, sampleSize)
48 SkImageRef_ashmem::~SkImageRef_ashmem() {
53 void SkImageRef_ashmem::closeFD() {
55 #ifdef DUMP_ASHMEM_LIFECYCLE
56 SkDebugf("=== ashmem close %d\n", fRec.fFD);
60 munmap(fRec.fAddr, fRec.fSize);
66 ///////////////////////////////////////////////////////////////////////////////
68 class AshmemAllocator : public SkBitmap::Allocator {
70 AshmemAllocator(SkAshmemRec* rec, const char name[])
71 : fRec(rec), fName(name) {}
73 virtual bool allocPixelRef(SkBitmap* bm, SkColorTable* ct) {
74 const size_t size = roundToPageSize(bm->getSize());
76 void* addr = fRec->fAddr;
78 SkASSERT(!fRec->fPinned);
81 SkASSERT(NULL == addr);
82 SkASSERT(0 == fRec->fSize);
84 fd = ashmem_create_region(fName, size);
85 #ifdef DUMP_ASHMEM_LIFECYCLE
86 SkDebugf("=== ashmem_create_region %s size=%d fd=%d\n", fName, size, fd);
89 SkDebugf("------- imageref_ashmem create failed <%s> %d\n",
94 int err = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE);
96 SkDebugf("------ ashmem_set_prot_region(%d) failed %d\n",
102 addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
103 if (-1 == (long)addr) {
104 SkDebugf("---------- mmap failed for imageref_ashmem size=%d\n",
115 SkASSERT(size == fRec->fSize);
116 (void)ashmem_pin_region(fd, 0, 0);
119 bm->setPixels(addr, ct);
120 fRec->fPinned = true;
125 // we just point to our caller's memory, these are not copies
130 bool SkImageRef_ashmem::onDecode(SkImageDecoder* codec, SkStreamRewindable* stream,
131 SkBitmap* bitmap, SkBitmap::Config config,
132 SkImageDecoder::Mode mode) {
134 if (SkImageDecoder::kDecodeBounds_Mode == mode) {
135 return this->INHERITED::onDecode(codec, stream, bitmap, config, mode);
138 // Ashmem memory is guaranteed to be initialized to 0.
139 codec->setSkipWritingZeroes(true);
141 AshmemAllocator alloc(&fRec, this->getURI());
143 codec->setAllocator(&alloc);
144 bool success = this->INHERITED::onDecode(codec, stream, bitmap, config,
146 // remove the allocator, since its on the stack
147 codec->setAllocator(NULL);
150 // remember the colortable (if any)
151 SkRefCnt_SafeAssign(fCT, bitmap->getColorTable());
155 ashmem_unpin_region(fRec.fFD, 0, 0);
156 fRec.fPinned = false;
163 bool SkImageRef_ashmem::onNewLockPixels(LockRec* rec) {
164 SkASSERT(fBitmap.getPixels() == NULL);
165 SkASSERT(fBitmap.getColorTable() == NULL);
167 // fast case: check if we can just pin and get the cached data
168 if (-1 != fRec.fFD) {
169 SkASSERT(fRec.fAddr);
170 SkASSERT(!fRec.fPinned);
171 int pin = ashmem_pin_region(fRec.fFD, 0, 0);
173 if (ASHMEM_NOT_PURGED == pin) { // yea, fast case!
174 fBitmap.setPixels(fRec.fAddr, fCT);
176 } else if (ASHMEM_WAS_PURGED == pin) {
177 ashmem_unpin_region(fRec.fFD, 0, 0);
178 // let go of our colortable if we lost the pixels. Well get it back
179 // again when we re-decode
184 #if defined(DUMP_ASHMEM_LIFECYCLE) || defined(TRACE_ASH_PURGE)
185 SkDebugf("===== ashmem purged %d\n", fBitmap.getSize());
188 SkDebugf("===== ashmem pin_region(%d) returned %d\n", fRec.fFD, pin);
192 // no FD, will create an ashmem region in allocator
195 return this->INHERITED::onNewLockPixels(rec);
198 void SkImageRef_ashmem::onUnlockPixels() {
199 this->INHERITED::onUnlockPixels();
201 if (-1 != fRec.fFD) {
202 SkASSERT(fRec.fAddr);
203 SkASSERT(fRec.fPinned);
205 ashmem_unpin_region(fRec.fFD, 0, 0);
206 fRec.fPinned = false;
209 // we clear this with or without an error, since we've either closed or
210 // unpinned the region
211 fBitmap.setPixels(NULL, NULL);
214 void SkImageRef_ashmem::flatten(SkWriteBuffer& buffer) const {
215 this->INHERITED::flatten(buffer);
216 buffer.writeString(getURI());
219 SkImageRef_ashmem::SkImageRef_ashmem(SkReadBuffer& buffer)
220 : INHERITED(buffer) {
224 fRec.fPinned = false;
228 buffer.readString(&uri);