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