michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkImageRef_ashmem.h"
michael@0: #include "SkImageDecoder.h"
michael@0: #include "SkReadBuffer.h"
michael@0: #include "SkWriteBuffer.h"
michael@0: #include "SkThread.h"
michael@0: 
michael@0: #include "android/ashmem.h"
michael@0: 
michael@0: #include <sys/mman.h>
michael@0: #include <unistd.h>
michael@0: 
michael@0: //#define TRACE_ASH_PURGE     // just trace purges
michael@0: 
michael@0: #ifdef DUMP_IMAGEREF_LIFECYCLE
michael@0:     #define DUMP_ASHMEM_LIFECYCLE
michael@0: #else
michael@0: //    #define DUMP_ASHMEM_LIFECYCLE
michael@0: #endif
michael@0: 
michael@0: // ashmem likes lengths on page boundaries
michael@0: static size_t roundToPageSize(size_t size) {
michael@0:     const size_t mask = getpagesize() - 1;
michael@0:     size_t newsize = (size + mask) & ~mask;
michael@0: //    SkDebugf("---- oldsize %d newsize %d\n", size, newsize);
michael@0:     return newsize;
michael@0: }
michael@0: 
michael@0: SkImageRef_ashmem::SkImageRef_ashmem(const SkImageInfo& info,
michael@0:                                      SkStreamRewindable* stream,
michael@0:                                      int sampleSize)
michael@0:     : SkImageRef(info, stream, sampleSize)
michael@0: {
michael@0:     fRec.fFD = -1;
michael@0:     fRec.fAddr = NULL;
michael@0:     fRec.fSize = 0;
michael@0:     fRec.fPinned = false;
michael@0: 
michael@0:     fCT = NULL;
michael@0: }
michael@0: 
michael@0: SkImageRef_ashmem::~SkImageRef_ashmem() {
michael@0:     SkSafeUnref(fCT);
michael@0:     this->closeFD();
michael@0: }
michael@0: 
michael@0: void SkImageRef_ashmem::closeFD() {
michael@0:     if (-1 != fRec.fFD) {
michael@0: #ifdef DUMP_ASHMEM_LIFECYCLE
michael@0:         SkDebugf("=== ashmem close %d\n", fRec.fFD);
michael@0: #endif
michael@0:         SkASSERT(fRec.fAddr);
michael@0:         SkASSERT(fRec.fSize);
michael@0:         munmap(fRec.fAddr, fRec.fSize);
michael@0:         close(fRec.fFD);
michael@0:         fRec.fFD = -1;
michael@0:     }
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: class AshmemAllocator : public SkBitmap::Allocator {
michael@0: public:
michael@0:     AshmemAllocator(SkAshmemRec* rec, const char name[])
michael@0:         : fRec(rec), fName(name) {}
michael@0: 
michael@0:     virtual bool allocPixelRef(SkBitmap* bm, SkColorTable* ct) {
michael@0:         const size_t size = roundToPageSize(bm->getSize());
michael@0:         int fd = fRec->fFD;
michael@0:         void* addr = fRec->fAddr;
michael@0: 
michael@0:         SkASSERT(!fRec->fPinned);
michael@0: 
michael@0:         if (-1 == fd) {
michael@0:             SkASSERT(NULL == addr);
michael@0:             SkASSERT(0 == fRec->fSize);
michael@0: 
michael@0:             fd = ashmem_create_region(fName, size);
michael@0: #ifdef DUMP_ASHMEM_LIFECYCLE
michael@0:             SkDebugf("=== ashmem_create_region %s size=%d fd=%d\n", fName, size, fd);
michael@0: #endif
michael@0:             if (-1 == fd) {
michael@0:                 SkDebugf("------- imageref_ashmem create failed <%s> %d\n",
michael@0:                          fName, size);
michael@0:                 return false;
michael@0:             }
michael@0: 
michael@0:             int err = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE);
michael@0:             if (err) {
michael@0:                 SkDebugf("------ ashmem_set_prot_region(%d) failed %d\n",
michael@0:                          fd, err);
michael@0:                 close(fd);
michael@0:                 return false;
michael@0:             }
michael@0: 
michael@0:             addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
michael@0:             if (-1 == (long)addr) {
michael@0:                 SkDebugf("---------- mmap failed for imageref_ashmem size=%d\n",
michael@0:                          size);
michael@0:                 close(fd);
michael@0:                 return false;
michael@0:             }
michael@0: 
michael@0:             fRec->fFD = fd;
michael@0:             fRec->fAddr = addr;
michael@0:             fRec->fSize = size;
michael@0:         } else {
michael@0:             SkASSERT(addr);
michael@0:             SkASSERT(size == fRec->fSize);
michael@0:             (void)ashmem_pin_region(fd, 0, 0);
michael@0:         }
michael@0: 
michael@0:         bm->setPixels(addr, ct);
michael@0:         fRec->fPinned = true;
michael@0:         return true;
michael@0:     }
michael@0: 
michael@0: private:
michael@0:     // we just point to our caller's memory, these are not copies
michael@0:     SkAshmemRec* fRec;
michael@0:     const char*  fName;
michael@0: };
michael@0: 
michael@0: bool SkImageRef_ashmem::onDecode(SkImageDecoder* codec, SkStreamRewindable* stream,
michael@0:                                  SkBitmap* bitmap, SkBitmap::Config config,
michael@0:                                  SkImageDecoder::Mode mode) {
michael@0: 
michael@0:     if (SkImageDecoder::kDecodeBounds_Mode == mode) {
michael@0:         return this->INHERITED::onDecode(codec, stream, bitmap, config, mode);
michael@0:     }
michael@0: 
michael@0:     // Ashmem memory is guaranteed to be initialized to 0.
michael@0:     codec->setSkipWritingZeroes(true);
michael@0: 
michael@0:     AshmemAllocator alloc(&fRec, this->getURI());
michael@0: 
michael@0:     codec->setAllocator(&alloc);
michael@0:     bool success = this->INHERITED::onDecode(codec, stream, bitmap, config,
michael@0:                                              mode);
michael@0:     // remove the allocator, since its on the stack
michael@0:     codec->setAllocator(NULL);
michael@0: 
michael@0:     if (success) {
michael@0:         // remember the colortable (if any)
michael@0:         SkRefCnt_SafeAssign(fCT, bitmap->getColorTable());
michael@0:         return true;
michael@0:     } else {
michael@0:         if (fRec.fPinned) {
michael@0:             ashmem_unpin_region(fRec.fFD, 0, 0);
michael@0:             fRec.fPinned = false;
michael@0:         }
michael@0:         this->closeFD();
michael@0:         return false;
michael@0:     }
michael@0: }
michael@0: 
michael@0: bool SkImageRef_ashmem::onNewLockPixels(LockRec* rec) {
michael@0:     SkASSERT(fBitmap.getPixels() == NULL);
michael@0:     SkASSERT(fBitmap.getColorTable() == NULL);
michael@0: 
michael@0:     // fast case: check if we can just pin and get the cached data
michael@0:     if (-1 != fRec.fFD) {
michael@0:         SkASSERT(fRec.fAddr);
michael@0:         SkASSERT(!fRec.fPinned);
michael@0:         int pin = ashmem_pin_region(fRec.fFD, 0, 0);
michael@0: 
michael@0:         if (ASHMEM_NOT_PURGED == pin) { // yea, fast case!
michael@0:             fBitmap.setPixels(fRec.fAddr, fCT);
michael@0:             fRec.fPinned = true;
michael@0:         } else if (ASHMEM_WAS_PURGED == pin) {
michael@0:             ashmem_unpin_region(fRec.fFD, 0, 0);
michael@0:             // let go of our colortable if we lost the pixels. Well get it back
michael@0:             // again when we re-decode
michael@0:             if (fCT) {
michael@0:                 fCT->unref();
michael@0:                 fCT = NULL;
michael@0:             }
michael@0: #if defined(DUMP_ASHMEM_LIFECYCLE) || defined(TRACE_ASH_PURGE)
michael@0:             SkDebugf("===== ashmem purged %d\n", fBitmap.getSize());
michael@0: #endif
michael@0:         } else {
michael@0:             SkDebugf("===== ashmem pin_region(%d) returned %d\n", fRec.fFD, pin);
michael@0:             return false;
michael@0:         }
michael@0:     } else {
michael@0:         // no FD, will create an ashmem region in allocator
michael@0:     }
michael@0: 
michael@0:     return this->INHERITED::onNewLockPixels(rec);
michael@0: }
michael@0: 
michael@0: void SkImageRef_ashmem::onUnlockPixels() {
michael@0:     this->INHERITED::onUnlockPixels();
michael@0: 
michael@0:     if (-1 != fRec.fFD) {
michael@0:         SkASSERT(fRec.fAddr);
michael@0:         SkASSERT(fRec.fPinned);
michael@0: 
michael@0:         ashmem_unpin_region(fRec.fFD, 0, 0);
michael@0:         fRec.fPinned = false;
michael@0:     }
michael@0: 
michael@0:     // we clear this with or without an error, since we've either closed or
michael@0:     // unpinned the region
michael@0:     fBitmap.setPixels(NULL, NULL);
michael@0: }
michael@0: 
michael@0: void SkImageRef_ashmem::flatten(SkWriteBuffer& buffer) const {
michael@0:     this->INHERITED::flatten(buffer);
michael@0:     buffer.writeString(getURI());
michael@0: }
michael@0: 
michael@0: SkImageRef_ashmem::SkImageRef_ashmem(SkReadBuffer& buffer)
michael@0:         : INHERITED(buffer) {
michael@0:     fRec.fFD = -1;
michael@0:     fRec.fAddr = NULL;
michael@0:     fRec.fSize = 0;
michael@0:     fRec.fPinned = false;
michael@0:     fCT = NULL;
michael@0: 
michael@0:     SkString uri;
michael@0:     buffer.readString(&uri);
michael@0:     this->setURI(uri);
michael@0: }