Improvements/additions to SkImageCache/SkLazyPixelRef.

src/ports/SkAshmemImageCache.cpp

-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkAshmemImageCache.h"
-#include "SkThread.h"
-
-#ifdef SK_DEBUG
-    #include "SkTSearch.h"
-#endif
-
-#include "android/ashmem.h"
-#include <sys/mman.h>
-#include <unistd.h>
-
-
-SkAshmemImageCache::SkAshmemImageCache() {}
-
-SK_DECLARE_STATIC_MUTEX(gAshmemMutex);
-
-SkAshmemImageCache* SkAshmemImageCache::GetAshmemImageCache() {
-    SkAutoMutexAcquire ac(&gAshmemMutex);
-    static SkAshmemImageCache gCache;
-    return &gCache;
-}
-
-#ifdef SK_DEBUG
-SkAshmemImageCache::~SkAshmemImageCache() {
-    SkASSERT(fRecs.count() == 0);
-}
-#endif
-
-// ashmem likes lengths on page boundaries.
-static size_t roundToPageSize(size_t size) {
-    const size_t mask = getpagesize() - 1;
-    size_t newSize = (size + mask) & ~mask;
-    return newSize;
-}
-
-void* SkAshmemImageCache::allocAndPinCache(size_t bytes, intptr_t* ID) {
-    SkASSERT(ID != NULL);
-
-    SkAutoMutexAcquire ac(&gAshmemMutex);
-
-    if (*ID != SkImageCache::UNINITIALIZED_ID) {
-        // This rec was previously allocated, but pinCache subsequently
-        // failed.
-        AshmemRec* pRec = reinterpret_cast<AshmemRec*>(*ID);
-        SkASSERT(roundToPageSize(bytes) == pRec->fSize);
-        SkASSERT(pRec->fFD != -1);
-        (void) ashmem_pin_region(pRec->fFD, 0, 0);
-#ifdef SK_DEBUG
-        pRec->fPinned = true;
-#endif
-        return pRec->fAddr;
-    }
-
-    AshmemRec rec;
-    rec.fSize = roundToPageSize(bytes);
-
-    rec.fFD = ashmem_create_region(NULL, rec.fSize);
-    if (-1 == rec.fFD) {
-        SkDebugf("ashmem_create_region failed\n");
-        return NULL;
-    }
-    int err = ashmem_set_prot_region(rec.fFD, PROT_READ | PROT_WRITE);
-    if (err != 0) {
-        SkDebugf("ashmem_set_prot_region failed\n");
-        close(rec.fFD);
-        return NULL;
-    }
-    rec.fAddr = mmap(NULL, rec.fSize, PROT_READ | PROT_WRITE, MAP_PRIVATE, rec.fFD, 0);
-    if (-1 == (long) rec.fAddr) {
-        SkDebugf("mmap failed\n");
-        close(rec.fFD);
-        return NULL;
-    }
-    (void) ashmem_pin_region(rec.fFD, 0, 0);
-#ifdef SK_DEBUG
-    rec.fPinned = true;
-#endif
-    // In release mode, we do not keep a pointer to this object. It will be destroyed
-    // either when pinCache returns NULL or when throwAwayCache is called.
-    AshmemRec* pRec = SkNEW_ARGS(AshmemRec, (rec));
-    *ID = reinterpret_cast<intptr_t>(pRec);
-#ifdef SK_DEBUG
-    this->appendRec(pRec);
-#endif
-    return rec.fAddr;
-}
-
-void* SkAshmemImageCache::pinCache(intptr_t ID) {
-    SkAutoMutexAcquire ac(&gAshmemMutex);
-    AshmemRec* rec = reinterpret_cast<AshmemRec*>(ID);
-    const int fd = rec->fFD;
-    int pin = ashmem_pin_region(fd, 0, 0);
-    if (ASHMEM_NOT_PURGED == pin) {
-#ifdef SK_DEBUG
-        rec->fPinned = true;
-#endif
-        return rec->fAddr;
-    }
-    ashmem_unpin_region(fd, 0, 0);
-    return NULL;
-}
-
-void SkAshmemImageCache::releaseCache(intptr_t ID) {
-    SkAutoMutexAcquire ac(&gAshmemMutex);
-    AshmemRec* rec = reinterpret_cast<AshmemRec*>(ID);
-    ashmem_unpin_region(rec->fFD, 0, 0);
-#ifdef SK_DEBUG
-    rec->fPinned = false;
-#endif
-}
-
-void SkAshmemImageCache::throwAwayCache(intptr_t ID) {
-    SkAutoMutexAcquire ac(&gAshmemMutex);
-    AshmemRec* rec = reinterpret_cast<AshmemRec*>(ID);
-    munmap(rec->fAddr, rec->fSize);
-    close(rec->fFD);
-#ifdef SK_DEBUG
-    SkASSERT(!rec->fPinned);
-    int index = this->findRec(rec);
-    SkASSERT(index >= 0);
-    fRecs.remove(index);
-#endif
-    SkDELETE(rec);
-}
-
-#ifdef SK_DEBUG
-void SkAshmemImageCache::appendRec(SkAshmemImageCache::AshmemRec* rec) {
-    int index = this->findRec(rec);
-    // Should not already exist.
-    SkASSERT(index < 0);
-    fRecs.insert(~index, 1, &rec);
-}
-
-int SkAshmemImageCache::AshmemRec::Compare(const SkAshmemImageCache::AshmemRec* a,
-                                           const SkAshmemImageCache::AshmemRec* b) {
-    return reinterpret_cast<intptr_t>(a) - reinterpret_cast<intptr_t>(b);
-}
-
-int SkAshmemImageCache::findRec(const SkAshmemImageCache::AshmemRec* rec) const {
-    return SkTSearch<AshmemRec>((const AshmemRec**)fRecs.begin(), fRecs.count(), rec,
-                                sizeof(intptr_t), AshmemRec::Compare);
-}
-
-SkImageCache::CacheStatus SkAshmemImageCache::getCacheStatus(intptr_t ID) const {
-    SkAutoMutexAcquire ac(&gAshmemMutex);
-    AshmemRec* rec = reinterpret_cast<AshmemRec*>(ID);
-    int index = this->findRec(rec);
-    if (index < 0) {
-        return SkImageCache::kThrownAway_CacheStatus;
-    }
-    return rec->fPinned ? SkImageCache::kPinned_CacheStatus
-                        : SkImageCache::kUnpinned_CacheStatus;
-}
-#endif