blob: 4cf47e3a2e350b6aa956a4aeedc089ff02e78cf5 [file] [log] [blame]
/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkPixelRef.h"
#include "SkFlattenableBuffers.h"
#include "SkThread.h"
SK_DEFINE_INST_COUNT(SkPixelRef)
// must be a power-of-2. undef to just use 1 mutex
#define PIXELREF_MUTEX_RING_COUNT 32
#ifdef PIXELREF_MUTEX_RING_COUNT
static int32_t gPixelRefMutexRingIndex;
static SK_DECLARE_MUTEX_ARRAY(gPixelRefMutexRing, PIXELREF_MUTEX_RING_COUNT);
#else
SK_DECLARE_STATIC_MUTEX(gPixelRefMutex);
#endif
static SkBaseMutex* get_default_mutex() {
#ifdef PIXELREF_MUTEX_RING_COUNT
// atomic_inc might be overkill here. It may be fine if once in a while
// we hit a race-condition and two subsequent calls get the same index...
int index = sk_atomic_inc(&gPixelRefMutexRingIndex);
return &gPixelRefMutexRing[index & (PIXELREF_MUTEX_RING_COUNT - 1)];
#else
return &gPixelRefMutex;
#endif
}
///////////////////////////////////////////////////////////////////////////////
int32_t SkNextPixelRefGenerationID();
int32_t SkNextPixelRefGenerationID() {
static int32_t gPixelRefGenerationID;
// do a loop in case our global wraps around, as we never want to
// return a 0
int32_t genID;
do {
genID = sk_atomic_inc(&gPixelRefGenerationID) + 1;
} while (0 == genID);
return genID;
}
///////////////////////////////////////////////////////////////////////////////
void SkPixelRef::setMutex(SkBaseMutex* mutex) {
if (NULL == mutex) {
mutex = get_default_mutex();
}
fMutex = mutex;
}
// just need a > 0 value, so pick a funny one to aid in debugging
#define SKPIXELREF_PRELOCKED_LOCKCOUNT 123456789
SkPixelRef::SkPixelRef(SkBaseMutex* mutex) : fPreLocked(false) {
this->setMutex(mutex);
fPixels = NULL;
fColorTable = NULL; // we do not track ownership of this
fLockCount = 0;
fGenerationID = 0; // signal to rebuild
fIsImmutable = false;
fPreLocked = false;
}
SkPixelRef::SkPixelRef(SkFlattenableReadBuffer& buffer, SkBaseMutex* mutex)
: INHERITED(buffer) {
this->setMutex(mutex);
fPixels = NULL;
fColorTable = NULL; // we do not track ownership of this
fLockCount = 0;
fIsImmutable = buffer.readBool();
fGenerationID = buffer.readUInt();
fPreLocked = false;
}
void SkPixelRef::setPreLocked(void* pixels, SkColorTable* ctable) {
#ifndef SK_IGNORE_PIXELREF_SETPRELOCKED
// only call me in your constructor, otherwise fLockCount tracking can get
// out of sync.
fPixels = pixels;
fColorTable = ctable;
fLockCount = SKPIXELREF_PRELOCKED_LOCKCOUNT;
fPreLocked = true;
#endif
}
void SkPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
this->INHERITED::flatten(buffer);
buffer.writeBool(fIsImmutable);
// We write the gen ID into the picture for within-process recording. This
// is safe since the same genID will never refer to two different sets of
// pixels (barring overflow). However, each process has its own "namespace"
// of genIDs. So for cross-process recording we write a zero which will
// trigger assignment of a new genID in playback.
if (buffer.isCrossProcess()) {
buffer.writeUInt(0);
} else {
buffer.writeUInt(fGenerationID);
}
}
void SkPixelRef::lockPixels() {
SkASSERT(!fPreLocked || SKPIXELREF_PRELOCKED_LOCKCOUNT == fLockCount);
if (!fPreLocked) {
SkAutoMutexAcquire ac(*fMutex);
if (1 == ++fLockCount) {
fPixels = this->onLockPixels(&fColorTable);
}
}
}
void SkPixelRef::unlockPixels() {
SkASSERT(!fPreLocked || SKPIXELREF_PRELOCKED_LOCKCOUNT == fLockCount);
if (!fPreLocked) {
SkAutoMutexAcquire ac(*fMutex);
SkASSERT(fLockCount > 0);
if (0 == --fLockCount) {
this->onUnlockPixels();
fPixels = NULL;
fColorTable = NULL;
}
}
}
bool SkPixelRef::lockPixelsAreWritable() const {
return this->onLockPixelsAreWritable();
}
bool SkPixelRef::onLockPixelsAreWritable() const {
return true;
}
uint32_t SkPixelRef::getGenerationID() const {
if (0 == fGenerationID) {
fGenerationID = SkNextPixelRefGenerationID();
}
return fGenerationID;
}
void SkPixelRef::notifyPixelsChanged() {
#ifdef SK_DEBUG
if (fIsImmutable) {
SkDebugf("========== notifyPixelsChanged called on immutable pixelref");
}
#endif
// this signals us to recompute this next time around
fGenerationID = 0;
}
void SkPixelRef::setImmutable() {
fIsImmutable = true;
}
bool SkPixelRef::readPixels(SkBitmap* dst, const SkIRect* subset) {
return this->onReadPixels(dst, subset);
}
bool SkPixelRef::onReadPixels(SkBitmap* dst, const SkIRect* subset) {
return false;
}
SkData* SkPixelRef::onRefEncodedData() {
return NULL;
}
///////////////////////////////////////////////////////////////////////////////
#ifdef SK_BUILD_FOR_ANDROID
void SkPixelRef::globalRef(void* data) {
this->ref();
}
void SkPixelRef::globalUnref() {
this->unref();
}
#endif