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/*
* Copyright 2010 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrResourceCache.h"
#include "GrResource.h"
DECLARE_SKMESSAGEBUS_MESSAGE(GrResourceInvalidatedMessage);
GrResourceKey::ResourceType GrResourceKey::GenerateResourceType() {
static int32_t gNextType = 0;
int32_t type = sk_atomic_inc(&gNextType);
if (type >= (1 << 8 * sizeof(ResourceType))) {
GrCrash("Too many Resource Types");
}
return static_cast<ResourceType>(type);
}
///////////////////////////////////////////////////////////////////////////////
GrResourceEntry::GrResourceEntry(const GrResourceKey& key, GrResource* resource)
: fKey(key), fResource(resource) {
// we assume ownership of the resource, and will unref it when we die
SkASSERT(resource);
resource->ref();
}
GrResourceEntry::~GrResourceEntry() {
fResource->setCacheEntry(NULL);
fResource->unref();
}
#ifdef SK_DEBUG
void GrResourceEntry::validate() const {
SkASSERT(fResource);
SkASSERT(fResource->getCacheEntry() == this);
fResource->validate();
}
#endif
///////////////////////////////////////////////////////////////////////////////
GrResourceCache::GrResourceCache(int maxCount, size_t maxBytes) :
fMaxCount(maxCount),
fMaxBytes(maxBytes) {
#if GR_CACHE_STATS
fHighWaterEntryCount = 0;
fHighWaterEntryBytes = 0;
fHighWaterClientDetachedCount = 0;
fHighWaterClientDetachedBytes = 0;
#endif
fEntryCount = 0;
fEntryBytes = 0;
fClientDetachedCount = 0;
fClientDetachedBytes = 0;
fPurging = false;
fOverbudgetCB = NULL;
fOverbudgetData = NULL;
}
GrResourceCache::~GrResourceCache() {
GrAutoResourceCacheValidate atcv(this);
EntryList::Iter iter;
// Unlike the removeAll, here we really remove everything, including locked resources.
while (GrResourceEntry* entry = fList.head()) {
GrAutoResourceCacheValidate atcv(this);
// remove from our cache
fCache.remove(entry->fKey, entry);
// remove from our llist
this->internalDetach(entry);
delete entry;
}
}
void GrResourceCache::getLimits(int* maxResources, size_t* maxResourceBytes) const{
if (NULL != maxResources) {
*maxResources = fMaxCount;
}
if (NULL != maxResourceBytes) {
*maxResourceBytes = fMaxBytes;
}
}
void GrResourceCache::setLimits(int maxResources, size_t maxResourceBytes) {
bool smaller = (maxResources < fMaxCount) || (maxResourceBytes < fMaxBytes);
fMaxCount = maxResources;
fMaxBytes = maxResourceBytes;
if (smaller) {
this->purgeAsNeeded();
}
}
void GrResourceCache::internalDetach(GrResourceEntry* entry,
BudgetBehaviors behavior) {
fList.remove(entry);
// update our stats
if (kIgnore_BudgetBehavior == behavior) {
fClientDetachedCount += 1;
fClientDetachedBytes += entry->resource()->sizeInBytes();
#if GR_CACHE_STATS
if (fHighWaterClientDetachedCount < fClientDetachedCount) {
fHighWaterClientDetachedCount = fClientDetachedCount;
}
if (fHighWaterClientDetachedBytes < fClientDetachedBytes) {
fHighWaterClientDetachedBytes = fClientDetachedBytes;
}
#endif
} else {
SkASSERT(kAccountFor_BudgetBehavior == behavior);
fEntryCount -= 1;
fEntryBytes -= entry->resource()->sizeInBytes();
}
}
void GrResourceCache::attachToHead(GrResourceEntry* entry,
BudgetBehaviors behavior) {
fList.addToHead(entry);
// update our stats
if (kIgnore_BudgetBehavior == behavior) {
fClientDetachedCount -= 1;
fClientDetachedBytes -= entry->resource()->sizeInBytes();
} else {
SkASSERT(kAccountFor_BudgetBehavior == behavior);
fEntryCount += 1;
fEntryBytes += entry->resource()->sizeInBytes();
#if GR_CACHE_STATS
if (fHighWaterEntryCount < fEntryCount) {
fHighWaterEntryCount = fEntryCount;
}
if (fHighWaterEntryBytes < fEntryBytes) {
fHighWaterEntryBytes = fEntryBytes;
}
#endif
}
}
// This functor just searches for an entry with only a single ref (from
// the texture cache itself). Presumably in this situation no one else
// is relying on the texture.
class GrTFindUnreffedFunctor {
public:
bool operator()(const GrResourceEntry* entry) const {
return entry->resource()->unique();
}
};
GrResource* GrResourceCache::find(const GrResourceKey& key, uint32_t ownershipFlags) {
GrAutoResourceCacheValidate atcv(this);
GrResourceEntry* entry = NULL;
if (ownershipFlags & kNoOtherOwners_OwnershipFlag) {
GrTFindUnreffedFunctor functor;
entry = fCache.find<GrTFindUnreffedFunctor>(key, functor);
} else {
entry = fCache.find(key);
}
if (NULL == entry) {
return NULL;
}
if (ownershipFlags & kHide_OwnershipFlag) {
this->makeExclusive(entry);
} else {
// Make this resource MRU
this->internalDetach(entry);
this->attachToHead(entry);
}
return entry->fResource;
}
void GrResourceCache::addResource(const GrResourceKey& key,
GrResource* resource,
uint32_t ownershipFlags) {
SkASSERT(NULL == resource->getCacheEntry());
// we don't expect to create new resources during a purge. In theory
// this could cause purgeAsNeeded() into an infinite loop (e.g.
// each resource destroyed creates and locks 2 resources and
// unlocks 1 thereby causing a new purge).
SkASSERT(!fPurging);
GrAutoResourceCacheValidate atcv(this);
GrResourceEntry* entry = SkNEW_ARGS(GrResourceEntry, (key, resource));
resource->setCacheEntry(entry);
this->attachToHead(entry);
fCache.insert(key, entry);
if (ownershipFlags & kHide_OwnershipFlag) {
this->makeExclusive(entry);
}
}
void GrResourceCache::makeExclusive(GrResourceEntry* entry) {
GrAutoResourceCacheValidate atcv(this);
// When scratch textures are detached (to hide them from future finds) they
// still count against the resource budget
this->internalDetach(entry, kIgnore_BudgetBehavior);
fCache.remove(entry->key(), entry);
#ifdef SK_DEBUG
fExclusiveList.addToHead(entry);
#endif
}
void GrResourceCache::removeInvalidResource(GrResourceEntry* entry) {
// If the resource went invalid while it was detached then purge it
// This can happen when a 3D context was lost,
// the client called GrContext::contextDestroyed() to notify Gr,
// and then later an SkGpuDevice's destructor releases its backing
// texture (which was invalidated at contextDestroyed time).
fClientDetachedCount -= 1;
fEntryCount -= 1;
size_t size = entry->resource()->sizeInBytes();
fClientDetachedBytes -= size;
fEntryBytes -= size;
}
void GrResourceCache::makeNonExclusive(GrResourceEntry* entry) {
GrAutoResourceCacheValidate atcv(this);
#ifdef SK_DEBUG
fExclusiveList.remove(entry);
#endif
if (entry->resource()->isValid()) {
// Since scratch textures still count against the cache budget even
// when they have been removed from the cache, re-adding them doesn't
// alter the budget information.
attachToHead(entry, kIgnore_BudgetBehavior);
fCache.insert(entry->key(), entry);
} else {
this->removeInvalidResource(entry);
}
}
/**
* Destroying a resource may potentially trigger the unlock of additional
* resources which in turn will trigger a nested purge. We block the nested
* purge using the fPurging variable. However, the initial purge will keep
* looping until either all resources in the cache are unlocked or we've met
* the budget. There is an assertion in createAndLock to check against a
* resource's destructor inserting new resources into the cache. If these
* new resources were unlocked before purgeAsNeeded completed it could
* potentially make purgeAsNeeded loop infinitely.
*
* extraCount and extraBytes are added to the current resource totals to account
* for incoming resources (e.g., GrContext is about to add 10MB split between
* 10 textures).
*/
void GrResourceCache::purgeAsNeeded(int extraCount, size_t extraBytes) {
if (fPurging) {
return;
}
fPurging = true;
this->purgeInvalidated();
this->internalPurge(extraCount, extraBytes);
if (((fEntryCount+extraCount) > fMaxCount ||
(fEntryBytes+extraBytes) > fMaxBytes) &&
NULL != fOverbudgetCB) {
// Despite the purge we're still over budget. See if Ganesh can
// release some resources and purge again.
if ((*fOverbudgetCB)(fOverbudgetData)) {
this->internalPurge(extraCount, extraBytes);
}
}
fPurging = false;
}
void GrResourceCache::purgeInvalidated() {
SkTDArray<GrResourceInvalidatedMessage> invalidated;
fInvalidationInbox.poll(&invalidated);
for (int i = 0; i < invalidated.count(); i++) {
// We're somewhat missing an opportunity here. We could use the
// default find functor that gives us back resources whether we own
// them exclusively or not, and when they're not exclusively owned mark
// them for purging later when they do become exclusively owned.
//
// This is complicated and confusing. May try this in the future. For
// now, these resources are just LRU'd as if we never got the message.
while (GrResourceEntry* entry = fCache.find(invalidated[i].key, GrTFindUnreffedFunctor())) {
this->deleteResource(entry);
}
}
}
void GrResourceCache::deleteResource(GrResourceEntry* entry) {
SkASSERT(1 == entry->fResource->getRefCnt());
// remove from our cache
fCache.remove(entry->key(), entry);
// remove from our llist
this->internalDetach(entry);
delete entry;
}
void GrResourceCache::internalPurge(int extraCount, size_t extraBytes) {
SkASSERT(fPurging);
bool withinBudget = false;
bool changed = false;
// The purging process is repeated several times since one pass
// may free up other resources
do {
EntryList::Iter iter;
changed = false;
// Note: the following code relies on the fact that the
// doubly linked list doesn't invalidate its data/pointers
// outside of the specific area where a deletion occurs (e.g.,
// in internalDetach)
GrResourceEntry* entry = iter.init(fList, EntryList::Iter::kTail_IterStart);
while (NULL != entry) {
GrAutoResourceCacheValidate atcv(this);
if ((fEntryCount+extraCount) <= fMaxCount &&
(fEntryBytes+extraBytes) <= fMaxBytes) {
withinBudget = true;
break;
}
GrResourceEntry* prev = iter.prev();
if (entry->fResource->unique()) {
changed = true;
this->deleteResource(entry);
}
entry = prev;
}
} while (!withinBudget && changed);
}
void GrResourceCache::purgeAllUnlocked() {
GrAutoResourceCacheValidate atcv(this);
// we can have one GrResource holding a lock on another
// so we don't want to just do a simple loop kicking each
// entry out. Instead change the budget and purge.
size_t savedMaxBytes = fMaxBytes;
int savedMaxCount = fMaxCount;
fMaxBytes = (size_t) -1;
fMaxCount = 0;
this->purgeAsNeeded();
#ifdef SK_DEBUG
SkASSERT(fExclusiveList.countEntries() == fClientDetachedCount);
SkASSERT(countBytes(fExclusiveList) == fClientDetachedBytes);
if (!fCache.count()) {
// Items may have been detached from the cache (such as the backing
// texture for an SkGpuDevice). The above purge would not have removed
// them.
SkASSERT(fEntryCount == fClientDetachedCount);
SkASSERT(fEntryBytes == fClientDetachedBytes);
SkASSERT(fList.isEmpty());
}
#endif
fMaxBytes = savedMaxBytes;
fMaxCount = savedMaxCount;
}
///////////////////////////////////////////////////////////////////////////////
#ifdef SK_DEBUG
size_t GrResourceCache::countBytes(const EntryList& list) {
size_t bytes = 0;
EntryList::Iter iter;
const GrResourceEntry* entry = iter.init(const_cast<EntryList&>(list),
EntryList::Iter::kTail_IterStart);
for ( ; NULL != entry; entry = iter.prev()) {
bytes += entry->resource()->sizeInBytes();
}
return bytes;
}
static bool both_zero_or_nonzero(int count, size_t bytes) {
return (count == 0 && bytes == 0) || (count > 0 && bytes > 0);
}
void GrResourceCache::validate() const {
fList.validate();
fExclusiveList.validate();
SkASSERT(both_zero_or_nonzero(fEntryCount, fEntryBytes));
SkASSERT(both_zero_or_nonzero(fClientDetachedCount, fClientDetachedBytes));
SkASSERT(fClientDetachedBytes <= fEntryBytes);
SkASSERT(fClientDetachedCount <= fEntryCount);
SkASSERT((fEntryCount - fClientDetachedCount) == fCache.count());
EntryList::Iter iter;
// check that the exclusively held entries are okay
const GrResourceEntry* entry = iter.init(const_cast<EntryList&>(fExclusiveList),
EntryList::Iter::kHead_IterStart);
for ( ; NULL != entry; entry = iter.next()) {
entry->validate();
}
// check that the shareable entries are okay
entry = iter.init(const_cast<EntryList&>(fList), EntryList::Iter::kHead_IterStart);
int count = 0;
for ( ; NULL != entry; entry = iter.next()) {
entry->validate();
SkASSERT(fCache.find(entry->key()));
count += 1;
}
SkASSERT(count == fEntryCount - fClientDetachedCount);
size_t bytes = countBytes(fList);
SkASSERT(bytes == fEntryBytes - fClientDetachedBytes);
bytes = countBytes(fExclusiveList);
SkASSERT(bytes == fClientDetachedBytes);
SkASSERT(fList.countEntries() == fEntryCount - fClientDetachedCount);
SkASSERT(fExclusiveList.countEntries() == fClientDetachedCount);
}
#endif // SK_DEBUG
#if GR_CACHE_STATS
void GrResourceCache::printStats() {
int locked = 0;
EntryList::Iter iter;
GrResourceEntry* entry = iter.init(fList, EntryList::Iter::kTail_IterStart);
for ( ; NULL != entry; entry = iter.prev()) {
if (entry->fResource->getRefCnt() > 1) {
++locked;
}
}
SkDebugf("Budget: %d items %d bytes\n", fMaxCount, fMaxBytes);
SkDebugf("\t\tEntry Count: current %d (%d locked) high %d\n",
fEntryCount, locked, fHighWaterEntryCount);
SkDebugf("\t\tEntry Bytes: current %d high %d\n",
fEntryBytes, fHighWaterEntryBytes);
SkDebugf("\t\tDetached Entry Count: current %d high %d\n",
fClientDetachedCount, fHighWaterClientDetachedCount);
SkDebugf("\t\tDetached Bytes: current %d high %d\n",
fClientDetachedBytes, fHighWaterClientDetachedBytes);
}
#endif
///////////////////////////////////////////////////////////////////////////////