| /* |
| * Copyright 2020 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrThreadSafeUniquelyKeyedProxyViewCache_DEFINED |
| #define GrThreadSafeUniquelyKeyedProxyViewCache_DEFINED |
| |
| #include "include/private/SkSpinlock.h" |
| #include "src/core/SkArenaAlloc.h" |
| #include "src/core/SkTDynamicHash.h" |
| #include "src/core/SkTInternalLList.h" |
| #include "src/gpu/GrSurfaceProxyView.h" |
| |
| // Ganesh creates a lot of utility textures (e.g., blurred-rrect masks) that need to be shared |
| // between the direct context and all the DDL recording contexts. This thread-safe cache |
| // allows this sharing. |
| // |
| // In operation, each thread will first check if the threaded cache possesses the required texture. |
| // |
| // If a DDL thread doesn't find a needed texture it will go off and create it on the cpu and then |
| // attempt to add it to the cache. If another thread had added it in the interim, the losing thread |
| // will discard its work and use the texture the winning thread had created. |
| // |
| // If the thread in possession of the direct context doesn't find the needed texture it should |
| // add a place holder view and then queue up the draw calls to complete it. In this way the |
| // gpu-thread has precedence over the recording threads. |
| // |
| // The invariants for this cache differ a bit from those of the proxy and resource caches. |
| // For this cache: |
| // |
| // only this cache knows the unique key - neither the proxy nor backing resource should |
| // be discoverable in any other cache by the unique key |
| // if a backing resource resides in the resource cache then there should be an entry in this |
| // cache |
| // an entry in this cache, however, doesn't guarantee that there is a corresponding entry in |
| // the resource cache - although the entry here should be able to generate that entry |
| // (i.e., be a lazy proxy) |
| // |
| // Wrt interactions w/ GrContext/GrResourceCache purging, we have: |
| // |
| // Both GrContext::abandonContext and GrContext::releaseResourcesAndAbandonContext will cause |
| // all the refs held in this cache to be dropped prior to clearing out the resource cache. |
| // |
| // For the size_t-variant of GrContext::purgeUnlockedResources, after an initial attempt |
| // to purge the requested amount of resources fails, uniquely held resources in this cache |
| // will be dropped in LRU to MRU order until the cache is under budget. Note that this |
| // prioritizes the survival of resources in this cache over those just in the resource cache. |
| class GrThreadSafeUniquelyKeyedProxyViewCache { |
| public: |
| GrThreadSafeUniquelyKeyedProxyViewCache(); |
| ~GrThreadSafeUniquelyKeyedProxyViewCache(); |
| |
| #if GR_TEST_UTILS |
| int numEntries() const SK_EXCLUDES(fSpinLock); |
| |
| size_t approxBytesUsedForHash() const SK_EXCLUDES(fSpinLock); |
| #endif |
| |
| void dropAllRefs() SK_EXCLUDES(fSpinLock); |
| void dropAllUniqueRefs(GrResourceCache* resourceCache) SK_EXCLUDES(fSpinLock); |
| |
| GrSurfaceProxyView find(const GrUniqueKey&) SK_EXCLUDES(fSpinLock); |
| |
| GrSurfaceProxyView add(const GrUniqueKey&, const GrSurfaceProxyView&) SK_EXCLUDES(fSpinLock); |
| |
| private: |
| struct Entry { |
| Entry(const GrUniqueKey& key, const GrSurfaceProxyView& view) : fKey(key), fView(view) {} |
| |
| // Note: the unique key is stored here bc it is never attached to a proxy or a GrTexture |
| GrUniqueKey fKey; |
| GrSurfaceProxyView fView; |
| |
| SK_DECLARE_INTERNAL_LLIST_INTERFACE(Entry); |
| |
| // for SkTDynamicHash |
| static const GrUniqueKey& GetKey(const Entry& e) { return e.fKey; } |
| static uint32_t Hash(const GrUniqueKey& key) { return key.hash(); } |
| }; |
| |
| Entry* getEntry(const GrUniqueKey&, const GrSurfaceProxyView&) SK_REQUIRES(fSpinLock); |
| void recycleEntry(Entry*) SK_REQUIRES(fSpinLock); |
| |
| GrSurfaceProxyView internalAdd(const GrUniqueKey&, |
| const GrSurfaceProxyView&) SK_REQUIRES(fSpinLock); |
| |
| mutable SkSpinlock fSpinLock; |
| |
| SkTDynamicHash<Entry, GrUniqueKey> fUniquelyKeyedProxyViewMap SK_GUARDED_BY(fSpinLock); |
| // The head of this list is the MRU |
| SkTInternalLList<Entry> fUniquelyKeyedProxyViewList SK_GUARDED_BY(fSpinLock); |
| |
| // TODO: empirically determine this from the skps |
| static const int kInitialArenaSize = 64 * sizeof(Entry); |
| |
| char fStorage[kInitialArenaSize]; |
| SkArenaAlloc fEntryAllocator{fStorage, kInitialArenaSize, kInitialArenaSize}; |
| Entry* fFreeEntryList SK_GUARDED_BY(fSpinLock); |
| }; |
| |
| #endif // GrThreadSafeUniquelyKeyedProxyViewCache_DEFINED |