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: #ifndef GrResource_DEFINED
michael@0: #define GrResource_DEFINED
michael@0: 
michael@0: #include "SkRefCnt.h"
michael@0: #include "SkTInternalLList.h"
michael@0: 
michael@0: class GrGpu;
michael@0: class GrContext;
michael@0: class GrResourceEntry;
michael@0: 
michael@0: /**
michael@0:  * Base class for the GPU resources created by a GrContext.
michael@0:  */
michael@0: class GrResource : public SkRefCnt {
michael@0: public:
michael@0:     SK_DECLARE_INST_COUNT(GrResource)
michael@0: 
michael@0:     /**
michael@0:      * Frees the resource in the underlying 3D API. It must be safe to call this
michael@0:      * when the resource has been previously abandoned.
michael@0:      */
michael@0:     void release();
michael@0: 
michael@0:     /**
michael@0:      * Removes references to objects in the underlying 3D API without freeing
michael@0:      * them. Used when the API context has been torn down before the GrContext.
michael@0:      */
michael@0:     void abandon();
michael@0: 
michael@0:     /**
michael@0:      * Tests whether a resource has been abandoned or released. All resources
michael@0:      * will be in this state after their creating GrContext is destroyed or has
michael@0:      * contextLost called. It's up to the client to test isValid() before
michael@0:      * attempting to use a resource if it holds refs on resources across
michael@0:      * ~GrContext, freeResources with the force flag, or contextLost.
michael@0:      *
michael@0:      * @return true if the resource has been released or abandoned,
michael@0:      *         false otherwise.
michael@0:      */
michael@0:     bool isValid() const { return NULL != fGpu; }
michael@0: 
michael@0:     /**
michael@0:      * Retrieves the size of the object in GPU memory. This is approximate since
michael@0:      * we aren't aware of additional padding or copies made by the driver.
michael@0:      *
michael@0:      * @return the size of the buffer in bytes
michael@0:      */
michael@0:     virtual size_t sizeInBytes() const = 0;
michael@0: 
michael@0:     /**
michael@0:      * Retrieves the context that owns the resource. Note that it is possible
michael@0:      * for this to return NULL. When resources have been release()ed or
michael@0:      * abandon()ed they no longer have an owning context. Destroying a
michael@0:      * GrContext automatically releases all its resources.
michael@0:      */
michael@0:     const GrContext* getContext() const;
michael@0:     GrContext* getContext();
michael@0: 
michael@0:     void setCacheEntry(GrResourceEntry* cacheEntry) { fCacheEntry = cacheEntry; }
michael@0:     GrResourceEntry* getCacheEntry() { return fCacheEntry; }
michael@0: 
michael@0:     void incDeferredRefCount() const {
michael@0:         SkASSERT(fDeferredRefCount >= 0);
michael@0:         ++fDeferredRefCount;
michael@0:     }
michael@0: 
michael@0:     void decDeferredRefCount() const {
michael@0:         SkASSERT(fDeferredRefCount > 0);
michael@0:         --fDeferredRefCount;
michael@0:         if (0 == fDeferredRefCount && this->needsDeferredUnref()) {
michael@0:             SkASSERT(this->getRefCnt() > 1);
michael@0:             this->unref();
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     int getDeferredRefCount() const { return fDeferredRefCount; }
michael@0: 
michael@0:     void setNeedsDeferredUnref() { fFlags |= kDeferredUnref_FlagBit; }
michael@0: 
michael@0: protected:
michael@0:     /**
michael@0:      * isWrapped indicates we have wrapped a client-created backend resource in a GrResource. If it
michael@0:      * is true then the client is responsible for the lifetime of the underlying backend resource.
michael@0:      * Otherwise, our onRelease() should free the resource.
michael@0:      */
michael@0:     GrResource(GrGpu* gpu, bool isWrapped);
michael@0:     virtual ~GrResource();
michael@0: 
michael@0:     GrGpu* getGpu() const { return fGpu; }
michael@0: 
michael@0:     // Derived classes should always call their parent class' onRelease
michael@0:     // and onAbandon methods in their overrides.
michael@0:     virtual void onRelease() {};
michael@0:     virtual void onAbandon() {};
michael@0: 
michael@0:     bool isInCache() const { return NULL != fCacheEntry; }
michael@0:     bool isWrapped() const { return kWrapped_FlagBit & fFlags; }
michael@0:     bool needsDeferredUnref() const { return SkToBool(kDeferredUnref_FlagBit & fFlags); }
michael@0: 
michael@0: private:
michael@0: #ifdef SK_DEBUG
michael@0:     friend class GrGpu; // for assert in GrGpu to access getGpu
michael@0: #endif
michael@0: 
michael@0:     // We're in an internal doubly linked list
michael@0:     SK_DECLARE_INTERNAL_LLIST_INTERFACE(GrResource);
michael@0: 
michael@0:     GrGpu*              fGpu;               // not reffed. The GrGpu can be deleted while there
michael@0:                                             // are still live GrResources. It will call
michael@0:                                             // release() on all such resources in its
michael@0:                                             // destructor.
michael@0:     GrResourceEntry*    fCacheEntry;        // NULL if not in cache
michael@0:     mutable int         fDeferredRefCount;  // How many references in deferred drawing buffers.
michael@0: 
michael@0:     enum Flags {
michael@0:         /**
michael@0:          * This resource wraps a GPU resource given to us by the user.
michael@0:          * Lifetime management is left up to the user (i.e., we will not
michael@0:          * free it).
michael@0:          */
michael@0:         kWrapped_FlagBit         = 0x1,
michael@0: 
michael@0:         /**
michael@0:          * This texture should be de-refed when the deferred ref count goes
michael@0:          * to zero. A resource gets into this state when the resource cache
michael@0:          * is holding a ref-of-obligation (i.e., someone needs to own it but
michael@0:          * no one else wants to) but doesn't really want to keep it around.
michael@0:          */
michael@0:         kDeferredUnref_FlagBit  = 0x2,
michael@0:     };
michael@0:     uint32_t         fFlags;
michael@0: 
michael@0:     typedef SkRefCnt INHERITED;
michael@0: };
michael@0: 
michael@0: #endif