Add reference base class to GrGpuResourcewith pending IO references.
BUG=skia:2889
R=robertphillips@google.com
Author: bsalomon@google.com
Review URL: https://codereview.chromium.org/533343002
diff --git a/include/gpu/GrGpuResource.h b/include/gpu/GrGpuResource.h
index 5e852a9..f18f5c5 100644
--- a/include/gpu/GrGpuResource.h
+++ b/include/gpu/GrGpuResource.h
@@ -18,25 +18,108 @@
class GrContext;
/**
- * Base class for objects that can be kept in the GrResourceCache.
+ * Base class for GrGpuResource. Handles the various types of refs we need. Separated out as a base
+ * class to isolate the ref-cnting behavior and provide friendship without exposing all of
+ * GrGpuResource.
+ *
+ * Gpu resources can have three types of refs:
+ * 1) Normal ref (+ by ref(), - by unref()): These are used by code that is issuing draw calls
+ * that read and write the resource via GrDrawTarget and by any object that must own a
+ * GrGpuResource and is itself owned (directly or indirectly) by Skia-client code.
+ * 2) Pending read (+ by addPendingRead(), - by readCompleted()): GrContext has scheduled a read
+ * of the resource by the GPU as a result of a skia API call but hasn't executed it yet.
+ * 3) Pending write (+ by addPendingWrite(), - by writeCompleted()): GrContext has scheduled a
+ * write to the resource by the GPU as a result of a skia API call but hasn't executed it yet.
+ *
+ * The latter two ref types are private and intended only for Gr core code.
*/
-class GrGpuResource : public SkNoncopyable {
+class GrGpuRef : public SkNoncopyable {
public:
- SK_DECLARE_INST_COUNT_ROOT(GrGpuResource)
+ SK_DECLARE_INST_COUNT_ROOT(GrGpuRef)
- // These method signatures are written to mirror SkRefCnt. However, we don't require
- // thread safety as GrCacheable objects are not intended to cross thread boundaries.
+ virtual ~GrGpuRef();
+
+ // Some of the signatures are written to mirror SkRefCnt so that GrGpuResource can work with
+ // templated helper classes (e.g. SkAutoTUnref). However, we have different categories of
+ // refs (e.g. pending reads). We also don't require thread safety as GrCacheable objects are
+ // not intended to cross thread boundaries.
// internal_dispose() exists because of GrTexture's reliance on it. It will be removed
// soon.
- void ref() const { ++fRefCnt; }
- void unref() const { --fRefCnt; if (0 == fRefCnt) { this->internal_dispose(); } }
- virtual void internal_dispose() const { SkDELETE(this); }
- bool unique() const { return 1 == fRefCnt; }
-#ifdef SK_DEBUG
- void validate() const {
- SkASSERT(fRefCnt > 0);
+ void ref() const {
+ ++fRefCnt;
+ // pre-validate once internal_dispose is removed (and therefore 0 ref cnt is not allowed).
+ this->validate();
}
+
+ void unref() const {
+ this->validate();
+ --fRefCnt;
+ if (0 == fRefCnt && 0 == fPendingReads && 0 == fPendingWrites) {
+ this->internal_dispose();
+ }
+ }
+
+ virtual void internal_dispose() const { SkDELETE(this); }
+
+ /** This is exists to service the old mechanism for recycling scratch textures. It will
+ be removed soon. */
+ bool unique() const { return 1 == (fRefCnt + fPendingReads + fPendingWrites); }
+
+ void validate() const {
+#ifdef SK_DEBUG
+ SkASSERT(fRefCnt >= 0);
+ SkASSERT(fPendingReads >= 0);
+ SkASSERT(fPendingWrites >= 0);
+ SkASSERT(fRefCnt + fPendingReads + fPendingWrites > 0);
#endif
+ }
+
+protected:
+ GrGpuRef() : fRefCnt(1), fPendingReads(0), fPendingWrites(0) {}
+
+private:
+ void addPendingRead() const {
+ this->validate();
+ ++fPendingReads;
+ }
+
+ void completedRead() const {
+ this->validate();
+ --fPendingReads;
+ if (0 == fRefCnt && 0 == fPendingReads && 0 == fPendingWrites) {
+ this->internal_dispose();
+ }
+ }
+
+ void addPendingWrite() const {
+ this->validate();
+ ++fPendingWrites;
+ }
+
+ void completedWrite() const {
+ this->validate();
+ --fPendingWrites;
+ if (0 == fRefCnt && 0 == fPendingReads && 0 == fPendingWrites) {
+ this->internal_dispose();
+ }
+ }
+
+private:
+ mutable int32_t fRefCnt;
+ mutable int32_t fPendingReads;
+ mutable int32_t fPendingWrites;
+
+ // These functions need access to the pending read/write member functions.
+ friend class GrDrawState;
+ friend class GrProgramResource;
+};
+
+/**
+ * Base class for objects that can be kept in the GrResourceCache.
+ */
+class GrGpuResource : public GrGpuRef {
+public:
+ SK_DECLARE_INST_COUNT(GrGpuResource)
/**
* Frees the object in the underlying 3D API. It must be safe to call this
@@ -154,13 +237,12 @@
uint32_t fFlags;
- mutable int32_t fRefCnt;
GrResourceCacheEntry* fCacheEntry; // NULL if not in cache
const uint32_t fUniqueID;
GrResourceKey fScratchKey;
- typedef SkNoncopyable INHERITED;
+ typedef GrGpuRef INHERITED;
};
#endif