1 files changed, 74 insertions, 0 deletions
diff --git a/src/gpu/GrPendingIOResource.h b/src/gpu/GrPendingIOResource.h
new file mode 100644
index 0000000000..9aeb65a2d3
--- /dev/null
+++ b/src/gpu/GrPendingIOResource.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrPendingIOResource_DEFINED
+#define GrPendingIOResource_DEFINED
+
+#include "GrGpuResource.h"
+#include "SkNoncopyable.h"
+#include "SkRefCnt.h"
+
+/**
+ * Helper for owning a pending read, write, read-write on a GrGpuResource. It never owns a regular
+ * ref.
+ */
+template <typename T, GrIOType IO_TYPE>
+class GrPendingIOResource : SkNoncopyable {
+public:
+    GrPendingIOResource(T* resource = nullptr) : fResource(nullptr) { this->reset(resource); }
+
+    GrPendingIOResource(const GrPendingIOResource& that) : GrPendingIOResource(that.get()) {}
+
+    void reset(T* resource = nullptr) {
+        if (resource) {
+            switch (IO_TYPE) {
+                case kRead_GrIOType:
+                    resource->addPendingRead();
+                    break;
+                case kWrite_GrIOType:
+                    resource->addPendingWrite();
+                    break;
+                case kRW_GrIOType:
+                    resource->addPendingRead();
+                    resource->addPendingWrite();
+                    break;
+            }
+        }
+        this->release();
+        fResource = resource;
+    }
+
+    ~GrPendingIOResource() { this->release(); }
+
+    explicit operator bool() const { return SkToBool(fResource); }
+
+    bool operator==(const GrPendingIOResource& other) const { return fResource == other.fResource; }
+
+    T* get() const { return fResource; }
+
+private:
+    void release() {
+        if (fResource) {
+            switch (IO_TYPE) {
+                case kRead_GrIOType:
+                    fResource->completedRead();
+                    break;
+                case kWrite_GrIOType:
+                    fResource->completedWrite();
+                    break;
+                case kRW_GrIOType:
+                    fResource->completedRead();
+                    fResource->completedWrite();
+                    break;
+            }
+        }
+    }
+
+    T* fResource;
+};
+
+#endif