1/*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef GrFakeRefObj_DEFINED
9#define GrFakeRefObj_DEFINED
10
11#include "SkTypes.h"
12#include "gl/GrGLInterface.h"
13
14////////////////////////////////////////////////////////////////////////////////
15// This object is used to track the OpenGL objects. We don't use real
16// reference counting (i.e., we don't free the objects when their ref count
17// goes to 0) so that we can detect invalid memory accesses. The refs we
18// are tracking in this class are actually OpenGL's references to the objects
19// not "ours"
20// Each object also gets a unique globally identifying ID
21class GrFakeRefObj : SkNoncopyable {
22public:
23    GrFakeRefObj()
24        : fRef(0)
25        , fMarkedForDeletion(false)
26        , fDeleted(false) {
27
28        // source for globally unique IDs - 0 is reserved!
29        static int fNextID = 0;
30
31        fID = ++fNextID;
32    }
33    virtual ~GrFakeRefObj() {};
34
35    void ref() {
36        fRef++;
37    }
38    void unref() {
39        fRef--;
40        GrAlwaysAssert(fRef >= 0);
41
42        // often in OpenGL a given object may still be in use when the
43        // delete call is made. In these cases the object is marked
44        // for deletion and then freed when it is no longer in use
45        if (0 == fRef && fMarkedForDeletion) {
46            this->deleteAction();
47        }
48    }
49    int getRefCount() const             { return fRef; }
50
51    GrGLuint getID() const              { return fID; }
52
53    void setMarkedForDeletion()         { fMarkedForDeletion = true; }
54    bool getMarkedForDeletion() const   { return fMarkedForDeletion; }
55
56    bool getDeleted() const             { return fDeleted; }
57
58    // The deleteAction fires if the object has been marked for deletion but
59    // couldn't be deleted earlier due to refs
60    virtual void deleteAction() {
61        this->setDeleted();
62    }
63
64protected:
65private:
66    int         fRef;               // ref count
67    GrGLuint    fID;                // globally unique ID
68    bool        fMarkedForDeletion;
69    // The deleted flag is only set when OpenGL thinks the object is deleted
70    // It is obviously still allocated w/in this framework
71    bool        fDeleted;
72
73    // setDeleted should only ever appear in the deleteAction method!
74    void setDeleted()                   { fDeleted = true; }
75};
76
77////////////////////////////////////////////////////////////////////////////////
78// Each class derived from GrFakeRefObj should use this macro to add a
79// factory creation entry point. This entry point is used by the GrGLDebug
80// object to instantiate the various objects
81// all globally unique IDs
82#define GR_DEFINE_CREATOR(className)                        \
83    public:                                                 \
84    static GrFakeRefObj *create ## className() {            \
85        return SkNEW(className);                            \
86    }
87
88#endif // GrFakeRefObj_DEFINED
89