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        , fHighRefCount(0)
26        , fMarkedForDeletion(false)
27        , fDeleted(false) {
28
29        // source for globally unique IDs - 0 is reserved!
30        static int fNextID = 0;
31
32        fID = ++fNextID;
33    }
34    virtual ~GrFakeRefObj() {};
35
36    void ref() {
37        fRef++;
38        if (fHighRefCount < fRef) {
39            fHighRefCount = fRef;
40        }
41    }
42    void unref() {
43        fRef--;
44        GrAlwaysAssert(fRef >= 0);
45
46        // often in OpenGL a given object may still be in use when the
47        // delete call is made. In these cases the object is marked
48        // for deletion and then freed when it is no longer in use
49        if (0 == fRef && fMarkedForDeletion) {
50            this->deleteAction();
51        }
52    }
53    int getRefCount() const             { return fRef; }
54    int getHighRefCount() const         { return fHighRefCount; }
55
56    GrGLuint getID() const              { return fID; }
57
58    void setMarkedForDeletion()         { fMarkedForDeletion = true; }
59    bool getMarkedForDeletion() const   { return fMarkedForDeletion; }
60
61    bool getDeleted() const             { return fDeleted; }
62
63    // The deleteAction fires if the object has been marked for deletion but
64    // couldn't be deleted earlier due to refs
65    virtual void deleteAction() {
66        this->setDeleted();
67    }
68
69protected:
70private:
71    int         fRef;               // ref count
72    int         fHighRefCount;      // high water mark of the ref count
73    GrGLuint    fID;                // globally unique ID
74    bool        fMarkedForDeletion;
75    // The deleted flag is only set when OpenGL thinks the object is deleted
76    // It is obviously still allocated w/in this framework
77    bool        fDeleted;
78
79    // setDeleted should only ever appear in the deleteAction method!
80    void setDeleted()                   { fDeleted = true; }
81};
82
83////////////////////////////////////////////////////////////////////////////////
84// Each class derived from GrFakeRefObj should use this macro to add a
85// factory creation entry point. This entry point is used by the GrGLDebug
86// object to instantiate the various objects
87// all globally unique IDs
88#define GR_DEFINE_CREATOR(className)                        \
89    public:                                                 \
90    static GrFakeRefObj *create ## className() {            \
91        return SkNEW(className);                            \
92    }
93
94#endif // GrFakeRefObj_DEFINED
95