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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
21 class GrFakeRefObj : SkNoncopyable {
22 public:
GrFakeRefObj()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     }
~GrFakeRefObj()33     virtual ~GrFakeRefObj() {}
34 
ref()35     void ref() {
36         fRef++;
37     }
unref()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     }
getRefCount()49     int getRefCount() const             { return fRef; }
50 
getID()51     GrGLuint getID() const              { return fID; }
52 
setMarkedForDeletion()53     void setMarkedForDeletion()         { fMarkedForDeletion = true; }
getMarkedForDeletion()54     bool getMarkedForDeletion() const   { return fMarkedForDeletion; }
55 
getDeleted()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
deleteAction()60     virtual void deleteAction() {
61         this->setDeleted();
62     }
63 
64 protected:
65 private:
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!
setDeleted()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() { return new className; }
85 
86 #endif // GrFakeRefObj_DEFINED
87