1 //===--------------------------- Refcount.h ------------------------------===//
2 //
3 //                              SPIR Tools
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===---------------------------------------------------------------------===//
9 /*
10  * Contributed by: Intel Corporation
11  */
12 
13 #ifndef __REF_COUNT_H__
14 #define __REF_COUNT_H__
15 
16 #include <assert.h>
17 
18 namespace SPIR {
19 
20 template <typename T>
21 class RefCount{
22 public:
RefCount()23   RefCount(): m_refCount(0), m_ptr(0) {
24   }
25 
RefCount(T * ptr)26   RefCount(T* ptr): m_ptr(ptr) {
27     m_refCount = new int(1);
28   }
29 
RefCount(const RefCount<T> & other)30   RefCount(const RefCount<T>& other) {
31     cpy(other);
32   }
33 
~RefCount()34   ~RefCount() {
35     if (m_refCount)
36       dispose();
37   }
38 
39   RefCount& operator=(const RefCount<T>& other) {
40     if(this == &other)
41       return *this;
42     if (m_refCount)
43       dispose();
44     cpy(other);
45     return *this;
46   }
47 
init(T * ptr)48   void init(T* ptr) {
49     assert(!m_ptr && "overrunning non NULL pointer");
50     assert(!m_refCount && "overrunning non NULL pointer");
51     m_refCount = new int(1);
52     m_ptr = ptr;
53   }
54 
isNull()55   bool isNull() const {
56     return (!m_ptr);
57   }
58 
59 // Pointer access
60   const T& operator*() const{
61     sanity();
62     return *m_ptr;
63   }
64 
65   T& operator*() {
66     sanity();
67     return *m_ptr;
68   }
69 
70   operator T*() {
71     return m_ptr;
72   }
73 
74   operator const T*() const{
75     return m_ptr;
76   }
77 
78   T* operator->() {
79     return m_ptr;
80   }
81 
82   const T* operator->() const{
83     return m_ptr;
84   }
85 private:
sanity()86   void sanity() const{
87     assert(m_ptr && "NULL pointer");
88     assert(m_refCount && "NULL ref counter");
89     assert(*m_refCount && "zero ref counter");
90   }
91 
cpy(const RefCount<T> & other)92   void cpy(const RefCount<T>& other) {
93     m_refCount = other.m_refCount;
94     m_ptr = other.m_ptr;
95     if (m_refCount) ++*m_refCount;
96   }
97 
dispose()98   void dispose() {
99     sanity();
100     if (0 == --*m_refCount) {
101       delete m_refCount;
102       delete m_ptr;
103       m_ptr = 0;
104       m_refCount = 0;
105     }
106   }
107 
108   int* m_refCount;
109   T* m_ptr;
110 };// End RefCount
111 
112 } // End SPIR namespace
113 
114 #endif//__REF_COUNT_H__
115