sc_context.hh revision 12853:e23d6f09069a 
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20/*****************************************************************************
21
22  sc_context.h -
23
24  Original Author: Martin Janssen, Synopsys, Inc.
25
26 *****************************************************************************/
27
28/*****************************************************************************
29
30  MODIFICATION LOG - modifiers, enter your name, affiliation, date and
31  changes you are making here.
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33      Name, Affiliation, Date:
34  Description of Modification:
35
36 *****************************************************************************/
37
38// $Log: sc_context.h,v $
39// Revision 1.2  2011/08/24 22:05:43  acg
40//  Torsten Maehne: initialization changes to remove warnings.
41//
42// Revision 1.1.1.1  2006/12/15 20:20:04  acg
43// SystemC 2.3
44//
45// Revision 1.5  2006/05/26 20:36:52  acg
46//  Andy Goodrich: added a using for sc_core::default_ptr_hash_fn to keep HP
47//  aCC happy.
48//
49// Revision 1.4  2006/03/21 00:00:31  acg
50//   Andy Goodrich: changed name of sc_get_current_process_base() to be
51//   sc_get_current_process_b() since its returning an sc_process_b instance.
52//
53// Revision 1.3  2006/01/13 18:53:57  acg
54// Andy Goodrich: added $Log command so that CVS comments are reproduced in
55// the source.
56//
57
58#ifndef __SYSTEMC_EXT_DT_FX_SC_CONTEXT_HH__
59#define __SYSTEMC_EXT_DT_FX_SC_CONTEXT_HH__
60
61#include <map>
62
63#include "../../core/sc_process_handle.hh"
64#include "../../utils/sc_report_handler.hh"
65
66namespace sc_dt
67{
68
69// classes defined in this module
70class sc_without_context;
71template <class T>
72class sc_global;
73template <class T>
74class sc_context;
75
76
77// ----------------------------------------------------------------------------
78//  CLASS : sc_without_context
79//
80//  Empty class that is used for its type only.
81// ----------------------------------------------------------------------------
82
83class sc_without_context {};
84
85
86// ----------------------------------------------------------------------------
87//  TEMPLATE CLASS : sc_global
88//
89//  Template global variable class; singleton; co-routine safe.
90// ----------------------------------------------------------------------------
91
92template <class T>
93class sc_global
94{
95    sc_global();
96    void update();
97
98  public:
99    static sc_global<T>* instance();
100    const T*& value_ptr();
101
102  private:
103    static sc_global<T> *m_instance;
104
105    std::map<void *, const T *> m_map;
106    void *m_proc; // context (current process or NULL)
107    const T *m_value_ptr;
108};
109
110
111// ----------------------------------------------------------------------------
112//  ENUM : sc_context_begin
113//
114//  Enumeration of context begin options.
115// ----------------------------------------------------------------------------
116
117enum sc_context_begin
118{
119    SC_NOW,
120    SC_LATER
121};
122
123
124// ----------------------------------------------------------------------------
125//  CLASS : sc_context
126//
127//  Template context class; co-routine safe.
128// ----------------------------------------------------------------------------
129
130template <class T>
131class sc_context
132{
133    // disabled
134    sc_context(const sc_context<T> &);
135    void *operator new(std::size_t);
136
137  public:
138    explicit sc_context(const T &, sc_context_begin=SC_NOW);
139    ~sc_context();
140
141    void begin();
142    void end();
143
144    static const T &default_value();
145    const T &value() const;
146
147  private:
148    sc_context &operator = (const sc_context &) /* = delete */;
149
150    const T m_value;
151    const T *&m_def_value_ptr;
152    const T *m_old_value_ptr;
153};
154
155
156// IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
157
158// ----------------------------------------------------------------------------
159//  TEMPLATE CLASS : sc_global
160//
161//  Template global variable class; singleton; co-routine safe.
162// ----------------------------------------------------------------------------
163
164template <class T>
165sc_global<T> *sc_global<T>::m_instance = 0;
166
167template <class T>
168inline sc_global<T>::sc_global() : m_map(),
169    // use &m_instance as unique "non-process" key (NULL denotes 'sc_main'
170    // context)
171    m_proc(&m_instance), m_value_ptr(0)
172{}
173
174
175template <class T>
176inline void
177sc_global<T>::update()
178{
179    void *p = (::sc_gem5::Process *)sc_core::sc_get_current_process_handle();
180    if (p != m_proc) {
181        const T *vp = m_map[p];
182        if (vp == 0) {
183            vp = new T(sc_without_context());
184            m_map.emplace(p, vp);
185        }
186        m_proc = p;
187        m_value_ptr = vp;
188    }
189}
190
191
192template <class T>
193inline sc_global<T> *
194sc_global<T>::instance()
195{
196    if (m_instance == 0) {
197        m_instance = new sc_global<T>;
198    }
199    return m_instance;
200}
201
202
203template <class T>
204inline const T *&
205sc_global<T>::value_ptr()
206{
207    update();
208    return m_value_ptr;
209}
210
211
212// ----------------------------------------------------------------------------
213//  CLASS : sc_context
214//
215//  Template context class; co-routine safe.
216// ----------------------------------------------------------------------------
217
218template <class T>
219inline sc_context<T>::sc_context(const T &value_, sc_context_begin begin_) :
220        m_value(value_),
221        m_def_value_ptr(sc_global<T>::instance()->value_ptr()),
222        m_old_value_ptr(0)
223{
224    if (begin_ == SC_NOW) {
225        m_old_value_ptr = m_def_value_ptr;
226        m_def_value_ptr = &m_value;
227    }
228}
229
230template <class T>
231inline sc_context<T>::~sc_context()
232{
233    if (m_old_value_ptr != 0) {
234        m_def_value_ptr = m_old_value_ptr;
235        m_old_value_ptr = 0;
236    }
237}
238
239
240template <class T>
241inline void
242sc_context<T>::begin()
243{
244    if (m_old_value_ptr == 0) {
245        m_old_value_ptr = m_def_value_ptr;
246        m_def_value_ptr = &m_value;
247    } else {
248        SC_REPORT_ERROR("context begin failed", 0);
249    }
250}
251
252template <class T>
253inline void
254sc_context<T>::end()
255{
256    if (m_old_value_ptr != 0) {
257        m_def_value_ptr = m_old_value_ptr;
258        m_old_value_ptr = 0;
259    } else {
260        SC_REPORT_ERROR("context end failed", 0);
261    }
262}
263
264
265template <class T>
266inline const T &
267sc_context<T>::default_value()
268{
269    return *sc_global<T>::instance()->value_ptr();
270}
271
272template <class T>
273inline const T &
274sc_context<T>::value() const
275{
276    return m_value;
277}
278
279} // namespace sc_dt
280
281#endif // __SYSTEMC_EXT_DT_FX_SC_CONTEXT_HH__
282