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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.
32
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#include "messages.hh"
66
67namespace sc_dt
68{
69
70// classes defined in this module
71class sc_without_context;
72template <class T>
73class sc_global;
74template <class T>
75class sc_context;
76
77
78// ----------------------------------------------------------------------------
79//  CLASS : sc_without_context
80//
81//  Empty class that is used for its type only.
82// ----------------------------------------------------------------------------
83
84class sc_without_context {};
85
86
87// ----------------------------------------------------------------------------
88//  TEMPLATE CLASS : sc_global
89//
90//  Template global variable class; singleton; co-routine safe.
91// ----------------------------------------------------------------------------
92
93template <class T>
94class sc_global
95{
96    sc_global();
97    void update();
98
99  public:
100    static sc_global<T>* instance();
101    const T*& value_ptr();
102
103  private:
104    static sc_global<T> *m_instance;
105
106    std::map<void *, const T *> m_map;
107    void *m_proc; // context (current process or NULL)
108    const T *m_value_ptr;
109};
110
111
112// ----------------------------------------------------------------------------
113//  ENUM : sc_context_begin
114//
115//  Enumeration of context begin options.
116// ----------------------------------------------------------------------------
117
118enum sc_context_begin
119{
120    SC_NOW,
121    SC_LATER
122};
123
124
125// ----------------------------------------------------------------------------
126//  CLASS : sc_context
127//
128//  Template context class; co-routine safe.
129// ----------------------------------------------------------------------------
130
131template <class T>
132class sc_context
133{
134    // disabled
135    sc_context(const sc_context<T> &);
136    void *operator new(std::size_t);
137
138  public:
139    explicit sc_context(const T &, sc_context_begin=SC_NOW);
140    ~sc_context();
141
142    void begin();
143    void end();
144
145    static const T &default_value();
146    const T &value() const;
147
148  private:
149    sc_context &operator = (const sc_context &) /* = delete */;
150
151    const T m_value;
152    const T *&m_def_value_ptr;
153    const T *m_old_value_ptr;
154};
155
156
157// IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
158
159// ----------------------------------------------------------------------------
160//  TEMPLATE CLASS : sc_global
161//
162//  Template global variable class; singleton; co-routine safe.
163// ----------------------------------------------------------------------------
164
165template <class T>
166sc_global<T> *sc_global<T>::m_instance = 0;
167
168template <class T>
169inline sc_global<T>::sc_global() : m_map(),
170    // use &m_instance as unique "non-process" key (NULL denotes 'sc_main'
171    // context)
172    m_proc(&m_instance), m_value_ptr(0)
173{}
174
175
176template <class T>
177inline void
178sc_global<T>::update()
179{
180    void *p = (::sc_gem5::Process *)sc_core::sc_get_current_process_handle();
181    if (p != m_proc) {
182        const T *vp = m_map[p];
183        if (vp == 0) {
184            vp = new T(sc_without_context());
185            m_map.emplace(p, vp);
186        }
187        m_proc = p;
188        m_value_ptr = vp;
189    }
190}
191
192
193template <class T>
194inline sc_global<T> *
195sc_global<T>::instance()
196{
197    if (m_instance == 0) {
198        m_instance = new sc_global<T>;
199    }
200    return m_instance;
201}
202
203
204template <class T>
205inline const T *&
206sc_global<T>::value_ptr()
207{
208    update();
209    return m_value_ptr;
210}
211
212
213// ----------------------------------------------------------------------------
214//  CLASS : sc_context
215//
216//  Template context class; co-routine safe.
217// ----------------------------------------------------------------------------
218
219template <class T>
220inline sc_context<T>::sc_context(const T &value_, sc_context_begin begin_) :
221        m_value(value_),
222        m_def_value_ptr(sc_global<T>::instance()->value_ptr()),
223        m_old_value_ptr(0)
224{
225    if (begin_ == SC_NOW) {
226        m_old_value_ptr = m_def_value_ptr;
227        m_def_value_ptr = &m_value;
228    }
229}
230
231template <class T>
232inline sc_context<T>::~sc_context()
233{
234    if (m_old_value_ptr != 0) {
235        m_def_value_ptr = m_old_value_ptr;
236        m_old_value_ptr = 0;
237    }
238}
239
240
241template <class T>
242inline void
243sc_context<T>::begin()
244{
245    if (m_old_value_ptr == 0) {
246        m_old_value_ptr = m_def_value_ptr;
247        m_def_value_ptr = &m_value;
248    } else {
249        SC_REPORT_ERROR(sc_core::SC_ID_CONTEXT_BEGIN_FAILED_, 0);
250    }
251}
252
253template <class T>
254inline void
255sc_context<T>::end()
256{
257    if (m_old_value_ptr != 0) {
258        m_def_value_ptr = m_old_value_ptr;
259        m_old_value_ptr = 0;
260    } else {
261        SC_REPORT_ERROR(sc_core::SC_ID_CONTEXT_END_FAILED_, 0);
262    }
263}
264
265
266template <class T>
267inline const T &
268sc_context<T>::default_value()
269{
270    return *sc_global<T>::instance()->value_ptr();
271}
272
273template <class T>
274inline const T &
275sc_context<T>::value() const
276{
277    return m_value;
278}
279
280} // namespace sc_dt
281
282#endif // __SYSTEMC_EXT_DT_FX_SC_CONTEXT_HH__
283