sc_simcontext.h

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/*****************************************************************************

  The following code is derived, directly or indirectly, from the SystemC
  source code Copyright (c) 1996-2014 by all Contributors.
  All Rights reserved.

  The contents of this file are subject to the restrictions and limitations
  set forth in the SystemC Open Source License (the "License");
  You may not use this file except in compliance with such restrictions and
  limitations. You may obtain instructions on how to receive a copy of the
  License at http://www.accellera.org/. Software distributed by Contributors
  under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
  ANY KIND, either express or implied. See the License for the specific
  language governing rights and limitations under the License.

 *****************************************************************************/

/*****************************************************************************

  sc_simcontext.h -- Definition of the simulation context class.

  Original Author: Stan Y. Liao, Synopsys, Inc.
                   Martin Janssen, Synopsys, Inc.

  CHANGE LOG AT THE END OF THE FILE
 *****************************************************************************/

#ifndef SC_SIMCONTEXT_H
#define SC_SIMCONTEXT_H

#include "sysc/kernel/sc_cmnhdr.h"
#include "sysc/kernel/sc_process.h"
#include "sysc/kernel/sc_status.h"
#include "sysc/kernel/sc_time.h"
#include "sysc/utils/sc_hash.h"
#include "sysc/utils/sc_pq.h"

namespace sc_core {

// forward declarations

class sc_cor;
class sc_cor_pkg;
class sc_event;
class sc_event_timed;
class sc_export_registry;
class sc_module;
class sc_module_name;
class sc_module_registry;
class sc_name_gen;
class sc_object;
class sc_object_manager;
class sc_phase_callback_registry;
class sc_process_handle;
class sc_port_registry;
class sc_prim_channel_registry;
class sc_process_table;
class sc_signal_bool_deval;
class sc_trace_file;
class sc_runnable;
class sc_process_host;
class sc_method_process;
class sc_cthread_process;
class sc_thread_process;

template< typename > class sc_plist;
typedef sc_plist< sc_process_b* > sc_process_list;

struct sc_curr_proc_info
{
    sc_process_b*     process_handle;
    sc_curr_proc_kind kind;
    sc_curr_proc_info() : process_handle( 0 ), kind( SC_NO_PROC_ ) {}
};

typedef const sc_curr_proc_info* sc_curr_proc_handle;

enum sc_stop_mode {          // sc_stop modes:
    SC_STOP_FINISH_DELTA,
    SC_STOP_IMMEDIATE
};
extern void sc_set_stop_mode( sc_stop_mode mode );
extern sc_stop_mode sc_get_stop_mode();

enum sc_starvation_policy 
{
    SC_EXIT_ON_STARVATION,
    SC_RUN_TO_TIME
};
extern void sc_start();
extern void sc_start( const sc_time& duration, 
                      sc_starvation_policy p=SC_RUN_TO_TIME );
inline void sc_start( int duration, sc_time_unit unit, 
                      sc_starvation_policy p=SC_RUN_TO_TIME )
{
    sc_start( sc_time((double)duration,unit), p );
}

inline void sc_start( double duration, sc_time_unit unit, 
                      sc_starvation_policy p=SC_RUN_TO_TIME )
{
    sc_start( sc_time(duration,unit), p );
}

extern void sc_stop();

// friend function declarations

sc_dt::uint64 sc_delta_count();
const std::vector<sc_event*>& sc_get_top_level_events(
                                const   sc_simcontext* simc_p);
const std::vector<sc_object*>& sc_get_top_level_objects(
                                const   sc_simcontext* simc_p);
bool    sc_is_running( const sc_simcontext* simc_p );
void    sc_pause();
bool    sc_end_of_simulation_invoked();
void    sc_start( const sc_time&, sc_starvation_policy );
bool    sc_start_of_simulation_invoked();
void    sc_set_time_resolution( double, sc_time_unit );
sc_time sc_get_time_resolution();
void    sc_set_default_time_unit( double, sc_time_unit );
sc_time sc_get_default_time_unit();
bool    sc_pending_activity_at_current_time( const sc_simcontext* );
bool    sc_pending_activity_at_future_time( const sc_simcontext* );
sc_time sc_time_to_pending_activity( const sc_simcontext* );

struct sc_invoke_method; 

// ----------------------------------------------------------------------------
//  CLASS : sc_simcontext
//
//  The simulation context.
// ----------------------------------------------------------------------------

class sc_simcontext
{
    friend struct sc_invoke_method; 
    friend class sc_event;
    friend class sc_module;
    friend class sc_object;
    friend class sc_time;
    friend class sc_clock;
    friend class sc_method_process;
    friend class sc_phase_callback_registry;
    friend class sc_process_b;
    friend class sc_process_handle;
    friend class sc_prim_channel;
    friend class sc_cthread_process;
    friend class sc_thread_process;
    friend sc_dt::uint64 sc_delta_count();
    friend const std::vector<sc_event*>& sc_get_top_level_events(
        const sc_simcontext* simc_p);
    friend const std::vector<sc_object*>& sc_get_top_level_objects(
        const sc_simcontext* simc_p);
    friend bool sc_is_running( const sc_simcontext* simc_p );
    friend void sc_pause();
    friend bool sc_end_of_simulation_invoked();
    friend void sc_start( const sc_time&, sc_starvation_policy );
    friend bool sc_start_of_simulation_invoked();
    friend void sc_thread_cor_fn(void*);
    friend sc_time sc_time_to_pending_activity( const sc_simcontext* );
    friend bool sc_pending_activity_at_current_time( const sc_simcontext* );
    friend bool sc_pending_activity_at_future_time( const sc_simcontext* );


    void init();
    void clean();

public:

    sc_simcontext();
    ~sc_simcontext();

    void initialize( bool = false );
    void cycle( const sc_time& );
    void simulate( const sc_time& duration );
    void stop();
    void end();
    void reset();

    int sim_status() const;
    bool elaboration_done() const;

    std::vector<sc_thread_handle>& get_active_invokers();

    sc_object_manager* get_object_manager();

    inline sc_status get_status() const;

    sc_object* active_object();

    void hierarchy_push( sc_module* );
    sc_module* hierarchy_pop();
    sc_module* hierarchy_curr() const;
    sc_object* first_object();
    sc_object* next_object();
    sc_object* find_object( const char* name );

    sc_module_registry* get_module_registry();
    sc_port_registry* get_port_registry();
    sc_export_registry* get_export_registry();
    sc_prim_channel_registry* get_prim_channel_registry();

    // to generate unique names for objects in an MT-Safe way
    const char* gen_unique_name( const char* basename_, 
                                 bool preserve_first = false 
                               );

    // process creation
    sc_process_handle create_cthread_process( 
    const char* name_p, bool free_host, SC_ENTRY_FUNC method_p, 
    sc_process_host* host_p, const sc_spawn_options* opt_p );

    sc_process_handle create_method_process( 
    const char* name_p, bool free_host, SC_ENTRY_FUNC method_p, 
    sc_process_host* host_p, const sc_spawn_options* opt_p );

    sc_process_handle create_thread_process( 
    const char* name_p, bool free_host, SC_ENTRY_FUNC method_p, 
    sc_process_host* host_p, const sc_spawn_options* opt_p );

    sc_curr_proc_handle get_curr_proc_info();
    sc_object* get_current_writer() const;
    bool write_check() const;
    void set_curr_proc( sc_process_b* );
    void reset_curr_proc();

    int next_proc_id();

    void add_trace_file( sc_trace_file* );
    void remove_trace_file( sc_trace_file* );

    friend void    sc_set_time_resolution( double, sc_time_unit );
    friend sc_time sc_get_time_resolution();
    friend void    sc_set_default_time_unit( double, sc_time_unit );
    friend sc_time sc_get_default_time_unit();

    const sc_time& max_time() const;
    const sc_time& time_stamp() const;

    sc_dt::uint64 change_stamp() const;
    sc_dt::uint64 delta_count() const;
    bool event_occurred( sc_dt::uint64 last_change_count ) const;
    bool evaluation_phase() const;
    bool is_running() const;
    bool update_phase() const;
    bool notify_phase() const;
    bool get_error();
    void set_error( sc_report* );

    sc_cor_pkg* cor_pkg()
        { return m_cor_pkg; }
    sc_cor* next_cor();

    const ::std::vector<sc_object*>& get_child_objects() const;

    void elaborate();
    void prepare_to_simulate();
    inline void initial_crunch( bool no_crunch );
    bool next_time( sc_time& t ) const; 
    bool pending_activity_at_current_time() const;

private:

    void add_child_event( sc_event* );
    void add_child_object( sc_object* );
    void remove_child_event( sc_event* );
    void remove_child_object( sc_object* );

    void crunch( bool once=false );

    int add_delta_event( sc_event* );
    void remove_delta_event( sc_event* );
    void add_timed_event( sc_event_timed* );

    void trace_cycle( bool delta_cycle );

    const ::std::vector<sc_event*>& get_child_events_internal() const;
    const ::std::vector<sc_object*>& get_child_objects_internal() const;

    void execute_method_next( sc_method_handle );
    void execute_thread_next( sc_thread_handle );

    sc_method_handle pop_runnable_method();
    sc_thread_handle pop_runnable_thread();

    void preempt_with( sc_method_handle );
    inline void preempt_with( sc_thread_handle );

    void push_runnable_method( sc_method_handle );
    void push_runnable_thread( sc_thread_handle );

    void push_runnable_method_front( sc_method_handle );
    void push_runnable_thread_front( sc_thread_handle );

    void remove_runnable_method( sc_method_handle );
    void remove_runnable_thread( sc_thread_handle );

    void requeue_current_process();
    void suspend_current_process();

    void do_sc_stop_action();
    void mark_to_collect_process( sc_process_b* zombie_p );

private:

    enum execution_phases {
        phase_initialize = 0,
        phase_evaluate,
        phase_update,
        phase_notify
    };
    sc_object_manager*          m_object_manager;

    sc_module_registry*         m_module_registry;
    sc_port_registry*           m_port_registry;
    sc_export_registry*         m_export_registry;
    sc_prim_channel_registry*   m_prim_channel_registry;
    sc_phase_callback_registry* m_phase_cb_registry;

    sc_name_gen*                m_name_gen;

    sc_process_table*           m_process_table;
    sc_curr_proc_info           m_curr_proc_info;
    sc_object*                  m_current_writer;
    bool                        m_write_check;
    int                         m_next_proc_id;

    std::vector<sc_thread_handle> m_active_invokers;

    std::vector<sc_event*>      m_child_events;
    std::vector<sc_object*>     m_child_objects;

    std::vector<sc_event*>      m_delta_events;
    sc_ppq<sc_event_timed*>*    m_timed_events;

    std::vector<sc_trace_file*> m_trace_files;
    bool                        m_something_to_trace;

    sc_runnable*                m_runnable;
    sc_process_list*            m_collectable;

    sc_time_params*             m_time_params;
    sc_time                     m_curr_time;
    mutable sc_time             m_max_time;
 
    sc_invoke_method*           m_method_invoker_p;
    sc_dt::uint64               m_change_stamp; // "time" change occurred.
    sc_dt::uint64               m_delta_count;
    bool                        m_forced_stop;
    bool                        m_paused;
    bool                        m_ready_to_simulate;
    bool                        m_elaboration_done;
    execution_phases            m_execution_phase;
    sc_report*                  m_error;
    bool                        m_in_simulator_control;   
    bool                        m_end_of_simulation_called;
    sc_status                   m_simulation_status;
    bool                        m_start_of_simulation_called;

    sc_cor_pkg*                 m_cor_pkg; // the simcontext's coroutine package
    sc_cor*                     m_cor;     // the simcontext's coroutine

private:

    // disabled
    sc_simcontext( const sc_simcontext& );
    sc_simcontext& operator = ( const sc_simcontext& );
};

// IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

// Not MT safe.

#if 1
extern sc_simcontext* sc_curr_simcontext;
extern sc_simcontext* sc_default_global_context;

inline sc_simcontext*
sc_get_curr_simcontext()
{
    if( sc_curr_simcontext == 0 ) {
        sc_default_global_context = new sc_simcontext;
        sc_curr_simcontext = sc_default_global_context;
    }
    return sc_curr_simcontext;
}
#else
    extern sc_simcontext* sc_get_curr_simcontext();
#endif // 0
inline sc_status sc_get_status()
{
    return sc_get_curr_simcontext()->get_status();
}


// IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII

inline
bool
sc_simcontext::elaboration_done() const
{
    return m_elaboration_done;
}


inline sc_status sc_simcontext::get_status() const
{
    return m_simulation_status != SC_RUNNING ? 
                  m_simulation_status :
                  (m_in_simulator_control ? SC_RUNNING : SC_PAUSED);
}

inline
int
sc_simcontext::sim_status() const
{
    if( m_error ) {
        return SC_SIM_ERROR;
    }
    if( m_forced_stop ) {
        return SC_SIM_USER_STOP;
    }
    return SC_SIM_OK;
}


inline
sc_object_manager*
sc_simcontext::get_object_manager()
{
    return m_object_manager;
}

inline
sc_module_registry*
sc_simcontext::get_module_registry()
{
    return m_module_registry;
}

inline
sc_port_registry*
sc_simcontext::get_port_registry()
{
    return m_port_registry;
}

inline
sc_export_registry*
sc_simcontext::get_export_registry()
{
    return m_export_registry;
}

inline
sc_prim_channel_registry*
sc_simcontext::get_prim_channel_registry()
{
    return m_prim_channel_registry;
}


inline
sc_curr_proc_handle
sc_simcontext::get_curr_proc_info()
{
    return &m_curr_proc_info;
}


inline
int
sc_simcontext::next_proc_id()
{
    return ( ++ m_next_proc_id );
}


inline
const sc_time&
sc_simcontext::max_time() const
{
    if ( m_max_time == SC_ZERO_TIME )
    {
        m_max_time = sc_time::from_value( ~sc_dt::UINT64_ZERO );
    }
    return m_max_time;
}

inline
sc_dt::uint64
sc_simcontext::change_stamp() const
{
    return m_change_stamp;
}

inline
const sc_time&
sc_simcontext::time_stamp() const
{
    return m_curr_time;
}


inline 
bool
sc_simcontext::event_occurred(sc_dt::uint64 last_change_stamp) const
{
    return m_change_stamp == last_change_stamp;
}

inline
bool
sc_simcontext::evaluation_phase() const
{
    return (m_execution_phase == phase_evaluate) &&
           m_ready_to_simulate;
}

inline
bool
sc_simcontext::update_phase() const
{
    return m_execution_phase == phase_update;
}

inline
bool
sc_simcontext::notify_phase() const
{
    return m_execution_phase == phase_notify;
}

inline
void
sc_simcontext::set_error( sc_report* err )
{
    delete m_error;
    m_error = err;
}


inline
bool
sc_simcontext::get_error()
{
    return m_error != NULL;
}

inline
int
sc_simcontext::add_delta_event( sc_event* e )
{
    m_delta_events.push_back( e );
    return ( m_delta_events.size() - 1 );
}

inline
void
sc_simcontext::add_timed_event( sc_event_timed* et )
{
    m_timed_events->insert( et );
}

inline sc_object* 
sc_simcontext::get_current_writer() const
{
    return m_current_writer;
}

inline bool 
sc_simcontext::write_check() const
{
    return m_write_check;
}

// ----------------------------------------------------------------------------

class sc_process_handle;
sc_process_handle sc_get_current_process_handle();

// Get the current object hierarchy context
//
// Returns a pointer the the sc_object (module or process) that
// would become the parent object of a newly created element
// of the SystemC object hierarchy, or NULL.
//
inline sc_object*
sc_get_current_object()
{
  return sc_get_curr_simcontext()->active_object();
}

inline
sc_process_b*
sc_get_current_process_b()
{
    return sc_get_curr_simcontext()->get_curr_proc_info()->process_handle;
}

// THE FOLLOWING FUNCTION IS DEPRECATED IN 2.1
extern sc_process_b* sc_get_curr_process_handle();

inline
sc_curr_proc_kind
sc_get_curr_process_kind()
{
    return sc_get_curr_simcontext()->get_curr_proc_info()->kind;
}


inline int sc_get_simulator_status()
{
    return sc_get_curr_simcontext()->sim_status();
}


// Generates unique names within each module.
extern
const char*
sc_gen_unique_name( const char* basename_, bool preserve_first = false );


// Set the random seed for controlled randomization -- not yet implemented
extern
void
sc_set_random_seed( unsigned int seed_ );


extern void sc_initialize();

extern const sc_time& sc_max_time();    // Get maximum time value.
extern const sc_time& sc_time_stamp();  // Current simulation time.
extern double sc_simulation_time();     // Current time in default time units.

inline
const std::vector<sc_event*>& sc_get_top_level_events(
    const sc_simcontext* simc_p = sc_get_curr_simcontext() )
{
    return simc_p->m_child_events;
}

inline
const std::vector<sc_object*>& sc_get_top_level_objects(
    const sc_simcontext* simc_p = sc_get_curr_simcontext() )
{
    return simc_p->m_child_objects;
}

extern sc_event* sc_find_event( const char* name );

extern sc_object* sc_find_object( const char* name );

inline
sc_dt::uint64 sc_delta_count()
{
    return sc_get_curr_simcontext()->m_delta_count;
}

inline 
bool sc_is_running( const sc_simcontext* simc_p = sc_get_curr_simcontext() )
{
    return simc_p->m_ready_to_simulate;
}

bool sc_is_unwinding();

inline void sc_pause()
{
    sc_get_curr_simcontext()->m_paused = true;
}

// Return indication if there are more processes to execute in this delta phase

inline bool sc_pending_activity_at_current_time
  ( const sc_simcontext* simc_p = sc_get_curr_simcontext() )
{
  return simc_p->pending_activity_at_current_time();
}

// Return indication if there are timed notifications in the future

inline bool sc_pending_activity_at_future_time
  ( const sc_simcontext* simc_p = sc_get_curr_simcontext() )
{
  sc_time ignored;
  return simc_p->next_time( ignored );
}

// Return indication if there are processes to run,
// or notifications in the future

inline bool sc_pending_activity
  ( const sc_simcontext* simc_p = sc_get_curr_simcontext() )
{
  return sc_pending_activity_at_current_time( simc_p )
      || sc_pending_activity_at_future_time( simc_p );
}

sc_time
sc_time_to_pending_activity
  ( const sc_simcontext* simc_p = sc_get_curr_simcontext() );


inline
bool
sc_end_of_simulation_invoked()
{
    return sc_get_curr_simcontext()->m_end_of_simulation_called;
}

inline bool sc_hierarchical_name_exists( const char* name )
{
    return sc_find_object(name) || sc_find_event(name);
}

inline
bool 
sc_start_of_simulation_invoked()
{
    return sc_get_curr_simcontext()->m_start_of_simulation_called;
}

// The following variable controls whether process control corners should
// be considered errors or not. See sc_simcontext.cpp for details on what
// happens if this value is set to true.

extern bool sc_allow_process_control_corners;

} // namespace sc_core

/*****************************************************************************

  MODIFICATION LOG - modifiers, enter your name, affiliation, date and
  changes you are making here.

      Name, Affiliation, Date: Andy Goodrich, Forte Design Systems 20 May 2003
  Description of Modification: - phase callbacks
                               - sc_stop mode

      Name, Affiliation, Date: Bishnupriya Bhattacharya, Cadence Design Systems,
                               25 August, 2003
  Description of Modification: - support for dynamic process
                               - support for sc export registry
                               - new member methods elaborate(), 
                 prepare_to_simulate(), and initial_crunch()
                 that are invoked by initialize() in that order
                               - add sc_get_last_created_process_handle() for 
                 use before simulation starts
                               
      Name, Affiliation, Date: Bishnupriya Bhattacharya, Cadence Design Systems,
                               3 March, 2004
  Description of Modification: add sc_get_curr_process_kind()

      Name, Affiliation, Date: 
  Description of Modification: 
                               
 *****************************************************************************/
// $Log: sc_simcontext.h,v $
// Revision 1.26  2011/09/05 21:20:22  acg
//  Andy Goodrich: result of automake invocation.
//
// Revision 1.25  2011/09/01 15:28:10  acg
//  Andy Goodrich: the aftermath of automake.
//
// Revision 1.24  2011/08/29 18:04:32  acg
//  Philipp A. Hartmann: miscellaneous clean ups.
//
// Revision 1.23  2011/08/26 20:46:10  acg
//  Andy Goodrich: moved the modification log to the end of the file to
//  eliminate source line number skew when check-ins are done.
//
// Revision 1.22  2011/08/24 22:05:51  acg
//  Torsten Maehne: initialization changes to remove warnings.
//
// Revision 1.21  2011/05/09 04:07:49  acg
//  Philipp A. Hartmann:
//    (1) Restore hierarchy in all phase callbacks.
//    (2) Ensure calls to before_end_of_elaboration.
//
// Revision 1.20  2011/04/08 18:26:07  acg
//  Andy Goodrich: added execute_method_next() to handle method dispatch
//   for asynchronous notifications that occur outside the evaluation phase.
//
// Revision 1.19  2011/04/05 20:50:57  acg
//  Andy Goodrich:
//    (1) changes to make sure that event(), posedge() and negedge() only
//        return true if the clock has not moved.
//    (2) fixes for method self-resumes.
//    (3) added SC_PRERELEASE_VERSION
//    (4) removed kernel events from the object hierarchy, added
//        sc_hierarchical_name_exists().
//
// Revision 1.18  2011/03/20 13:43:23  acg
//  Andy Goodrich: added async_signal_is() plus suspend() as a corner case.
//
// Revision 1.17  2011/03/07 18:25:19  acg
//  Andy Goodrich: tightening of check for resume on a disabled process to
//  only produce an error if it is ready to run.
//
// Revision 1.16  2011/03/06 15:58:50  acg
//  Andy Goodrich: added escape to turn off process control corner case
//  checks.
//
// Revision 1.15  2011/03/05 04:45:16  acg
//  Andy Goodrich: moved active process calculation to the sc_simcontext class.
//
// Revision 1.14  2011/03/05 01:39:21  acg
//  Andy Goodrich: changes for named events.
//
// Revision 1.13  2011/02/18 20:27:14  acg
//  Andy Goodrich: Updated Copyrights.
//
// Revision 1.12  2011/02/13 21:47:38  acg
//  Andy Goodrich: update copyright notice.
//
// Revision 1.11  2011/02/13 21:34:35  acg
//  Andy Goodrich: added SC_UNITIALIZED enum value to process status so
//  its possible to detect throws before initialization.
//
// Revision 1.10  2011/02/11 13:25:24  acg
//  Andy Goodrich: Philipp A. Hartmann's changes:
//    (1) Removal of SC_CTHREAD method overloads.
//    (2) New exception processing code.
//
// Revision 1.9  2011/02/01 21:18:56  acg
//  Andy Goodrich: addition of new preempt_with() method used to immediately
//  throw exceptions from threads.
//
// Revision 1.8  2011/01/25 20:50:37  acg
//  Andy Goodrich: changes for IEEE 1666 2011.
//
// Revision 1.7  2011/01/19 23:21:50  acg
//  Andy Goodrich: changes for IEEE 1666 2011
//
// Revision 1.6  2011/01/18 20:10:45  acg
//  Andy Goodrich: changes for IEEE1666_2011 semantics.
//
// Revision 1.5  2010/07/22 20:02:33  acg
//  Andy Goodrich: bug fixes.
//
// Revision 1.4  2009/05/22 16:06:29  acg
//  Andy Goodrich: process control updates.
//
// Revision 1.3  2008/05/22 17:06:26  acg
//  Andy Goodrich: updated copyright notice to include 2008.
//
// Revision 1.2  2007/09/20 20:32:35  acg
//  Andy Goodrich: changes to the semantics of throw_it() to match the
//  specification. A call to throw_it() will immediately suspend the calling
//  thread until all the throwees have executed. At that point the calling
//  thread will be restarted before the execution of any other threads.
//
// Revision 1.1.1.1  2006/12/15 20:20:05  acg
// SystemC 2.3
//
// Revision 1.13  2006/05/08 18:00:06  acg
// Andy Goodrich: added David Long's forward declarations for friend
//   functions, methods, and operators to keep the Microsoft compiler happy.
//
// Revision 1.11  2006/04/11 23:13:21  acg
//   Andy Goodrich: Changes for reduced reset support that only includes
//   sc_cthread, but has preliminary hooks for expanding to method and thread
//   processes also.
//
// Revision 1.10  2006/03/21 00:00:34  acg
//   Andy Goodrich: changed name of sc_get_current_process_base() to be
//   sc_get_current_process_b() since its returning an sc_process_b instance.
//
// Revision 1.9  2006/01/26 21:04:54  acg
//  Andy Goodrich: deprecation message changes and additional messages.
//
// Revision 1.8  2006/01/24 20:49:05  acg
// Andy Goodrich: changes to remove the use of deprecated features within the
// simulator, and to issue warning messages when deprecated features are used.
//
// Revision 1.7  2006/01/19 00:29:52  acg
// Andy Goodrich: Yet another implementation for signal write checking. This
// one uses an environment variable SC_SIGNAL_WRITE_CHECK, that when set to
// DISABLE will disable write checking on signals.
//
// Revision 1.6  2006/01/18 21:42:37  acg
// Andy Goodrich: Changes for check writer support.
//
// Revision 1.5  2006/01/13 18:44:30  acg
// Added $Log to record CVS changes into the source.
//
// Revision 1.4  2006/01/03 23:18:44  acg
// Changed copyright to include 2006.
//
// Revision 1.3  2005/12/20 22:11:10  acg
// Fixed $Log lines.
//
// Revision 1.2  2005/12/20 22:02:30  acg
// Changed where delta cycles are incremented to match IEEE 1666. Added the
// event_occurred() method to hide how delta cycle comparisions are done within
// sc_simcontext. Changed the boolean update_phase to an enum that shows all
// the phases.

#endif