sc_thread_process.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
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 *****************************************************************************/

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

  sc_thread_process.h -- Thread process declarations

  Original Author: Andy Goodrich, Forte Design Systems, 4 August 2005
               

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


#if !defined(sc_thread_process_h_INCLUDED)
#define sc_thread_process_h_INCLUDED

#include "sysc/kernel/sc_spawn_options.h"
#include "sysc/kernel/sc_process.h"
#include "sysc/kernel/sc_cor.h"
#include "sysc/kernel/sc_event.h"
#include "sysc/kernel/sc_except.h"
#include "sysc/kernel/sc_reset.h"

// DEBUGGING MACROS:
//
// DEBUG_MSG(NAME,P,MSG)
//     MSG  = message to print
//     NAME = name that must match the process for the message to print, or
//            null if the message should be printed unconditionally.
//     P    = pointer to process message is for, or NULL in which case the
//            message will not print.
#if 0
#   define DEBUG_NAME ""
#   define DEBUG_MSG(NAME,P,MSG) \
    { \
        if ( P && ( (strlen(NAME)==0) || !strcmp(NAME,P->name())) ) \
          std::cout << "**** " << sc_time_stamp() << " ("  \
                    << sc_get_current_process_name() << "): " << MSG \
                    << " - " << P->name() << std::endl; \
    }
#else
#   define DEBUG_MSG(NAME,P,MSG) 
#endif


namespace sc_core {

// forward references:
class sc_event_and_list;
class sc_event_or_list;
class sc_reset;
void sc_thread_cor_fn( void* );
void sc_set_stack_size( sc_thread_handle, std::size_t );
class sc_event;
class sc_join;
class sc_module;
class sc_process_handle;
class sc_process_table;
class sc_simcontext;
class sc_runnable;

sc_cor* get_cor_pointer( sc_process_b* process_p );
void sc_set_stack_size( sc_thread_handle thread_h, std::size_t size );
void wait( sc_simcontext* );
void wait( const sc_event&, sc_simcontext* );
void wait( const sc_event_or_list&, sc_simcontext* );
void wait( const sc_event_and_list&, sc_simcontext* );
void wait( const sc_time&, sc_simcontext* );
void wait( const sc_time&, const sc_event&, sc_simcontext* );
void wait( const sc_time&, const sc_event_or_list&, sc_simcontext* );
void wait( const sc_time&, const sc_event_and_list&, sc_simcontext* );

//==============================================================================
// sc_thread_process -
//
//==============================================================================
class sc_thread_process : public sc_process_b {
    friend void sc_thread_cor_fn( void* );
    friend void sc_set_stack_size( sc_thread_handle, std::size_t );
    friend class sc_event;
    friend class sc_join;
    friend class sc_module;
    friend class sc_process_b;
    friend class sc_process_handle;
    friend class sc_process_table;
    friend class sc_simcontext;
    friend class sc_runnable;
    friend sc_cor* get_cor_pointer( sc_process_b* process_p );

    friend void wait( sc_simcontext* );
    friend void wait( const sc_event&, sc_simcontext* );
    friend void wait( const sc_event_or_list&, sc_simcontext* );
    friend void wait( const sc_event_and_list&, sc_simcontext* );
    friend void wait( const sc_time&, sc_simcontext* );
    friend void wait( const sc_time&, const sc_event&, sc_simcontext* );
    friend void wait( const sc_time&, const sc_event_or_list&, sc_simcontext* );
    friend void wait( const sc_time&, const sc_event_and_list&, sc_simcontext*);
  public:
    sc_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 );

    virtual const char* kind() const
        { return "sc_thread_process"; }

  protected:
    // may not be deleted manually (called from sc_process_b)
    virtual ~sc_thread_process();

    virtual void disable_process( 
        sc_descendant_inclusion_info descendants = SC_NO_DESCENDANTS );
    virtual void enable_process( 
        sc_descendant_inclusion_info descendants = SC_NO_DESCENDANTS );
    virtual void kill_process(
        sc_descendant_inclusion_info descendants = SC_NO_DESCENDANTS );
    sc_thread_handle next_exist();
    sc_thread_handle next_runnable();
    virtual void prepare_for_simulation();
    virtual void resume_process( 
        sc_descendant_inclusion_info descendants = SC_NO_DESCENDANTS );
    void set_next_exist( sc_thread_handle next_p );
    void set_next_runnable( sc_thread_handle next_p );

    void set_stack_size( std::size_t size );
    inline void suspend_me();
    virtual void suspend_process( 
        sc_descendant_inclusion_info descendants = SC_NO_DESCENDANTS );
    virtual void throw_reset( bool async );
    virtual void throw_user( const sc_throw_it_helper& helper,
        sc_descendant_inclusion_info descendants = SC_NO_DESCENDANTS );

    bool trigger_dynamic( sc_event* );
    inline void trigger_static();

    void wait( const sc_event& );
    void wait( const sc_event_or_list& );
    void wait( const sc_event_and_list& );
    void wait( const sc_time& );
    void wait( const sc_time&, const sc_event& );
    void wait( const sc_time&, const sc_event_or_list& );
    void wait( const sc_time&, const sc_event_and_list& );
    void wait_cycles( int n=1 );

  protected:
    void add_monitor( sc_process_monitor* monitor_p );
    void remove_monitor( sc_process_monitor* monitor_p);
    void signal_monitors( int type = 0 );

  protected:
    sc_cor*                          m_cor_p;        // Thread's coroutine.
    std::vector<sc_process_monitor*> m_monitor_q;    // Thread monitors.
    std::size_t                      m_stack_size;   // Thread stack size.
    int                              m_wait_cycle_n; // # of waits to be done.

  private: // disabled
    sc_thread_process( const sc_thread_process& );
    const sc_thread_process& operator = ( const sc_thread_process& );

};

//------------------------------------------------------------------------------
//"sc_thread_process::set_stack_size"
//
//------------------------------------------------------------------------------
inline void sc_thread_process::set_stack_size( std::size_t size )
{
    assert( size );
    m_stack_size = size;
}

//------------------------------------------------------------------------------
//"sc_thread_process::suspend_me"
//
// This method suspends this object instance in favor of the next runnable
// process. Upon awakening we check to see if an exception should be thrown. 
// There are two types of exceptions that can be thrown, synchronous reset
// and asynchronous reset. At a future time there may be more asynchronous
// exceptions.  If an asynchronous reset is seen and there is not static reset
// specified, or the static reset is not active then clear the throw
// type for the next time this method is called.
//
// Notes:
//   (1) For an explanation of how the reset mechanism works see the top of
//       the file sc_reset.cpp.
//   (2) The m_sticky_reset field is used to handle synchronous resets that
//       are enabled via the sc_process_handle::sync_reset_on() method. These
//       resets are not generated by a signal, but rather are modal by 
//       method call: sync_reset_on() - sync_reset_off().
//------------------------------------------------------------------------------
inline void sc_thread_process::suspend_me()
{
    // remember, if we're currently unwinding

    bool unwinding_preempted = m_unwinding;

    sc_simcontext* simc_p = simcontext();
    sc_cor*         cor_p = simc_p->next_cor();

    // do not switch, if we're about to execute next (e.g. suicide)

    if( m_cor_p != cor_p )
    {
        DEBUG_MSG( DEBUG_NAME , this, "suspending thread");
        simc_p->cor_pkg()->yield( cor_p );
        DEBUG_MSG( DEBUG_NAME , this, "resuming thread");
    }

    // IF THERE IS A THROW TO BE DONE FOR THIS PROCESS DO IT NOW:
    //
    // (1) Optimize THROW_NONE for speed as it is the normal case.
    // (2) If this thread is already unwinding then suspend_me() was
    //     called from the catch clause to throw an exception on another
    //     process, so just go back to the catch clause.

    if ( m_throw_status == THROW_NONE ) return;

    if ( m_unwinding ) return;

    switch( m_throw_status )
    {
      case THROW_ASYNC_RESET:
      case THROW_SYNC_RESET:
        DEBUG_MSG( DEBUG_NAME , this, "throwing reset for");
        if ( m_reset_event_p ) m_reset_event_p->notify();
        throw sc_unwind_exception( this, true ); 

      case THROW_USER:
        DEBUG_MSG( DEBUG_NAME, this, "invoking throw_it for");
        m_throw_status = m_active_areset_n ? THROW_ASYNC_RESET :
                                          (m_active_reset_n ? THROW_SYNC_RESET :
                                          THROW_NONE);
        m_throw_helper_p->throw_it();
        break;

      case THROW_KILL:
        DEBUG_MSG( DEBUG_NAME, this, "throwing kill for");
        throw sc_unwind_exception( this, false );

      default: // THROWING_NOW
        sc_assert( unwinding_preempted );
        DEBUG_MSG( DEBUG_NAME, this, "restarting thread");
        break;
    }
}


//------------------------------------------------------------------------------
//"sc_thread_process::wait"
//
//------------------------------------------------------------------------------
inline
void
sc_thread_process::wait( const sc_event& e )
{   
    if( m_unwinding )
        SC_REPORT_ERROR( SC_ID_WAIT_DURING_UNWINDING_, name() );

    m_event_p = &e; // for cleanup.
    e.add_dynamic( this );
    m_trigger_type = EVENT;
    suspend_me();
}

inline
void
sc_thread_process::wait( const sc_event_or_list& el )
{   
    if( m_unwinding )
        SC_REPORT_ERROR( SC_ID_WAIT_DURING_UNWINDING_, name() );

    el.add_dynamic( this );
    m_event_list_p = &el;
    m_trigger_type = OR_LIST;
    suspend_me();
}

inline
void
sc_thread_process::wait( const sc_event_and_list& el )
{
    if( m_unwinding )
        SC_REPORT_ERROR( SC_ID_WAIT_DURING_UNWINDING_, name() );

    el.add_dynamic( this );
    m_event_list_p = &el;
    m_event_count = el.size();
    m_trigger_type = AND_LIST;
    suspend_me();
}

inline
void
sc_thread_process::wait( const sc_time& t )
{
    if( m_unwinding )
        SC_REPORT_ERROR( SC_ID_WAIT_DURING_UNWINDING_, name() );

    m_timeout_event_p->notify_internal( t );
    m_timeout_event_p->add_dynamic( this );
    m_trigger_type = TIMEOUT;
    suspend_me();
}

inline
void
sc_thread_process::wait( const sc_time& t, const sc_event& e )
{
    if( m_unwinding )
        SC_REPORT_ERROR( SC_ID_WAIT_DURING_UNWINDING_, name() );

    m_timeout_event_p->notify_internal( t );
    m_timeout_event_p->add_dynamic( this );
    e.add_dynamic( this );
    m_event_p = &e;
    m_trigger_type = EVENT_TIMEOUT;
    suspend_me();
}

inline
void
sc_thread_process::wait( const sc_time& t, const sc_event_or_list& el )
{
    if( m_unwinding )
        SC_REPORT_ERROR( SC_ID_WAIT_DURING_UNWINDING_, name() );

    m_timeout_event_p->notify_internal( t );
    m_timeout_event_p->add_dynamic( this );
    el.add_dynamic( this );
    m_event_list_p = &el;
    m_trigger_type = OR_LIST_TIMEOUT;
    suspend_me();
}

inline
void
sc_thread_process::wait( const sc_time& t, const sc_event_and_list& el )
{
    if( m_unwinding )
        SC_REPORT_ERROR( SC_ID_WAIT_DURING_UNWINDING_, name() );

    m_timeout_event_p->notify_internal( t );
    m_timeout_event_p->add_dynamic( this );
    el.add_dynamic( this );
    m_event_list_p = &el;
    m_event_count = el.size();
    m_trigger_type = AND_LIST_TIMEOUT;
    suspend_me();
}

//------------------------------------------------------------------------------
//"sc_thread_process::wait_cycles"
//
// This method suspends this object instance for the specified number of cycles.
// A cycle is defined as the event the thread is set up to staticly wait on.
// The field m_wait_cycle_n is set to one less than the number of cycles to
// be waited for, since the value is tested before being decremented in 
// the simulation kernel.
//------------------------------------------------------------------------------
inline
void
sc_thread_process::wait_cycles( int n )
{   
    if( m_unwinding )
        SC_REPORT_ERROR( SC_ID_WAIT_DURING_UNWINDING_, name() );

    m_wait_cycle_n = n-1;
    suspend_me();
}

//------------------------------------------------------------------------------
//"sc_thread_process::miscellaneous support"
//
//------------------------------------------------------------------------------
inline
void sc_thread_process::add_monitor(sc_process_monitor* monitor_p)
{
    m_monitor_q.push_back(monitor_p);
}


inline
void sc_thread_process::remove_monitor(sc_process_monitor* monitor_p)
{
    int mon_n = m_monitor_q.size();

    for ( int mon_i = 0; mon_i < mon_n; mon_i++ )
    {
    if  ( m_monitor_q[mon_i] == monitor_p )
        {
            m_monitor_q[mon_i] = m_monitor_q[mon_n-1];
            m_monitor_q.resize(mon_n-1);
        }
    }
}

inline
void sc_thread_process::set_next_exist(sc_thread_handle next_p)
{
    m_exist_p = next_p;
}

inline
sc_thread_handle sc_thread_process::next_exist()
{
    return (sc_thread_handle)m_exist_p;
}

inline
void sc_thread_process::set_next_runnable(sc_thread_handle next_p)
{
    m_runnable_p = next_p;
}

inline
sc_thread_handle sc_thread_process::next_runnable()
{
    return (sc_thread_handle)m_runnable_p;
}

inline sc_cor* get_cor_pointer( sc_process_b* process_p )
{
    sc_thread_handle thread_p = DCAST<sc_thread_handle>(process_p);
    return thread_p->m_cor_p;
}

//------------------------------------------------------------------------------
//"sc_thread_process::trigger_static"
//
// This inline method adds the current thread to the queue of runnable
// processes, if required.  This is the case if the following criteria
// are met:
//   (1) The process is in a runnable state.
//   (2) The process is not already on the run queue.
//   (3) The process is expecting a static trigger,
//       dynamic event waits take priority.
//   (4) The process' static wait count is zero.
//
// If the triggering process is the same process, the trigger is
// ignored as well, unless SC_ENABLE_IMMEDIATE_SELF_NOTIFICATIONS
// is defined.
//------------------------------------------------------------------------------
inline
void
sc_thread_process::trigger_static()
{
    // No need to try queueing this thread if one of the following is true:
    //    (a) its disabled
    //    (b) its already queued for execution
    //    (c) its waiting on a dynamic event
    //    (d) its wait count is not satisfied

    if ( (m_state & ps_bit_disabled) || is_runnable() ||
          m_trigger_type != STATIC )
        return;

#if ! defined( SC_ENABLE_IMMEDIATE_SELF_NOTIFICATIONS )
    if( SC_UNLIKELY_( sc_get_current_process_b() == this ) )
    {
        report_immediate_self_notification();
        return;
    }
#endif // SC_ENABLE_IMMEDIATE_SELF_NOTIFICATIONS

    if ( m_wait_cycle_n > 0 )
    {
        --m_wait_cycle_n;
        return;
    }

    // If we get here then the thread is has satisfied its wait criteria, if 
    // its suspended mark its state as ready to run. If its not suspended then 
    // push it onto the runnable queue.

    if ( m_state & ps_bit_suspended )
    {
        m_state = m_state | ps_bit_ready_to_run;
    }
    else
    {
        simcontext()->push_runnable_thread(this);
    }
}

#undef DEBUG_MSG
#undef DEBUG_NAME

} // namespace sc_core 

// $Log: sc_thread_process.h,v $
// Revision 1.30  2011/08/26 20:46:11  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 1.29  2011/08/24 23:36:12  acg
//  Andy Goodrich: removed break statements that can never be reached and
//  which causes warnings in the Greenhills C++ compiler.
//
// Revision 1.28  2011/04/14 22:34:27  acg
//  Andy Goodrich: removed dead code.
//
// Revision 1.27  2011/04/13 05:02:18  acg
//  Andy Goodrich: added missing check to the wake up code in suspend_me()
//  so that we just return if the call to suspend_me() was issued from a
//  stack unwinding.
//
// Revision 1.26  2011/04/13 02:44:26  acg
//  Andy Goodrich: added m_unwinding flag in place of THROW_NOW because the
//  throw status will be set back to THROW_*_RESET if reset is active and
//  the check for an unwind being complete was expecting THROW_NONE as the
//  clearing of THROW_NOW.
//
// Revision 1.25  2011/04/11 22:05:14  acg
//  Andy Goodrich: use the DEBUG_NAME macro in DEBUG_MSG invocations.
//
// Revision 1.24  2011/04/10 22:12:32  acg
//  Andy Goodrich: adding debugging macros.
//
// Revision 1.23  2011/04/08 22:41:28  acg
//  Andy Goodrich: added comment pointing to the description of the reset
//  mechanism in sc_reset.cpp.
//
// Revision 1.22  2011/04/08 18:27:33  acg
//  Andy Goodrich: added check to make sure we don't schedule a running process
//  because of it issues a notify() it is sensitive to.
//
// Revision 1.21  2011/04/05 06:22:38  acg
//  Andy Goodrich: expanded comment for trigger_static() initial vetting.
//
// Revision 1.20  2011/04/01 21:24:57  acg
//  Andy Goodrich: removed unused code.
//
// Revision 1.19  2011/02/19 08:30:53  acg
//  Andy Goodrich: Moved process queueing into trigger_static from
//  sc_event::notify.
//
// Revision 1.18  2011/02/18 20:27:14  acg
//  Andy Goodrich: Updated Copyrights.
//
// Revision 1.17  2011/02/17 19:55:58  acg
//  Andy Goodrich:
//    (1) Changed signature of trigger_dynamic() back to a bool.
//    (2) Simplified process control usage.
//    (3) Changed trigger_static() to recognize process controls and to
//        do the down-count on wait(N), allowing the elimination of
//        ready_to_run().
//
// Revision 1.16  2011/02/16 22:37:31  acg
//  Andy Goodrich: clean up to remove need for ps_disable_pending.
//
// Revision 1.15  2011/02/13 21:47:38  acg
//  Andy Goodrich: update copyright notice.
//
// Revision 1.14  2011/02/13 21:35:54  acg
//  Andy Goodrich: added error for performing a wait() during unwinding.
//
// Revision 1.13  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 1.12  2011/02/01 23:01:53  acg
//  Andy Goodrich: removed dead code.
//
// Revision 1.11  2011/02/01 21:18:01  acg
//  Andy Goodrich:
//  (1) Changes in throw processing for new process control rules.
//  (2) Support of new process_state enum values.
//
// Revision 1.10  2011/01/25 20:50:37  acg
//  Andy Goodrich: changes for IEEE 1666 2011.
//
// Revision 1.9  2011/01/19 23:21:50  acg
//  Andy Goodrich: changes for IEEE 1666 2011
//
// Revision 1.8  2011/01/18 20:10:45  acg
//  Andy Goodrich: changes for IEEE1666_2011 semantics.
//
// Revision 1.7  2011/01/06 17:59:58  acg
//  Andy Goodrich: removed debugging output.
//
// Revision 1.6  2010/07/22 20:02:33  acg
//  Andy Goodrich: bug fixes.
//
// Revision 1.5  2009/07/28 01:10:53  acg
//  Andy Goodrich: updates for 2.3 release candidate.
//
// Revision 1.4  2009/05/22 16:06:29  acg
//  Andy Goodrich: process control updates.
//
// Revision 1.3  2009/03/12 22:59:58  acg
//  Andy Goodrich: updates for 2.4 stuff.
//
// Revision 1.2  2008/05/22 17:06:06  acg
//  Andy Goodrich: formatting and comments.
//
// Revision 1.1.1.1  2006/12/15 20:20:05  acg
// SystemC 2.3
//
// Revision 1.7  2006/05/08 17:57:13  acg
//  Andy Goodrich: Added David Long's forward declarations for friend functions
//  to keep the Microsoft C++ compiler happy.
//
// Revision 1.6  2006/04/20 17:08:17  acg
//  Andy Goodrich: 3.0 style process changes.
//
// Revision 1.5  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 1.4  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 1.3  2006/01/13 18:44:30  acg
// Added $Log to record CVS changes into the source.

#endif // !defined(sc_thread_process_h_INCLUDED)