sc_semaphore.cpp

来自「基于4个mips核的noc设计」· C++ 代码 · 共 126 行

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  source code Copyright (c) 1996-2002 by all Contributors.
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  set forth in the SystemC Open Source License Version 2.3 (the "License");
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/*****************************************************************************

  sc_semaphore.cpp -- The sc_semaphore primitive channel class.

  Original Author: Martin Janssen, Synopsys, Inc., 2001-05-21

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

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

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#include "systemc/communication/sc_communication_ids.h"
#include "systemc/communication/sc_semaphore.h"
#include "systemc/kernel/sc_simcontext.h"


// ----------------------------------------------------------------------------
//  CLASS : sc_semaphore
//
//  The sc_semaphore primitive channel class.
// ----------------------------------------------------------------------------

const char* const sc_semaphore::kind_string = "sc_semaphore";


// error reporting

void
sc_semaphore::report_error( int id, const char* add_msg ) const
{
    char msg[BUFSIZ];
    if( add_msg != 0 ) {
	sprintf( msg, "%s: semaphore '%s'", add_msg, name() );
    } else {
	sprintf( msg, "semaphore '%s'", name() );
    }
    SC_REPORT_ERROR( id, msg );
}


// constructors

sc_semaphore::sc_semaphore( int init_value_ )
: sc_prim_channel( sc_gen_unique_name( "semaphore" ) ),
  m_value( init_value_ )
{
    if( m_value < 0 ) {
	report_error( SC_ID_INVALID_SEMAPHORE_VALUE_ );
    }
}

sc_semaphore::sc_semaphore( const char* name_, int init_value_ )
: sc_prim_channel( name_ ), m_value( init_value_ )
{
    if( m_value < 0 ) {
	report_error( SC_ID_INVALID_SEMAPHORE_VALUE_ );
    }
}


// interface methods

// lock (take) the semaphore, block if not available

int
sc_semaphore::wait()
{
    while( in_use() ) {
	sc_prim_channel::wait( m_free );
    }
    -- m_value;
    return 0;
}


// lock (take) the semaphore, return -1 if not available

int
sc_semaphore::trywait()
{
    if( in_use() ) {
	return -1;
    }
    -- m_value;
    return 0;
}


// unlock (give) the semaphore

int
sc_semaphore::post()
{
    ++ m_value;
    m_free.notify();
    return 0;
}


// Taf!