sc_host_semaphore.h

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  with this work for additional information regarding copyright ownership.
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/*****************************************************************************

  sc_host_semaphore.h -- A "real" semaphore for the underlying host system
*/
#ifndef SC_HOST_SEMAPHORE_H_INCLUDED_
#define SC_HOST_SEMAPHORE_H_INCLUDED_

#ifndef SC_INCLUDE_WINDOWS_H
#  define SC_INCLUDE_WINDOWS_H // include Windows.h, if needed
#endif
#include "sysc/kernel/sc_cmnhdr.h"
#include "sysc/communication/sc_semaphore_if.h"

#if !defined(WIN32) && !defined(_WIN32) // use POSIX semaphore
#include <semaphore.h>
#endif

namespace sc_core {

// ----------------------------------------------------------------------------
//  CLASS : sc_host_semaphore
//
//   Wrapping an OS semaphore on the simulation host
// ----------------------------------------------------------------------------

class SC_API sc_host_semaphore : public sc_semaphore_if
{
#if defined(WIN32) || defined(_WIN32) // use Windows Semaphore

    typedef HANDLE underlying_type;

    void do_init(int init)
    {
      m_sem = CreateSemaphore( NULL, init, LONG_MAX, NULL );
      sc_assert( m_sem != NULL );
    }
    void do_wait()
      { WaitForSingleObject( m_sem, INFINITE ); }
    bool do_trywait()
      { return ( WaitForSingleObject( m_sem, 0 ) == WAIT_OBJECT_0 ); }
    void do_post()
      { ReleaseSemaphore( m_sem, 1, NULL ); }
    void do_destroy()
      { CloseHandle( m_sem ); }

#else // use POSIX semaphore

    typedef sem_t underlying_type;

    void do_init(int init) { sem_init( &m_sem, 0, init ); }
    void do_wait()         { sem_wait( &m_sem ); }
    bool do_trywait()      { return ( sem_trywait( &m_sem ) == 0 ); }
    void do_post()         { sem_post( &m_sem ); }
    void do_destroy()      { sem_close( &m_sem ); }

#endif // platform-specific implementation

public:

    // constructors and destructor

    explicit sc_host_semaphore(int init = 0) : m_sem()
      { do_init(init); }
    virtual ~sc_host_semaphore()
      { do_destroy(); }

    // interface methods

    // lock (take) the semaphore, block if not available
    virtual int wait()
      { do_wait(); return 0; }

    // lock (take) the semaphore, return -1 if not available
    virtual int trywait()
      { return do_trywait() ? 0 : -1; }

    // unlock (give) the semaphore
    virtual int post()
      { do_post(); return 0; }

    // get the value of the semaphore (not supported)
    virtual int get_value() const
      { sc_assert(false && "not supported on sc_host_semaphore"); return -1; }

private:
    underlying_type m_sem;
};

} // namespace sc_core

#endif // SC_HOST_SEMAPHORE_H_INCLUDED_
// Taf!