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#ifndef CYGONCE_SEMAPHORE_H

#define CYGONCE_SEMAPHORE_H

//=============================================================================

//

//      semaphore.h

//

//      POSIX semaphore header

//

//=============================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

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

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under

// the terms of the GNU General Public License as published by the Free

// Software Foundation; either version 2 or (at your option) any later version.

//

// eCos is distributed in the hope that it will be useful, but WITHOUT ANY

// WARRANTY; without even the implied warranty of MERCHANTABILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

//

// You should have received a copy of the GNU General Public License along

// with eCos; if not, write to the Free Software Foundation, Inc.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

// License. However the source code for this file must still be made available

// in accordance with section (3) of the GNU General Public License.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

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

//####ECOSGPLCOPYRIGHTEND####

//=============================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):     nickg

// Contributors:  nickg

// Date:          2000-03-17

// Purpose:       POSIX semaphore header

// Description:   This header contains all the definitions needed to support

//                semaphores under eCos. The reader is referred to the POSIX

//                standard or equivalent documentation for details of the

//                functionality contained herein.

//              

// Usage:

//              #include <semaphore.h>

//              ...

//              

//

//####DESCRIPTIONEND####

//

//=============================================================================

#include <pkgconf/hal.h>

#include <pkgconf/kernel.h>

#include <pkgconf/posix.h>

#include <stddef.h>             // NULL, size_t

#include <limits.h>

#include <sys/types.h>

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

// Semaphore object definition

// This structure must exactly correspond in size and layout to the underlying

// eCos C++ class that implements this object.

typedef struct

{

  CYG_WORD32    sem_value;

  CYG_ADDRESS   sem_queue;

} sem_t;

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

// Semaphore functions

// Initialize semaphore to value.

// pshared is not supported under eCos.

externC int sem_init  (sem_t *sem, int pshared, unsigned int value);

// Destroy the semaphore.

externC int sem_destroy  (sem_t *sem);

// Decrement value if >0 or wait for a post.

externC int sem_wait  (sem_t *sem);

// Decrement value if >0, return -1 if not.

externC int sem_trywait  (sem_t *sem);

// Increment value and wake a waiter if one is present.

externC int sem_post  (sem_t *sem);

// Get current value

externC int sem_getvalue  (sem_t *sem, int *sval);

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

// Named semaphore functions

// These are an optional feature under eCos

// Open an existing named semaphore, or create it.

externC sem_t *sem_open  (const char *name, int oflag, ...);

// Close descriptor for semaphore.

externC int sem_close  (sem_t *sem);

// Remove named semaphore

externC int sem_unlink  (const char *name);

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

// Special return value for sem_open()

#define SEM_FAILED      ((sem_t *)NULL)

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

#endif // ifndef CYGONCE_SEMAPHORE_H

// End of semaphore.h