/* Copyright (C) 1998 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
  to anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer
  to the GNU General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given
  to you along with GNU Ghostscript so you can know your rights and
  responsibilities.  It should be in a file named COPYING.  Among other
  things, the copyright notice and this notice must be preserved on all
  copies.
  
  Aladdin Enterprises supports the work of the GNU Project, but is not
  affiliated with the Free Software Foundation or the GNU Project.  GNU
  Ghostscript, as distributed by Aladdin Enterprises, does not require any
  GNU software to build or run it.
*/

/*$Id: gxsync.h $ */
/* Interface to synchronization primitives */

/* Initial version 2/1/98 by John Desrosiers (soho@crl.com) */

#if !defined(gxsync_INCLUDED)
 #define gxsync_INCLUDED

#include "gpsync.h"
#include "gsmemory.h"

/* This module abstracts the platform-specific synchronization primitives. */
/* Since these routines will see heavy use, performance is important. */

/* ----- Semaphore interface ----- */
/* These have the usual queued, counting semaphore semantics: at init time, */
/* the event count is set to 0 ('wait' will wait until 1st signal). */
typedef struct gx_semaphore_s {
    gs_memory_t *memory;	/* allocator to free memory */
    gp_semaphore native;	/* MUST BE LAST last since length is undef'd */
    /*  platform-dep impl, len is gp_semaphore_sizeof() */
} gx_semaphore_t;

gx_semaphore_t *		/* returns a new semaphore, 0 if error */
               gx_semaphore_alloc(P1(
					gs_memory_t * memory	/* memory allocator to use */
				  ));
void
     gx_semaphore_free(P1(
			     gx_semaphore_t * sema	/* semaphore to delete */
		       ));

 #define gx_semaphore_wait(sema)  gp_semaphore_wait(&(sema)->native)
 #define gx_semaphore_signal(sema)  gp_semaphore_signal(&(sema)->native)


/* ----- Monitor interface ----- */
/* These have the usual monitor semantics: at init time, */
/* the event count is set to 1 (1st 'enter' succeeds immediately). */
typedef struct gx_monitor_s {
    gs_memory_t *memory;	/* allocator to free memory */
    gp_monitor native;		/* platform-dep impl, len is gp_monitor_sizeof() */
} gx_monitor_t;

gx_monitor_t *			/* returns a new monitor, 0 if error */
             gx_monitor_alloc(P1(
				    gs_memory_t * memory	/* memory allocator to use */
			      ));
void
     gx_monitor_free(P1(
			   gx_monitor_t * mon	/* monitor to delete */
		     ));

 #define gx_monitor_enter(sema)  gp_monitor_enter(&(sema)->native)
 #define gx_monitor_leave(sema)  gp_monitor_leave(&(sema)->native)

#endif /* !defined(gxsync_INCLUDED) */
