pstoraster/gpsync.h

   1 /* Copyright (C) 1998 Aladdin Enterprises.  All rights reserved.
   2
   3   This file is part of GNU Ghostscript.
   4
   5   GNU Ghostscript is distributed in the hope that it will be useful, but
   6   WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
   7   to anyone for the consequences of using it or for whether it serves any
   8   particular purpose or works at all, unless he says so in writing.  Refer
   9   to the GNU General Public License for full details.
  10
  11   Everyone is granted permission to copy, modify and redistribute GNU
  12   Ghostscript, but only under the conditions described in the GNU General
  13   Public License.  A copy of this license is supposed to have been given
  14   to you along with GNU Ghostscript so you can know your rights and
  15   responsibilities.  It should be in a file named COPYING.  Among other
  16   things, the copyright notice and this notice must be preserved on all
  17   copies.
  18
  19   Aladdin Enterprises supports the work of the GNU Project, but is not
  20   affiliated with the Free Software Foundation or the GNU Project.  GNU
  21   Ghostscript, as distributed by Aladdin Enterprises, does not require any
  22   GNU software to build or run it.
  23 */
  24
  25 /*$Id$ */
  26 /* Interface to platform-dependent synchronization primitives */
  27
  28 #if !defined(gpsync_INCLUDED)
  29 #define gpsync_INCLUDED
  30
  31 /* Initial version 4/1/98 by John Desrosiers (soho@crl.com). */
  32 /* 8/9/98 L. Peter Deutsch (ghost@aladdin.com) Changed ...sizeof to
  33    procedures, added some comments. */
  34
  35 /* -------- Synchronization primitives ------- */
  36
  37 /*
  38  * Semaphores support wait/signal semantics: a wait operation will allow
  39  * control to proceed iff the number of signals since semaphore creation
  40  * is greater than the number of waits.
  41  */
  42 typedef struct {
  43     void *dummy_;
  44 } gp_semaphore;
  45
  46 uint gp_semaphore_sizeof(P0());
  47 /*
  48  * Hack: gp_semaphore_open(0) succeeds iff it's OK for the memory manager
  49  * to move a gp_semaphore in memory.
  50  */
  51 int gp_semaphore_open(P1(gp_semaphore * sema));
  52 int gp_semaphore_close(P1(gp_semaphore * sema));
  53 int gp_semaphore_wait(P1(gp_semaphore * sema));
  54 int gp_semaphore_signal(P1(gp_semaphore * sema));
  55
  56 /*
  57  * Monitors support enter/leave semantics: at most one thread can have
  58  * entered and not yet left a given monitor.
  59  */
  60 typedef struct {
  61     void *dummy_;
  62 } gp_monitor;
  63
  64 uint gp_monitor_sizeof(P0());
  65 /*
  66  * Hack: gp_monitor_open(0) succeeds iff it's OK for the memory manager
  67  * to move a gp_monitor in memory.
  68  */
  69 int gp_monitor_open(P1(gp_monitor * mon));
  70 int gp_monitor_close(P1(gp_monitor * mon));
  71 int gp_monitor_enter(P1(gp_monitor * mon));
  72 int gp_monitor_leave(P1(gp_monitor * mon));
  73
  74 /*
  75  * A new thread starts by calling a procedure, passing it a void * that
  76  * allows it to gain access to whatever data it needs.
  77  */
  78 typedef void (*gp_thread_creation_callback_t) (P1(void *));
  79 int gp_create_thread(P2(gp_thread_creation_callback_t, void *));
  80
  81 #endif /* !defined(gpsync_INCLUDED) */