libguile/coop-threads.h

   1 /* classes: h_files */
   2
   3 #ifndef COOP_THREADSH
   4 #define COOP_THREADSH
   5
   6 /*      Copyright (C) 1996 Free Software Foundation, Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this software; see the file COPYING.  If not, write to
  20  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  21  * Boston, MA 02111-1307 USA
  22  *
  23  * As a special exception, the Free Software Foundation gives permission
  24  * for additional uses of the text contained in its release of GUILE.
  25  *
  26  * The exception is that, if you link the GUILE library with other files
  27  * to produce an executable, this does not by itself cause the
  28  * resulting executable to be covered by the GNU General Public License.
  29  * Your use of that executable is in no way restricted on account of
  30  * linking the GUILE library code into it.
  31  *
  32  * This exception does not however invalidate any other reasons why
  33  * the executable file might be covered by the GNU General Public License.
  34  *
  35  * This exception applies only to the code released by the
  36  * Free Software Foundation under the name GUILE.  If you copy
  37  * code from other Free Software Foundation releases into a copy of
  38  * GUILE, as the General Public License permits, the exception does
  39  * not apply to the code that you add in this way.  To avoid misleading
  40  * anyone as to the status of such modified files, you must delete
  41  * this exception notice from them.
  42  *
  43  * If you write modifications of your own for GUILE, it is your choice
  44  * whether to permit this exception to apply to your modifications.
  45  * If you do not wish that, delete this exception notice.  */
  46 \f
  47
  48 /* This file is only included by coop-threads.c while coop-defs.h is
  49    included by threads.h, which, in turn, is included by
  50    libguile.h. */
  51
  52 /* The coop_t struct is declared in coop-defs.h. */
  53
  54 #include "libguile/__scm.h"
  55
  56 #include <time.h>
  57
  58 #include "coop-defs.h"
  59 #include "../qt/qt.h"
  60
  61 /* This code is based on a sample thread libraru by David Keppel.
  62    Portions of this file fall under the following copyright: */
  63
  64 /*
  65  * QuickThreads -- Threads-building toolkit.
  66  * Copyright (c) 1993 by David Keppel
  67  *
  68  * Permission to use, copy, modify and distribute this software and
  69  * its documentation for any purpose and without fee is hereby
  70  * granted, provided that the above copyright notice and this notice
  71  * appear in all copies.  This software is provided as a
  72  * proof-of-concept and for demonstration purposes; there is no
  73  * representation about the suitability of this software for any
  74  * purpose.
  75  */
  76
  77 /* A queue is a circular list of threads.  The queue head is a
  78    designated list element.  If this is a uniprocessor-only
  79    implementation we can store the `main' thread in this, but in a
  80    multiprocessor there are several `heavy' threads but only one run
  81    queue.  A fancier implementation might have private run queues,
  82    which would lead to a simpler (trivial) implementation */
  83
  84 typedef struct coop_q_t {
  85   coop_t t;
  86   coop_t *tail;
  87 } coop_q_t;
  88
  89 /* A Mutex variable is made up of a owner thread, and a queue of threads
  90    waiting on the mutex */
  91
  92 typedef struct coop_m {
  93   coop_t *owner;          /* Mutex owner */
  94   coop_q_t waiting;      /* Queue of waiting threads */
  95 } coop_m;
  96
  97 /* A Condition variable is made up of a list of threads waiting on the
  98    condition. */
  99
 100 typedef struct coop_c {
 101   coop_q_t waiting;      /* Queue of waiting threads */
 102 } coop_c;
 103
 104 /* Each thread starts by calling a user-supplied function of this
 105    type. */
 106
 107 typedef void (coop_userf_t)(void *p0);
 108
 109 /* Call this before any other primitives. */
 110 extern void coop_init();
 111
 112 /* When one or more threads are created by the main thread,
 113    the system goes multithread when this is called.  It is done
 114    (no more runable threads) when this returns. */
 115
 116 extern void coop_start (void);
 117
 118 /* Create a thread and make it runable.  When the thread starts
 119    running it will call `f' with arguments `p0' and `p1'. */
 120
 121 extern coop_t *coop_create (coop_userf_t *f, void *p0);
 122
 123 /* The current thread stops running but stays runable.
 124    It is an error to call `coop_yield' before `coop_start'
 125    is called or after `coop_start' returns. */
 126
 127 extern void coop_yield (void);
 128
 129 /* Like `coop_yield' but the thread is discarded.  Any intermediate
 130    state is lost.  The thread can also terminate by simply
 131    returning. */
 132
 133 extern void coop_abort (void);
 134
 135 extern coop_q_t coop_global_runq;       /* A queue of runable threads. */
 136 extern coop_q_t coop_global_sleepq;
 137 extern coop_q_t coop_global_allq;       /* A queue of all threads. */
 138 extern coop_t *coop_global_curr;        /* Currently-executing thread. */
 139
 140 #endif /* COOP_THREADSH */