libguile/coop-defs.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM_COOP_DEFS_H
   4 #define SCM_COOP_DEFS_H
   5
   6 /* Copyright (C) 1996,1997,1998,1999,2000,2001, 2002 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
  47 \f
  48
  49 #include "libguile/__scm.h"
  50 #include "libguile/iselect.h"
  51
  52 #if SCM_HAVE_WINSOCK2_H
  53 # include <winsock2.h>
  54 #endif
  55
  56 #ifdef GUILE_PTHREAD_COMPAT
  57 #include <pthread.h>
  58 #endif
  59
  60 /* This file is included by threads.h, which, in turn, is included by
  61    libguile.h while coop-threads.h only is included by
  62    coop-threads.c. */
  63
  64 /* The coop_t struct must be declared here, since macros in this file
  65    refer to the data member. */
  66
  67 /* The notion of a thread is merged with the notion of a queue.
  68    Thread stuff: thread status (sp) and stuff to use during
  69    (re)initialization.  Queue stuff: next thread in the queue
  70    (next). */
  71
  72 struct qt_t;
  73
  74 typedef struct coop_t {
  75   struct qt_t *sp;       /* QuickThreads handle. */
  76   void *sto;             /* `malloc'-allocated stack. */
  77
  78   struct coop_t *next;    /* Next thread in the queue. */
  79
  80   struct coop_t *all_next;
  81   struct coop_t *all_prev;
  82
  83   void *data;            /* Thread local data */
  84   void **specific;       /* Data associated with keys */
  85   int n_keys;            /* Upper limit for keys on this thread */
  86
  87   void *base;            /* Base of stack */
  88   void *top;             /* Top of stack */
  89
  90   void *joining;         /* A queue of threads waiting to join this
  91                             thread */
  92
  93   SCM handle;            /* SCM handle, protected via scm_all_threads. */
  94
  95   int nfds;
  96   SELECT_TYPE *readfds;
  97   SELECT_TYPE *writefds;
  98   SELECT_TYPE *exceptfds;
  99   int timeoutp;
 100   struct timeval wakeup_time;   /* Time to stop sleeping */
 101   int _errno;
 102   int retval;
 103
 104 #ifdef GUILE_PTHREAD_COMPAT
 105   pthread_t dummy_thread;
 106   pthread_mutex_t dummy_mutex;
 107 #endif
 108 } coop_t;
 109
 110 /* A queue is a circular list of threads.  The queue head is a
 111    designated list element.  If this is a uniprocessor-only
 112    implementation we can store the `main' thread in this, but in a
 113    multiprocessor there are several `heavy' threads but only one run
 114    queue.  A fancier implementation might have private run queues,
 115    which would lead to a simpler (trivial) implementation */
 116
 117 typedef struct coop_q_t {
 118   coop_t t;
 119   coop_t *tail;
 120 } coop_q_t;
 121
 122 /* A Mutex variable is made up of a owner thread, and a queue of threads
 123    waiting on the mutex */
 124
 125 typedef struct coop_m {
 126   coop_t *owner;          /* Mutex owner */
 127   int level;              /* for recursive locks. */
 128   coop_q_t waiting;      /* Queue of waiting threads */
 129 } coop_m;
 130
 131 typedef int coop_mattr;
 132
 133 SCM_API int coop_mutex_init (coop_m*);
 134 SCM_API int coop_new_mutex_init (coop_m*, coop_mattr*);
 135 SCM_API int coop_mutex_lock (coop_m*);
 136 SCM_API int coop_mutex_trylock (coop_m*);
 137 SCM_API int coop_mutex_unlock (coop_m*);
 138 SCM_API int coop_mutex_destroy (coop_m*);
 139
 140 /* A Condition variable is made up of a list of threads waiting on the
 141    condition. */
 142
 143 typedef struct coop_c {
 144   coop_q_t waiting;      /* Queue of waiting threads */
 145 } coop_c;
 146
 147 typedef int coop_cattr;
 148
 149 SCM_API int coop_condition_variable_init (coop_c*);
 150 SCM_API int coop_new_condition_variable_init (coop_c*, coop_cattr*);
 151 SCM_API int coop_condition_variable_wait_mutex (coop_c*, coop_m*);
 152 SCM_API int coop_condition_variable_timed_wait_mutex (coop_c*,
 153                                                       coop_m*,
 154                                                       const scm_t_timespec *abstime);
 155 SCM_API int coop_condition_variable_signal (coop_c*);
 156 SCM_API int coop_condition_variable_broadcast (coop_c*);
 157 SCM_API int coop_condition_variable_destroy (coop_c*);
 158
 159 typedef int coop_k;
 160
 161 typedef coop_k scm_t_key;
 162
 163 SCM_API int coop_key_create (coop_k *keyp, void (*destruktor) (void *value));
 164 SCM_API int coop_setspecific (coop_k key, const void *value);
 165 SCM_API void *coop_getspecific (coop_k key);
 166 SCM_API int coop_key_delete (coop_k);
 167 #define scm_key_create coop_key_create
 168 #define scm_setspecific coop_setspecific
 169 #define scm_getspecific coop_getspecific
 170 #define scm_key_delete coop_key_delete
 171
 172 SCM_API coop_t *coop_global_curr;             /* Currently-executing thread. */
 173
 174 SCM_API void coop_join (coop_t *t);
 175 SCM_API void coop_yield (void);
 176
 177 SCM_API size_t scm_switch_counter;
 178 SCM_API size_t scm_thread_count;
 179
 180 \f
 181 /* Some iselect functions.  */
 182
 183 /* I'm not sure whether these three declarations should be here.
 184    They're really defined in iselect.c, so you'd think they'd go in
 185    iselect.h, but they use coop_t, defined above, which uses things
 186    defined in iselect.h.  Basically, we're making at best a flailing
 187    (and failing) attempt at modularity here, and I don't have time to
 188    rethink this at the moment.  This code awaits a Hero.  --JimB
 189  */
 190 SCM_API void coop_timeout_qinsert (coop_q_t *, coop_t *);
 191 SCM_API coop_t *coop_next_runnable_thread (void);
 192 SCM_API coop_t *coop_wait_for_runnable_thread_now (struct timeval *);
 193 SCM_API coop_t *coop_wait_for_runnable_thread (void);
 194
 195
 196 \f
 197
 198 /* Cooperative threads don't need to have these defined */
 199
 200 #define SCM_CRITICAL_SECTION_START
 201 #define SCM_CRITICAL_SECTION_END
 202
 203 \f
 204
 205 #define SCM_NO_CRITICAL_SECTION_OWNER 0
 206 #define SCM_THREAD_SWITCH_COUNT       50 /* was 10 /mdj */
 207
 208 \f
 209
 210 #if 0
 211 #define SCM_THREAD_SWITCHING_CODE \
 212 do { \
 213   if (scm_thread_count > 1) \
 214     coop_yield(); \
 215 } while (0)
 216
 217 #else
 218 #define SCM_THREAD_SWITCHING_CODE \
 219 do { \
 220   if (scm_thread_count > 1) \
 221   { \
 222     scm_switch_counter--; \
 223     if (scm_switch_counter == 0) \
 224       { \
 225         scm_switch_counter = SCM_THREAD_SWITCH_COUNT; \
 226         coop_yield(); \
 227       } \
 228   } \
 229 } while (0)
 230
 231 #endif
 232
 233 /* For pthreads, this is a value associated with a specific key.
 234  * For coop, we use a special field for increased efficiency.
 235  */
 236 #define SCM_THREAD_LOCAL_DATA (coop_global_curr->data)
 237 #define SCM_SET_THREAD_LOCAL_DATA(ptr) (coop_global_curr->data = (ptr))
 238
 239 #endif  /* SCM_COOP_DEFS_H */
 240
 241 /*
 242   Local Variables:
 243   c-file-style: "gnu"
 244   End:
 245 */