libguile/coop-defs.h

   1 /* classes: h_files */
   2
   3 #ifndef COOP_DEFSH
   4 #define COOP_DEFSH
   5
   6 /*      Copyright (C) 1996, 1997, 1998, 1999, 2000 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 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  48    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  49 \f
  50
  51 # ifdef TIME_WITH_SYS_TIME
  52 #  include <sys/time.h>
  53 #  include <time.h>
  54 # else
  55 #  ifdef HAVE_SYS_TIME_H
  56 #   include <sys/time.h>
  57 #  else
  58 #   ifdef HAVE_TIME_H
  59 #    include <time.h>
  60 #   endif
  61 #  endif
  62 # endif
  63
  64 #ifdef GUILE_ISELECT
  65 #include "iselect.h"
  66 #endif
  67
  68 #ifdef GUILE_PTHREAD_COMPAT
  69 #include <pthread.h>
  70 #endif
  71
  72 /* This file is included by threads.h, which, in turn, is included by
  73    libguile.h while coop-threads.h only is included by
  74    coop-threads.c. */
  75
  76 /* The coop_t struct must be declared here, since macros in this file
  77    refer to the data member. */
  78
  79 /* The notion of a thread is merged with the notion of a queue.
  80    Thread stuff: thread status (sp) and stuff to use during
  81    (re)initialization.  Queue stuff: next thread in the queue
  82    (next). */
  83
  84 struct qt_t;
  85
  86 typedef struct coop_t {
  87   struct qt_t *sp;       /* QuickThreads handle. */
  88 #ifndef GUILE_PTHREAD_COMPAT
  89   void *sto;             /* `malloc'-allocated stack. */
  90 #endif
  91
  92   struct coop_t *next;    /* Next thread in the queue. */
  93
  94   struct coop_t *all_next;
  95   struct coop_t *all_prev;
  96
  97   void *data;            /* Thread local data */
  98   void **specific;       /* Data associated with keys */
  99   int n_keys;            /* Upper limit for keys on this thread */
 100
 101   void *base;            /* Base of stack */
 102   void *top;             /* Top of stack */
 103
 104   void *joining;         /* A queue of threads waiting to join this
 105                             thread */
 106
 107 #ifdef GUILE_ISELECT
 108   int nfds;
 109   SELECT_TYPE *readfds;
 110   SELECT_TYPE *writefds;
 111   SELECT_TYPE *exceptfds;
 112   int timeoutp;
 113   struct timeval wakeup_time;   /* Time to stop sleeping */
 114   int _errno;
 115   int retval;
 116 #else
 117   time_t wakeup_time;    /* Time to stop sleeping */
 118 #endif
 119
 120 #ifdef GUILE_PTHREAD_COMPAT
 121   pthread_t dummy_thread;
 122   pthread_mutex_t dummy_mutex;
 123 #endif
 124 } coop_t;
 125
 126 /* A queue is a circular list of threads.  The queue head is a
 127    designated list element.  If this is a uniprocessor-only
 128    implementation we can store the `main' thread in this, but in a
 129    multiprocessor there are several `heavy' threads but only one run
 130    queue.  A fancier implementation might have private run queues,
 131    which would lead to a simpler (trivial) implementation */
 132
 133 typedef struct coop_q_t {
 134   coop_t t;
 135   coop_t *tail;
 136 } coop_q_t;
 137
 138 /* A Mutex variable is made up of a owner thread, and a queue of threads
 139    waiting on the mutex */
 140
 141 typedef struct coop_m {
 142   coop_t *owner;          /* Mutex owner */
 143   coop_q_t waiting;      /* Queue of waiting threads */
 144 } coop_m;
 145
 146 typedef int coop_mattr;
 147
 148 typedef coop_m scm_mutex_t;
 149
 150 extern int coop_mutex_init (coop_m*);
 151 extern int coop_new_mutex_init (coop_m*, coop_mattr*);
 152 extern int coop_mutex_lock (coop_m*);
 153 extern int coop_mutex_trylock (coop_m*);
 154 extern int coop_mutex_unlock (coop_m*);
 155 extern int coop_mutex_destroy (coop_m*);
 156 #define scm_mutex_init coop_mutex_init
 157 #define scm_mutex_lock coop_mutex_lock
 158 #define scm_mutex_trylock coop_mutex_lock
 159 #define scm_mutex_unlock coop_mutex_unlock
 160 #define scm_mutex_destroy coop_mutex_destroy
 161
 162 /* A Condition variable is made up of a list of threads waiting on the
 163    condition. */
 164
 165 typedef struct coop_c {
 166   coop_q_t waiting;      /* Queue of waiting threads */
 167 } coop_c;
 168
 169 typedef int coop_cattr;
 170
 171 typedef coop_c scm_cond_t;
 172
 173 #ifndef HAVE_STRUCT_TIMESPEC
 174 /* POSIX.4 structure for a time value.  This is like a `struct timeval' but
 175    has nanoseconds instead of microseconds.  */
 176 struct timespec
 177 {
 178   long int tv_sec;              /* Seconds.  */
 179   long int tv_nsec;             /* Nanoseconds.  */
 180 };
 181 #endif
 182
 183 extern int coop_condition_variable_init (coop_c*);
 184 extern int coop_new_condition_variable_init (coop_c*, coop_cattr*);
 185 extern int coop_condition_variable_wait_mutex (coop_c*, coop_m*);
 186 extern int coop_condition_variable_timed_wait_mutex (coop_c*,
 187                                                      coop_m*,
 188                                                      const struct timespec *abstime);
 189 extern int coop_condition_variable_signal (coop_c*);
 190 extern int coop_condition_variable_destroy (coop_c*);
 191 #define scm_cond_init coop_new_condition_variable_init
 192 #define scm_cond_wait coop_condition_variable_wait_mutex
 193 #define scm_cond_timedwait coop_condition_variable_timed_wait_mutex
 194 #define scm_cond_signal coop_condition_variable_signal
 195 #define scm_cond_broadcast coop_condition_variable_signal /* yes */
 196 #define scm_cond_destroy coop_condition_variable_destroy
 197
 198 typedef int coop_k;
 199
 200 typedef coop_k scm_key_t;
 201
 202 extern int coop_key_create (coop_k *keyp, void (*destructor) (void *value));
 203 extern int coop_setspecific (coop_k key, const void *value);
 204 extern void *coop_getspecific (coop_k key);
 205 extern int coop_key_delete (coop_k);
 206 #define scm_key_create coop_key_create
 207 #define scm_setspecific coop_setspecific
 208 #define scm_getspecific coop_getspecific
 209 #define scm_key_delete coop_key_delete
 210
 211 extern coop_t *coop_global_curr;        /* Currently-executing thread. */
 212
 213 extern void coop_join (coop_t *t);
 214 extern void coop_yield (void);
 215
 216 extern size_t scm_switch_counter;
 217 extern size_t scm_thread_count;
 218
 219 \f
 220 /* Some iselect functions.  */
 221
 222 /* I'm not sure whether these three declarations should be here.
 223    They're really defined in iselect.c, so you'd think they'd go in
 224    iselect.h, but they use coop_t, defined above, which uses things
 225    defined in iselect.h.  Basically, we're making at best a flailing
 226    (and failing) attempt at modularity here, and I don't have time to
 227    rethink this at the moment.  This code awaits a Hero.  --JimB */
 228 #ifdef GUILE_ISELECT
 229 void coop_timeout_qinsert (coop_q_t *, coop_t *);
 230 #endif
 231 extern coop_t *coop_next_runnable_thread (void);
 232 extern coop_t *coop_wait_for_runnable_thread_now (struct timeval *);
 233 extern coop_t *coop_wait_for_runnable_thread (void);
 234
 235
 236 \f
 237
 238 /* Cooperative threads don't need to have these defined */
 239
 240 #define SCM_THREAD_CRITICAL_SECTION_START
 241 #define SCM_THREAD_CRITICAL_SECTION_END
 242
 243 \f
 244
 245 #define SCM_NO_CRITICAL_SECTION_OWNER 0
 246 #define SCM_THREAD_SWITCH_COUNT       50 /* was 10 /mdj */
 247
 248 \f
 249
 250 #define SCM_THREAD_DEFER
 251 #define SCM_THREAD_ALLOW
 252 #define SCM_THREAD_REDEFER
 253 #define SCM_THREAD_REALLOW_1
 254 #define SCM_THREAD_REALLOW_2
 255
 256 #if 0
 257 #define SCM_THREAD_SWITCHING_CODE \
 258 do { \
 259   if (scm_thread_count > 1) \
 260     coop_yield(); \
 261 } while (0)
 262
 263 #else
 264 #define SCM_THREAD_SWITCHING_CODE \
 265 do { \
 266   if (scm_thread_count > 1) \
 267   { \
 268     scm_switch_counter--; \
 269     if (scm_switch_counter == 0) \
 270       { \
 271         scm_switch_counter = SCM_THREAD_SWITCH_COUNT; \
 272         coop_yield(); \
 273       } \
 274   } \
 275 } while (0)
 276
 277 #endif
 278
 279 /* For pthreads, this is a value associated with a specific key.
 280  * For coop, we use a special field for increased efficiency.
 281  */
 282 #define SCM_THREAD_LOCAL_DATA (coop_global_curr->data)
 283 #define SCM_SET_THREAD_LOCAL_DATA(ptr) (coop_global_curr->data = (ptr))
 284
 285 #endif /* COOP_DEFSH */
 286
 287 /*
 288   Local Variables:
 289   c-file-style: "gnu"
 290   End:
 291 */