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