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