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 library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library 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 GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  */
  22
  23 \f
  24
  25 #include "libguile/__scm.h"
  26 #include "libguile/iselect.h"
  27
  28 #if SCM_HAVE_WINSOCK2_H
  29 # include <winsock2.h>
  30 #endif
  31
  32 #ifdef GUILE_PTHREAD_COMPAT
  33 #include <pthread.h>
  34 #endif
  35
  36 /* This file is included by threads.h, which, in turn, is included by
  37    libguile.h while coop-threads.h only is included by
  38    coop-threads.c. */
  39
  40 /* The coop_t struct must be declared here, since macros in this file
  41    refer to the data member. */
  42
  43 /* The notion of a thread is merged with the notion of a queue.
  44    Thread stuff: thread status (sp) and stuff to use during
  45    (re)initialization.  Queue stuff: next thread in the queue
  46    (next). */
  47
  48 struct qt_t;
  49
  50 typedef struct coop_t {
  51   struct qt_t *sp;       /* QuickThreads handle. */
  52   void *sto;             /* `malloc'-allocated stack. */
  53
  54   struct coop_t *next;    /* Next thread in the queue. */
  55
  56   struct coop_t *all_next;
  57   struct coop_t *all_prev;
  58
  59   void *data;            /* Thread local data */
  60   void **specific;       /* Data associated with keys */
  61   int n_keys;            /* Upper limit for keys on this thread */
  62
  63   void *base;            /* Base of stack */
  64   void *top;             /* Top of stack */
  65
  66   void *joining;         /* A queue of threads waiting to join this
  67                             thread */
  68
  69   SCM handle;            /* SCM handle, protected via scm_all_threads. */
  70
  71   int nfds;
  72   SELECT_TYPE *readfds;
  73   SELECT_TYPE *writefds;
  74   SELECT_TYPE *exceptfds;
  75   int timeoutp;
  76   struct timeval wakeup_time;   /* Time to stop sleeping */
  77   int _errno;
  78   int retval;
  79
  80 #ifdef GUILE_PTHREAD_COMPAT
  81   pthread_t dummy_thread;
  82   pthread_mutex_t dummy_mutex;
  83 #endif
  84 } coop_t;
  85
  86 /* A queue is a circular list of threads.  The queue head is a
  87    designated list element.  If this is a uniprocessor-only
  88    implementation we can store the `main' thread in this, but in a
  89    multiprocessor there are several `heavy' threads but only one run
  90    queue.  A fancier implementation might have private run queues,
  91    which would lead to a simpler (trivial) implementation */
  92
  93 typedef struct coop_q_t {
  94   coop_t t;
  95   coop_t *tail;
  96 } coop_q_t;
  97
  98 /* A Mutex variable is made up of a owner thread, and a queue of threads
  99    waiting on the mutex */
 100
 101 typedef struct coop_m {
 102   coop_t *owner;          /* Mutex owner */
 103   int level;              /* for recursive locks. */
 104   coop_q_t waiting;      /* Queue of waiting threads */
 105 } coop_m;
 106
 107 typedef int coop_mattr;
 108
 109 SCM_API int coop_mutex_init (coop_m*);
 110 SCM_API int coop_new_mutex_init (coop_m*, coop_mattr*);
 111 SCM_API int coop_mutex_lock (coop_m*);
 112 SCM_API int coop_mutex_trylock (coop_m*);
 113 SCM_API int coop_mutex_unlock (coop_m*);
 114 SCM_API int coop_mutex_destroy (coop_m*);
 115
 116 /* A Condition variable is made up of a list of threads waiting on the
 117    condition. */
 118
 119 typedef struct coop_c {
 120   coop_q_t waiting;      /* Queue of waiting threads */
 121 } coop_c;
 122
 123 typedef int coop_cattr;
 124
 125 SCM_API int coop_condition_variable_init (coop_c*);
 126 SCM_API int coop_new_condition_variable_init (coop_c*, coop_cattr*);
 127 SCM_API int coop_condition_variable_wait_mutex (coop_c*, coop_m*);
 128 SCM_API int coop_condition_variable_timed_wait_mutex (coop_c*,
 129                                                       coop_m*,
 130                                                       const scm_t_timespec *abstime);
 131 SCM_API int coop_condition_variable_signal (coop_c*);
 132 SCM_API int coop_condition_variable_broadcast (coop_c*);
 133 SCM_API int coop_condition_variable_destroy (coop_c*);
 134
 135 typedef int coop_k;
 136
 137 typedef coop_k scm_t_key;
 138
 139 SCM_API int coop_key_create (coop_k *keyp, void (*destruktor) (void *value));
 140 SCM_API int coop_setspecific (coop_k key, const void *value);
 141 SCM_API void *coop_getspecific (coop_k key);
 142 SCM_API int coop_key_delete (coop_k);
 143 #define scm_key_create coop_key_create
 144 #define scm_setspecific coop_setspecific
 145 #define scm_getspecific coop_getspecific
 146 #define scm_key_delete coop_key_delete
 147
 148 SCM_API coop_t *coop_global_curr;             /* Currently-executing thread. */
 149
 150 SCM_API void coop_join (coop_t *t);
 151 SCM_API void coop_yield (void);
 152
 153 SCM_API size_t scm_switch_counter;
 154 SCM_API size_t scm_thread_count;
 155
 156 \f
 157 /* Some iselect functions.  */
 158
 159 /* I'm not sure whether these three declarations should be here.
 160    They're really defined in iselect.c, so you'd think they'd go in
 161    iselect.h, but they use coop_t, defined above, which uses things
 162    defined in iselect.h.  Basically, we're making at best a flailing
 163    (and failing) attempt at modularity here, and I don't have time to
 164    rethink this at the moment.  This code awaits a Hero.  --JimB
 165  */
 166 SCM_API void coop_timeout_qinsert (coop_q_t *, coop_t *);
 167 SCM_API coop_t *coop_next_runnable_thread (void);
 168 SCM_API coop_t *coop_wait_for_runnable_thread_now (struct timeval *);
 169 SCM_API coop_t *coop_wait_for_runnable_thread (void);
 170
 171
 172 \f
 173
 174 /* Cooperative threads don't need to have these defined */
 175
 176 #define SCM_CRITICAL_SECTION_START
 177 #define SCM_CRITICAL_SECTION_END
 178
 179 \f
 180
 181 #define SCM_NO_CRITICAL_SECTION_OWNER 0
 182 #define SCM_THREAD_SWITCH_COUNT       50 /* was 10 /mdj */
 183
 184 \f
 185
 186 #if 0
 187 #define SCM_THREAD_SWITCHING_CODE \
 188 do { \
 189   if (scm_thread_count > 1) \
 190     coop_yield(); \
 191 } while (0)
 192
 193 #else
 194 #define SCM_THREAD_SWITCHING_CODE \
 195 do { \
 196   if (scm_thread_count > 1) \
 197   { \
 198     scm_switch_counter--; \
 199     if (scm_switch_counter == 0) \
 200       { \
 201         scm_switch_counter = SCM_THREAD_SWITCH_COUNT; \
 202         coop_yield(); \
 203       } \
 204   } \
 205 } while (0)
 206
 207 #endif
 208
 209 /* For pthreads, this is a value associated with a specific key.
 210  * For coop, we use a special field for increased efficiency.
 211  */
 212 #define SCM_THREAD_LOCAL_DATA (coop_global_curr->data)
 213 #define SCM_SET_THREAD_LOCAL_DATA(ptr) (coop_global_curr->data = (ptr))
 214
 215 #endif  /* SCM_COOP_DEFS_H */
 216
 217 /*
 218   Local Variables:
 219   c-file-style: "gnu"
 220   End:
 221 */