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, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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
  35 # define GC_THREADS 1
  36 # include <gc/gc.h>
  37 #endif
  38
  39 /* This file is included by threads.h, which, in turn, is included by
  40    libguile.h while coop-threads.h only is included by
  41    coop-threads.c. */
  42
  43 /* The coop_t struct must be declared here, since macros in this file
  44    refer to the data member. */
  45
  46 /* The notion of a thread is merged with the notion of a queue.
  47    Thread stuff: thread status (sp) and stuff to use during
  48    (re)initialization.  Queue stuff: next thread in the queue
  49    (next). */
  50
  51 struct qt_t;
  52
  53 typedef struct coop_t {
  54   struct qt_t *sp;       /* QuickThreads handle. */
  55   void *sto;             /* `malloc'-allocated stack. */
  56
  57   struct coop_t *next;    /* Next thread in the queue. */
  58
  59   struct coop_t *all_next;
  60   struct coop_t *all_prev;
  61
  62   void *data;            /* Thread local data */
  63   void **specific;       /* Data associated with keys */
  64   int n_keys;            /* Upper limit for keys on this thread */
  65
  66   void *base;            /* Base of stack */
  67   void *top;             /* Top of stack */
  68
  69   void *joining;         /* A queue of threads waiting to join this
  70                             thread */
  71
  72   SCM handle;            /* SCM handle, protected via scm_all_threads. */
  73
  74   int nfds;
  75   SELECT_TYPE *readfds;
  76   SELECT_TYPE *writefds;
  77   SELECT_TYPE *exceptfds;
  78   int timeoutp;
  79   struct timeval wakeup_time;   /* Time to stop sleeping */
  80   int _errno;
  81   int retval;
  82
  83 #ifdef GUILE_PTHREAD_COMPAT
  84   pthread_t dummy_thread;
  85   pthread_mutex_t dummy_mutex;
  86 #endif
  87 } coop_t;
  88
  89 /* A queue is a circular list of threads.  The queue head is a
  90    designated list element.  If this is a uniprocessor-only
  91    implementation we can store the `main' thread in this, but in a
  92    multiprocessor there are several `heavy' threads but only one run
  93    queue.  A fancier implementation might have private run queues,
  94    which would lead to a simpler (trivial) implementation */
  95
  96 typedef struct coop_q_t {
  97   coop_t t;
  98   coop_t *tail;
  99 } coop_q_t;
 100
 101 /* A Mutex variable is made up of a owner thread, and a queue of threads
 102    waiting on the mutex */
 103
 104 typedef struct coop_m {
 105   coop_t *owner;          /* Mutex owner */
 106   int level;              /* for recursive locks. */
 107   coop_q_t waiting;      /* Queue of waiting threads */
 108 } coop_m;
 109
 110 typedef int coop_mattr;
 111
 112 SCM_API int coop_mutex_init (coop_m*);
 113 SCM_API int coop_new_mutex_init (coop_m*, coop_mattr*);
 114 SCM_API int coop_mutex_lock (coop_m*);
 115 SCM_API int coop_mutex_trylock (coop_m*);
 116 SCM_API int coop_mutex_unlock (coop_m*);
 117 SCM_API int coop_mutex_destroy (coop_m*);
 118
 119 /* A Condition variable is made up of a list of threads waiting on the
 120    condition. */
 121
 122 typedef struct coop_c {
 123   coop_q_t waiting;      /* Queue of waiting threads */
 124 } coop_c;
 125
 126 typedef int coop_cattr;
 127
 128 SCM_API int coop_condition_variable_init (coop_c*);
 129 SCM_API int coop_new_condition_variable_init (coop_c*, coop_cattr*);
 130 SCM_API int coop_condition_variable_wait_mutex (coop_c*, coop_m*);
 131 SCM_API int coop_condition_variable_timed_wait_mutex (coop_c*,
 132                                                       coop_m*,
 133                                                       const scm_t_timespec *abstime);
 134 SCM_API int coop_condition_variable_signal (coop_c*);
 135 SCM_API int coop_condition_variable_broadcast (coop_c*);
 136 SCM_API int coop_condition_variable_destroy (coop_c*);
 137
 138 typedef int coop_k;
 139
 140 typedef coop_k scm_t_key;
 141
 142 SCM_API int coop_key_create (coop_k *keyp, void (*destruktor) (void *value));
 143 SCM_API int coop_setspecific (coop_k key, const void *value);
 144 SCM_API void *coop_getspecific (coop_k key);
 145 SCM_API int coop_key_delete (coop_k);
 146 #define scm_key_create coop_key_create
 147 #define scm_setspecific coop_setspecific
 148 #define scm_getspecific coop_getspecific
 149 #define scm_key_delete coop_key_delete
 150
 151 SCM_API coop_t *coop_global_curr;             /* Currently-executing thread. */
 152
 153 SCM_API void coop_join (coop_t *t);
 154 SCM_API void coop_yield (void);
 155
 156 SCM_API size_t scm_switch_counter;
 157 SCM_API size_t scm_thread_count;
 158
 159 \f
 160 /* Some iselect functions.  */
 161
 162 /* I'm not sure whether these three declarations should be here.
 163    They're really defined in iselect.c, so you'd think they'd go in
 164    iselect.h, but they use coop_t, defined above, which uses things
 165    defined in iselect.h.  Basically, we're making at best a flailing
 166    (and failing) attempt at modularity here, and I don't have time to
 167    rethink this at the moment.  This code awaits a Hero.  --JimB
 168  */
 169 SCM_API void coop_timeout_qinsert (coop_q_t *, coop_t *);
 170 SCM_API coop_t *coop_next_runnable_thread (void);
 171 SCM_API coop_t *coop_wait_for_runnable_thread_now (struct timeval *);
 172 SCM_API coop_t *coop_wait_for_runnable_thread (void);
 173
 174
 175 \f
 176
 177 /* Cooperative threads don't need to have these defined */
 178
 179 #define SCM_CRITICAL_SECTION_START
 180 #define SCM_CRITICAL_SECTION_END
 181
 182 \f
 183
 184 #define SCM_NO_CRITICAL_SECTION_OWNER 0
 185 #define SCM_THREAD_SWITCH_COUNT       50 /* was 10 /mdj */
 186
 187 \f
 188
 189 #if 0
 190 #define SCM_THREAD_SWITCHING_CODE \
 191 do { \
 192   if (scm_thread_count > 1) \
 193     coop_yield(); \
 194 } while (0)
 195
 196 #else
 197 #define SCM_THREAD_SWITCHING_CODE \
 198 do { \
 199   if (scm_thread_count > 1) \
 200   { \
 201     scm_switch_counter--; \
 202     if (scm_switch_counter == 0) \
 203       { \
 204         scm_switch_counter = SCM_THREAD_SWITCH_COUNT; \
 205         coop_yield(); \
 206       } \
 207   } \
 208 } while (0)
 209
 210 #endif
 211
 212 /* For pthreads, this is a value associated with a specific key.
 213  * For coop, we use a special field for increased efficiency.
 214  */
 215 #define SCM_THREAD_LOCAL_DATA (coop_global_curr->data)
 216 #define SCM_SET_THREAD_LOCAL_DATA(ptr) (coop_global_curr->data = (ptr))
 217
 218 #endif  /* SCM_COOP_DEFS_H */
 219
 220 /*
 221   Local Variables:
 222   c-file-style: "gnu"
 223   End:
 224 */