libguile/null-threads.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM_NULL_THREADS_H
   4 #define SCM_NULL_THREADS_H
   5
   6 /* Copyright (C) 2002 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 /* The null-threads implementation.  We provide the standard API, but
  50    no new threads can be created.
  51 */
  52
  53 /* We can't switch so don't bother trying.
  54 */
  55 #undef  SCM_THREAD_SWITCHING_CODE
  56 #define SCM_THREAD_SWITCHING_CODE
  57
  58 #define scm_t_thread int
  59
  60 /* The "(void)(...)" constructs in the expansions are there to ensure
  61    that the side effects of the argument expressions take place.
  62 */
  63
  64 #define scm_thread_create(th,proc,data) ((void)(proc), (void)(data), ENOTSUP)
  65 #define scm_thread_join(th)             do { (void)(th); abort(); } while(0)
  66 #define scm_thread_detach(th)           do { (void)(th); abort(); } while(0)
  67 #define scm_thread_self()               0
  68
  69 #define scm_t_mutex int
  70
  71 #define scm_mutex_init(mx)              do { (void)(mx); } while(0)
  72 #define scm_mutex_destroy(mx)           do { (void)(mx); } while(0)
  73 #define scm_mutex_lock(mx)              do { (void)(mx); } while(0)
  74 #define scm_mutex_trylock(mx)           ((void)(mx), 1)
  75 #define scm_mutex_unlock(mx)            do { (void)(mx); } while(0)
  76
  77 #define scm_t_cond int
  78
  79 #define scm_cond_init(cv)               do { (void)(cv); } while(0)
  80 #define scm_cond_destroy(cv)            do { (void)(cv); } while(0)
  81 #define scm_cond_wait(cv,mx)            ((void)(cv), (void)(mx), ENOTSUP)
  82 #define scm_cond_timedwait(cv,mx,at)    ((void)(cv), (void)(mx), (void)(at), \
  83                                          ENOTSUP)
  84 #define scm_cond_signal(cv)             do { (void)(cv); } while(0)
  85 #define scm_cond_broadcast(cv)          do { (void)(cv); } while(0)
  86
  87 #define scm_thread_select               select
  88
  89 typedef void **scm_t_key;
  90
  91 #define scm_key_create(keyp)            do { *(keyp) = malloc(sizeof(void*)); \
  92                                            } while(0)
  93 #define scm_key_delete(key)             do { free(key); } while(0)
  94 #define scm_key_setspecific(key, value) do { *(key) = (value); } while(0)
  95 #define scm_key_getspecific(key)        *(key)
  96
  97 #if 0
  98
  99 /* These are the actual prototypes of the functions/macros defined
 100    above.  We list them here for reference. */
 101
 102 typedef int scm_t_thread;
 103
 104 SCM_API int  scm_thread_create (scm_t_thread *th,
 105                                 void (*proc) (void *), void *data);
 106 SCM_API void scm_thread_join (scm_t_thread th);
 107 SCM_API void scm_thread_detach (scm_t_thread th);
 108 SCM_API scm_t_thread scm_thread_self (void);
 109
 110 typedef int scm_t_mutex;
 111
 112 SCM_API void scm_mutex_init (scm_t_mutex *mx);
 113 SCM_API void scm_mutex_destroy (scm_t_mutex *mx);
 114 SCM_API void scm_mutex_lock (scm_t_mutex *mx);
 115 SCM_API int  scm_mutex_trylock (scm_t_mutex *mx);
 116 SCM_API void scm_mutex_unlock (scm_t_mutex *mx);
 117
 118 typedef int scm_t_cond;
 119
 120 SCM_API void scm_cond_init (scm_t_cond *cv);
 121 SCM_API void scm_cond_destroy (scm_t_cond *cv);
 122 SCM_API void scm_cond_wait (scm_t_cond *cv, scm_t_mutex *mx);
 123 SCM_API int  scm_cond_timedwait (scm_t_cond *cv, scm_t_mutex *mx,
 124                                  struct timespec *abstime);
 125 SCM_API void scm_cond_signal (scm_t_cond *cv);
 126 SCM_API void scm_cond_broadcast (scm_t_cond *cv);
 127
 128 typedef int scm_t_key;
 129
 130 SCM_API void scm_key_create (scm_t_key *keyp);
 131 SCM_API void scm_key_delete (scm_t_key key);
 132 SCM_API void scm_key_setspecific (scm_t_key key, const void *value);
 133 SCM_API void *scm_key_getspecific (scm_t_key key);
 134
 135 SCM_API int  scm_thread_select (int nfds,
 136                                 SELECT_TYPE *readfds,
 137                                 SELECT_TYPE *writefds,
 138                                 SELECT_TYPE *exceptfds,
 139                                 struct timeval *timeout);
 140
 141 #endif
 142
 143 #endif  /* SCM_NULL_THREADS_H */
 144
 145 /*
 146   Local Variables:
 147   c-file-style: "gnu"
 148   End:
 149 */