diff options
Diffstat (limited to 'libguile/threads-plugin.c')
-rw-r--r-- | libguile/threads-plugin.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/libguile/threads-plugin.c b/libguile/threads-plugin.c new file mode 100644 index 000000000..e6671daf1 --- /dev/null +++ b/libguile/threads-plugin.c @@ -0,0 +1,201 @@ +/* Copyright (C) 2002 Free Software Foundation, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this software; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, + * Boston, MA 02111-1307 USA + * + * As a special exception, the Free Software Foundation gives permission + * for additional uses of the text contained in its release of GUILE. + * + * The exception is that, if you link the GUILE library with other files + * to produce an executable, this does not by itself cause the + * resulting executable to be covered by the GNU General Public License. + * Your use of that executable is in no way restricted on account of + * linking the GUILE library code into it. + * + * This exception does not however invalidate any other reasons why + * the executable file might be covered by the GNU General Public License. + * + * This exception applies only to the code released by the + * Free Software Foundation under the name GUILE. If you copy + * code from other Free Software Foundation releases into a copy of + * GUILE, as the General Public License permits, the exception does + * not apply to the code that you add in this way. To avoid misleading + * anyone as to the status of such modified files, you must delete + * this exception notice from them. + * + * If you write modifications of your own for GUILE, it is your choice + * whether to permit this exception to apply to your modifications. + * If you do not wish that, delete this exception notice. */ + + + + +int scm_i_plugin_mutex_size = 0; +int (*scm_i_plugin_mutex_init) (scm_t_mutex *, const scm_t_mutexattr *); +int (*scm_i_plugin_mutex_lock) (scm_t_mutex *); +int (*scm_i_plugin_mutex_unlock) (scm_t_mutex *); + +int scm_i_plugin_rec_mutex_size = 0; +int (*scm_i_plugin_rec_mutex_init) (scm_t_rec_mutex *, + const scm_t_mutexattr *); +int (*scm_i_plugin_rec_mutex_destroy) (scm_t_rec_mutex *); +int (*scm_i_plugin_rec_mutex_lock) (scm_t_rec_mutex *); +int (*scm_i_plugin_rec_mutex_trylock) (scm_t_rec_mutex *); +int (*scm_i_plugin_rec_mutex_unlock) (scm_t_rec_mutex *); + +int (*scm_i_plugin_cond_wait) (scm_t_cond *, scm_t_mutex *); +int (*scm_i_plugin_cond_timedwait) (scm_t_cond *, + scm_t_mutex *, + const struct timespec *); + +typedef struct rec_mutex { +#ifdef SCM_DEBUG_THREADS + int kind; +#endif + scm_t_mutex mutex; + scm_thread *owner; + int count; +} rec_mutex; + +/* Mutex for recursive mutex administration */ +static scm_t_mutex rec_mutex_mutex; + +static int +rec_mutex_init (scm_t_rec_mutex *mx, const scm_t_mutexattr *a) +{ + rec_mutex *m = (rec_mutex *) mx; + scm_i_plugin_mutex_init (&m->mutex, &scm_i_plugin_mutex); + m->owner = 0; + m->count = 0; +#ifdef SCM_DEBUG_THREADS + m->kind = REC_MUTEX; +#endif + return 0; +} + +static int +rec_mutex_destroy (scm_t_rec_mutex *mx) +{ + rec_mutex *m = (rec_mutex *) mx; + return scm_i_plugin_mutex_destroy (&m->mutex); +} + +static int +rec_mutex_lock (scm_t_rec_mutex *mx) +{ + rec_mutex *m = (rec_mutex *) mx; + scm_thread *t = SCM_CURRENT_THREAD; + scm_i_plugin_mutex_lock (&rec_mutex_mutex); +#ifdef SCM_DEBUG_THREADS + if (m->kind != REC_MUTEX) + { + fprintf (stderr, + m->kind == FAST_MUTEX + ? "locking wrong mutex type\n" + : "locking uninitialized mutex\n"); + abort (); + } +#endif + if (m->count && m->owner == t) + { + ++m->count; + scm_i_plugin_mutex_unlock (&rec_mutex_mutex); + } + else + { + scm_i_plugin_mutex_unlock (&rec_mutex_mutex); + scm_i_plugin_mutex_lock (&m->mutex); + m->count = 1; + m->owner = t; + } + return 0; +} + +static int +rec_mutex_trylock (scm_t_rec_mutex *mx) +{ + rec_mutex *m = (rec_mutex *) mx; + scm_thread *t = SCM_CURRENT_THREAD; + scm_i_plugin_mutex_lock (&rec_mutex_mutex); + if (m->owner != 0 && m->owner != t) + return EBUSY; + else if (m->count) + { + ++m->count; + scm_i_plugin_mutex_unlock (&rec_mutex_mutex); + } + else + { + scm_i_plugin_mutex_unlock (&rec_mutex_mutex); + scm_i_plugin_mutex_lock (&m->mutex); + m->count = 1; + m->owner = t; + } + return 0; +} + +static int +rec_mutex_unlock (scm_t_rec_mutex *mx) +{ + rec_mutex *m = (rec_mutex *) mx; + scm_i_plugin_mutex_lock (&rec_mutex_mutex); +#ifdef SCM_DEBUG_THREADS + if (m->kind != REC_MUTEX) + { + fprintf (stderr, + m->kind == FAST_MUTEX + ? "locking wrong mutex type\n" + : "locking uninitialized mutex\n"); + abort (); + } + if (m->count == 0) + { + fprintf (stderr, "unlocking unlocked mutex\n"); + abort (); + } +#endif + if (!--m->count) + { + m->owner = 0; + scm_i_plugin_mutex_unlock (&m->mutex); + } + scm_i_plugin_mutex_unlock (&rec_mutex_mutex); + return 0; +} + +#ifndef SCM_MUTEXATTR_SETTYPE_DECLARED +int pthread_mutexattr_settype (pthread_mutexattr_t *, int); +#endif + +void +scm_init_threads_plugin () +{ + if (scm_i_plugin_rec_mutex_size == 0) + { + scm_i_plugin_rec_mutex_size = sizeof (rec_mutex); + scm_i_plugin_mutex_init (&rec_mutex_mutex, &scm_i_plugin_mutex); + scm_i_plugin_rec_mutex_init = rec_mutex_init; + scm_i_plugin_rec_mutex_destroy = rec_mutex_destroy; + scm_i_plugin_rec_mutex_lock = rec_mutex_lock; + scm_i_plugin_rec_mutex_trylock = rec_mutex_trylock; + scm_i_plugin_rec_mutex_unlock = rec_mutex_unlock; + } + if (scm_i_plugin_mutex_size > SCM_MUTEX_MAXSIZE + || scm_i_plugin_rec_mutex_size > SCM_REC_MUTEX_MAXSIZE) + { + fprintf (stderr, "Internal error: Need to upgrade mutex size\n"); + abort (); + } +} |