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-rw-r--r--libguile/threads-plugin.c201
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 ();
+ }
+}