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+/* classes: h_files */
+
+#ifndef SCM_COOP_PTHREADS_H
+#define SCM_COOP_PTHREADS_H
+
+/* 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. */
+
+
+
+/* The coop-pthreads implementation. We provide implement threads,
+ mutices and condition variables using the pthread ones, but only
+ one thread can ever be active inside Guile at any one time.
+*/
+
+#include <pthread.h>
+
+/* Since only one thread can be active anyway, we don't need to do
+ anything special around critical sections. In fact, that's the
+ reason we do only support cooperative threading: Guile's critical
+ regions have not been completely identified yet. (I think.) */
+
+#define SCM_CRITICAL_SECTION_START
+#define SCM_CRITICAL_SECTION_END
+
+#define SCM_THREAD_SWITCH_COUNT 50
+
+extern pthread_t guile_thread; /* for debugging */
+
+#define SCM_THREAD_SWITCHING_CODE \
+do { \
+ if (guile_thread != pthread_self ()) \
+ abort (); \
+ scm_switch_counter--; \
+ if (scm_switch_counter == 0) \
+ { \
+ scm_switch_counter = SCM_THREAD_SWITCH_COUNT; \
+ scm_yield(); \
+ } \
+} while (0)
+
+SCM_API int scm_switch_counter;
+
+struct scm_copt_thread;
+
+typedef struct scm_copt_thread {
+
+ /* A condition variable for sleeping on.
+ */
+ pthread_cond_t block;
+
+ scm_root_state *root;
+ SCM handle;
+ pthread_t pthread;
+ SCM result;
+
+} scm_copt_thread;
+
+/* We implement our own mutex type since we want them to be 'fair',
+ we want to do fancy things while waiting for them (like running
+ asyncs) and we want to support waiting on many things at once.
+*/
+typedef struct scm_copt_mutex {
+ /* the mutex for this data structure. */
+ pthread_mutex_t mutex;
+ /* the thread currently owning the mutex, or NULL. */
+ scm_copt_thread *owner;
+ /* how much the owner owns us. */
+ int level;
+ /* the threads waiting for this mutex. */
+ SCM waiting;
+} scm_copt_mutex;
+
+typedef scm_copt_mutex scm_t_mutex;
+
+SCM_API void scm_copt_mutex_init (scm_copt_mutex *m);
+SCM_API void scm_copt_mutex_lock (scm_copt_mutex *m);
+SCM_API void scm_copt_mutex_unlock (scm_copt_mutex *m);
+SCM_API void scm_copt_mutex_destroy (scm_copt_mutex *m);
+
+#define scm_mutex_init scm_copt_mutex_init
+#define scm_mutex_lock scm_copt_mutex_lock
+#define scm_mutex_unlock scm_copt_mutex_unlock
+#define scm_mutex_destroy scm_copt_mutex_destroy
+
+typedef pthread_cond_t scm_t_cond;
+
+#define scm_cond_init(c) pthread_cond_init ((c), NULL)
+#define scm_cond_wait pthread_cond_wait
+#define scm_cond_signal pthread_cond_signal
+#define scm_cond_broadcast pthread_cond_broadcast
+#define scm_cond_destroy pthread_cond_destroy
+
+#define SCM_THREAD_LOCAL_DATA (scm_copt_thread_data ())
+#define SCM_SET_THREAD_LOCAL_DATA(ptr) (scm_copt_set_thread_data (ptr))
+
+SCM_API void *scm_copt_thread_data (void);
+SCM_API void scm_copt_set_thread_data (void *);
+
+#endif /* SCM_COOP_PTHREAD_H */
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/