* coop-pthreads.h, coop-pthreads.c: New, but unfinished.

libguile/coop-pthreads.h

@@ -0,0 +1,144 @@
+/* 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:
+*/