cm_tc16_mutex, (a))
#define SCM_VALIDATE_CONDVAR(pos, a) \
  scm_assert_smob_type (scm_tc16_condvar, (a))

SCM_API SCM scm_spawn_thread (scm_t_catch_body body, void *body_data,
			      scm_t_catch_handler handler, void *handler_data);

SCM_API void *scm_without_guile (void *(*func)(void *), void *data);
SCM_API void *scm_with_guile (void *(*func)(void *), void *data);

SCM_INTERNAL void scm_threads_prehistory (void *);
SCM_INTERNAL void scm_init_threads (void);
SCM_INTERNAL void scm_init_threads_default_dynamic_state (void);

SCM_INTERNAL void scm_i_dynwind_pthread_mutex_lock_block_asyncs (scm_i_pthread_mutex_t *mutex);

SCM_API SCM scm_call_with_new_thread (SCM thunk, SCM handler);
SCM_API SCM scm_yield (void);
SCM_API SCM scm_cancel_thread (SCM t);
SCM_API SCM scm_join_thread (SCM t);
SCM_API SCM scm_join_thread_timed (SCM t, SCM timeout, SCM timeoutval);
SCM_API SCM scm_thread_p (SCM t);

SCM_API SCM scm_make_mutex (void);
SCM_API SCM scm_make_recursive_mutex (void);
SCM_API SCM scm_make_mutex_with_kind (SCM kind);
SCM_API SCM scm_lock_mutex (SCM m);
SCM_API SCM scm_timed_lock_mutex (SCM m, SCM timeout);
SCM_API void scm_dynwind_lock_mutex (SCM mutex);
SCM_API SCM scm_try_mutex (SCM m);
SCM_API SCM scm_unlock_mutex (SCM m);
SCM_API SCM scm_mutex_p (SCM o);
SCM_API SCM scm_mutex_locked_p (SCM m);
SCM_API SCM scm_mutex_owner (SCM m);
SCM_API SCM scm_mutex_level (SCM m);

SCM_API SCM scm_make_condition_variable (void);
SCM_API SCM scm_wait_condition_variable (SCM cond, SCM mutex);
SCM_API SCM scm_timed_wait_condition_variable (SCM cond, SCM mutex,
					       SCM abstime);
SCM_API SCM scm_signal_condition_variable (SCM cond);
SCM_API SCM scm_broadcast_condition_variable (SCM cond);
SCM_API SCM scm_condition_variable_p (SCM o);

SCM_API SCM scm_current_thread (void);
SCM_API SCM scm_all_threads (void);

SCM_API int scm_c_thread_exited_p (SCM thread);
SCM_API SCM scm_thread_exited_p (SCM thread);

#ifdef BUILDING_LIBGUILE

/* Though we don't need the key for SCM_I_CURRENT_THREAD if we have TLS,
   we do use it for cleanup purposes.  */
SCM_INTERNAL scm_i_pthread_key_t scm_i_thread_key;

# ifdef SCM_HAVE_THREAD_STORAGE_CLASS

SCM_INTERNAL SCM_THREAD_LOCAL scm_thread *scm_i_current_thread;
#  define SCM_I_CURRENT_THREAD (scm_i_current_thread)

# else /* !SCM_HAVE_THREAD_STORAGE_CLASS */

#  define SCM_I_CURRENT_THREAD						\
    ((scm_thread *) scm_i_pthread_getspecific (scm_i_thread_key))

# endif /* !SCM_HAVE_THREAD_STORAGE_CLASS */

#endif /* BUILDING_LIBGUILE */

SCM_INTERNAL scm_i_pthread_mutex_t scm_i_misc_mutex;

/* Convenience functions for working with the pthread API in guile
   mode.
*/

#if SCM_USE_PTHREAD_THREADS
SCM_API int scm_pthread_mutex_lock (pthread_mutex_t *mutex);
SCM_API void scm_dynwind_pthread_mutex_lock (pthread_mutex_t *mutex);
SCM_API int scm_pthread_cond_wait (pthread_cond_t *cond,
				   pthread_mutex_t *mutex);
SCM_API int scm_pthread_cond_timedwait (pthread_cond_t *cond,
					pthread_mutex_t *mutex,
					const scm_t_timespec *abstime);
#endif

/* More convenience functions.
 */

SCM_API unsigned int scm_std_sleep (unsigned int);
SCM_API unsigned long scm_std_usleep (unsigned long);

SCM_API SCM scm_total_processor_count (void);
SCM_API SCM scm_current_processor_count (void);

#endif  /* SCM_THREADS_H */