coop_condition_variable_init, coop_condition_variable_wait,
coop_condition_variable_signal): Changed return type from `void'
to `int'. This is to adhere closer to the pthreads interface.
This, in turn, is part of an attempt to provide C versions of the
mutex and condition variable primitives which can be part of a
frontend to COOP or pthreads.
* coop.c (coop_mutex_destroy, coop_condition_variable_wait_mutex,
coop_condition_variable_destroy): New functions.
* coop-threads.c (scm_wait_condition_variable): Use
coop_condition_variable_wait_mutex.
* coop-threads.h, coop-defs.h (coop_q_t, coop_m, coop_c):
Definitions moved to coop-defs.h.
* coop-defs.h (scm_mutex_init, scm_mutex_lock, scm_mutex_unlock,
scm_mutex_destroy, scm_cond_init, scm_cond_wait, scm_cond_signal,
scm_cond_destroy): New C interface to mutecis and cond vars.
* coop.c (coop_qinit): Initialize fields used by
scm_internal_select.
(coop_qget, coop_qget, coop_tmp_queue): Made global.
(coop_next_runnable_thread): If GUILE_ISELECT enabled, use
replacement in iselect.c.
(coop_mutex_lock, coop_condition_variable_wait, coop_abort,
coop_join): If GUILE_ISELECT enabled, use
coop_wait_for_runnable_thread instead of
coop_next_runnable_thread.
(usleep, sleep): New replacements for system functions if
GUILE_ISELECT is enabled.
* coop-threads.h: Declare coop_wait_for_runnable_thread.
* coop-defs.h (coop_t): Added fields used by scm_internal_select.
* filesys.c: Added #include "iselect.h". Moved FD-macros to
iselect.h. Implement Scheme level `select' using
scm_internal_select. (See NEWS.)
* genio.c (scm_getc): Block with scm_internal_select. (See NEWS.)
* init.c: Call scm_init_iselect.
