* threads.c: Include null-threads.c when !USE_COOP_THREADS.
(scm_init_threads): Use generic type names scm_t_mutex and
scm_t_coop instead of coop_m and coop_t.
scm_i_thread_root when USE_THREADS is defined. Use scm_root
otherwise.
* scmsigs.c (take_signal): Only call scm_i_thread_root when
USE_THREADS is defined. Use scm_root otherwise.
(scm_sigaction_for_thread): Ignore THREAD argument when
USE_THREADS is not defined. Also, move THREAD argument defaulting
out of HAVE_SIGACTION section, which was a bug.
scm_call_with_unblocked_asyncs, scm_c_call_with_blocked_asyncs,
scm_c_call_with_unblocked_asyncs): New prototypes.
(scm_mask_signals, scm_unmask_signals): Deprecated.
(scm_mask_ints): Turned into a macro.
* async.c (scm_mask_ints): Removed.
(scm_run_asyncs): Do not set scm_mask_ints while running an async.
this should not be necessary.
(scm_async_click): Test block_asyncs instead of scm_mask_ints.
(scm_mask_signals, scm_unmask_signals): Deprecated. Emit
deprecation warning and check for errornous use. Set block_asyncs
instead of scm_mask_ints.
(increase_block, decrease_block, scm_call_with_blocked_asyncs,
scm_call_with_unblocked_asyncs, scm_c_call_with_blocked_asyncs,
scm_c_call_with_unblocked_asyncs): New.
cell to SCM_BOOL_F, not SCM_EOL.
(scm_i_queue_async_cell): Queue the cell at the end of the list,
and only if the handler procedure is not already present.
(scm_system_async_mark_for_thread): Initialize cdr of handler cell
with SCM_BOOL_F.
* scmsigs.c (scm_sigaction_for_thread): Likewise.
scm_lt_dlopenext, and scm_lt_dlerror.
(sysdep_dynl_unlink): switch to scm_lt_dlhandle, scm_lt_dlclose,
and scm_lt_dlerror.
(sysdep_dynl_func): switch to scm_lt_dlhandle, scm_lt_dlsym,
and scm_lt_dlerror.
(sysdep_dynl_init): switch to scm_lt_dlinit();
* scmsigs.c (got_signal): Removed.
(signal_handler_cells, signal_handler_threads): New.
(take_signal): Queue the cell of the signal for the specified
thread. Reset the signal handler on systems that don't have
sigaction.
(sys_deliver_signals): Removed.
(close_1): New.
(scm_sigaction_for_thread): Renamed from scm_sigaction and
extended to also set the thread of a signal and allocate a cell
for it. Keep the Scheme name "sigaction". Check that signum is
within range. Also, use SCM_VECTOR_REF instead of SCM_VELTS.
(scm_sigaction): Implement in terms of scm_sigaction_for_thread.
(scm_init_scmsigs): Allocate signal_handler_cells and
signal_handler_threads vectors.
* coop-threads.c (all_threads, scm_current_thread,
scm_all_threads, scm_i_thread_root): New.
(scm_threads_init): Add main thread to all_threads.
(scheme_launch_thread): Remove thread from all_threads when it
terminates.
(scm_call_with_new_thread): Initialize handle slot of coop_t
structure and add new thread to all_threads.
(scm_spawn_thread): Likewise.
