* exceptions.cc (sfta): Eliminate obsolete function.
(sgmb): Eliminate obsolete function.
(class stack_info): Remove MS method for walking the stack.
(stack_info::init): Just initialize required fields.
(stack_info::brute_force): Rename to stack_info::walk.
(handle_exceptions): Pass derived frame pointer to sig_send.
(interrupt_setup): Clear saved frame pointer here.
(interrupt_on_return): thestack is no longer a pointer.
(call_handler): Accept a flag to indicate when a signal was sent from other
than the main thread. Use saved frame pointer for determining where to place
signal handler call.
(sig_handle): Accept "nonmain" argument. Pass it to call_handler.
* fhandler_tty.cc (fhandler_tty_common::__acquire_output_mutex): Change
debugging output slightly.
* (fhandler_tty_common::__release_output_mutex): Ditto.
(fhandler_tty_slave::read): Fix a comment, remove a goto.
* sigproc.cc (sig_send): Accept an optional frame pointer argument for use when
suspending the main process. sigcomplete_main is an autoreset event now. Save
frame pointer for non-main operation.
(wait_sig): Make sigcomplete_main an autoreset event. Eliminate NOSIGQUEUE.
Pass rc to sig_handle to signify if this was a nonmain process.
* sigproc.h: Reflect change to sig_send argument.
* syscalls.cc (swab): Eliminate swab function since it is now available in
newlib.
* winsup.h (signal_dispatch): Change CONTEXT cx to DWORD ebp.
* debug.cc (iscygthread): New function.
* debug.h: Declare it.
* exceptions.cc (set_process_mask): Flush pending signals.
(handle_sigsuspend): No need to flush pending signals.
(call_handler): Refine previous tests of muto ownership. Only clear wait()'s
when we have definitely responded to a signal.
* fhandler_console.cc (fhandler_console::read): Don't set EINTR if executing in
a "cygwin" thread.
* sigproc.cc (proc_subproc): Use second argument to control whether CLEARWAIT
actually sets "signalled" flag.
* sync.h (muto): Add 'unstable' method.
interruptible.
(call_handler): Avoid suspending a thread if it owns a mutex. Only set
signal_arrived if the thread was actually interrupted.
(events_init): Initialize module information needed by interruptible().
(sigdelayed): Don't call sig_dispatch_pending since it could screw up
* init.cc (dll_entry): Record module handle of main for use by interruptible().
(proc_subproc): Reorganize handling of terminated child so that the bulk of the
processing comes from the signal thread.
(wait_sig): Force processing of waiting threads if SIGCHLD is not processed.
* sync.cc (muto::release): Set tid == 0 after lock is released or signal
processor will be confused.