* Rewrite keyboard and async I/O handling to improve performance and reduce dependency on async I/O signals
Replaces the SIGIO handler, which used to process X events in the interrupt context, with
a stub routine that sets a flag to signal processing is required.
Actual event processing is moved to the main dispatch loop where Lisp periodic interrupts
are handled.
Removes the X connection file descriptor from the set of fds contributing to SIGIO events
and moves the processing of X events to where the Lisp periodic interrupt is handled in
the main dispatch loop. This code is already guarded by a check for XPending() so can
be called regardless of whether any file descriptors are known to be ready.
Actual processing of async I/O events and X events are handled by procedures
process_io_events() and process_Xevents() respectively. For the most part these are
a renaming of getsignaldata() and getXsignaldata().
The Lisp periodic timer (VTALRM) was set to operate with a 25000 us period (40 Hz),
but on modern hardware it is possible to run this timer with a period of 10000 us (100 Hz)
Incidentally, a bug was noted (and fixed) in the X event handling code for motion events:
Mouse motion without any keyboard activity should not add an entry to the keyboard event
ring buffer as these events do not represent a key state change.
Since the ring buffer is of limited size, when it is filled new events are ignored
until the buffered events are processed. This resulted in the loss of a key/mouse button
transition (up or down) if the mouse was moved about "too much" between keyboard events.
A few incidental cleanups were also made:
- KBDEventFlg initialization fixed (wrong semantic type)
- Event_Req renamed to IO_Signalled (more appropriate name)
- int_io_open() sets up process (self) to handle SIGIO generated by O_ASYNC operations
- LOCK_X_EVENTS turned off since X library calls can no longer happen in an interrupt context
* Use of O_ASYNC must depend on the symbol being defined (looking at you, Cygwin)
* Add SA_RESTART flag to sigaction for SIGVTALRM periodic interrupt
* LOCK_X_UPDATE is no longer needed and should not be defined by default for Solaris in version.h
* Remove static char *id = from all source files.
The same information is included in a comment in each source file.
* Remove unused template file 'id'
* FD_ISSET requires that the fd being tested is >= 0, so unset fd -1 causes trouble.
* Remove code to enable X I/O signal generation from xinit.c
If the I/O signals are enabled before the signal handler has
been set up, the default action on receipt of a SIGPOLL or SIGIO
will be that the program exits. For now, turn the signals off,
as they aren't necessary and may not even be an improvement.
* Ensure fds are declared as signed and initialized (to -1)
The global fds may be accessed from the signal handler before any
particular device has been opened. Ensure that the fds are initialized
statically and that the value is distinguishable from all valid descriptors.
modified: initdsp.c
modified: initkbd.c
modified: keyevent.c
modified: osmsg.c
modified: rs232c.c
modified: timer.c
modified: tty.c
Some code that was maintaining an fd_set with only a single fd was replaced
with just the fd as int, which can be added to the global fd_set as needed.
More testing is required for less usual configurations such as host TCP/UDP/IP
and direct ethernet (packet filter or NIT) I/O.
modified: src/common.c
modified: src/ether.c
modified: src/inet.c
modified: src/initkbd.c
modified: src/kbdsubrs.c
modified: src/keyevent.c
modified: src/main.c
modified: src/osmsg.c
modified: src/rawrs232c.c
modified: src/rpc.c
modified: src/rs232c.c
modified: src/tty.c
modified: src/uraid.c
modified: src/xinit.c
