* 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
* Lock X updates for all systems and lock around X cleanup at exit
All systems which could generate I/O interrupts on the X file descriptor need
to have locking enabled, or there is a high probability that the X library
will deadlock. This requirement may be removed in the future with restructuring
of the way that the interrupt driven I/O is handled.
Ensure that the appropriate XLOCK/XUNLOCK is done around the X window
closing code.
* Also lock X updates when building with CMake.
The default targets differ depending on the display type and whether networking
is configured in or not, so it's more appropriate in the individual fragments
* `LOGINT` is only useful when `MAIKO_HANDLE_CONSOLE_MESSAGES`
is set.
* Only define some variables if `MAIKO_HANDLE_CONSOLE_MESSAGES`
is set. Flag them as static.
* Remove setting `LOGINT` from the build system as it isn't
needed because we aren't handling console messages.
Rather than having to specify or omit -DBYTESWAP in the Makefile
fragment for each system we can detect whether the system requires
byte swapping based on the __BYTE_ORDER__ C preprocessor definition.
Update CMakeLists.txt to account for this as well.
This feature was controlled by the compilation flag `OPDISP`
which would enable some bits of assembler on the x86 (ISC or DOS)
or some other specialized code on SPARC. On SPARC hardware, there
was a special compilation process that would preprocess the code
and generate dispatch tables.
We do this now when this feature is enabled using gcc's computed
gotos feature. This is available in clang and some other compilers.
Notably, it isn't present in Visual Studio.
This doesn't decrease our portability at all as this feature is
optional and it replaces specialized assembler code with C using
compiler extensions (making it cross-platform).
In doing this, we've removed a bunch of related code, however,
it is likely that other pieces yet remain and will be removed
in subsequent commits as we clean things up and refine them.
This feature remains disabled by default for now.
This is the old way that releases were built and isn't relevant
today. It made a variety of assumptions about how things were
linked and allowed for the user to re-link an executable, but
that isn't something we need to do any longer.
This doesn't yet remove the checksum, ldechecksum, and related
scripts.
This removes SYSVSIGNALS as we're always and only using POSIX
signals now.
Some platform differences have been papered over. We used to
only ignore SIGPIPE when using BSD signals, but we now ignore
it all the time.
While the SIGFPE code will now compile, it hasn't been updated
to work on modern OSes fully yet as it will need to enable
the correct FP exceptions.
* Always follow NEW_STORAGE code paths.
This removes the code paths for the pre-NEW_STORAGE code.
* Remove NEW_STORAGE from build system.
The code no longer refers to `NEW_STORAGE`, so we can remove
this from the build system.
CLX is a Common Lisp implementation of the X client library.
It has some code in C, which was present here as `src/socket.c`
and `src/socdvr.c`, exposed via opcodes in `src/subr.c`. This code
had been removed (with prejudice apparently) by commenting out
the code in `src/subr.c` with `#if NEVER`.
This code would've been used by the Medley system images, but
that code doesn't appear to be present. (There may or may not
be something related in `XMAS` in the Medley repository.)
The FSERROR define is on all the time now. It was not controlling
all of the functionality, with many places setting Lisp_errnno
outside of the code controlled by the define.
