Commit Graph

13 Commits

Author SHA1 Message Date
sperber 33c14d7901 First stab at implementing SELECT/SELECT!:
- extend the VM interrupts to distinguish between read and write
  events
- add new ADD-PENDING-CHANNEL instruction to the VM
- add WAIT-FOR-CHANNELS procedure to the run-time system
- implement SELECT and SELECT! on top of that in newports.scm

This runs some basic tests, but in general should be considered
largely untested.

Moreover, SELECT/SELECT! never detect any exceptional conditions---the
returned vectors are always empty.  This is because the VM doesn't
really track those, and it's unclear whether it would be worth the
effort.
2002-08-20 14:03:01 +00:00
sperber ac343ba970 Replace Martin's implementation of selective blocking by the one in
Scheme 48 1.0.1.

Namely, instead of associating a list of queues with every thread, we
associate a single cell, holding the thread.  That cell is stored in
thread queues, and once a thread is made runnable again, the cell is
set to #f.  The thread-queue accessors ignore cells containing #f.

Implement an experimental OBTAIN-LOCK-MULTIPLE to test the whole
thing.
2002-08-16 14:11:50 +00:00
sperber 1d35626709 Redo the forking-without-the-threads fix in a way not involving
command levels (as there *are* no command levels for things like scsh
-c):

There's now a new asynchronous event, similar to SPAWN, called NARROW.
It spawns off a new scheduler with just one thread (which runs the
thunk provided as an argument to NARROW) and blocks the current one
until the narrowed scheduler finishes.

For this to work, two schedulers need to be in place: the root
scheduler which performs the housekeeping, and another one inside that
which is the one the program uses---otherwise it's the root scheduler
that's blocked, and that means no housekeeping gets done.  This is
trivially the case for interactive mode, as the command-levels all
have their own schedulers, but we also need to make sure scsh's entry
point fires up its own initial scheduler.
2002-05-03 13:42:36 +00:00
mainzelm fe5c9a3783 Cells for thread-env's fluid-cell-{ref,set!}. 2002-04-04 08:45:28 +00:00
sperber 12ced00589 Make sure port locks get released after I/O errors. 2002-02-26 14:40:21 +00:00
sperber 136e313af7 New implementation of (no-inheritance) thread-local cells and thread
fluids.

New implementation of syslog.

Both are to be compatible with what's actually probably going into
Scheme 48.
2001-12-03 15:21:46 +00:00
mainzelm fe6a9db1e5 Renamed scsh-events to sigevents. 2001-10-18 09:02:52 +00:00
mainzelm 68eb897e20 Merged in macro expander changes from Scheme 48 0.56. 2001-07-09 14:15:05 +00:00
sperber 21a8e255eb Added thread-cells structure for thread-local cells.
These can be used (together with fluids) to implement something akin
to PLT's and Chez's parameters for holding thread-local state such as
CWD, syslog channel, etc.
2001-05-22 14:58:15 +00:00
mainzelm 9b4bb8a19d Adapted some of Richard's changes for char-ready? and output-port-ready?. 2001-03-23 10:59:07 +00:00
mainzelm c1d6d368e5 Built the event system directly into the RTS. Built sighandlers above
it. Removed machinery in low-interrupt.
2001-01-09 15:52:52 +00:00
marting 81358acc7b added threads-internal to port's packages for steal-port 1999-10-05 14:30:28 +00:00
marting 606245fc41 *** empty log message *** 1999-09-14 12:45:02 +00:00