[project @ 2000-04-12 17:33:16 by simonmar]
This commit fixes the trace/stderr problem, and also fixes some other
problems with the I/O library.
- handles now contain a list of free buffers, which are
guaranteed to be the same size as the primary handle buffer.
- hPutStr now doesn't evaluate any part of the input string with
the handle locked. Instead, it acquires a buffer from the handle
copies characters into it, then commits the buffer. This is
better for concurrency too, because the handle is only locked
while we're actually reading/writing, not while evaluating.
- there were an even number of off-by-one errors in the I/O system
which compensated for each other. This has been fixed.
- made the I/O subsystem a little more exception-safe. It still
isn't totally exception-safe, but I can't face doing that
without a complete rewrite of this thing in Haskell.
- add hPutBufFull and hGetBufFull. The compiler probably needs to
be updated to use these too.