Subject: Re: pthreads plan
To: Greg Hudson <ghudson@mit.edu>
From: Giles Lean <giles@nemeton.com.au>
List: tech-userlevel
Date: 11/07/1999 05:31:14
On Sat, 06 Nov 1999 10:44:45 -0500  Greg Hudson wrote:

> If possible, it would be really neat to avoid the situation where
> there are threaded objects and non-threaded objects, and never the
> twain shall meet.

I concur.  Avoiding support questions about having to recompile code
with _REENTRANT is a worthy goal.

> I think the major sticking point is getc() and putc(), which need to
> be (a) fast in normal programs, and (b) MT-safe in pthreads programs.
> You can get the overhead for normal programs down to a single
> condition check by introducing a global flag which gets set when the
> first thread is created.

I would prefer this, if the performance impact is acceptable.

Library implementors still have to be very careful not to make
assumptions that a program is not threaded just because Right Now it
is only single threaded.

Regards,

Giles