Re: Python threads under SunOS

Sjoerd Mullender (Sjoerd.Mullender@cwi.nl)
Wed, 08 Dec 1993 16:13:51 +0100

On Wed, Dec 8 1993 Quentin Stafford-Fraser wrote:

> Could anyone enlighten me as to the current status of the SunOS
> threads support?

I have recently ported the threads module to Solaris 2.3. I don't
know if this is good enough for you. It seems to work pretty well.

I wrote the thread library (actually just a common interface for
various threads libraries) on top of which the threads module was
written (by Guido). I have not done any experiments with the threads
module on SunOS 4.1.X, but because I know something about the SunOS
threads library, I don't think the threads module will work very well.

> The Makefile says something about an exiting multi-threaded python
> leaving the terminal in non-blocking mode, but it doesn't seem to do
> this for me, after my very brief experiments. (I presume I _would_ notice?)

I guess this depends on the way the python process terminates. Under
certain conditions, the SunOS library puts the terminal in
non-blocking mode. This may not always be properly reset by the
library.

> Is anybody using threads under SunOS, or does anyone have experiences
> which have persuaded them not to?

There is no real kernel support for multiple threads in SunOS. This
means that the SunOS threads library uses signals and non-blocking I/O
to do its work. Also, thread scheduling is pre-emptive. For these
reasons (and also because we just don't have much software that uses
threads) we don't use the threads module on SunOS.

Sjoerd Mullender
CWI, dept. CST, Kruislaan 413, 1098 SJ Amsterdam, Netherlands
email: Sjoerd.Mullender@cwi.nl fax: +31 20 592 4199
phone: +31 20 592 4127 telex: 12571 mactr nl