Does PHP process requests sequentially on one CPU?

[Bruce W.1]

With ASP.NET I've found that request are processed sequentially, one at
a time, at least on a server with one CPU. If one request blocks for
some reason, maybe on a long database query, then all users must wait
until it completes, for their request to process.

This leaves me wondering about PHP running on IIS and Window. Does this
hold true for PHP also?

What about PHP on Unix? Does this allow true simultaneous processing of
all requests when the server has a single CPU?

Thanks for your help.

[CountScubula]

Re: Does PHP process requests sequentially on one CPU?

"Bruce W.1" <no@direct.emai l> wrote in message
news:4023C0B9.F 438544F@direct. email...[color=blue]
> With ASP.NET I've found that request are processed sequentially, one at
> a time, at least on a server with one CPU. If one request blocks for
> some reason, maybe on a long database query, then all users must wait
> until it completes, for their request to process.
>
> This leaves me wondering about PHP running on IIS and Window. Does this
> hold true for PHP also?
>
> What about PHP on Unix? Does this allow true simultaneous processing of
> all requests when the server has a single CPU?
>
> Thanks for your help.[/color]

This is a Windows/IIS issue, I forget where, but you can change the
threading model I believe.

--
Mike Bradley
http://www.gzentools.com -- free online php tools

[Andy Hassall]

Re: Does PHP process requests sequentially on one CPU?

On Fri, 06 Feb 2004 11:28:41 -0500, "Bruce W.1" <no@direct.emai l> wrote:
[color=blue]
>With ASP.NET I've found that request are processed sequentially, one at
>a time, at least on a server with one CPU. If one request blocks for
>some reason, maybe on a long database query, then all users must wait
>until it completes, for their request to process.
>
>This leaves me wondering about PHP running on IIS and Window. Does this
>hold true for PHP also?
>
>What about PHP on Unix? Does this allow true simultaneous processing of
>all requests when the server has a single CPU?[/color]

This almost certainly depends on your host webserver. Apache on Unix spawns
multiple processes to serve requests, and so they would timeshare as usual on a
single CPU. On Windows it spawns multiple threads - which are also timeshared
simultanously. In both cases, anything blocking would almost certainly be
yielded by the OS scheduler to another process/thread.

I have no idea about the IIS process/thread model - is it documented?

I don't think it's a PHP issue, though.

--
Andy Hassall <andy@andyh.co. uk> / Space: disk usage analysis tool
<http://www.andyh.co.uk > / <http://www.andyhsoftwa re.co.uk/space>

[Chung Leong]

Re: Does PHP process requests sequentially on one CPU?

Sounds more like a locking issue, or perhaps a lisencing issue.

Uzytkownik "Bruce W.1" <no@direct.emai l> napisal w wiadomosci
news:4023C0B9.F 438544F@direct. email...[color=blue]
> With ASP.NET I've found that request are processed sequentially, one at
> a time, at least on a server with one CPU. If one request blocks for
> some reason, maybe on a long database query, then all users must wait
> until it completes, for their request to process.
>
> This leaves me wondering about PHP running on IIS and Window. Does this
> hold true for PHP also?
>
> What about PHP on Unix? Does this allow true simultaneous processing of
> all requests when the server has a single CPU?
>
> Thanks for your help.[/color]