[pmwiki-users] Best installation choices for PmWiki on Win2000 with IIS5?

Joachim Durchholz jo at durchholz.org
Fri May 5 02:22:52 CDT 2006

Hartl, Bob schrieb:
> Concerning whether or not PHP and its libraries are "thread-safe"...
> I installed PHP 4.4.2 on Win2000/IIS using ISAPI -- and the first thing
> I did was to run the suggested php script that calls phpinfo().  The
> phpinfo page I got back was a long list of "settings" which included
> "Thread Safety = enabled."
> 1) Does this mean that everything included with the PHP 4.4.2 install
> package (including extensions that were included with the install
> package) is "thread safe?"

Well, sort of. I have been unable to find the meaning of this setting in 
the PHP documentation.

The general advice is "PHP doesn't know which of the hundreds of 
libraries it calls are thread-safe and which aren't. On Windows, most 
basic libraries are; on Unix, most aren't."
In other words, you can't be sure.

> 2) I assume other extensions (not included in the install package) might
> not be thread safe, correct?

Even those in the install package might be not thread safe. PHP has no 
way to know.

> 3) Since the PHP core engine I'm using is thread safe, does this mean it
> would object -- flag as an error -- an extension that wasn't "thread
> safe?"

Since PHP doesn't know about the thread safety of the libraries it uses 
(many of which are built and maintained by third parties), it cannot do 
any diagnostics on the issue.

> 4) By libraries do you mean extensions -- or are they two different
> things?  (I'm an ASP/VBScript guy, so PHP and its terminology is still
> new to me.)

Most things are both :-)

E.g. the mysql functions are language extensions: if they aren't 
compiled in, using them will give you a syntax error.
However, to implement them, PHP calls out to external libraries provided 
by MySQL AB.

> Thanks Joachim, you've been a big help.

You're welcome :-)


More information about the pmwiki-users mailing list