Thanks Jochem, Roman :)


On 12/13/06, Jochem Maas <jochem@[...].com>  wrote:
> 
>  Kai Xiang wrote:
>  > On 12/13/06, Roman Neuhauser <neuhauser@[...].cz> wrote:
>  >
>  >> # maillist.kai@[...].com / 2006-12-13 14:15:26 +0800:
>  >> > I'm new here and looking PHP these days, howerver , I'm confused by
>  how
>  >> it
>  >> > works, and here is some questions I have.
>  >> > Is there any old bird wanna help me out?
>  >> >
>  >> > 1. I heard there is a zend engine inside PHP playing the role as a
>  >> virtual
>  >> > machine, and PHP excution have 2 step, first compile to opcode and
>  then
>  >> > excute the opcode,
>  >> > so is that means the php are compiled only once per file? or still
>  need
>  >> to
>  >> > recompile when another request issued to the server? also I heard
>  about
>  >> the
>  >> > caching extention about php, is it talking about caching the opcode?
>  >> is't
>  >> > caching the opcode or excute results? how it shares between the
>  >> requests?
>  >>
>  >> Both kinds of things exist, with different sharing strategies.
>  >
>  >
>  > Can you tell it more detail, opcode caching cache the compiled opcode,
>  so
>  > not any compile needed anymore if no source changed? what about results,
>  > what kind of methdology it's taking?
> 
>  you can get a good idea of APC from the changelog:
> 
>         http://pecl.php.net/package-changelog.php?package=APC
> 
>  Zend als offers opcode caching as part of their suite of products ... Im
>  not all to familiar with Zend's stuff but no doubt their website has
>  plenty
>  of info.
> 
>  >
>  >
>  >
>  >> > 3. Take linux apache for example, if compiled as a apache module, and
>  >> using
>  >> > prefork threading model, for example, if I have 100 process, is that
>  >> means I
>  >> > have 100 copy of PHP library local data(I assume only one reentrant
>  >> > excutable image) in each process? compare to a worker model, like 10
>  >> process
>  >> > and 10 threads in each one process, should it make a difference that
>  we
>  >> only
>  >> > have 10 copy of PHP library local data ?
>  >>
>  >> Practical concerns make your question moot: even if the basic
>  >> distribution was all threadsafe, you're bound to hit a library that
>  uses
>  >> strtok(3) or strerror(3), or static variables. How much of the code you
>  >> rely on is labelled by its authors as threadsafe?
>  >
>  >
>  > So it is not a good idea to use worker and php module at the same time,
>  but
> 
>  correct - stick with the prefork module with apache, I believe *think* it
>  is possible
>  to safely use a threaded module if you decide to go the FastCGI route but
>  I maybe
>  thinking this because I completely misunderstood what someone was saying
>  about FastCGI
>  (I remember reading quite abit about FastCGI in posts made to
>  internals@[...].net
>  by core-dev/Zend-Founder Andi Gutmans - although I can't say I understood
>  everything I read!)
> 
>  > if no threadsafe problem , maybe my thinking is right?
>  > Btw, I thought strerror in libc were thread-safe.
>  >
>  >
> 
>