On 27/10/2008, De Groot, Cees <[EMAIL PROTECTED]> wrote:
> Hi,
>
>  We're using HC in order to access an internal high-volume service
>  (thousands reqs/sec), and we noticed that DefaultHttpParams is
>  synchronized all over the place. This kills concurrency (I have a thread
>  dump showing ~1200 threads waiting there ;-)), and I don't think it is
>  necessary - it should be possible to read settings without having to
>  acquire locks first.

That's not necessarily true. Synchronize does more than provide mutual
exclusion - i.e. locking - it also ensures that fields written in one
thread are correctly seen in another.

Without synch. there is no guarantee that reader threads will see the
latest value written to a variable, as the JVM is free to cache
variables locally. The synch. forces a memory flush  (for writers) and
memory refetch (for readers).

>  We found some references to this issue on the Net, but none on this
>  mailing list. Is this a known issue? Is this something that needs
>  fixing?
>
>  Thanks,
>
>  Cees de Groot
>
>  ---------------------------------------------------------------------
>  To unsubscribe, e-mail: [EMAIL PROTECTED]
>  For additional commands, e-mail: [EMAIL PROTECTED]
>
>

---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to