Re: [Dazuko-devel] 2.0.6 released

[Calin A. Culianu]

On Wed, 23 Mar 2005, John Ogness wrote:

> Sami Tikka wrote:
> > P.S. A somewhat-related question: If I have a threaded application (and I 
> > do) and one or more of the threads register with dazuko, does dazuko 
> > intercept file accesses of threads belonging to the same process but have 
> > not registered with dazuko? (I have been working with the assumption that 
> > dazuko intercepts all threads, regardless of process, if they have not been 
> > registered.)
>
> For Linux, threads are implemented with different PID's. So yes, each thread 
> is handled differently.

This actually isn't always the case -- there is a concept of a thread-id 
in linux and some implementations of pthreads use the clone() system call 
in such a way that all threads share the same PID.  In fact, the NPTL 
pthread library I believe does this.  If you want to figure out which 
thread you are in, you actually have to look at the thread-id (TID) using 
the linux-specific system call gettid().  How that impacts Dazuko?  No 
idea.. but.. I just wanted to clarify that on some distros threads do 
share the same PID as the original process from which they came!