Re: [boost] Attempting resolution of Threads & Exceptions Issue

From: Peter Dimov (pdimov_at_[hidden])
Date: 2002-08-12 17:04:15

From: "William E. Kempf" <williamkempf_at_[hidden]>
>
> For an example I'll once again go back to the classic bounded buffer.
Let's
> imagine that I create a thread that's going to write out several items to
> this buffer... a lot more than the buffer can handle with out another
thread
> reading the values out.

What is the return value of the writer thread, and who is supposed to join()
it?

> Let's also imagine that I create yet another thread
> to read this values out and sum them up.  The result I'll return to the
> caller when he join()s.  This is very similar to an async call, but
between
> the call invocation and the returning of the result there's important
> inter-thread interactions going on.  With exception propagation I'm
> concerned not only that the user may not call join() because he's not
> interested in the result, only that the processing occurs, and thus could
> never receive the exception.  No, I'm also concerned that if exception
> propogation is the norm the niave user is lulled into thinking exception
> handling is taken care of internally, and thus dead lock occurs when the
> writing thread throws an exception while the reading thread is blocked
> trying to read a value that will now never be added to the buffer.

Why does the writing thread throw an exception? Why is exception propagation
in effect for the writer thread?