[c++-pthreads] Re: pthread_cancel and EH: let's try this again

[Wil Evers]

Gabriel Dos Reis wrote:

> Wil Evers <wil at bogo.xs4all.nl> writes:

> | In other words, #2 has the desirable property that it does not break
> | existing code that assumes destructors *never* throw. I suspect that a
> | lot of code relies on that assumption, and I know for sure that
> | practically all of my code does.
> | 
> | Supposing model #1 is accepted, then how do we cope with existing code
> | that assumes destructors never throw, or, more generally, with code
> | that was not written to deal with exceptions thrown from cancellation
> | points?
> 
> Destructors that throw usually lead to brittle codes.  The
> problems are with those destructors, not with the cancellation model
> implemented for C++. The destructors should be fixed, because that
> problem is independent of multithreading.

I disagree; one of the problems with mapping cancellation requests to 
C++ exceptions is that certain system calls that did not throw before 
are changed into functions that do, and that existing (destructor or 
non-destructor) code won't always be able to deal with that.

- Wil