kern/33951: pthread_cancel is ignored

[Petri Helenius]

David Xu wrote:

>>
> I had enabled asynchornous cancelling for M:N thread in libkse but not 
> 1:1 thread,
> simplest way to support asynchronous cancelling for 1:1 is to use 
> signal, but it will
> occupy a signal like Linux's SIGUSR1, another way is to use upcall,  
> but  it is
> slight complicated.
>
One of the features I dislike with linuxthreads is that it eats one of 
the two USR signals. It complicates things like debugging because then 
you have to read files instead of just using one signal to set debug=0 
and the other to debug++.

Pete