A target has-a 1:N threads?

[Andrew Cagney]

> Hello,
> 
> At present GDB maintains a thread-db that contains all the "threads" known to GDB.  The list is cross-target.  That is, it can include both LWPs from the lower "process layer" and "threads" from the higher "thread layer".
> 
> I think the currently implicit target <-> thread relationship should be made more explicit:
> 
> - thread_info should point back at it's target
> - a target should let you iterate over its "threads"
> 
> This, I belive, will help clean-up the current tid:pid dance.  A thread would always know its target and hence thread operations would always be applied at the correct level.

Make that 0:N threads.  I forgot the targets that don't have threads.

Andrew