Re: [PATCH RFA] lin-lwp.c: Block SIGCHLD events when attaching

[Kevin Buettner <kevinb@cygnus.com>]

On Nov 19, 11:53pm, Kevin Buettner wrote:

> I just tried it.  It seems to behave about the same.  It usually attaches
> okay, but I am able to reproduce the "Cannot find new threads: generic error"
> by using Jim's trick of repeatedly attaching and detaching.

I now know a little bit more about this problem.

First, I should explain that I'm using Jim Blandy's trick of

    set height 0
    break <somewhere that will be hit by one or more threads>
    while 1
     attach <pid of main process>
     continue
     detach
    end

The "Cannot find new threads:  generic error" seems to occur just (or
shortly) after one of the early threads has exited.  Tomorrow, I'll
write a test to see if it's possible at all to attach to a
multithreaded process in which one of the threads has exited.

Kevin