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Date: Wed, 07 Nov 2001 22:48:00 -0000
From: Kevin Buettner <kevinb@cygnus.com>
Message-Id: <1011120071710.ZM17562@ocotillo.lan>
In-Reply-To: Kevin Buettner <kevinb@cygnus.com>
        "Re: [PATCH RFA] lin-lwp.c: Block SIGCHLD events when attaching" (Nov 19, 11:53pm)
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To: "H . J . Lu" <hjl@lucon.org>
Subject: Re: [PATCH RFA] lin-lwp.c: Block SIGCHLD events when attaching
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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