Re: Race condition hangs on multiple mintty/tcsh? Brad Wetmore

[Brad Wetmore <bradfordwetmore@hotmail.com>]

[I apologize if this doesn't thread correctly:  I've been getting the digest, and can't respond directly.  And I have no idea how my name ended up in the Subject line:  Rookie Move!]

More debug information, and a workaround/solution:

I am running:

    Windows 10 Version 1909, fully patched.
    Cygwin v3.1.6-1
    Openssh v8.3p1-1
    mintty v3.2.0-1
    tcsh v6.22.02-1

The issue seems to be a race condition setting up ssh-agent, and then immediately starting up the the mintty/tcsh terminals. My guess is that something in ssh-agent is not fully setup yet, and is causing read hiccups in mintty.

My startup script looks like:

     #!/bin/sh

    if [ -z "$SSH_AGENT_PID" ] ; then
         echo "Starting ssh-agent"
         eval $(ssh-agent)
         ssh-add
         #sleep 3
     fi

    C:/cygwin64/bin/mintty.exe -i /usr/share/mintty/icon/wsl.ico \
         --position 0,0 --size 80x24 --fg black --bg white /bin/tcsh &
     #sleep 1
     ...9 more invocations deleted...

Without the sleep 3 after starting ssh-agent, I see one of three conditions:

1. The mintty window is created, but immediately crashes printing a dozen or so "Use "exit" to leave tcsh" before it does. At least that I think it says, it happens fast! ;)

2. The mintty window is created, and is ready for input. On the first keypress, it prints a dozen or so "Use "exit" to leave tcsh" and crashes.

3. The mintty window is created, and hangs. No prompt.

I get conditions #1/2 when I don't pause between mintty invocations.
I get condition #2 when I pause for 1 second between mintty invocations.

If I pause for 3 seconds after starting ssh-agent, then everything works as expected.

Note this issue occurs only during the first setup of 10 terminals. Running it again does not tickle the issue, probably because ssh-agent is fully up.

Hope this helps.

Brad