esix package consumes 100% cpu

[scruss]

Ubuntu release:
    Description: Ubuntu 16.10
    Release: 16.10

Package & version:

esix:
  Installed: 1-2ubuntu1
  Candidate: 1-2ubuntu1
  Version table:
 *** 1-2ubuntu1 500
        500 http://ca.archive.ubuntu.com/ubuntu yakkety/multiverse amd64 Packages
        500 http://ca.archive.ubuntu.com/ubuntu yakkety/multiverse i386 Packages
        100 /var/lib/dpkg/status

Expected results:

1. Launch esix in terminal
2. Interact with ESI-X language REPL

Actual results:

1. Launch esix in terminal
2. Interact with ESI-X language REPL
3. Computer CPU usage climbs to 100% as REPL busy-waits for input.

Suggested bug fix:

Modify /usr/share/esix/esix.cfg from:

    load esix.bin
    run 5400

to

    set cpu idle
    load esix.bin
    run 5400

This will cause the simh PDP-8 emulator that runs the ESI-X binary to throttle down when it detects a busy loop. It may take 25-30 seconds for CPU usage to calm down.

Severity:

Low, but rampant CPU usage is a bit rude.

Notes:

1. This is almost certainly an upstream bug, but the Debian maintainer has abandoned the package.

2. It may be helpful to note in the documentation that esix can be exited by typing Ctrl-E, then `quit` from the PDP-8 simulator shell.

3. (aside) The esix code is now over 50 years old, making it likely the oldest running Debian/Ubuntu package ...

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: esix 1-2ubuntu1
ProcVersionSignature: Ubuntu 4.8.0-34.36-generic 4.8.11
Uname: Linux 4.8.0-34-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.3-0ubuntu8.2
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Jan 30 16:25:49 2017
Dependencies:
 gcc-6-base 6.2.0-5ubuntu12
 libc6 2.24-3ubuntu2
 libgcc1 1:6.2.0-5ubuntu12
 libpcap0.8 1.7.4-2
 simh 3.8.1-5build1
InstallationDate: Installed on 2015-03-08 (694 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
PackageArchitecture: all
SourcePackage: esix
UpgradeStatus: Upgraded to yakkety on 2016-12-02 (59 days ago)

[dino99 (9d9)]

This is an unsupported release now. Please think to install the next LTS 'Bionic 18.04'

http://cdimage.ubuntu.com/ubuntu-next/daily-live/current/
https://www.omgubuntu.co.uk/2018/02/ubuntu-18-04-minimal-install-option

[scruss (scruss)]

Still affects esix-1-3 in 17.10 (Artful Aardvark), so valid. 18.04 not offered for upgrade yet.