Thinking about this some...

So as best as I can tell, doStop() results in a one-off executor getting used and then interrupted, which I assume leads to the interrupt(boolean forShutdown) method of the AsynchronousExecution getting called, and that prints the "Click here to forcibly terminate running steps" link in the console (and clicking that calls doTerm(), which tries to terminate any FlowNode running and prints the "Click here to forcibly kill entire build" link, and clicking that results in everything getting killed).

Is it viable to track that process, i.e., have a transient variable marking whether doStop() has been called, whether doTerm() has been called, and whether doKill() has been called, and then have a transient action that renders the appropriate link in the side panel depending on state? i.e., isBuilding() needs to be true to have any link show up there, if doStop() hasn't been called, the link says "Abort the build" and calls doStop(), if doStop() has been called but doTerm() has not, the link says "Forcibly terminate running steps" and calls doTerm(), and if doTerm() has been called but doKill() has not, the link says "Forcibly kill entire build" and calls doKill().

Thoughts?

Preliminary PR up at https://github.com/jenkinsci/workflow-job-plugin/pull/4

New PR up at https://github.com/jenkinsci/workflow-job-plugin/pull/33

New PR up at https://github.com/jenkinsci/workflow-job-plugin/pull/33

Code changed in jenkins
User: Andrew Bayer
Path:
src/main/java/org/jenkinsci/plugins/workflow/job/WorkflowRun.java
src/main/resources/org/jenkinsci/plugins/workflow/job/WorkflowRun/sidepanel.jelly
src/test/java/org/jenkinsci/plugins/workflow/job/WorkflowRunRestartTest.java
http://jenkins-ci.org/commit/workflow-job-plugin/4a4d3848a9fe906d4985993fd6021d87a34b24a5
Log:
[FIXED JENKINS-33721] - Add contextual term/kill in side panel.