This is a plugin which modifies an existing task, such that it will print a formatted thread dump to *err* if your program is stuck in one place for too long. This is especially useful in CI environments where you are not able to run jstack directly on the process.

lein jammin <seconds> test

If none of the threads in your tests are active for the specified duration, then it will print out a series of stack traces like this, with the historically most active thread first:

 == Things seem to be stuck. ==


main

                                                              sun.misc.Unsafe.park                      Unsafe.java
                                       java.util.concurrent.locks.LockSupport.park                 LockSupport.java:  186
       java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt  AbstractQueuedSynchronizer.java:  834
java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly  AbstractQueuedSynchronizer.java:  994
  java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly  AbstractQueuedSynchronizer.java: 1303
                                         java.util.concurrent.CountDownLatch.await              CountDownLatch.java:  236
                                                  clojure.core/promise/reify/deref                         core.clj: 6553
                                                                clojure.core/deref                         core.clj: 2200
...

To use this plugin, add this to your project.clj:

:plugins [[lein-jammin "0.1.1"]]

license

Copyright © 2015 Zach Tellman

Distributed under the MIT License.