private void terminateThreads()

in tooling/camel-karaf-maven-plugin/src/main/java/org/apache/camel/maven/KarafRunMojo.java [519:582]
54 lines of code
12 McCabe index (conditional complexity)

    private void terminateThreads(ThreadGroup threadGroup) {
        long startTime = System.currentTimeMillis();
        Set<Thread> uncooperativeThreads = new HashSet<>(); // these were not responsive
        // to interruption
        for (Collection<Thread> threads = getActiveThreads(threadGroup);
             !threads.isEmpty();
             threads = getActiveThreads(threadGroup), threads
                     .removeAll(uncooperativeThreads)) {
            // Interrupt all threads we know about as of this instant (harmless
            // if spuriously went dead (! isAlive())
            // or if something else interrupted it ( isInterrupted() ).
            for (Thread thread : threads) {
                getLog().debug("interrupting thread " + thread);
                thread.interrupt();
            }
            // Now join with a timeout and call stop() (assuming flags are set
            // right)
            for (Thread thread : threads) {
                if (!thread.isAlive()) {
                    continue; // and, presumably it won't show up in
                    // getActiveThreads() next iteration
                }
                if (daemonThreadJoinTimeout <= 0) {
                    joinThread(thread, 0); // waits until not alive; no timeout
                    continue;
                }
                long timeout = daemonThreadJoinTimeout - (System.currentTimeMillis() - startTime);
                if (timeout > 0) {
                    joinThread(thread, timeout);
                }
                if (!thread.isAlive()) {
                    continue;
                }
                uncooperativeThreads.add(thread); // ensure we don't process
                // again
                if (stopUnresponsiveDaemonThreads) {
                    getLog().warn("thread " + thread + " will be Thread.stop()'ed");
                    thread.stop();
                } else {
                    getLog().warn("thread " + thread
                            + " will linger despite being asked to die via interruption");
                }
            }
        }
        if (!uncooperativeThreads.isEmpty()) {
            getLog().warn("NOTE: "
                    + uncooperativeThreads.size()
                    + " thread(s) did not finish despite being asked to "
                    + " via interruption. This is not a problem with exec:java, it is a problem with the running code."
                    + " Although not serious, it should be remedied.");
        } else {
            int activeCount = threadGroup.activeCount();
            if (activeCount != 0) {
                // TODO this may be nothing; continue on anyway; perhaps don't
                // even log in future
                Thread[] threadsArray = new Thread[1];
                threadGroup.enumerate(threadsArray);
                if (getLog().isDebugEnabled()) {
                    getLog().debug("strange; " + activeCount + " thread(s) still active in the group "
                            + threadGroup + " such as " + threadsArray[0]);
                }
            }
        }
    }