Check if a Grails' service method is already running with certain parameter

Question

I'm using grails 4.0.6 and I need to check if a given service's method is in execution with a certain domain object's instance. In this case, the method takes a long time to run and it is called with a parameter (a domain class' instance). If it is called again with the same instance that it is currently in execution with, the call must be aborted. I tried setting a flag in the domain class (and flushed the update) however it is not reflected in the new call. Any hints are appreciated.

Answer 1

If you need to abort the second call, use a Lock. If you just don't want them running concurrently, use a synchronized block.

Lock:

class MyService {
    static def locks = [:]

    def someMethod(inputParam) {
        def key = "${inputParam.class}${inputParam.id}"
        def lock = locks.get(key)
        if (!lock) {
            lock = new ReentrantLock()
            locks.put(key, lock)
        }
        if (lock.tryLock()) {
            // do your work here
            lock.unlock()
        }
    }
}

Synchronized:

Your service method would pretty much be

synchronized (key) {
    // your work
}

Any of this may need tweaks...I just typed it in here without any testing!