lock.lock();
            try {
                if (waiting > 0) {
                    condition.signalAll();
                }
            } finally {
                lock.unlock();
            }
        }

        @VisibleForTesting
        boolean isWaiting() {
            lock.lock();
            try {
                return waiting > 0;
            } finally {
                lock.unlock();

In this scenario of "fast food burgers with your crush", as there is a lot of waiting 🕙, it makes a lot more sense to have a concurrent system ⏸🔀⏯.

This is the case for most of the web applications.

Many, many users, but your server is waiting 🕙 for their not-so-good connection to send their requests.

And then waiting 🕙 again for the responses to come back.

}

// conditionalProgressRequester will request progress notification if there
// is a request waiting for watch cache to be fresh.
type conditionalProgressRequester struct {
	clock                TickerFactory
	requestWatchProgress WatchProgressRequester
	contextMetadata      metadata.MD

	mux     sync.Mutex
	cond    *sync.Cond
	waiting int
	stopped bool
}

func (pr *conditionalProgressRequester) Run(stopCh <-chan struct{}) {

        e.causes.message == [
            'Failed to handle GET /a due to a timeout waiting to be released. Waiting for 0 further requests, received [GET /a, GET /b], released [], not yet received [GET /c]',
            'Failed to handle GET /b due to a timeout waiting to be released. Waiting for 0 further requests, received [GET /a, GET /b], released [], not yet received [GET /c]'
        ]
    }

        setup:
        buildFile.text = """
            task hang {
                doLast {
                    ${server.callFromBuild("waiting")}
                }
            }
        """.stripIndent()

        def sync = server.expectConcurrentAndBlock("waiting", "waiting")
        def resultHandler = new TestResultHandler()

        when:
        def connector = toolingApi.connector()

              def sanityWaitUntil = System.currentTimeMillis() + 120000
              println 'waiting for file...'
              while(!file('stop.txt').exists()) {
                Thread.sleep(300)
                assert System.currentTimeMillis() < sanityWaitUntil : "Timeout waiting for file"
              }
              println 'no more waiting!'
            }
            def stopNow() {
              assert file('stop.txt').createNewFile()

    def "receive blocks until message available"() {
        def waiting = new CountDownLatch(1)
        def received = new CountDownLatch(1)
        def result = null

        when:
        start {
            waiting.countDown()
            result = daemonConnection.receive(20, TimeUnit.SECONDS)
            received.countDown()
        }
        waiting.await()
        Thread.sleep(500)

        exitCode: 1
        finishedAt: "2006-01-01T01:01:01Z"
        message: messageValue
        reason: reasonValue
        signal: 2
        startedAt: "2005-01-01T01:01:01Z"
      waiting:
        message: messageValue
        reason: reasonValue
    name: nameValue
    ready: true
    resources:
      claims:
      - name: nameValue
      limits:
        limitsKey: "0"
      requests:

		EvGoSysBlock, EvGoBlockGC:
		g = ev.G
		init = gState{noseq, gRunning}
		next = gState{noseq, gWaiting}
		return
	case EvGoSched, EvGoPreempt:
		g = ev.G
		init = gState{noseq, gRunning}
		next = gState{noseq, gRunnable}
		return
	case EvGoUnblock, EvGoSysExit:
		g = ev.Args[0]
		init = gState{ev.Args[1], gWaiting}
		next = gState{ev.Args[1] + 1, gRunnable}
		return
	case EvGoUnblockLocal, EvGoSysExitLocal:

     * @throws IllegalStateException when new work is submitted for an operation while another thread is waiting in {@link #waitForCompletion(BuildOperationRef, ProjectLockRetention)} for the same operation.
     */
    void registerWork(BuildOperationRef operation, AsyncWorkCompletion completion);

    /**
     * Blocks waiting for the completion of all items of asynchronous work associated with the provided build operation.