public void waitUntilAllAgentDisconnected() {
		int trial = 1;
		while (trial++ < 40) {
			if (this.runningThread != 0) {
				synchronized (eventSyncCondition) {
					eventSyncCondition.waitNoInterrruptException(500);
				}
				// Every 10 times send the signal again.
				if (trial % 10 == 0) {
					sendStopMessageToAgents();
				}
			} else {
				return;
			}
		}
		throw processException("Connection is not completed for 20 sec");
	}
Wait until the count of running threads becomes 0. If the elapsed time
is over 10 seconds, an {@link NGrinderRuntimeException} is thrown.
ngrinder-core/src/main/java/net/grinder/SingleConsole.java