multithread: java condition await timeout but can't return

Lock sharedLock = new ReentrantLock();
Condition condition = lock.newCondition();

main thread:

sharedLock.lock();
childThread.start();
condition.await(5, TimeUnit.SECONDS);
sharedLock.unlock();

child thread:

sharedLock.lock();
//do something, may take a long time
Thread.sleep(10);// sleep to simulate a long execution
condition.signal();
sharedLock.unlock();

Suppose child thread send a network request and wait for response, I want main thread wait at most 5 seconds, if timeout, retry the request. but when the await() timeout, it cannot acquire lock because child thread still hold it, so it still wait the lock until child thread release it, which takes 10 seconds.

How can I achieve my requirement that main thread wait child thread's signal, but have a bounded timeout?