public class countdownlatch
int getcount(
) protected int tryacquireshared(int acquires)
protected boolean tryreleaseshared(int releases)}}
private final sync sync
; /**
* constructs a initialized with the given count.
** @param count the number of times
must be invoked
* before threads can pass through
* @throws illegalargumentexception if
is negative
*/public countdownlatch(int count)
}
new countdownlatch(1)
;
public countdownlatch(int count)
sync(int count)
使用await()方法
public void await(
) throws interruptedexception
public final void acquiresharedinterruptibly(int arg)
throws interruptedexception
countdownlatch.class
protected int tryacquireshared(int acquires)
private void doacquiresharedinterruptibly(int arg)
throws interruptedexception }if
(shouldparkafte***iledacquire(p, node)
&& parkandcheckinterrupt(
)) throw new interruptedexception();
}} finally
}
countdown方法
public void countdown(
) protected boolean tryreleaseshared(int releases)
}
public final boolean releaseshared(int arg)
return
false
;}
這樣就實現了在countdown執行到state為0時，依次啟用了所有在佇列中的掛起執行緒。
public class countdownlatchtest
@override
public void run(
)catch (interruptedexception e)}}
public static void main(string[
] args)
try catch (interruptedexception e)
}}
thread sleep
done
thread sleep
done
thread sleep
done
thread sleep
done
thread sleep
done
main thread run
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