我使用 ReentrantLock 實現生產者消費者問題public class Processor { Lock lock = new ReentrantLock(true); Condition condn = lock.newCondition(); public void produce() throws InterruptedException{ lock.lock(); System.out.println("inside producer method"); condn.await(); System.out.println("thread again wakeup"); lock.unlock(); } public void consume() throws InterruptedException{ lock.lock(); Thread.sleep(1000); condn.signal(); System.out.println("will i ever be ok "); lock.unlock(); }}ReentrantLock 同步了兩種方法，但有時進程會死鎖o/p 在生產者方法中我會不會沒事在運行堆轉儲時Reference Handler" #2 daemon prio=10 os_prio=31 cpu=0.26ms elapsed=540.35s tid=0x00007fd5f186f800 nid=0x4603 等待條件 [0x0000700002357000] java.lang.Thread.State: RUNNABLE at java.lang.ref.Reference.waitForReferencePendingList([email protected]/Native Method) at java.lang.ref.Reference.processPendingReferences([email protected]/Reference.java:241) at java.lang.ref.Reference$ReferenceHandler.run([email protected]/Reference.java:213)"Finalizer" #3 daemon prio=8 os_prio=31 cpu=0.67ms elapsed=540.35s tid=0x00007fd5f1883000 nid=0x4303 in Object.wait() [0x000070000245a000] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait([email protected]/Native Method) - waiting on <0x0000000787f08f80> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove([email protected]/ReferenceQueue.java:155) - waiting to re-lock in wait() <0x0000000787f08f80> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove([email protected]/ReferenceQueue.java:176) at java.lang.ref.Finalizer$FinalizerThread.run([email protected]/Finalizer.java:170)"Signal Dispatcher" #4 daemon prio=9 os_prio=31 cpu=0.34ms elapsed=540.27s tid=0x00007fd5f1884000 nid=0x3903 waiting on condition [0x0000000000000000] java.lang.Thread.State: RUNNABLE為什么即使在我使用釋放鎖后它也會死鎖 condn.signal();
2 回答
慕沐林林
TA貢獻2016條經驗 獲得超9個贊
你可以用Phaser它。關鍵是Phaser制片人問“我錯過了一些消費嗎？” 如果不是，它正在等待，如果是，它會立即繼續進行。這是一個例子：
public class Processor {
private final Phaser phaser = new Phaser(1);
private volatile int lastPhaseId = 0;
public void produce() throws InterruptedException{
System.out.println("inside producer method");
lastPhaseId = phaser.awaitAdvance(lastPhaseId);
System.out.println("thread again wakeup");
}
public void consume() throws InterruptedException{
Thread.sleep(1000);
phaser.arrive();
System.out.println("will i ever be ok ");
}
}
這適用于單個消費者的情況。如果假設有多個消費者，則phase.arrive()需要互斥訪問和/或注冊方相應更改（取決于您需要什么語義）
添加回答
舉報
0/150
提交
取消