代码1:
class BCWCExamples {
public Object lock;
boolean someCondition;
public void NoChecking() throws InterruptedException {
synchronized(lock) {
//Defect due to not checking a wait condition at all
lock.wait();
}
}
代码2:
public void IfCheck() throws InterruptedException {
synchronized(lock) {
// Defect due to not checking the wait condition with a loop.
// If the wait is woken up by a spurious wakeup, we may continue
// without someCondition becoming true.
if(!someCondition) {
lock.wait();
}
}
}
代码3:
public void OutsideLockLoop() throws InterruptedException {
// Defect. It is possible for someCondition to become true after
// the check but before acquiring the lock. This would cause this thread
// to wait unnecessarily, potentially for quite a long time.
while(!someCondition) {
synchronized(lock) {
lock.wait();
}
}
}
代码4:
public void Correct() throws InterruptedException {
// Correct checking of the wait condition. The condition is checked
// before waiting inside the locked region, and is rechecked after wait
// returns.
synchronized(lock) {
while(!someCondition) {
lock.wait();
}
}
}
}
注意:有其他地方的通知
代码1中没有等待条件，因此存在无限等待，但为什么其他3个代码(2,3,4)中发生无限等待
请检查代码中的注释以便更好地理解请帮助我，我是java等待和通知的新手
最佳答案
在您的示例中，我没有看到任何 lock.notify() 或 lock.notifyAll() 调用。
简短的回答:您将wait()除非您在同一个对象lock上调用notify()。
有关更多信息，请考虑查看下一个链接:
关于java无限等待问题？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41120182/