JDK7_hashmap扩容导致死循环代码
MapDeadLock
十个线程同时跑
package hellohash;
public class MapDeadLock {
public static void main(String[] args) {
for(int i = 0;i<10;i++) {
new Thread(new DevThread()).start();
}
}
}
DevThread
用AtomicInteger 增加一百万次.
package hellohash;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
public class DevThread implements Runnable {
private static Map<Integer,Integer> map = new HashMap<Integer,Integer>(2);
private static AtomicInteger atomicInteger = new AtomicInteger();
@Override
public void run() {
while (atomicInteger.get() < 1000000) {
map.put(atomicInteger.get(), atomicInteger.get());
atomicInteger.incrementAndGet();//加1
}
}
}
如图