多线程摘录 007
* 测试多线程程序的安全性和生存型
??? - 不要做出"伪"测试代码, 即让有问题的代码也能通过的测试
* 测试要关注的几点
??? - 吞吐量
??? - 响应时间
??? - 伸缩性(是否资源越多, 吞吐量越大?)
* 如何测试有阻塞的方法
??????? The obvious way to do this is via interruptionstart a blocking activity in a separate thread, wait until the thread blocks, interrupt it, and then assert that the blocking operation completed
??????? void testTakeBlocksWhenEmpty() {
??????????? final BoundedBuffer<Integer> bb = new BoundedBuffer<Integer>(10);
??????????? Thread taker = new Thread() {
??????????????? public void run() {
??????????????????? try {
??????????????????????? int unused = bb.take(); //阻塞
??????????????????????? fail(); // if we get here, it's an error
??????????????????? } catch (InterruptedException success) {
??????????????????????? //忽略中断
??????????????????? }
??????????????? }};
??????????? try {
??????????????? taker.start();
??????????????? Thread.sleep(LOCKUP_DETECT_TIMEOUT);
??????????????? taker.interrupt();
??????????????? taker.join(LOCKUP_DETECT_TIMEOUT);
??????????????? assertFalse(taker.isAlive());
??????????? } catch (Exception unexpected) {
??????????????? fail();
??????????? }
??????? }
* 不要使用Thread.getState, 不可靠

* xorShift随机数算法
static int xorShift(int y) {
??? y ^= (y << 6);
??? y ^= (y >>> 21);
??? y ^= (y << 7);
??? return y;
}

转自：http://hi.baidu.com/iwishyou2/blog/item/14adde1f66272f02304e15fe.html