AtomicLong.updateAndGet()超级费CPU，并发一多就100%

[yangxuanjia]

原来：

// spin get next available cursor
long currentCursor = cursor.get();
long nextCursor = cursor.updateAndGet(old -> old == tail.get() ? old : old + 1);

// trigger padding in an async-mode if reach the threshold
long currentTail = tail.get();

改成下面这样是否可以？？？

// spin get next available cursor
long currentCursor = cursor.get();
long currentTail = tail.get();

long nextCursor = currentCursor;
if (currentCursor != currentTail) {
    nextCursor = cursor.incrementAndGet();
}

[zxy1994]

原来：

// spin get next available cursor
long currentCursor = cursor.get();
long nextCursor = cursor.updateAndGet(old -> old == tail.get() ? old : old + 1);

// trigger padding in an async-mode if reach the threshold
long currentTail = tail.get();

改成下面这样是否可以？？？

// spin get next available cursor
long currentCursor = cursor.get();
long currentTail = tail.get();

long nextCursor = currentCursor;
if (currentCursor != currentTail) {
    nextCursor = cursor.incrementAndGet();
}

您好，请问下你这个是什么工具？看起来很直观，谢谢大佬