func threadPrint(threadNum int, threadName string, mu sync.Locker) {
for i < 9 {
fmt.Println("......", threadNum, threadName, "S-1")
mu.Lock()
if i >= 9 {
mu.Unlock()
continue
}
if i < 3 && i%3 != threadNum {
fmt.Println("......", threadNum, threadName, "S-2")
mu.Unlock()
continue
}

fmt.Printf("%d: %s\n", i, threadName)
i += 1
fmt.Println("......", threadNum, threadName, "S-3")
mu.Unlock()
}
end <- struct{}{}
}

...... 0 A S-1
0: A
...... 0 A S-3
...... 0 A S-1
...... 0 A S-2
...... 0 A S-1
...... 0 A S-2
...... 2 C S-1
...... 1 B S-1
...... 2 C S-2
...... 2 C S-1
1: B
...... 1 B S-3
...... 1 B S-1
2: C
...... 2 C S-3
...... 2 C S-1
...... 0 A S-1
3: B
...... 1 B S-3
...... 1 B S-1
4: C
...... 2 C S-3
...... 2 C S-1
5: A
...... 0 A S-3
...... 0 A S-1
6: B
...... 1 B S-3
...... 1 B S-1
7: C
...... 2 C S-3
...... 2 C S-1
8: A
...... 0 A S-3


打印一些状态可以看出一些端倪