理解Thread.sleep()函数（理解sleep()函数线程。）.docVIP

理解Thread.sleep()函数（理解sleep()函数线程。） We may often use the Thread.Sleep function to suspend threads for some time. So, do you have the right understanding of the use of this function? Think about the following two questions: 1, suppose this is 2008-4-7 12:00:00.000, and if I call Thread.Sleep (1000), will this thread be awakened at 2008-4-7 12:00:01.000? 2. The code using a seemingly unintelligible words (0): Thread.Sleep. Since its Sleep 0 milliseconds, whats the difference between getting rid of this code and getting rid of it? Lets review the operating system principle first. There are many strategies for CPU competition in operating systems. The Unix system uses a time slice algorithm, while Windows is preemptive. In the time slice algorithm, all the processes are queued. The operating system, in their order, assigns each process a period of time, that is, the time the process allows to run. If the process is still running at the end of the time slice, the CPU will be stripped and assigned to another process. If the process blocks or ends before the end of the time slice, the CPU switches immediately. All the scheduler has to do is to maintain a list of ready processes, and when the process runs out of its time slice, it is moved to the end of the queue. The so-called preemptive operating system, that is, if a process gets CPU time, unless it itself to abandon the use of CPU, otherwise it will completely occupy CPU. Therefore, we can see that in preemptive operating systems, the operating system assumes that all processes are good quality and will automatically withdraw from CPU. In the preemptive operating system, assuming there are a number of processes, the operating system according to their priority and starvation time (how long have not used CPU), give them a priority to calculate the total. The operating system then passes the CPU to the highest priority process. When the process is completed or the initiative is suspended, the operating system will recalcul