题目内容
Given a hard disk of 200 tracks (Track 0‐199) with Track 0 being the innermost track. Write down the track numbers the disk head will travel for the following 4 disk scheduling algorithms with the following sequence of disk track requests: 93, 129, 98, 110, 43, 155, 150, 47, 40. The disk head has just finished a request at track 115 and is currently at track 108. What is the total distance (in cylinders) that the disk arm moves to satisfy all the pending requests.1）FCFS 2）SCAN 3）SSTF 4）C-LOOK
查看答案
搜索结果不匹配？点我反馈
更多问题
A database is shared among several concurrent processes. Reader processes want only to read the database, whereas writer processes want to update the database. Readers can access the shared data simultaneously, while the writers should have exclusive access to the shared database. Now you need to solve the problem using semaphores.The semaphore mutex is used to ensure mutual exclusion when the variable readcount is updated. he readcount variable keeps track of how many processes are currently reading the object. The semaphore wrt functions as a mutual-exclusion semaphore for the writers.(1) Initialize the semaphore mutex and wrt.(2 points)(2) Given the code of writer processes, please write the code of reader processes.(8 points)
磁粉检测能检查出的缺陷是:
下列哪些材料可以进行磁粉检测?
钢材表面裂痕最适合的检测方法是哪一种?
微信支付 
支付宝支付