编程知识 cdmana.com

Level 4 computer network engineer - Summary of notes on some topics of operating system [21 ~ 30 questions]

Computer level 4 notes

The operating system part :(21~30 topic )

Because the length is too long , To ensure the quality of learning , Then it is divided into four parts ( Four blogs )
Every time 10 Entitled an article , Other topics are in my Level 4 computer network engineer Columns can be found in

The first 21 topic :

  1. The file system implements the of files Access by name Which of the following work is done : File directory search

  2. Which method You can't be used for Improve the efficiency of file directory retrieval Limit the number of subdirectories

  3. In the file system , A data structure must be established for each file that contains at least the file name and the physical storage address of the file , be called : File control block

  4. Which structure belongs to the file Logical structure Unstructured ( Flow structure )

  5. Which structure belongs to the file Physical structure Index structure 、 Link structure 、 Continuous structure

  6. about Built on tape drive File system , The most suitable file physical structure is : Sequential structure

  7. File system , If the logic continuity The file information of is stored in Serial number In the disk block of , This structure is called : Sequential structure

  8. File system , The reasonable location for storing file access control information is : File control block (FCB)

  9. File system , Set the current working directory The main purpose of : Speed up file retrieval

  10. For the file system with tree directory structure , By operating system user Decide how to set the current working directory

  11. For files that need frequent access , What kind of file Best for continuous access Sequence file

  12. Which is performed by operating system Back to : File descriptor

  13. When creating a file, the attribute that can set the default value is : Retention period of documents

  14. You do not need to set when creating a file : File descriptor

  15. Which one be not in File control block (FCB) in : File usage times 、 Number of file modifications 、 File allocation table 、 List of files opened by the user ( belt “ frequency ” “ surface ”)

  16. Usually Binary executable What kind of logical structure of the file : Flow structure

The first 22 topic :

  1. Open the file before using it . After successful execution of the open file system call , The system will return a message to the user : File descriptor
  2. Open file What I did when I was a kid : Fill in the document reading and writing method in the document control block
  3. After the last backup New addition Backup your data , This method is called : Incremental dump
  4. When using the file system , It's usually done explicitly open() operation , The purpose of this is : File control block (FCB) Read in memory
  5. When using the file system , It's usually done explicitly close() operation , The purpose of this is : File control block (FCB) Read in disk and cache
  6. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-XytPsSu3-1652247327987)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220121140457985.png)] Insert picture description here

​ analysis : use 2555900 ÷ 4096 that will do = 623.5≈ 624, choose D

  1. In the physical structure of the file , fit Random access and easy file expansion Yes. : Index structure

  2. Which item is related to the document Physical structure relevant : user For documents access The way

  3. Reading and writing Hard disk when , Which operation takes the shortest time : The data transfer

  4. Usually yes External storage The process of device access is completed in a certain order . The correct order is : read state —》 Set up data —》 Set up Address —》 Set up control —》 Reread status ( Brief notes : Outside 、 shape 、 Count 、 The earth 、 system )

  5. After opening the file, the system No value returned return File descriptor

  6. The whole system ( It's one for each file ) Set up a user open file table

  7. The system opens the contents of the file table entry Not allowed to be modified ( It changes at any time )

  8. The process is in Open a file In the process of , The correct sequence of operation is : lookup FCB Main department —》 Check the opening method —》 Check user identity —》 Fill in the process open file form

  9. The process is in create a file In the process of , The correct sequence of operation is : Check the validity of parameters —》 Check for duplicate names —》 lookup FCB Free space —》 Fill in FCB

  10. ( Open file , Look for the FCB, Look at the opening method ; create a file , Let's look at legitimacy first , See if there is a duplicate name ;)

  11. A process is in The contents of the open file have been modified during operation , When the process closes the file , The correct sequence of operation is : Find files —》 modify FCB Related content —》 Set up FCB by “ Inactive ”—》 Write back to disk

  12. The process is in Delete a file In the process of , The operation sequence is correct Yes. : Find files —》 Check the validity of deletion —》 Take back FCB resources —》 Reclaim file storage space

  13. Which one No The information necessary to make up the file directory : File path information

The first 23 topic :

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-t8h6MiKD-1652247327988)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220122101651072.png)] Insert picture description here

analysis : There is no group operation , use The length of each logical record ÷ Block size = Utilization of disk space ,80 ÷ 1024 , choose A

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-GZtKY0xE-1652247327989)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220122102119562.png)] Insert picture description here

analysis : front 10 term 10 block , Primary index table 100 block , Secondary index table 100^2 , Add up :10110, choose B

  1. The elevator algorithm is : Scanning algorithm (SCAN)
  2. The average seek time is short But the algorithm that can easily cause hunger is : Shortest seek time first algorithm SSTF
  3. Which method It has nothing to do with improving disk read and write speed : Optimize equipment allocation scheme
  4. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-MpGEKEwS-1652247327990)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220122104953277.png)] Insert picture description here

analysis : use Logical block number ÷ ( cylinder x A sector ) = 385961 ÷ (2500 x 80) = 1( Rounding down ), Get the corresponding disk surface , Immediate selection B

  1. Operating system , Of documents Conversion from logical block number to disk block number By which decision : Physical structure

  2. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-BZjrhzKU-1652247327991)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220122152510516.png)] Insert picture description here

    analysis :**( summary : Shortest seek algorithm —— Who's near it , Choose who )** Choose the distance first 105 The closest number , Look at the options ,110 Closest to it ; Then choose to leave 110 Near number , Choose in turn , Elected to 12 when , This is the smallest number , Then choose from the number with a large distance ( basis “ Move in the direction of increasing track number ”), Then choose the nearest number in turn .

  3. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-S4VYwskE-1652247327992)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220122153358068.png)] Insert picture description here

analysis :155, In the access request sequence , look for Than 155 Small and nearest number (110), Look for a comparison 110 Small and nearest number (68), Look down in turn .( We must have a beginning and an end , Then start from the large number and increase in close order , That is, first reduce and then increase

summary :SCAN Dispatch ( Elevator scheduling ) Algorithm :1) The track number moves in the direction of decreasing , Then the access sequence is : First decrease and then increase

2) The direction in which the track number increases , Then the access sequence is : First increase and then decrease

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-HOU3T73H-1652247327992)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220122154557434.png)] Insert picture description here

[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-IPCgOXRK-1652247327993)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220122154615610.png)] Insert picture description here

analysis : distance 155 The latest number :155-110 = 45,170 -155 = 15,155 -12 = 143

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-7BuCpECT-1652247327994)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220122154905955.png)] Insert picture description here

analysis : First come, first served : Just arrange it in the above order

The first 24 topic :

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-ypG9h6zC-1652247327995)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123113643738.png)] Insert picture description here

analysis : Use group operation ( It can improve the utilization of disk space ),

computing method :( Logical record length x Block factor )÷ Block size = (80 x 12) ÷ 1024 ≈ 93%, choose D

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-BeJfa3Jr-1652247327995)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123135412664.png)] Insert picture description here

    analysis : for the first time ,10 block ; The second time ,110 block ; third time ,>110 block , therefore , choose 3 Time , choose B

  2. UNIX Operating system , The management of free area in file system usually adopts : Group linking

  3. In a multi-level directory file system , The user's first access to the file is usually given Pathname of the file , Later access to the file usually uses : File descriptor

  4. Advantages of tree directory : To simplify the Added directory management

  5. File directory , user Sure Can not be establish root directory

  6. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-kO66tnP2-1652247327996)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123140152889.png)] Insert picture description here

analysis : use 32 ÷ 8 = 4 byte , Reuse 512 ÷ 4 = 128, So before 10 One directly points to the disk block number ,128 The power of points to the primary index table ,128 The quadratic power of points to the secondary index table ,128 The third power of points to the three-level index table , choose C

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-MnyWiqvR-1652247327997)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123140827258.png)] Insert picture description here

9.[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-OohW6qGE-1652247327997)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123141308146.png)] Insert picture description here

analysis :1KB = 1024, 1024÷ 4 = 256 = 2^8, So choose B

The first 25 topic :

  1. Optimize which time Can significantly improve Disk read / write performance : Seek time
  2. Optimizing those times can improve disk read and write performance : Seek time Rotation time Transmission time
  3. about FAT32 file system , What kind of file physical structure does it use : Link structure
  4. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-bHuTGRdX-1652247327998)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123142419339.png)] Insert picture description here

analysis : First reduction , After division ;1) Block number - Number of columns = 30 - 16 = 14 ; 2) Block number ÷ Number of columns = 30 ÷ 16 = 1( Rounding down )

​ The answer is :1 That's ok 14 The corresponding bit of the column

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-RUMGR68q-1652247328001)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123142908141.png)] Insert picture description here

  2. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-qQOVL1YO-1652247328001)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123143204881.png)] Insert picture description here

analysis : use 4096 ÷ 4 = 1024 = 2^10, choose A

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-1woN7H4Z-1652247328003)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123143413312.png)] Insert picture description here

[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-Q1K4vgEe-1652247328003)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123143442026.png)] Insert picture description here

analysis : Search for keywords **“ front ”** How to do questions : The correct answer must be : even numbers +0.5 , choose B; because :(1+ Physical block ( It must be an even number ))÷ 2 = even numbers .5 , Use skills if you can't , should

Calculation :256 ÷ (512 ÷ 32) = 32,(1 + 32) ÷ 2 = 16.5

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-PkTRQLOC-1652247328004)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123144711272.png)] Insert picture description here

analysis : Search for keywords “ after ” , Method : Set the number of directory files to X, be X = (256( The value in the stem ) * 10( Fixed value )) / 1024 ,X Round up to get :3, Substitute into the formula :(X+1) / 2 + 1, have to :3, That is, the average number of visits is 3.

The first 26 topic :

  1. Equipment list The role of : establish Logic Equipment and Physics Correspondence between devices

  2. Press... For the equipment Information exchange unit To classify , Can be divided into : Block devices and character devices

  3. Peripheral According to the way of data transmission, it can be divided into many types , Usually disk What kind of equipment is considered : Block device

  4. Peripheral According to the way of data transmission, it can be divided into many types , Usually keyboard What kind of equipment is considered : Character device

  5. Disk reads and writes are in blocks , Usually disk Of I/O The main control method is :DMA The way

  6. Disk reads and writes are in blocks , Usually keyboard Of I/O The main control method is : Interrupt mode

  7. In a computer operating system , Set the of device management function Main purpose yes : Convenient for users

  8. In a computer operating system , Set the of management Main task One is : adopt buffer High technical matching 、 Low speed equipment ; adopt fictitious Technology to improve device concurrency ; adopt Coordinate Technology to avoid equipment conflict ; adopt Interface Technology provides users with consistent system calls ( Generally choose A)

  9. " Nothing to do with the device Systems software " Which function does the layer complete : Provide consistent system calls

  10. utilize Interrupt technology The main purpose of equipment management is : Improve equipment efficiency

  11. In the task of equipment management , The right is : Match external devices with different speeds

  12. Do not belong to The task of equipment management : Speed up the data transmission of input and output devices

  13. In the task of equipment management , The right is : Ensure that the system uses the equipment safely and correctly

  14. Unwanted The work completed by the equipment management module is : Handle missing page interrupt

The first 27 topic :

  1. Which technology can improve the efficiency of low-speed equipment : Device buffering technology
  2. In the operating system I/O The management of , Buffer pool management focuses on : Realize the synchronization of process access buffer
  3. take coml The work of mapping to the actual physical device is in I/O Which layer of management is completed : Equipment management
  4. stay I/O In equipment management , The main reason for introducing buffer technology is : Match the transmission speed of different external devices
  5. stay I/O In equipment management , Equipment allocation The main data structure and distribution order of are : System Equipment list —》 equipment Control table —》 controller Control table ( From big to small )
  6. stay I/O In equipment management , The main purpose of setting up the equipment independent layer is : Shielded I/O Diversity of device drivers , User friendly
  7. The user process is waiting for a command from the keyboard , Keep checking ** Whether the completion bit of the status register is 1,** The I/O The equipment control mode is called : Program direct control mode
  8. CPU With peripherals most of the time parallel Work . When CPU After starting the peripheral , There is no need to check its working status , You can continue to execute the main program , The I/O The equipment control mode is called : Interrupt control mode
  9. Controller from CPU Take full control of the bus , Data exchange Not pass CPU, And directly in memory and I/O Between equipment , such I/O The equipment control mode is called :DMA The way
  10. The system introduces a different from CPU Special function unit of , He Have their own instructions and procedures , It can realize the unified management of peripheral devices and the data transmission between peripheral devices and memory , The I/O The equipment control mode is called : Channel control mode
  11. Do not belong to The channel type is : Sequential channel
  12. CPU First configure I/O equipment , Then continue to execute the main program , Do not query the status until the I/O The equipment is ready , and ** towards CPU Send a signal requesting service .** that , The I/O The control mode is called : Interrupt control mode
  13. stay I/O In the software hierarchy , Device independent software layer Realized The main function yes : Provide and equipment irrelevant Logical block of ; For the equipment Unified naming ; Settings for different speeds Use a buffer to match ; To the user Report error handling
  14. Which can improve I/O performance : Apply buffering technology to reduce or alleviate the transmission speed gap between different devices

The first 28 topic :

  1. Deadlock occurs One of the reasons for this is : Misallocation of resources , Another reason is : Processes are advanced in the wrong order

  2. The process appears Hunger Refer to : The priority of the process is low and the process is not scheduled for a long time

  3. Different I/O Devices can work in parallel

  4. When the user Use external devices when , Its control Command transmission path of control equipment In turn : user application layer —》 equipment Independent layer —》 equipment Driver layer —》 equipment Hardware

  5. In all kinds of buffer in , Which one is error Of : High speed cache

  6. For systems Exclusive device in the system , by Prevent deadlocks . The best allocation strategy should be : Static allocation , Lock when allocating

  7. The related process Go into blocking mode **, And can't wake up **—— Deadlock

  8. The related process There's no obstruction , Can be scheduled , however No progress —— Live lock

  9. The related process There's no obstruction , however Scheduling is pushed back indefinitely —— hunger

  10. The related process Go into blocking mode , And can wake up —— normal ( Don't worry )

  11. Memory belongs to —— Reusable resources

  12. Clock interrupt belongs to —— Non reusable resources

  13. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly  Insert picture description here

    analysis : if , Grab different kinds of resources , Choose A; If we say to grab similar resources , Choose B.

  14. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-FTHQVVm6-1652247328005)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123162521720.png)] Insert picture description here

  15. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-JmdIaKwA-1652247328006)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123162823484.png)] Insert picture description here

analysis : process P1 Have a printer and apply for a scanner ,“ Request and maintain ”—— There is one , Want another

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-ze1xtGws-1652247328007)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123163056766.png)] Insert picture description here

analysis :“ Mutually exclusive ”—— There is only one resource , There were two people who robbed , choose A

17.[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-HfccIJtL-1652247328008)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123163244327.png)] Insert picture description here

analysis :“ Inalienable ”—— The process has not finished loading , Just want something else , choose B.

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-7UcCT6Xw-1652247328008)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123163406202.png)] Insert picture description here

analysis :“ Loop waiting for ”——P1 etc. P2,P2 etc. P1

  1. Can be used for Deadlock detection and recovery Yes. : Timed to enter Set the restore point , If running If blocked, return to the restore point

The first 29 topic :

  1. The deadlock state must be unsafe , An unsafe state is not necessarily a deadlock state .

  2. Banker algorithm is an algorithm to deal with deadlock , Its realization is : Deadlock avoidance algorithm

  3. Which method can't release the deadlock : Modify environment variables

  4. There are many ways to solve the deadlock problem , among resources The orderly distribution method belongs to : Deadlock prevention ( Follow resources of , Namely The prevention of ; Follow Banker of , Namely avoid

  5. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-BJ8W0vZY-1652247328009)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123164454997.png)] Insert picture description here

    analysis : use 9/4( Rounding down ) + 1 = 3

  6. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-Ls60n4T8-1652247328009)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123164713318.png)] Insert picture description here

  7. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-3tvZf7H7-1652247328010)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123164810135.png)] Insert picture description here

  8. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-6SF83RHX-1652247328010)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123164852191.png)] Insert picture description here

analysis : A deadlock has occurred , Resolve the deadlock by killing the deadlock process —— Deadlock relieve

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-s6DGisyO-1652247328010)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123165327275.png)] Insert picture description here

10.[ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-rU5tVbjT-1652247328011)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123165616706.png)] Insert picture description here

analysis :“ One way traffic ”—— Destroyed Loop wait condition ;“ Flyover ”—— Destroyed mutual exclusion ;“ Yellow gridlines ”—— Destroyed The condition of indivisibility ;“ traffic lights ”—— Destroyed Request and hold conditions

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-89FuNHww-1652247328012)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123170247161.png)] Insert picture description here

  2. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-ID0UuELx-1652247328013)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123171208192.png)] Insert picture description here

  3. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-PgtNKDd6-1652247328013)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123171557339.png)] Insert picture description here

  4. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-JytH6lfe-1652247328014)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123171724273.png)] Insert picture description here

  5. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-gRrNWaoR-1652247328014)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123171932065.png)] Insert picture description here

analysis : choose A

The first 30 topic :

  1. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-IK0E2Ooy-1652247328015)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123175448862.png)] Insert picture description here

analysis :7 ÷ 3 = 2( Rounding down ),2 + 1 = 3, choose 3

  1. The description of deadlock theorem is : If and only if The current resource allocation diagram is Incompletely reducible

  2. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-0jA5o80V-1652247328015)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123201419391.png)] Insert picture description here

  3. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-f1TfdgWQ-1652247328017)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123201800934.png)] Insert picture description here

  4. [ Failed to transfer the external chain picture , The origin station may have anti-theft chain mechanism , It is suggested to save the pictures and upload them directly (img-rrtJl39j-1652247328017)(C:\Users\86152\AppData\Roaming\Typora\typora-user-images\image-20220123202010531.png)] Insert picture description here

版权声明
本文为[HHppGo]所创,转载请带上原文链接,感谢
https://cdmana.com/2022/134/202205141324526591.html

Scroll to Top