10. Consider a file F to be shared by N processes. Each process i has ID i (1 <= i <= N). The file can be accessed concurrently by multiple processes, if the sum of the IDs of these processes is less than or equal to M. a) Write a monitor that will control access to the file. That means the monitor will implement two functions, request() and release(), that will be called by a process that would like to access the file. You also need to define the monitor variables required for the solution. A process will call the request() function before accessing the file and release() function when it has finished accessing the file.

10. Consider a file F to be shared by N processes. Each process i has ID i (1 <= i <= N). The file can be accessed concurrently by multiple processes, if the sum of the IDs of these processes is less than or equal to M. a) Write a monitor that will control access to the file. That means the monitor will implement two functions, request() and release(), that will be called by a process that would like to access the file. You also need to define the monitor variables required for the solution. A process will call the request() function before accessing the file and release() function when it has finished accessing the file.

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Similar questions

Write a C program which creates a child process to find all txt files in the root directory (i.e., “/") and stores the output in a text file called “all_txt_files.txtť". If the child process execution takes more than t seconds (measured at the parent), the parent should abort the execution of that child. Otherwise, after the child process termination, the parent has to create another child which will count the number of records in all_txt_files.txt and print out the output. The program should not allow the creation of orphan processes. - You need to include the C header file time.h to roughly count the execution time of the child process and play with different values of t so that both cases may happen. Another option may be the alarm system call. - You can use redirection (i.e., “>") to redirect the output of find to a txt file (e.g., find / - name "*. txt" > all_txt_files.txt). It's not a problem if find cannot access some directories. - You can count the number of lines in a txt…
Write a C program which takes four command line arguments: two file names and twonumber of elements. Your program must check if correct number of arguments aresupplied and terminate if not. Your main process must create three processes: The firstand second processes must open / create files by the given names and fill them with thegiven number of random integers (one integer per line) and terminate. The thirdprocess must execute “sort” command with necessary arguments so that it numericallysorts both files and display the combined result on screen.Before creating the third child process, main process must wait for the other two child processes to end.
A dentist office is currently using paper files to manage all office activities. To make their work easier, the office decided to build a software system to manage those activities instead of using their old paper-way methods. The office patients can take their appointments either by phone or by walking in person to the office lobby. In either way, the receptionist schedules an appointment for the patient with the desired date and time. The system shall not allow scheduling appointments with the same doctor for a duration of less than 30 minutes. Of course, the system shall accept appointments for a specific doctor if the doctor is working on that time. This means that the system shall keep track of each doctor working schedule. The office receptionist enters doctors working schedule in the form of working days for each week. For example, a doctor work schedule can be on Monday, Wednesday, and Thursday from 9:00 am until 4:00 pm for all weeks until June 01, 2021. Now, the office…
7. The program su enables a UNIX user to access another user's account. Unless the first user is the superuser, su requires that the password of the second user be given. A (possibly apocryphal) version of su would ask for the user's password and, if it could not determine if the password was correct because the password file could not be opened, immediately grant superuser access so that the user could fix the problem. Discuss which of the design principles this approach meets, and which ones it violates.
EXCERSICES 1. Use the template below to write a C-program that creates two processes: "Process A" (the process with which the program starts execution) and "Process B" (A's child). The Process A forks Process B. To identify which process writes the output, each process puts its id at the beginning of each line (see the sample output). Each process performs the following operations. Process A: After spawning Process B, it waits for Process B to terminate. After Process B's termination, it will write your home directory (use HOME environment variable) and its process ID, and terminates. Process B: After being spawned from Process A, it sleeps for three seconds (using sleep(). Then, it writes process IDs of itself and Process A immediately. After that, executes ps command (using system library) and terminates. Sample output: -/a.out 9181:1 am the parent, I will create child process 9182:1 am the child, I will sleep for 3 seconds 9182:My parent pid is 9181 9182:the ps command PID TTY TIME…
Write in g++ Design and implement a simple, interactive shell program that prompts the user for a command, parses the command, and then executes it with a child process. In your solution you are required to use execv(), which means that you will have to read the PATH environment, then search each directory in the PATH for the command file name that appears on the command line.
Consider user accounts on a computer system with a Web server configured to provide user Web areas. In general, this uses a standard directory name, such as “public_html,” in a user’s home directory. However, access control needs to be properly set to allow users (with or without user accounts on the system) to browse the webpages. Assuming there are one main page (index.html), two pictures files (a.jpg and b.jpg) stored in an sub-directory (Image) and one pdf file (c.pdf) stored in an sub-directory (Doc), all under the public_html. (a) Specify the access matrix for each directory (excluding home directory) and files that allows everyone to view the webpage. (b) Draw a directed graph that represented to the access matrix
Consider user accounts on a computer system with a Web server configured to provide user Web areas. In general, this uses a standard directory name, such as “public_html,” in a user’s home directory. However, access control needs to be properly set to allow users (with or without user accounts on the system) to browse the webpages. Assuming there are one main page (index.html), two pictures files (a.jpg and b.jpg) stored in an sub-directory (Image) and one pdf file (c.pdf) stored in an sub-directory (Doc), all under the public_html. Specify the access control for each directory and files that allows everyone to view the webpage.
b) Create the following path expressions. There can be only 4 instances of B at any given time, concurrently to this the processes A and C work maximally one instance in mutual exclusion. 4:(B), 1: (A; C) The process C has to be executed before th concurrent processes A and B. C:(A, B) Process A can be executed, after the process B or C have been finished. B and C can be active with two incarnations. 2: (B, C); A
Suppose that a shopkeeper decided that customers who come first will be served first. A list of customers must be maintained so that anyone can be accessed randomly. Your program must remember operations performed in the opposite order. The entries should be managed based on the order of arrival and also be deleted when no longer needed. The size of a file is unknown. A list must be maintained so that elements can be added to the beginning or end in O (1).Based on the above scenario you have a list of different data structures, choose appropriate among them and implement using java. It is important that the structure has flexible memory management.
Write a C program mexp that multiplies a square matrix by itself a specified number of times. mexp takes a single argument, which is the path to a file containing a square (k × k) matrix M and a non-negative exponent n. It computes Mn and prints the result. Note that the size of the matrix is not known statically. You must use malloc to allocate space for the matrix once you obtain its size from the input file.To compute Mn , it is sufficient to multiply M by itself n −1 times. That is, M3 = M ×M ×M . Naturally, a different strategy is needed for M0 .Input format The first line of the input file contains an integer k. This indicates the size of the matrix M , which has k rows and k columns.The next k lines in the input file contain k integers. These indicate the content of M. Each line corresponds to a row, beginning with the first (top) row.The final line contains an integer n. This indicates the number of times M will be multiplied by itself. n is guaranteed to be non-negative, but…
Write a C program which creates two childprocesses. One of the child processes mustopen data1.txt and fill it with 10 randomintegers (0-9). The other child process mustopen data2.txt and fill it with 10 randomletters (a-z). In the meanwhile, parent mustprint both child processes' id's and wait forthem to finish.