Given 3 concurrent processes P1, P2 and P3, we suppose that initially the shared variable x = 4. a) List all the possible values for x. b) Use one or more semaphores (use primitives signal and wait) in order to get x=13.1 c) Can we use only one semaphore to get x=11? Explain your answer. P1 P2 x=x-2; P3 ... x=x*3;

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It is a computer science question based on Operating systems Need the answer and explained solution for "PART (b) ONLY"

I need to implement in C the First-come, first-served (FCFS), which schedules tasks in the order in which they request the CPU. Priorities range from 1 to 10. Where the file driver.c reads in the schedule of tasks, inserts each task into a linked list, and invokes the process scheduler by calling the schedule() function. The schedule() function executes each task according to the specified scheduling algorithm. Tasks selected for execution on the CPU are determined by the pickNextTask() function and are executed by invoking the run() function defined in the CPU.c file. A Makefile is used to determine the specific scheduling algorithm that will be invoked by driver.

Consider a computer environment in which there are 4 magnetic drives, 2 printers, 3 scanners, and 1 optical drive. Three processes P1, P2, P3 are using these resources. At any point in time, the allocations and requests for these resources are as follows. Allocations: Magnetic drive Printer Scanner Optical drive P1 1 P2 2 1 P3 1 Requests: Magnetic drive 2 Printer Scanner Optical drive P1 1 P2 1 1 P3 2 1 Is there any way that the processes can complete without deadlock? If yes, explain how. If not, explain why not.

Write a C program that will creates two processes P1 & P2. P1 will ask the user to enter an integers N and then sends them to P2. P2 will print the sum of the first N odd numbers. Ex: N = 2 sum = 1 +3 = 4 N = 4 sum = 1 + 3 + 5 + 7 = 16 The inter-processes communication should be done using pipes.

Write a C program to create two processes P1 and P2. P1 takes 2 integers (x,y) and passes it to P2. P2 performs mathematical operations over receivedintegers and sends it back the output array to P1 for printing.

Consider a disk queue with requests for I/O to blocks on cylinders 47, 38, 121, 191, 87, 11, 92, 10. The C-LOOK scheduling algorithm is used. The head is initially at cylinder number 63, moving towards larger cylinder numbers on its servicing pass. The cylinders are numbered from 0 to 199. The total head movement (in number of cylinders) incurred while servicing these requests is

Write a C program that takes a list of command line arguments, each of which is the full path of a command (such as /bin/ls, /bin/ps, /bin/date, /bin/who, /bin/uname etc). Assume the number of such commands is N, your program would then create N direct child processes (ie, the parent of these child processes is the same original process), each of which executing one of the N commands. You should make sure that these N commands are executed concurrently, not sequentially one after the other. The parent process should be waiting for each child process to terminate. When a child process terminates, the parent process should print one line on the standard output stating that the relevant command has completed successfully or not successfully (such as "Command /bin/who has completed successfully", or "Command /bin/who has not completed successfully"). Once all of its child processes have terminated, the parent process should print "All done, bye-bye!" before it itself terminates. Note: do…

Code must be in C/C++ language using MPI Suppose comm_sz = 8 and the vector x = (0,1,2,...,15) has been distributed among the processes using a block distribution. Implement an allgather operation using a butterfly structured communication (see diagram below) and point-to-point communication functions