Operating System Question. Need to be solved on LINUX in C. Threads should be used. (threads library)

COMP301 - OPERATING SYSTEMS Fall 2021 Assignment - 2 DUE: 29 January 2021, 11:59PM Task Requirements Modify the following code to demonstrate context switching between parallel running threads. The program must fulfil the following requirements: . . . . There should be 4 threads created using Pthreads API. While all/any the threads are running, the main() function should be waiting for the threads to finish their execution. The 1st thread should continuously print the character "1" in a loop. the 2nd thread should continuously print the character "2" in a loop. the 3rd thread should continuously print the character "3" in a loop. The 4th thread should continuously check for keyboard input. As soon as the user presses the Q key, the program should terminate. Right before termination, the main() function displays the number of 1's, 2's, and 3's printed out by each thread. . . . Sample Output 11111111111111111 111111111222222222221111 111112222222222 2222233333333333333312222222222222111111112222222221111111111111222222 2222222222222222211 1111 11133333333333333331333333311111 111111111333 3333332222222222222111111111113333333322222222222111111111111333333333 33332222222222222233333333333333333311 11133333333333222 2222222223 Number of 1s = 141 Number of 2s = 121 Number of 3s = 98