Help with three small C programs. Programs must be written in C.Problem 1: Write a program that...

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Help with three small C programs. Programs must be written in C.Problem 1:  Write a program that creates multiple worker threads to calculate the sum of float point values saved in a file. Each thread calculates a partial sum, and the main thread adds up the partial sums. Your program will read the float point values from a file and print out the sum on the screen. The number of worker threads, as well as the file containing the float point values, are specified in the command line.  For example.  problem_1    4   ./file_containing_values  You may use gendata.c attached with the assignment to generate the file. Your main thread can memory-map the file, such that the worker threads can access the float point values  in the file easily. Problem 2:  Write a program that creates multiple processes to multiply two matrices of float point values. One matrix is saved in a file. The other matrix is an identity matrix  (https://en.wikipedia.org/wiki/Identity_matrix)  of  the  same  size. Your  program  should save the product matrix into another file. Because the product should be the same as the first  matrix,  you  can  easily  check  whether  your  program  produce  correct  results  by comparing the product matrix against the first matrix. Use cmp command to compare (https://linux.die.net/man/1/cmp).   The  number  of  processes,  the  file  containing  the  first  matrix,  and  the  file  saving  the product matrix, should be specified in the command line. The identity matrix should be generated dynamically ( determine the size based on the size of the input file (i.e., the one  containing the first matrix)).  problem_2   4   ./file_containing_one_matrix  ./file_saving_product_matrix  You  may  use gendata.c attached  with  the  assignment  to  generate  the  file  for  the  first matrix.  To  ensure  correctness,  your  program  can  assume  that  each  matrix  is  square  (NxN).  So, when you generate the input file, ensure that the number of float point values in the file is a square number (https://en.wikipedia.org/wiki/Square_number).  To check the results, use cmp  cmp ./file_containing_one_matrix  ./file_saving_product_matrix  Hint:   Your processes can memory-map the files to share data easily.  Refer to the multi-threaded matrix multiplication program in the slides for how to multiple two matrices in parallel. Problem 3:  Write a program that create multiple processes to calculate an approximation of π.  Refer to the multi-threaded program calculating an an approximation of π in the slides.  The  number  of  processes  and  the  number  of  terms  required  to  calculate  the approximation should be specified in the command line (refer to the program in the slides). You may choose an IPC method (pipe, FIFO, or shm) you like in your implementation. But, pipe fits most. FIFO and shm are over-kills.   PowerPoint Presentation Creating Threads - pthread_create() #include  int pthread_create ( pthread_t *thread,  //variable to store returned thread ID pthread_attr_t *attr,  // thread attributes  void * (*start_routine)(void *), //function to run  void * arg);  //args to pass to new thread attr is to change the default thread attributes of the newly created thread stack size, schedulizing parameters, and initial detached state Most invocations of pthread_create() pass NULL for attr to use default attributes. pthread_create() returns 0 if succeed. On error, pthread_create() returns a nonzero error code directly (without the use of errno) and the contents of thread are undefined. 7/27/2022 cs431-cotter 1 7/27/2022 cs431-cotter 1 #include  #include  #include  /* Global variables and data in heap are shared by all threads */ void * start_routine(void *id){  /* main func of a thread */ int *myid = (int *)id; /* private data defined in the function if there are any*/ printf(“Greatings from thread %d
”,*myid);  pthread_exit(NULL);  /*thread ends when pthread_exit is called or the function ends*/  } main(int argc, char *argv[]) {     /* main thread creates and controls new threads*/ pthread_t thread[10]; int ret, i, index[10]; for (i=0;isize;  	array = argument->array;  	sum = argument->sum;    	*sum = 0;  	for (i=0;iarray = array; arg->size=100; arg->sum = ∑   	if (pthread_create(&worker_thread, NULL, do_work,(void *)arg)) {     	    fprintf(stderr,”Error while creating thread
”);     	    exit(1);   	}   	...   	if (pthread_join(worker_thread, &return_value)) {     	    fprintf(stderr,”Error while waiting for thread
”);     	    exit(1);   	} 		printf("%f
", arg->sum); } Several ways a thread may be terminated A thread returns from its start routine. This is akin to a process finishes when returns from main(). A thread invokes pthread_exit() This is akin to calling exit(). A thread is canceled by another thread via pthread_cancel() This is akin to being sent the SIGKILL signal via kill(). The process terminates, and all the threads are killed The process returns from its main() function. The process terminates via exit(). The process executes a new binary image via exec…(). Terminating a thread void pthread_exit (void *retval); The calling thread terminates itself.  retval is provided to any thread waiting on the terminating thread’s death int pthread_cancel (pthread_t thread); pthread_cancel() sends a cancellation request to the thread. Whether and when a thread is cancellable depends on its cancellation state and cancellation type. Returns 0 if cancellation request is sent successfully; returns an error code if thread is invalid Joining threads int pthread_join (pthread_t thread, void **retval); Joining allows one thread to block while waiting for the termination of another if retval is not NULL, it saves the return value the terminated thread passed to pthread_exit() or returned from its start routine All threads in Pthreads are peers; any thread may join any other. On error, pthread_join() returns a nonzero error code. common “bugs” that first-time pthread programmers make pthread_join() is not called in main thread the main thread may reach the end of main() and exit other threads are killed when main thread finishes It possible that they have NOT had a chance to compute a result When creating multiple threads, store handles of different threads at different locations (avoid overwriting). Typically use an array of thread handles One reason has been explained earlier. The other reason is that way you’ll be able to call pthread_join() for each thread Also, note that the following code is sequential! 	 for (i=0; i  double a[4000][4000], b[4000][4000], c[4000][4000]; int N, Nthreads, myid[200];  pthread_t tid[200]; void *mymm(void *arg) {   int myrank, i, j, k;   myrank = *(int *)arg;   for (i=0; i int myid[100], N, Nthreads;  double sum[100], h;   pthread_t tid[200]; void *mycpi(void *arg) {   int myrank, i, j;    double x;      myrank = *(int *)arg;   h   = 1.0 / (double) N;   sum[myrank] = 0.0;   for(i=N/Nthreads*myrank+1; i

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Problem 1: Write a program that creates multiple worker threads to calculate the sum of float point values saved in a file. Each thread calculates a partial sum, and the main thread adds up the...

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