Question: ************************************************************ main.c ************************************************************ #include #include #include #include functions.h int MIN = 9999; /*Used when you implement the thread function */ int main(int argc, char *argv[])
************************************************************
main.c
************************************************************
#include
#include
#include
#include "functions.h"
int MIN = 9999; /*Used when you implement the thread function */
int main(int argc, char *argv[])
{
int *array;
struct ArrayPackage onePackage;
int size = 0;
int num_threads;
int increments;
int min = 9999;
pthread_t *thread_ids;
void *p_status;
if (pthread_mutex_init(&min_lock, NULL) != 0)
{
perror("Could not create mutex for MIN: ");
return 1;
}
printf("How many threads? ");
scanf("%d", &num_threads);
thread_ids = (pthread_t *)malloc(sizeof(pthread_t *) * num_threads);
do
{
printf("How big is the array (100 elements or more)?");
scanf("%i", &size);
} while (size
array = (int *)malloc(sizeof(int) * size);
increments = size / num_threads;
if (initialize(array, size) != 0)
{
printf("initialization error ");
exit(1);
}
printArray(array, size);
for (int i = 0; i
{
struct ArrayPackage *onePack =
(struct ArrayPackage *)malloc(sizeof(struct ArrayPackage));
/*-------------------------------------------------------------------*/
/* Store the array, the start, and the end into the onePack instance */
/*---------------------------------------------------------------------*/
/* Call the pthread_create */
}
for (int i = 0; i
{
/*---------------------------------------------------------------------*/
/*Call the join */
}
/*-----------------------------------------------------------------------*/
/* The following call to findMin will be taken out when you implement the thread function*/
if (findMin(array, size, &min) != 0)
{
printf("someFunction error ");
exit(1);
}
/*-----------------------------------------------------------------------*/
/* The following line will have to be changed */
printf("min value in array is: %d ", min);
free(array);
free(thread_ids);
return 0;
}
************************************************************
functions.h
************************************************************
#ifndef FUNCTIONS_H
#define FUNCTIONS_H
#include
#include
#include
#include
struct ArrayPackage
{
int *array;
int start;
int end;
};
extern int MIN;
pthread_mutex_t min_lock;
int initialize(int *array, int length);
int findMin(int *array, int length, int *min);
int printArray(int *array, int length);
#endif
************************************************************
functions.c
************************************************************
/* FUNCTION: initialize
* This function should initialize the array
* to random values between 1 and 500
*
* The arguments are:
* array: pointer to an array of integer values
* length: size of array
*
* It returns:
* 0: on success
* non-zero: on an error
*/
int initialize(int *array, int length)
{
srand(getpid());
int i;
for (i = 0; i
{
array[i] = rand() % 500 + 1;
}
return 0;
}
/* FUNCTION: findMin
* This function should find the smallest element in the array and
* return it through the argument min.
*
* The arguments are:
* array: pointer to an array of integer values
* length: size of array
* min: set to the smallest value in array
*
* It returns:
* 0: on success
* non-zero: on an error
*/
int findMin(int *array, int length, int *min)
{
int i;
*min = array[0];
for (i = 1; i
{
if (*min > array[i])
{
*min = array[i];
}
}int findMin(int *array, int length, int *min)
{
int i;
*min = array[0];
for (i = 1; i
{
if (*min > array[i])
{
*min = array[i];
}
}
return 0;
}
/* FUNCTION: printArray
* This function should print all the elements of the array
*
* The arguments are:
* array: pointer to an array of integer values
* length: size of array
*
* It returns:
* 0: on success
* non-zero: on an error
*/
int printArray(int *array, int length)
{
int i;
for (i = 0; i
{
printf("%d ", array[i]);
// add a newline character for readability
if ((i + 1) % 15 == 0)
{
printf(" ");
}
}
printf(" ");
return 0;
}
return 0;
}
/* FUNCTION: printArray
* This function should print all the elements of the array
*
* The arguments are:
* array: pointer to an array of integer values
* length: size of array
*
* It returns:
* 0: on success
* non-zero: on an error
*/
int printArray(int *array, int length)
{
int i;
for (i = 0; i
{
printf("%d ", array[i]);
// add a newline character for readability
if ((i + 1) % 15 == 0)
{
printf(" ");
}
}
printf(" ");
return 0;
}
Change main
load the onePack instance with the array, the start and end of indices that you want to work within the array
for the last thread, the end index will be the size of the array
add the call to the pthread_create
add the call to the pthread_join
remove the original call to the findMin function
modify the variable that is printed to display the global minimum
Change findMin
turn findMin into a thread function (hint: two void *)
create a pointer to a struct ArrayPackage
you might want to store the pieces of ArrayPackage into variables
print the "start" and the "end" that is sent to the thread function using the ArrayPackage
loop from "start" to "end" to find the minimum of the array
note: anytime you print or anytime you work with the global MIN, you will want to have a mutex_lock and mutex_unlock around that code
Although there are different approaches, the approach we are expecting is that this function returns NULL.
Please ensure that you are cleaning up memory for the arguments allocated in main
Sample runs
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