Write a multithreaded program that calculates various statistical values for a l

Question

Write a multithreaded program that calculates various statistical values for a list of numbers. This program will be passed a series of numbers on the command and will then create three separate worker threads. One thread will determine the average of the numbers, the second will determine the maximum value, and the third will determine the minimum value. For example, suppose your program is passed the integers

90 81 78 95 79 72 85

The program will report

The average value is 82

The minimum value is 72

The maximum value is 95

The variables representing the average, minimum, and maximum values will be stored

globally. The worker threads will set these values, and the parent thread will output the values once the workers have exited.

Explanation / Answer

#include <unistd.h>

#include <stdio.h>

#include <pthread.h>

#include <stdlib.h>


void* the_thread( void* );
void get_position();

struct position_t
{
int x;
int y;
};

namespace {
pthread_key_t position_key;

enum {
NUMBER_OF_THREADS = 2
};
}

int main(int argc, char **argv)
{
int result = pthread_key_create( &position_key, NULL );
printf( "pthread_key_create -- key: %u, result: %i ",
position_key, result );

pthread_t threads[NUMBER_OF_THREADS];
for (unsigned int i = 0; i < NUMBER_OF_THREADS; ++i )
{

position_t* position = new position_t();


position->x = ( 1 + i ) * 11;
position->y = ( 1 + i ) * 13;


result = pthread_create( &threads[i], NULL, the_thread, position );
}


sleep( 5 );


abort();
return 0;
}

void* the_thread( void* position )
{
int result = pthread_setspecific( position_key, position );

printf( "Thread: 0x%.8x, key: %u, value: 0x%.8x, result: %i ",
pthread_self(), position_key, position, result );

get_position();
return 0;
}

void get_position()
{
position_t* position =
reinterpret_cast< position_t* >( pthread_getspecific( position_key ) );

printf( "Thread: 0x%.8x, key: %u, position: 0x%.8x, x: %i, y: %i ",
pthread_self(), position_key, position, position->x, position->y );


while( true ) {};
}

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.