/*
 ============================================================================
 Name        : C_ThreadProblem.c
 Author      : 
 Version     :
 Copyright   : Your copyright notice
 Description : Hello World in C, Ansi-style
 ============================================================================
 */

#include <stdio.h>
#include <pthread.h>

static volatile int counter = 0;
// mythread()
//
// Simply adds 1 to counter repeatedly, in a loop
// No, this is not how you would add 10,000,000 to
// a counter, but it shows the problem nicely.
//
void *mythread(void *arg) {
	printf("%s: begin\n", (char *) arg);
	int i;
	for (i = 0; i < 1e7; i++) {
		counter = counter + 1;
	}
	printf("%s: done\n", (char *) arg);
	return NULL;
}
// main()
//
// Just launches two threads (pthread_create)
// and then waits for them (pthread_join)
//
int main(int argc, char *argv[]) {
	pthread_t p1, p2;
	printf("main: begin (counter = %d)\n", counter);
	pthread_create(&p1, NULL, mythread, "A");
	pthread_create(&p2, NULL, mythread, "B");
	// join waits for the threads to finish
	pthread_join(p1, NULL);
	pthread_join(p2, NULL);
	printf("main: done with both (counter = %d)\n",
			counter);
	return 0;
}