Passing Data to Multi Threads
- by alaamh
I study this code from some book:
#include <pthread.h>
#include <stdio.h>
/* Parameters to print_function. */
struct char_print_parms {
/* The character to print. */
char character;
/* The number of times to print it. */
int count;
};
/* Prints a number of characters to stderr, as given by PARAMETERS,
which is a pointer to a struct char_print_parms. */
void* char_print(void* parameters) {
/* Cast the cookie pointer to the right type. */
struct char_print_parms* p = (struct char_print_parms*) parameters;
int i;
for (i = 0; i < p->count; ++i)
fputc(p->character, stderr);
return NULL;
}
/* The main program. */
int main() {
pthread_t thread1_id;
pthread_t thread2_id;
struct char_print_parms thread1_args;
struct char_print_parms thread2_args;
/* Create a new thread to print 30,000 ’x’s. */
thread1_args.character = 'x';
thread1_args.count = 30000;
pthread_create(&thread1_id, NULL, &char_print, &thread1_args);
/* Create a new thread to print 20,000 o’s. */
thread2_args.character = 'o';
thread2_args.count = 20000;
pthread_create(&thread2_id, NULL, &char_print, &thread2_args);
usleep(20);
return 0;
}
after running this code, I see different result each time. and some time corrupted result. what is wrong and what the correct way to do that?
