simple.c

linux 多线程例子

/********************************************************
 * An example source module to accompany...
 *
 * "Using POSIX Threads: Programming with Pthreads"
 *     by Brad nichols, Dick Buttlar, Jackie Farrell
 *     O'Reilly & Associates, Inc.
 *
 ********************************************************
 * simple.c
 *
 * Simple serial example.  Calls three procedures.
 */

#include <stdio.h>

void do_one_thing(int *);
void do_another_thing(int *);
void do_wrap_up(int, int);

int r1 = 0, r2 = 0;

extern int
main(void)
{
  
  do_one_thing(&r1);
  
  do_another_thing(&r2);

  do_wrap_up(r1, r2);
 
  return 0; 
}

void do_one_thing(int *pnum_times)
{
  int i, j, x;
  
  for (i = 0;  i < 4; i++) {
    printf("doing one thing\n");
    for (j = 0; j < 10000; j++) x = x + i;
    (*pnum_times)++;
  }

}

void do_another_thing(int *pnum_times)
{
  int i, j, x;
  
  for (i = 0;  i < 4; i++) {
    printf("doing another \n"); 
    for (j = 0; j < 10000; j++) x = x + i;
    (*pnum_times)++;
  }

}

void do_wrap_up(int one_times, int another_times)
{
  int total;

  total = one_times + another_times;
  printf("All done, one thing %d, another %d for a total of %d\n",
	one_times, another_times, total);
}