ch12-setjmp.c

linux编程精髓 源代码

/* ch12-setjmp.c --- demonstrate setjmp()/longjmp() and volatile. */

#include <stdio.h>
#include <setjmp.h>

jmp_buf env;

/* comeback --- do a longjmp */

void comeback(void)
{
	longjmp(env, 1);
	printf("This line is never printed\n");
}

/* main --- call setjmp, fiddle with vars, print values */

int main(void)
{
	int i = 5;
	volatile int j = 6;

	if (setjmp(env) == 0) {		/* first time */
		i++;
		j++;
		printf("first time: i = %d, j = %d\n", i, j);
		comeback();
	} else				/* second time */
		printf("second time: i = %d, j = %d\n", i, j);

	return 0;
}