Example of jemalloc test failure code

failtest.c

#include <errno.h>
#include <stdio.h>

#include "jemalloc/jemalloc.h"

int
main(int argc, char **argv)
{
	int	*thing, frob, res;
	size_t	frobsize;

	/* Test 1: Make sure things are actually working like we expect. */
	thing = je_malloc(12 * sizeof(int));
	printf("Test 1: thing=%p errno=%d\n", thing, errno);
	je_free(thing);

	/* Test 2: Make sure we can retrieve the initial value, should be 0. */
	frob = 0;
	frobsize = sizeof(frob);
	res = je_mallctl("testing.malloc_fail", &frob, &frobsize, NULL, 0);
	printf("Test 2: res=%d frob=%d\n", res, frob);

	/* Test 3: Make sure we can set a new value. */
	frob = ENOMEM;
	res = je_mallctl("testing.malloc_fail", NULL, 0, &frob, frobsize);
	printf("Test 3: res=%d\n", res);

	/* Test 4: Make sure setting the value worked. */
	frob = 0;
	frobsize = sizeof(frob);
	res = je_mallctl("testing.malloc_fail", &frob, &frobsize, NULL, 0);
	printf("Test 4: res=%d frob=%d\n", res, frob);

	/* Test 5: Make sure that malloc now fails. */
	thing = je_malloc(12 * sizeof(int));
	printf("Test 5: thing=%p errno=%d\n", thing, errno);

	/* Test 6: Make sure that the value reset. */
	frob = 0;
	frobsize = sizeof(frob);
	res = je_mallctl("testing.malloc_fail", &frob, &frobsize, NULL, 0);
	printf("Test 6: res=%d frob=%d\n", res, frob);

	/* Test 7: Make sure everything's back to normal. */
	errno = 0;
	thing = je_malloc(12 * sizeof(int));
	printf("Test 7: thing=%p errno=%d\n", thing, errno);
	je_free(thing);
}