Function test_atomic_exchange

dpdk/app/test/test_atomic.c:399–443

* The atomic exchange test sets up a token in memory and * then spins up multiple lcores whose job is to generate * new tokens, exchange that new token for the old one held * in memory, and then verify that the old token is still * valid (i.e. the exchange did not corrupt the token). * * A token is made up of random data and 8 bits of crc * covering that random data. The following is an ex

 * +------------+------------+
 */
static int
test_atomic_exchange(__rte_unused void *arg)
{
	int i;
	test16_t nt16, ot16; /* new token, old token */
	test32_t nt32, ot32;
	test64_t nt64, ot64;

	/* Wait until all of the other threads have been dispatched */
	while (rte_atomic32_read(&synchro) == 0)
		;

	/*
	 * Let the battle begin! Every thread attempts to steal the current
	 * token with an atomic exchange operation and install its own newly
	 * generated token. If the old token is valid (i.e. it has the
	 * appropriate crc32 hash for the data) then the test iteration has
	 * passed.  If the token is invalid, increment the counter.
	 */
	for (i = 0; i < N; i++) {

		/* Test 64bit Atomic Exchange */
		nt64.u64 = rte_rand();
		nt64.u8[7] = get_crc8(&nt64.u8[0], sizeof(nt64) - 1);
		ot64.u64 = rte_atomic64_exchange(&token64, nt64.u64);
		if (ot64.u8[7] != get_crc8(&ot64.u8[0], sizeof(ot64) - 1))
			rte_atomic64_inc(&count);

		/* Test 32bit Atomic Exchange */
		nt32.u32 = (uint32_t)rte_rand();
		nt32.u8[3] = get_crc8(&nt32.u8[0], sizeof(nt32) - 1);
		ot32.u32 = rte_atomic32_exchange(&token32, nt32.u32);
		if (ot32.u8[3] != get_crc8(&ot32.u8[0], sizeof(ot32) - 1))
			rte_atomic64_inc(&count);

		/* Test 16bit Atomic Exchange */
		nt16.u16 = (uint16_t)rte_rand();
		nt16.u8[1] = get_crc8(&nt16.u8[0], sizeof(nt16) - 1);
		ot16.u16 = rte_atomic16_exchange(&token16, nt16.u16);
		if (ot16.u8[1] != get_crc8(&ot16.u8[0], sizeof(ot16) - 1))
			rte_atomic64_inc(&count);
	}

	return 0;
}
static int
test_atomic(void)
{