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/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2022 Ericsson AB
*/
#include <rte_seqlock.h>
#include <rte_cycles.h>
#include <rte_malloc.h>
#include <rte_random.h>
#include <inttypes.h>
#include "test.h"
struct __rte_cache_aligned data {
rte_seqlock_t lock;
uint64_t a;
alignas(RTE_CACHE_LINE_SIZE) uint64_t b;
alignas(RTE_CACHE_LINE_SIZE) uint64_t c;
};
struct reader {
struct data *data;
RTE_ATOMIC(uint8_t) stop;
};
#define WRITER_RUNTIME 2.0 /* s */
#define WRITER_MAX_DELAY 100 /* us */
#define INTERRUPTED_WRITER_FREQUENCY 1000
#define WRITER_INTERRUPT_TIME 1 /* us */
static int
writer_run(void *arg)
{
struct data *data = arg;
uint64_t deadline;
deadline = rte_get_timer_cycles() +
WRITER_RUNTIME * rte_get_timer_hz();
while (rte_get_timer_cycles() < deadline) {
bool interrupted;
uint64_t new_value;
unsigned int delay;
new_value = rte_rand();
interrupted = rte_rand_max(INTERRUPTED_WRITER_FREQUENCY) == 0;
rte_seqlock_write_lock(&data->lock);
data->c = new_value;
data->b = new_value;
if (interrupted)
rte_delay_us_block(WRITER_INTERRUPT_TIME);
data->a = new_value;
rte_seqlock_write_unlock(&data->lock);
delay = rte_rand_max(WRITER_MAX_DELAY);
rte_delay_us_block(delay);
}
return TEST_SUCCESS;
}
#define INTERRUPTED_READER_FREQUENCY 1000
#define READER_INTERRUPT_TIME 1000 /* us */
static int
reader_run(void *arg)
{
struct reader *r = arg;
int rc = TEST_SUCCESS;
while (rte_atomic_load_explicit(&r->stop, rte_memory_order_relaxed) == 0 &&
rc == TEST_SUCCESS) {
struct data *data = r->data;
bool interrupted;
uint32_t sn;
uint64_t a;
uint64_t b;
uint64_t c;
interrupted = rte_rand_max(INTERRUPTED_READER_FREQUENCY) == 0;
do {
sn = rte_seqlock_read_begin(&data->lock);
a = data->a;
if (interrupted)
rte_delay_us_block(READER_INTERRUPT_TIME);
c = data->c;
b = data->b;
} while (rte_seqlock_read_retry(&data->lock, sn));
if (a != b || b != c) {
printf("Reader observed inconsistent data values "
"%" PRIu64 " %" PRIu64 " %" PRIu64 "\n",
a, b, c);
rc = TEST_FAILED;
}
}
return rc;
}
static void
reader_stop(struct reader *reader)
{
rte_atomic_store_explicit(&reader->stop, 1, rte_memory_order_relaxed);
}
#define NUM_WRITERS 2 /* main lcore + one worker */
#define MIN_NUM_READERS 2
#define MIN_LCORE_COUNT (NUM_WRITERS + MIN_NUM_READERS)
/* Only a compile-time test */
static rte_seqlock_t __rte_unused static_init_lock = RTE_SEQLOCK_INITIALIZER;
static int
test_seqlock(void)
{
struct reader readers[RTE_MAX_LCORE];
unsigned int num_lcores;
unsigned int num_readers;
struct data *data;
unsigned int i;
unsigned int lcore_id;
unsigned int reader_lcore_ids[RTE_MAX_LCORE];
unsigned int worker_writer_lcore_id = 0;
int rc = TEST_SUCCESS;
num_lcores = rte_lcore_count();
if (num_lcores < MIN_LCORE_COUNT) {
printf("Too few cores to run test. Skipping.\n");
return TEST_SKIPPED;
}
num_readers = num_lcores - NUM_WRITERS;
data = rte_zmalloc(NULL, sizeof(struct data), 0);
if (data == NULL) {
printf("Failed to allocate memory for seqlock data\n");
return TEST_FAILED;
}
i = 0;
RTE_LCORE_FOREACH_WORKER(lcore_id) {
if (i == 0) {
rte_eal_remote_launch(writer_run, data, lcore_id);
worker_writer_lcore_id = lcore_id;
} else {
unsigned int reader_idx = i - 1;
struct reader *reader = &readers[reader_idx];
reader->data = data;
reader->stop = 0;
rte_eal_remote_launch(reader_run, reader, lcore_id);
reader_lcore_ids[reader_idx] = lcore_id;
}
i++;
}
if (writer_run(data) != 0 ||
rte_eal_wait_lcore(worker_writer_lcore_id) != 0)
rc = TEST_FAILED;
for (i = 0; i < num_readers; i++) {
reader_stop(&readers[i]);
if (rte_eal_wait_lcore(reader_lcore_ids[i]) != 0)
rc = TEST_FAILED;
}
rte_free(data);
return rc;
}
REGISTER_FAST_TEST(seqlock_autotest, true, true, test_seqlock);
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