[PATCH v4 06/11] test/timer: replace volatile with C11 atomics

Stephen Hemminger
2026-03-05T17:54:16Z

Replace volatile variables in test_timer_secondary shared memory
structure with RTE_ATOMIC() and rte_atomic_*_explicit() operations.

Change expected_count and expired_count from int to unsigned int
since they are non-negative counters.

Fixes: 50247fe03fe0 ("test/timer: exercise new APIs in secondary process")
Cc: stable@dpdk.org

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
app/test/test_timer_secondary.c | 28 +++++++++++++++++++---------
1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/app/test/test_timer_secondary.c b/app/test/test_timer_secondary.c
index c80dee9c6c..57ab39130d 100644
--- a/app/test/test_timer_secondary.c
+++ b/app/test/test_timer_secondary.c
@@ -12,7 +12,9 @@
#include <rte_timer.h>
#include <rte_cycles.h>
#include <rte_mempool.h>
+#include <rte_pause.h>
#include <rte_random.h>
+#include <rte_stdatomic.h>

#include "test.h"

@@ -41,12 +43,12 @@ struct test_info {
unsigned int sec_lcore;
unsigned int num_timers;
uint32_t timer_data_id;
- volatile int expected_count;
- volatile int expired_count;
+ RTE_ATOMIC(unsigned int) expected_count;
+ RTE_ATOMIC(unsigned int) expired_count;
struct rte_mempool *tim_mempool;
struct rte_timer *expired_timers[NUM_TIMERS_MAX];
int expired_timers_idx;
- volatile int exit_flag;
+ RTE_ATOMIC(int) exit_flag;
};

static int
@@ -76,7 +78,8 @@ handle_expired_timer(struct rte_timer *tim)
{
struct test_info *test_info = tim->arg;

- test_info->expired_count++;
+ rte_atomic_fetch_add_explicit(&test_info->expired_count, 1,
+ rte_memory_order_relaxed);
test_info->expired_timers[test_info->expired_timers_idx++] = tim;
}

@@ -88,7 +91,8 @@ timer_manage_loop(void *arg)
uint64_t prev_tsc = 0, cur_tsc, diff_tsc;
struct test_info *test_info = arg;

- while (!test_info->exit_flag) {
+ while (!rte_atomic_load_explicit(&test_info->exit_flag,
+ rte_memory_order_acquire)) {
cur_tsc = rte_rdtsc();
diff_tsc = cur_tsc - prev_tsc;

@@ -163,7 +167,8 @@ test_timer_secondary(void)
/* must set exit flag even on error case, so check ret later */

rte_delay_ms(500);
- test_info->exit_flag = 1;
+ rte_atomic_store_explicit(&test_info->exit_flag, 1,
+ rte_memory_order_release);

TEST_ASSERT_SUCCESS(ret, "Secondary process execution failed");
rte_eal_wait_lcore(*mgr_lcorep);
@@ -172,7 +177,10 @@ test_timer_secondary(void)
rte_timer_alt_dump_stats(test_info->timer_data_id, stdout);
#endif

- return test_info->expected_count == test_info->expired_count ?
+ return rte_atomic_load_explicit(&test_info->expected_count,
+ rte_memory_order_relaxed) ==
+ rte_atomic_load_explicit(&test_info->expired_count,
+ rte_memory_order_relaxed) ?
TEST_SUCCESS : TEST_FAILED;

} else if (proc_type == RTE_PROC_SECONDARY) {
@@ -202,7 +210,8 @@ test_timer_secondary(void)
if (ret < 0)
return TEST_FAILED;

- test_info->expected_count++;
+ rte_atomic_fetch_add_explicit(&test_info->expected_count,
+ 1, rte_memory_order_relaxed);

/* randomly leave timer running or stop it */
if (rte_rand() & 1)
@@ -211,7 +220,8 @@ test_timer_secondary(void)
ret = rte_timer_alt_stop(test_info->timer_data_id,
tim);
if (ret == 0) {
- test_info->expected_count--;
+ rte_atomic_fetch_sub_explicit(&test_info->expected_count,
+ 1, rte_memory_order_relaxed);
rte_mempool_put(test_info->tim_mempool,
(void *)tim);
}
--
2.51.0