[PATCH v5 bpf-next 16/17] selftests: xsk: Remove mutex and condition variable

[Maciej Fijalkowski]

From: Björn Töpel <bjorn.to...@intel.com>

The usage of the condition variable is broken, and overkill. Replace it
with a pthread barrier.

Signed-off-by: Björn Töpel <bjorn.to...@intel.com>
---
 tools/testing/selftests/bpf/xdpxceiver.c | 33 ++++--------------------
 tools/testing/selftests/bpf/xdpxceiver.h |  3 +--
 2 files changed, 6 insertions(+), 30 deletions(-)

diff --git a/tools/testing/selftests/bpf/xdpxceiver.c 
b/tools/testing/selftests/bpf/xdpxceiver.c
index 95d9d35dbb93..084ba052fa89 100644
--- a/tools/testing/selftests/bpf/xdpxceiver.c
+++ b/tools/testing/selftests/bpf/xdpxceiver.c
@@ -126,18 +126,6 @@ static void __exit_with_error(int error, const char *file, 
const char *func, int
                               test_type == TEST_TYPE_STATS ? "Stats" : "",\
                               test_type == TEST_TYPE_BPF_RES ? "BPF RES" : ""))
 
-static void init_sync_resources(void)
-{
-       pthread_mutex_init(&sync_mutex, NULL);
-       pthread_cond_init(&signal_rx_condition, NULL);
-}
-
-static void destroy_sync_resources(void)
-{
-       pthread_mutex_destroy(&sync_mutex);
-       pthread_cond_destroy(&signal_rx_condition);
-}
-
 static void *memset32_htonl(void *dest, u32 val, u32 size)
 {
        u32 *ptr = (u32 *)dest;
@@ -876,9 +864,7 @@ static void *worker_testapp_validate_rx(void *arg)
        fds[0].fd = xsk_socket__fd(ifobject->xsk->xsk);
        fds[0].events = POLLIN;
 
-       pthread_mutex_lock(&sync_mutex);
-       pthread_cond_signal(&signal_rx_condition);
-       pthread_mutex_unlock(&sync_mutex);
+       pthread_barrier_wait(&barr);
 
        while (1) {
                if (test_type != TEST_TYPE_STATS) {
@@ -903,24 +889,19 @@ static void *worker_testapp_validate_rx(void *arg)
 
 static void testapp_validate(void)
 {
-       struct timespec max_wait = { 0, 0 };
        bool bidi = test_type == TEST_TYPE_BIDI;
        bool bpf = test_type == TEST_TYPE_BPF_RES;
 
-       pthread_mutex_lock(&sync_mutex);
+       if (pthread_barrier_init(&barr, NULL, 2))
+               exit_with_error(errno);
 
        /*Spawn RX thread */
        pthread_create(&t0, NULL, ifdict_rx->func_ptr, ifdict_rx);
 
-       if (clock_gettime(CLOCK_REALTIME, &max_wait))
-               exit_with_error(errno);
-       max_wait.tv_sec += TMOUT_SEC;
-
-       if (pthread_cond_timedwait(&signal_rx_condition, &sync_mutex, 
&max_wait) == ETIMEDOUT)
+       pthread_barrier_wait(&barr);
+       if (pthread_barrier_destroy(&barr))
                exit_with_error(errno);
 
-       pthread_mutex_unlock(&sync_mutex);
-
        /*Spawn TX thread */
        pthread_create(&t1, NULL, ifdict_tx->func_ptr, ifdict_tx);
 
@@ -1160,15 +1141,11 @@ int main(int argc, char **argv)
 
        ksft_set_plan(TEST_MODE_MAX * TEST_TYPE_MAX);
 
-       init_sync_resources();
-
        for (i = 0; i < TEST_MODE_MAX; i++) {
                for (j = 0; j < TEST_TYPE_MAX; j++)
                        run_pkt_test(i, j);
        }
 
-       destroy_sync_resources();
-
 cleanup:
        for (int i = 0; i < MAX_INTERFACES; i++) {
                if (ifdict[i]->ns_fd != -1)
diff --git a/tools/testing/selftests/bpf/xdpxceiver.h 
b/tools/testing/selftests/bpf/xdpxceiver.h
index 78863820fb81..ef219c0785eb 100644
--- a/tools/testing/selftests/bpf/xdpxceiver.h
+++ b/tools/testing/selftests/bpf/xdpxceiver.h
@@ -148,8 +148,7 @@ static struct ifobject *ifdict_rx;
 static struct ifobject *ifdict_tx;
 
 /*threads*/
-pthread_mutex_t sync_mutex;
-pthread_cond_t signal_rx_condition;
+pthread_barrier_t barr;
 pthread_t t0, t1;
 
 TAILQ_HEAD(head_s, pkt) head = TAILQ_HEAD_INITIALIZER(head);
-- 
2.20.1