git: 7b26124ae106 - main - libtpool/tests: Fix a flaky test

[Mark Johnston]

The branch main has been updated by markj:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=7b26124ae106283952e1e61d07f0eecda5c361a0

commit 7b26124ae106283952e1e61d07f0eecda5c361a0
Author:     Mark Johnston <ma...@freebsd.org>
AuthorDate: 2025-06-25 14:19:27 +0000
Commit:     Mark Johnston <ma...@freebsd.org>
CommitDate: 2025-06-25 17:17:08 +0000

    libtpool/tests: Fix a flaky test
    
    I occasionally see failures due to pthread_barrier_wait() not returning
    0.  There is another possible non-error return value, so allow that too.
    While here, check the result in tp_delay() as well.
    
    Fixes:          5c1ba994a8bc ("Add a regression test for a libtpool bug")
    Differential Revision:  https://reviews.freebsd.org/D50967
---
 cddl/lib/libtpool/tests/libtpool_test.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/cddl/lib/libtpool/tests/libtpool_test.c 
b/cddl/lib/libtpool/tests/libtpool_test.c
index 42726a13420c..42bce269cb23 100644
--- a/cddl/lib/libtpool/tests/libtpool_test.c
+++ b/cddl/lib/libtpool/tests/libtpool_test.c
@@ -11,9 +11,12 @@ static void
 tp_delay(void *arg)
 {
        pthread_barrier_t *barrier = arg;
+       int r;
 
        /* Block this task until all thread pool workers have been created. */
-       pthread_barrier_wait(barrier);
+       r = pthread_barrier_wait(barrier);
+       ATF_REQUIRE_MSG(r == 0 || r == PTHREAD_BARRIER_SERIAL_THREAD,
+           "pthread_barrier_wait failed: %s", strerror(r));
 }
 
 /*
@@ -38,7 +41,6 @@ ATF_TC_BODY(complete_exhaustion, tc)
        int nworkers;
        int r, i;
 
-
        len = sizeof(max_threads_per_proc);
        r = sysctlbyname("kern.threads.max_threads_per_proc",
            &max_threads_per_proc, &len, NULL, 0);
@@ -65,7 +67,9 @@ ATF_TC_BODY(complete_exhaustion, tc)
        ATF_REQUIRE_EQ(tpool_dispatch(tp1, tp_delay, NULL), -1);
 
        /* Cleanup */
-       ATF_REQUIRE_EQ(pthread_barrier_wait(&barrier), 0);
+       r = pthread_barrier_wait(&barrier);
+       ATF_REQUIRE_MSG(r == 0 || r == PTHREAD_BARRIER_SERIAL_THREAD,
+           "pthread_barrier_wait failed: %s", strerror(r));
        tpool_wait(tp1);
        tpool_wait(tp0);
 }