[PATCH v2 3/5] selftests/futex: read atomic variable value with atomic_read

[Yuwen Chen <ywen.chen@foxmail.com>]

Directly reading the internal value of atomic_t externally does
not meet the encapsulation requirements. A new function
atomic_read is added to obtain the value of an atomic variable.

Signed-off-by: Yuwen Chen <ywen.chen@foxmail.com>
---
 .../selftests/futex/functional/futex_requeue_pi.c    | 12 ++++++------
 .../functional/futex_requeue_pi_signal_restart.c     |  4 ++--
 tools/testing/selftests/futex/include/atomic.h       | 12 ++++++++++++
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/futex/functional/futex_requeue_pi.c b/tools/testing/selftests/futex/functional/futex_requeue_pi.c
index f299d75848cd4..5d845b052891b 100644
--- a/tools/testing/selftests/futex/functional/futex_requeue_pi.c
+++ b/tools/testing/selftests/futex/functional/futex_requeue_pi.c
@@ -201,7 +201,7 @@ void *broadcast_wakerfn(void *arg)
 	int i = 0;
 
 	ksft_print_dbg_msg("Waker: waiting for waiters to block\n");
-	while (waiters_blocked.val < THREAD_MAX)
+	while (atomic_read(&waiters_blocked) < THREAD_MAX)
 		usleep(1000);
 	usleep(1000);
 
@@ -218,7 +218,7 @@ void *broadcast_wakerfn(void *arg)
 		ksft_exit_fail_msg("FUTEX_CMP_REQUEUE_PI failed\n");
 	} else if (++i < MAX_WAKE_ITERS) {
 		task_count += args->ret;
-		if (task_count < THREAD_MAX - waiters_woken.val)
+		if (task_count < THREAD_MAX - atomic_read(&waiters_woken))
 			goto continue_requeue;
 	} else {
 		ksft_exit_fail_msg("max broadcast iterations (%d) reached with %d/%d tasks woken or requeued\n",
@@ -247,13 +247,13 @@ void *signal_wakerfn(void *arg)
 	int i = 0;
 
 	ksft_print_dbg_msg("Waker: waiting for waiters to block\n");
-	while (waiters_blocked.val < THREAD_MAX)
+	while (atomic_read(&waiters_blocked) < THREAD_MAX)
 		usleep(1000);
 	usleep(1000);
 
-	while (task_count < THREAD_MAX && waiters_woken.val < THREAD_MAX) {
+	while (task_count < THREAD_MAX && atomic_read(&waiters_woken) < THREAD_MAX) {
 		ksft_print_dbg_msg("task_count: %d, waiters_woken: %d\n",
-		     task_count, waiters_woken.val);
+		     task_count, atomic_read(&waiters_woken));
 		if (args->lock) {
 			ksft_print_dbg_msg("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n",
 			    f2, &f2);
@@ -293,7 +293,7 @@ void *signal_wakerfn(void *arg)
 		args->ret = task_count;
 
 	ksft_print_dbg_msg("Waker: exiting with %d\n", args->ret);
-	ksft_print_dbg_msg("Waker: waiters_woken: %d\n", waiters_woken.val);
+	ksft_print_dbg_msg("Waker: waiters_woken: %d\n", atomic_read(&waiters_woken));
 	pthread_exit((void *)&args->ret);
 }
 
diff --git a/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c b/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c
index e34ee0f9ebccd..29f93916b46da 100644
--- a/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c
+++ b/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c
@@ -70,7 +70,7 @@ int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg,
 void handle_signal(int signo)
 {
 	ksft_print_dbg_msg("signal received %s requeue\n",
-	     requeued.val ? "after" : "prior to");
+	     atomic_read(&requeued) ? "after" : "prior to");
 }
 
 void *waiterfn(void *arg)
@@ -83,7 +83,7 @@ void *waiterfn(void *arg)
 	old_val = f1;
 	res = futex_wait_requeue_pi(&f1, old_val, &(f2), NULL,
 				    FUTEX_PRIVATE_FLAG);
-	if (!requeued.val || errno != EWOULDBLOCK) {
+	if (!atomic_read(&requeued) || errno != EWOULDBLOCK) {
 		ksft_test_result_fail("unexpected return from futex_wait_requeue_pi: %d (%s)\n",
 		     res, strerror(errno));
 		ksft_print_dbg_msg("w2:futex: %x\n", f2);
diff --git a/tools/testing/selftests/futex/include/atomic.h b/tools/testing/selftests/futex/include/atomic.h
index 428bcd921bb53..c0dccb1b966ba 100644
--- a/tools/testing/selftests/futex/include/atomic.h
+++ b/tools/testing/selftests/futex/include/atomic.h
@@ -76,4 +76,16 @@ atomic_set(atomic_t *addr, int newval)
 	return newval;
 }
 
+/**
+ * atomic_read() - Atomic read
+ * @addr:	Address of the variable to read
+ *
+ * Return the value of addr->val.
+ */
+static inline int
+atomic_read(atomic_t *addr)
+{
+	return addr->val;
+}
+
 #endif
-- 
2.34.1