tests: posix: cond: test to ensure there is no resource leakage

Add a test to ensure that `pthread_cond_t` can be used over
and over again and that there is no resource leakage with proper
usage.

Signed-off-by: Chris Friedt <[email protected]>

Author: cfriedt

tests/posix/common/src/cond.c

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2022 Meta
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/ztest.h>
+
+#include <pthread.h>
+
+/**
+ * @brief Test to demonstrate limited condition variable resources
+ *
+ * @details Exactly CONFIG_MAX_PTHREAD_COND_COUNT can be in use at once.
+ */
+ZTEST(posix_apis, test_posix_cond_resource_exhausted)
+{
+	size_t i;
+	pthread_cond_t m[CONFIG_MAX_PTHREAD_COND_COUNT + 1];
+
+	for (i = 0; i < CONFIG_MAX_PTHREAD_COND_COUNT; ++i) {
+		zassert_ok(pthread_cond_init(&m[i], NULL), "failed to init cond %zu", i);
+	}
+
+	/* try to initialize one more than CONFIG_MAX_PTHREAD_COND_COUNT */
+	zassert_equal(i, CONFIG_MAX_PTHREAD_COND_COUNT);
+	zassert_not_equal(0, pthread_cond_init(&m[i], NULL), "should not have initialized cond %zu",
+			  i);
+
+	for (; i > 0; --i) {
+		zassert_ok(pthread_cond_destroy(&m[i - 1]), "failed to destroy cond %zu", i - 1);
+	}
+}
+
+/**
+ * @brief Test to that there are no condition variable resource leaks
+ *
+ * @details Demonstrate that condition variables may be used over and over again.
+ */
+ZTEST(posix_apis, test_posix_cond_resource_leak)
+{
+	pthread_cond_t m;
+
+	for (size_t i = 0; i < 2 * CONFIG_MAX_PTHREAD_COND_COUNT; ++i) {
+		zassert_ok(pthread_cond_init(&m, NULL), "failed to init cond %zu", i);
+		zassert_ok(pthread_cond_destroy(&m), "failed to destroy cond %zu", i);
+	}
+}