tests: libc: add tests for iso c11 threads

Add tests to verify functionality of the C11 `<threads.h>` API.

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

tests/lib/c_lib/prj.conf

@@ -4,3 +4,7 @@ CONFIG_TEST_USERSPACE=y
 CONFIG_ZTEST_FATAL_HOOK=y
 CONFIG_MINIMAL_LIBC_NON_REENTRANT_FUNCTIONS=y
 CONFIG_MINIMAL_LIBC_RAND=y
+
+CONFIG_POSIX_API=y
+CONFIG_DYNAMIC_THREAD=y
+CONFIG_DYNAMIC_THREAD_POOL_SIZE=1

tests/lib/c_lib/src/test_thrd.c

@@ -0,0 +1,161 @@
+/*
+ * Copyright (c) 2023, Meta
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdint.h>
+#include <threads.h>
+
+#include <zephyr/sys_clock.h>
+#include <zephyr/ztest.h>
+
+ZTEST(test_c_lib, test_thrd_sleep)
+{
+	int64_t end;
+	int64_t start;
+	struct timespec duration = {0};
+	struct timespec remaining;
+	const uint16_t delay_ms[] = {0, 100, 200, 400};
+
+	zassert_not_equal(0, thrd_sleep(NULL, NULL));
+	zassert_ok(thrd_sleep(&duration, NULL));
+	zassert_ok(thrd_sleep(&duration, &duration));
+
+	for (int i = 0; i < ARRAY_SIZE(delay_ms); ++i) {
+		duration = (struct timespec){.tv_nsec = delay_ms[i] * NSEC_PER_MSEC};
+		remaining = (struct timespec){.tv_sec = 4242, .tv_nsec = 4242};
+
+		printk("sleeping %d ms\n", delay_ms[i]);
+		start = k_uptime_get();
+		zassert_ok(thrd_sleep(&duration, &remaining));
+		end = k_uptime_get();
+		zassert_equal(remaining.tv_sec, 0);
+		zassert_equal(remaining.tv_nsec, 0);
+		zassert_true(end - start >= delay_ms[i]);
+	}
+}
+
+static int thrd_create_join_fn(void *arg)
+{
+	uintptr_t *x = (uintptr_t *)arg;
+
+	if (x != NULL) {
+		*x = 0xb105f00d;
+	}
+
+	return 42;
+}
+
+ZTEST(test_c_lib, test_thrd_create_join)
+{
+	thrd_t thr;
+	int res = 0;
+	uintptr_t x = 0;
+	thrd_start_t fun = thrd_create_join_fn;
+
+	if (false) {
+		/* pthread_create() is not hardened for degenerate cases like this */
+		zassert_equal(thrd_error, thrd_create(NULL, NULL, NULL));
+		zassert_equal(thrd_error, thrd_create(NULL, NULL, &x));
+		zassert_equal(thrd_error, thrd_create(NULL, fun, NULL));
+		zassert_equal(thrd_error, thrd_create(NULL, fun, &x));
+		zassert_equal(thrd_error, thrd_create(&thr, NULL, NULL));
+		zassert_equal(thrd_error, thrd_create(&thr, NULL, &x));
+	}
+
+	zassert_equal(thrd_success, thrd_create(&thr, fun, NULL));
+	zassert_equal(thrd_success, thrd_join(thr, NULL));
+
+	zassert_equal(thrd_success, thrd_create(&thr, fun, &x));
+	zassert_equal(thrd_success, thrd_join(thr, &res));
+	zassert_equal(0xb105f00d, x, "expected: %d actual: %d", 0xb105f00d, x);
+	zassert_equal(42, res);
+}
+
+static int thrd_exit_fn(void *arg)
+{
+	uintptr_t *x = (uintptr_t *)arg;
+
+	*x = 0xb105f00d;
+
+	thrd_exit(73);
+
+	return 42;
+
+	CODE_UNREACHABLE;
+}
+
+ZTEST(test_c_lib, test_thrd_exit)
+{
+	thrd_t thr;
+	int res = 0;
+	uintptr_t x = 0;
+
+	zassert_equal(thrd_success, thrd_create(&thr, thrd_exit_fn, &x));
+	zassert_equal(thrd_success, thrd_join(thr, &res));
+	zassert_equal(0xb105f00d, x);
+	zassert_equal(73, res);
+}
+
+ZTEST(test_c_lib, test_thrd_yield)
+{
+	thrd_yield();
+}
+
+static thrd_t child;
+static thrd_t parent;
+
+static int thrd_current_equal_fn(void *arg)
+{
+	ARG_UNUSED(arg);
+
+	zassert_equal(thrd_current(), child);
+	zassert_not_equal(child, parent);
+
+	zassert_true(thrd_equal(thrd_current(), child));
+	zassert_false(thrd_equal(child, parent));
+
+	return 0;
+}
+
+ZTEST(test_c_lib, test_thrd_current_equal)
+{
+	parent = thrd_current();
+
+	zassert_equal(thrd_success, thrd_create(&child, thrd_current_equal_fn, NULL));
+	zassert_equal(thrd_success, thrd_join(child, NULL));
+}
+
+static bool detached_thread_is_probably_done;
+
+static int thrd_detach_fn(void *arg)
+{
+	ARG_UNUSED(arg);
+
+	detached_thread_is_probably_done = true;
+	return 73;
+}
+
+ZTEST(test_c_lib, test_thrd_detach)
+{
+	thrd_t thr;
+
+	zassert_equal(thrd_success, thrd_create(&thr, thrd_detach_fn, NULL));
+	zassert_equal(thrd_success, thrd_detach(thr));
+	zassert_equal(thrd_error, thrd_join(thr, NULL));
+
+	do {
+		k_msleep(100);
+	} while (!detached_thread_is_probably_done);
+}
+
+ZTEST(test_c_lib, test_thrd_reuse)
+{
+	thrd_t thr;
+
+	for (int i = 0; i < 42; ++i) {
+		zassert_equal(thrd_success, thrd_create(&thr, thrd_create_join_fn, NULL));
+		zassert_equal(thrd_success, thrd_join(thr, NULL));
+	}
+}

tests/lib/c_lib/testcase.yaml

@@ -38,3 +38,9 @@ tests:
     extra_configs:
       - CONFIG_MINIMAL_LIBC=y
       - CONFIG_MINIMAL_LIBC_STRING_ERROR_TABLE=n
+  libraries.libc.minimal.thrd:
+    tags: minimal_libc
+    extra_configs:
+      - CONFIG_POSIX_API=y
+      - CONFIG_DYNAMIC_THREAD=y
+      - CONFIG_DYNAMIC_THREAD_POOL_SIZE=1