[libc-commits] [libc] [libc] add timeout and clock conversion utilities (PR #91905)

[Schrodinger ZHU Yifan via libc-commits]

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@@ -0,0 +1,60 @@
+//===-- unit tests for linux's timeout utilities --------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/CPP/expected.h"
+#include "src/__support/time/linux/abs_timeout.h"
+#include "src/__support/time/linux/monotonicity.h"
+#include "test/UnitTest/Test.h"
+
+namespace LIBC_NAMESPACE {
+namespace internal {
+TEST(LlvmLibcSupportLinuxTimeoutTest, NegativeSecond) {
+  timespec ts = {-1, 0};
+  cpp::expected<AbsTimeout, AbsTimeout::Error> result =
+      AbsTimeout::from_timespec(ts, false);
+  ASSERT_FALSE(result.has_value());
+  ASSERT_EQ(result.error(), AbsTimeout::Error::BeforeEpoch);
+}
+TEST(LlvmLibcSupportLinuxTimeoutTest, OverflowNano) {
+  using namespace time_units;
+  timespec ts = {0, 2_s_ns};
+  cpp::expected<AbsTimeout, AbsTimeout::Error> result =
+      AbsTimeout::from_timespec(ts, false);
+  ASSERT_FALSE(result.has_value());
+  ASSERT_EQ(result.error(), AbsTimeout::Error::Invalid);
+}
+TEST(LlvmLibcSupportLinuxTimeoutTest, UnderflowNano) {
+  timespec ts = {0, -1};
+  cpp::expected<AbsTimeout, AbsTimeout::Error> result =
+      AbsTimeout::from_timespec(ts, false);
+  ASSERT_FALSE(result.has_value());
+  ASSERT_EQ(result.error(), AbsTimeout::Error::Invalid);
+}
+TEST(LlvmLibcSupportLinuxTimeoutTest, NoChangeIfClockIsMonotonic) {
+  timespec ts = {10000, 0};
+  cpp::expected<AbsTimeout, AbsTimeout::Error> result =
+      AbsTimeout::from_timespec(ts, false);
+  ASSERT_TRUE(result.has_value());
+  ensure_monotonicity(*result);
+  ASSERT_FALSE(result->is_realtime());
+  ASSERT_EQ(result->get_timespec().tv_sec, static_cast<time_t>(10000));
+  ASSERT_EQ(result->get_timespec().tv_nsec, static_cast<time_t>(0));
+}
+TEST(LlvmLibcSupportLinuxTimeoutTest, ValidAfterConversion) {
+  timespec ts;
+  internal::clock_gettime(CLOCK_REALTIME, &ts);
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SchrodingerZhu wrote:

Fixed. I will leave `ensure_monotonicity` for ADL. 

https://github.com/llvm/llvm-project/pull/91905