[libc-commits] [libc] [llvm] [libc][windows] start time API implementation (PR #117775)
Schrodinger ZHU Yifan via libc-commits
libc-commits at lists.llvm.org
Wed Dec 4 08:06:15 PST 2024
https://github.com/SchrodingerZhu updated https://github.com/llvm/llvm-project/pull/117775
>From 60137454d110c4efb65e5cf1bcdc84245b411253 Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Tue, 26 Nov 2024 11:46:51 -0800
Subject: [PATCH 1/9] [libc][windows] start time API implementation
---
libc/config/windows/entrypoints.txt | 3 +
libc/hdr/types/clockid_t.h | 2 +-
.../llvm-libc-macros/windows/CMakeLists.txt | 6 ++
.../windows/time-macros-ext.h | 15 ++++
libc/src/CMakeLists.txt | 2 +-
libc/src/__support/time/CMakeLists.txt | 7 ++
.../time/{linux => }/clock_gettime.h | 10 +--
libc/src/__support/time/linux/CMakeLists.txt | 2 +-
.../__support/time/linux/clock_conversion.h | 2 +-
.../__support/time/linux/clock_gettime.cpp | 2 +-
.../src/__support/time/windows/CMakeLists.txt | 16 ++++
.../__support/time/windows/clock_gettime.cpp | 89 +++++++++++++++++++
libc/src/time/CMakeLists.txt | 10 ++-
libc/src/time/linux/CMakeLists.txt | 21 +----
libc/src/time/linux/clock.cpp | 2 +-
libc/src/time/linux/clock_gettime.cpp | 2 +-
libc/src/time/linux/gettimeofday.cpp | 2 +-
libc/src/time/{linux => }/time.cpp | 9 +-
.../threads/linux/raw_mutex_test.cpp | 2 +-
.../llvm-project-overlay/libc/BUILD.bazel | 2 +-
20 files changed, 167 insertions(+), 39 deletions(-)
create mode 100644 libc/include/llvm-libc-macros/windows/CMakeLists.txt
create mode 100644 libc/include/llvm-libc-macros/windows/time-macros-ext.h
rename libc/src/__support/time/{linux => }/clock_gettime.h (72%)
create mode 100644 libc/src/__support/time/windows/CMakeLists.txt
create mode 100644 libc/src/__support/time/windows/clock_gettime.cpp
rename libc/src/time/{linux => }/time.cpp (82%)
diff --git a/libc/config/windows/entrypoints.txt b/libc/config/windows/entrypoints.txt
index 8f0b50bcc83ea2..d0796b85aec2af 100644
--- a/libc/config/windows/entrypoints.txt
+++ b/libc/config/windows/entrypoints.txt
@@ -95,6 +95,9 @@ set(TARGET_LIBC_ENTRYPOINTS
# errno.h entrypoints
libc.src.errno.errno
+
+ # time.h entrypoints
+ libc.src.time.time
)
set(TARGET_LIBM_ENTRYPOINTS
diff --git a/libc/hdr/types/clockid_t.h b/libc/hdr/types/clockid_t.h
index 333342072a2ff2..06fafc5b150612 100644
--- a/libc/hdr/types/clockid_t.h
+++ b/libc/hdr/types/clockid_t.h
@@ -9,7 +9,7 @@
#ifndef LLVM_LIBC_HDR_TYPES_CLOCKID_T_H
#define LLVM_LIBC_HDR_TYPES_CLOCKID_T_H
-#ifdef LIBC_FULL_BUILD
+#if defined(LIBC_FULL_BUILD) || defined(_MSC_VER)
#include "include/llvm-libc-types/clockid_t.h"
diff --git a/libc/include/llvm-libc-macros/windows/CMakeLists.txt b/libc/include/llvm-libc-macros/windows/CMakeLists.txt
new file mode 100644
index 00000000000000..48afc795178a0d
--- /dev/null
+++ b/libc/include/llvm-libc-macros/windows/CMakeLists.txt
@@ -0,0 +1,6 @@
+add_header(
+ time_macros_ext
+ HDR
+ time-macros-ext.h
+)
+
diff --git a/libc/include/llvm-libc-macros/windows/time-macros-ext.h b/libc/include/llvm-libc-macros/windows/time-macros-ext.h
new file mode 100644
index 00000000000000..e629a92f371c4a
--- /dev/null
+++ b/libc/include/llvm-libc-macros/windows/time-macros-ext.h
@@ -0,0 +1,15 @@
+//===-- Windows Time Macros Extension -------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_WINDOWS_TIME_MACROS_EXT_H
+#define LLVM_LIBC_MACROS_WINDOWS_TIME_MACROS_EXT_H
+
+#define CLOCK_MONOTONIC 0
+#define CLOCK_REALTIME 1
+
+#endif // LLVM_LIBC_MACROS_WINDOWS_TIME_MACROS_EXT_H
diff --git a/libc/src/CMakeLists.txt b/libc/src/CMakeLists.txt
index 02c193e635362e..dd3b51886edfea 100644
--- a/libc/src/CMakeLists.txt
+++ b/libc/src/CMakeLists.txt
@@ -13,6 +13,7 @@ add_subdirectory(stdio)
add_subdirectory(stdlib)
add_subdirectory(string)
add_subdirectory(wchar)
+add_subdirectory(time)
if(${LIBC_TARGET_OS} STREQUAL "linux")
add_subdirectory(dirent)
@@ -40,5 +41,4 @@ add_subdirectory(setjmp)
add_subdirectory(signal)
add_subdirectory(spawn)
add_subdirectory(threads)
-add_subdirectory(time)
add_subdirectory(locale)
diff --git a/libc/src/__support/time/CMakeLists.txt b/libc/src/__support/time/CMakeLists.txt
index 89ddffb099388b..e73f2744b15a0e 100644
--- a/libc/src/__support/time/CMakeLists.txt
+++ b/libc/src/__support/time/CMakeLists.txt
@@ -2,6 +2,13 @@ if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
add_subdirectory(${LIBC_TARGET_OS})
endif()
+add_object_library(
+ clock_gettime
+ ALIAS
+ DEPENDS
+ libc.src.__support.time.${LIBC_TARGET_OS}.clock_gettime
+)
+
add_header_library(
units
HDRS
diff --git a/libc/src/__support/time/linux/clock_gettime.h b/libc/src/__support/time/clock_gettime.h
similarity index 72%
rename from libc/src/__support/time/linux/clock_gettime.h
rename to libc/src/__support/time/clock_gettime.h
index f7f996ce7c1975..584bf546cd60cd 100644
--- a/libc/src/__support/time/linux/clock_gettime.h
+++ b/libc/src/__support/time/clock_gettime.h
@@ -6,21 +6,17 @@
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_CLOCK_GETTIME_H
-#define LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_CLOCK_GETTIME_H
+#ifndef LLVM_LIBC_SRC___SUPPORT_TIME_CLOCK_GETTIME_H
+#define LLVM_LIBC_SRC___SUPPORT_TIME_CLOCK_GETTIME_H
#include "hdr/types/clockid_t.h"
#include "hdr/types/struct_timespec.h"
#include "src/__support/error_or.h"
-#if defined(SYS_clock_gettime64)
-#include <linux/time_types.h>
-#endif
-
namespace LIBC_NAMESPACE_DECL {
namespace internal {
ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts);
} // namespace internal
} // namespace LIBC_NAMESPACE_DECL
-#endif // LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_CLOCK_GETTIME_H
+#endif // LLVM_LIBC_SRC___SUPPORT_TIME_CLOCK_GETTIME_H
diff --git a/libc/src/__support/time/linux/CMakeLists.txt b/libc/src/__support/time/linux/CMakeLists.txt
index 94ed09e6521524..6fec7eeba99add 100644
--- a/libc/src/__support/time/linux/CMakeLists.txt
+++ b/libc/src/__support/time/linux/CMakeLists.txt
@@ -1,7 +1,7 @@
add_object_library(
clock_gettime
HDRS
- clock_gettime.h
+ ../clock_gettime.h
SRCS
clock_gettime.cpp
DEPENDS
diff --git a/libc/src/__support/time/linux/clock_conversion.h b/libc/src/__support/time/linux/clock_conversion.h
index 7a52873263a14c..ac5357d308d7c5 100644
--- a/libc/src/__support/time/linux/clock_conversion.h
+++ b/libc/src/__support/time/linux/clock_conversion.h
@@ -10,7 +10,7 @@
#define LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_CLOCK_CONVERSION_H
#include "src/__support/macros/config.h"
-#include "src/__support/time/linux/clock_gettime.h"
+#include "src/__support/time/clock_gettime.h"
#include "src/__support/time/units.h"
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/__support/time/linux/clock_gettime.cpp b/libc/src/__support/time/linux/clock_gettime.cpp
index 3a0eca417724ac..944fc0a2b80fe7 100644
--- a/libc/src/__support/time/linux/clock_gettime.cpp
+++ b/libc/src/__support/time/linux/clock_gettime.cpp
@@ -6,7 +6,7 @@
//
//===----------------------------------------------------------------------===//
-#include "src/__support/time/linux/clock_gettime.h"
+#include "src/__support/time/clock_gettime.h"
#include "hdr/types/clockid_t.h"
#include "hdr/types/struct_timespec.h"
#include "src/__support/OSUtil/linux/vdso.h"
diff --git a/libc/src/__support/time/windows/CMakeLists.txt b/libc/src/__support/time/windows/CMakeLists.txt
new file mode 100644
index 00000000000000..24b5fa7e086265
--- /dev/null
+++ b/libc/src/__support/time/windows/CMakeLists.txt
@@ -0,0 +1,16 @@
+add_object_library(
+ clock_gettime
+ HDRS
+ ../clock_gettime.h
+ SRCS
+ clock_gettime.cpp
+ DEPENDS
+ libc.hdr.types.struct_timespec
+ libc.hdr.types.clockid_t
+ libc.hdr.errno_macros
+ libc.include.llvm-libc-macros.windows.time_macros_ext
+ libc.src.__support.common
+ libc.src.__support.error_or
+ libc.src.__support.OSUtil.osutil
+ libc.src.__support.CPP.atomic
+)
diff --git a/libc/src/__support/time/windows/clock_gettime.cpp b/libc/src/__support/time/windows/clock_gettime.cpp
new file mode 100644
index 00000000000000..6e0b7e028c9789
--- /dev/null
+++ b/libc/src/__support/time/windows/clock_gettime.cpp
@@ -0,0 +1,89 @@
+//===--- clock_gettime windows implementation -------------------*- C++ -*-===//
+//
+// 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/time/clock_gettime.h"
+#include "include/llvm-libc-macros/windows/time-macros-ext.h"
+#include "src/__support/CPP/atomic.h"
+#include "src/__support/CPP/bit.h"
+#include "src/__support/time/units.h"
+#include <Windows.h>
+
+#ifdef __clang__
+#define UNINITIALIZED [[clang::uninitialized]]
+#else
+#define UNINITIALIZED
+#endif
+
+namespace LIBC_NAMESPACE_DECL {
+
+static long long get_ticks_per_second() {
+ static cpp::Atomic<long long> frequency = 0;
+ if (!frequency) {
+ UNINITIALIZED LARGE_INTEGER buffer;
+ // On systems that run Windows XP or later, the function will always
+ // succeed and will thus never return zero.
+ ::QueryPerformanceFrequency(&buffer);
+ frequency = buffer.QuadPart;
+ return buffer.QuadPart;
+ }
+ return frequency.load(cpp::MemoryOrder::RELAXED);
+}
+
+ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
+ using namespace time_units;
+ ErrorOr<int> ret = 0;
+ __try {
+ switch (clockid) {
+ default:
+ ret = cpp::unexpected(EINVAL);
+ break;
+
+ case CLOCK_MONOTONIC: {
+ // see
+ // https://learn.microsoft.com/en-us/windows/win32/sysinfo/acquiring-high-resolution-time-stamps
+ // Is the performance counter monotonic (non-decreasing)?
+ // Yes. QPC does not go backward.
+ UNINITIALIZED LARGE_INTEGER buffer;
+ // On systems that run Windows XP or later, the function will always
+ // succeed and will thus never return zero.
+ ::QueryPerformanceCounter(&buffer);
+ long long freq = get_ticks_per_second();
+ long long ticks = buffer.QuadPart;
+ long long tv_sec = ticks / freq;
+ long long tv_nsec = (ticks % freq) * 1_s_ns / freq;
+ ts->tv_sec = static_cast<decltype(ts->tv_sec)>(tv_sec);
+ ts->tv_nsec = static_cast<decltype(ts->tv_nsec)>(tv_nsec);
+ break;
+ }
+ case CLOCK_REALTIME: {
+ // https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimepreciseasfiletime
+ // GetSystemTimePreciseAsFileTime
+ // This function is best suited for high-resolution time-of-day
+ // measurements, or time stamps that are synchronized to UTC
+ UNINITIALIZED FILETIME file_time;
+ UNINITIALIZED ULARGE_INTEGER time;
+ ::GetSystemTimePreciseAsFileTime(&file_time);
+ time.LowPart = file_time.dwLowDateTime;
+ time.HighPart = file_time.dwHighDateTime;
+
+ // adjust to POSIX epoch (from Jan 1, 1601 to Jan 1, 1970)
+ constexpr unsigned long long HNS_PER_SEC = 1_s_ns / 100ULL;
+ time.QuadPart -= (11644473600ULL * HNS_PER_SEC);
+ unsigned long long tv_sec = time.QuadPart / HNS_PER_SEC;
+ unsigned long long tv_nsec = (time.QuadPart % HNS_PER_SEC) * 100ULL;
+ ts->tv_sec = static_cast<decltype(ts->tv_sec)>(tv_sec);
+ ts->tv_nsec = static_cast<decltype(ts->tv_nsec)>(tv_nsec);
+ break;
+ }
+ }
+ } __except (EXCEPTION_EXECUTE_HANDLER) {
+ ret = cpp::unexpected(EFAULT);
+ }
+ return ret;
+}
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/time/CMakeLists.txt b/libc/src/time/CMakeLists.txt
index f18e74a15e6fc2..3e8e6882ffc5d4 100644
--- a/libc/src/time/CMakeLists.txt
+++ b/libc/src/time/CMakeLists.txt
@@ -106,9 +106,15 @@ add_entrypoint_object(
add_entrypoint_object(
time
- ALIAS
+ SRCS
+ time.cpp
+ HDRS
+ time_func.h
DEPENDS
- .${LIBC_TARGET_OS}.time
+ libc.hdr.time_macros
+ libc.hdr.types.time_t
+ libc.src.__support.time.clock_gettime
+ libc.src.errno.errno
)
add_entrypoint_object(
diff --git a/libc/src/time/linux/CMakeLists.txt b/libc/src/time/linux/CMakeLists.txt
index 31fd7d1e64c85c..314623f9f425e7 100644
--- a/libc/src/time/linux/CMakeLists.txt
+++ b/libc/src/time/linux/CMakeLists.txt
@@ -1,16 +1,3 @@
-add_entrypoint_object(
- time
- SRCS
- time.cpp
- HDRS
- ../time_func.h
- DEPENDS
- libc.hdr.time_macros
- libc.hdr.types.time_t
- libc.src.__support.time.linux.clock_gettime
- libc.src.errno.errno
-)
-
add_entrypoint_object(
timespec_get
SRCS
@@ -20,7 +7,7 @@ add_entrypoint_object(
DEPENDS
libc.hdr.time_macros
libc.hdr.types.struct_timespec
- libc.src.__support.time.linux.clock_gettime
+ libc.src.__support.time.clock_gettime
libc.src.errno.errno
)
@@ -34,7 +21,7 @@ add_entrypoint_object(
libc.hdr.time_macros
libc.hdr.types.clock_t
libc.src.__support.time.units
- libc.src.__support.time.linux.clock_gettime
+ libc.src.__support.time.clock_gettime
libc.src.__support.CPP.limits
libc.src.errno.errno
)
@@ -62,7 +49,7 @@ add_entrypoint_object(
DEPENDS
libc.hdr.types.clockid_t
libc.hdr.types.struct_timespec
- libc.src.__support.time.linux.clock_gettime
+ libc.src.__support.time.clock_gettime
libc.src.errno.errno
)
@@ -75,7 +62,7 @@ add_entrypoint_object(
DEPENDS
libc.hdr.time_macros
libc.hdr.types.suseconds_t
- libc.src.__support.time.linux.clock_gettime
+ libc.src.__support.time.clock_gettime
libc.src.__support.time.units
libc.src.errno.errno
)
diff --git a/libc/src/time/linux/clock.cpp b/libc/src/time/linux/clock.cpp
index f43e1bcad6a3a1..ee4fa82b4f8944 100644
--- a/libc/src/time/linux/clock.cpp
+++ b/libc/src/time/linux/clock.cpp
@@ -11,7 +11,7 @@
#include "src/__support/CPP/limits.h"
#include "src/__support/common.h"
#include "src/__support/macros/config.h"
-#include "src/__support/time/linux/clock_gettime.h"
+#include "src/__support/time/clock_gettime.h"
#include "src/__support/time/units.h"
#include "src/errno/libc_errno.h"
diff --git a/libc/src/time/linux/clock_gettime.cpp b/libc/src/time/linux/clock_gettime.cpp
index a2b20a6dbc9879..743c644d65d024 100644
--- a/libc/src/time/linux/clock_gettime.cpp
+++ b/libc/src/time/linux/clock_gettime.cpp
@@ -9,7 +9,7 @@
#include "src/time/clock_gettime.h"
#include "src/__support/common.h"
#include "src/__support/macros/config.h"
-#include "src/__support/time/linux/clock_gettime.h"
+#include "src/__support/time/clock_gettime.h"
#include "src/errno/libc_errno.h"
namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/time/linux/gettimeofday.cpp b/libc/src/time/linux/gettimeofday.cpp
index 19d9988ae73a6e..e8ddf482fc9840 100644
--- a/libc/src/time/linux/gettimeofday.cpp
+++ b/libc/src/time/linux/gettimeofday.cpp
@@ -11,7 +11,7 @@
#include "hdr/types/suseconds_t.h"
#include "src/__support/common.h"
#include "src/__support/macros/config.h"
-#include "src/__support/time/linux/clock_gettime.h"
+#include "src/__support/time/clock_gettime.h"
#include "src/__support/time/units.h"
#include "src/errno/libc_errno.h"
diff --git a/libc/src/time/linux/time.cpp b/libc/src/time/time.cpp
similarity index 82%
rename from libc/src/time/linux/time.cpp
rename to libc/src/time/time.cpp
index 20fb86e8e29dbb..e3615d995116b8 100644
--- a/libc/src/time/linux/time.cpp
+++ b/libc/src/time/time.cpp
@@ -9,14 +9,17 @@
#include "hdr/time_macros.h"
#include "src/__support/common.h"
#include "src/__support/macros/config.h"
-#include "src/__support/time/linux/clock_gettime.h"
+#include "src/__support/time/clock_gettime.h"
#include "src/errno/libc_errno.h"
#include "src/time/time_func.h"
+#ifdef _MSC_VER
+#include "include/llvm-libc-macros/windows/time-macros-ext.h"
+#endif
+
namespace LIBC_NAMESPACE_DECL {
-LLVM_LIBC_FUNCTION(time_t, time, (time_t * tp)) {
- // TODO: Use the Linux VDSO to fetch the time and avoid the syscall.
+LLVM_LIBC_FUNCTION(time_t, time, (time_t *tp)) {
struct timespec ts;
auto result = internal::clock_gettime(CLOCK_REALTIME, &ts);
if (!result.has_value()) {
diff --git a/libc/test/src/__support/threads/linux/raw_mutex_test.cpp b/libc/test/src/__support/threads/linux/raw_mutex_test.cpp
index 918f5d35c94f42..dadc706421d06e 100644
--- a/libc/test/src/__support/threads/linux/raw_mutex_test.cpp
+++ b/libc/test/src/__support/threads/linux/raw_mutex_test.cpp
@@ -12,7 +12,7 @@
#include "src/__support/OSUtil/syscall.h"
#include "src/__support/threads/linux/raw_mutex.h"
#include "src/__support/threads/sleep.h"
-#include "src/__support/time/linux/clock_gettime.h"
+#include "src/__support/time/clock_gettime.h"
#include "src/stdlib/exit.h"
#include "src/sys/mman/mmap.h"
#include "src/sys/mman/munmap.h"
diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index c5a0076d2ef308..9aab193663fba8 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -1477,7 +1477,7 @@ libc_support_library(
libc_support_library(
name = "__support_time_linux_clock_gettime",
- hdrs = ["src/__support/time/linux/clock_gettime.h"],
+ hdrs = ["src/__support/time/clock_gettime.h"],
target_compatible_with = select({
"@platforms//os:linux": [],
"//conditions:default": ["@platforms//:incompatible"],
>From 60ce1865ee15f572a66b42414f8c9413aeee5ea5 Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Tue, 26 Nov 2024 12:11:40 -0800
Subject: [PATCH 2/9] [libc][windows] enable test and fix namespace placement
---
libc/src/__support/time/windows/clock_gettime.cpp | 3 ++-
libc/test/src/CMakeLists.txt | 2 +-
libc/test/src/time/CMakeLists.txt | 2 +-
libc/test/src/time/time_test.cpp | 2 --
4 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/libc/src/__support/time/windows/clock_gettime.cpp b/libc/src/__support/time/windows/clock_gettime.cpp
index 6e0b7e028c9789..f2be368352835f 100644
--- a/libc/src/__support/time/windows/clock_gettime.cpp
+++ b/libc/src/__support/time/windows/clock_gettime.cpp
@@ -20,7 +20,7 @@
#endif
namespace LIBC_NAMESPACE_DECL {
-
+namespace internal {
static long long get_ticks_per_second() {
static cpp::Atomic<long long> frequency = 0;
if (!frequency) {
@@ -86,4 +86,5 @@ ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
}
return ret;
}
+} // namespace internal
} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/src/CMakeLists.txt b/libc/test/src/CMakeLists.txt
index 8ac8f91e98d4cc..606f6d837e4fe7 100644
--- a/libc/test/src/CMakeLists.txt
+++ b/libc/test/src/CMakeLists.txt
@@ -59,6 +59,7 @@ add_subdirectory(stdio)
add_subdirectory(stdlib)
add_subdirectory(string)
add_subdirectory(wchar)
+add_subdirectory(time)
# Depends on utilities in stdlib
add_subdirectory(inttypes)
@@ -82,7 +83,6 @@ add_subdirectory(network)
add_subdirectory(setjmp)
add_subdirectory(signal)
add_subdirectory(spawn)
-add_subdirectory(time)
add_subdirectory(locale)
if(${LIBC_TARGET_OS} STREQUAL "linux")
diff --git a/libc/test/src/time/CMakeLists.txt b/libc/test/src/time/CMakeLists.txt
index 7151526b72b26d..19f90869852251 100644
--- a/libc/test/src/time/CMakeLists.txt
+++ b/libc/test/src/time/CMakeLists.txt
@@ -157,8 +157,8 @@ add_libc_unittest(
SRCS
time_test.cpp
DEPENDS
- libc.include.time
libc.src.time.time
+ libc.src.__support.time.windows.clock_gettime
libc.src.errno.errno
)
diff --git a/libc/test/src/time/time_test.cpp b/libc/test/src/time/time_test.cpp
index d3d4dc9a285158..7cdb4e834633e5 100644
--- a/libc/test/src/time/time_test.cpp
+++ b/libc/test/src/time/time_test.cpp
@@ -9,8 +9,6 @@
#include "src/time/time_func.h"
#include "test/UnitTest/Test.h"
-#include <time.h>
-
TEST(LlvmLibcTimeTest, SmokeTest) {
time_t t1;
time_t t2 = LIBC_NAMESPACE::time(&t1);
>From 471fb1e83608d02bdd25fc8ae330531a4e0684b5 Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Tue, 26 Nov 2024 12:15:33 -0800
Subject: [PATCH 3/9] [libc][windows] fix format
---
libc/src/time/time.cpp | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/libc/src/time/time.cpp b/libc/src/time/time.cpp
index e3615d995116b8..a233676e702998 100644
--- a/libc/src/time/time.cpp
+++ b/libc/src/time/time.cpp
@@ -18,8 +18,7 @@
#endif
namespace LIBC_NAMESPACE_DECL {
-
-LLVM_LIBC_FUNCTION(time_t, time, (time_t *tp)) {
+LLVM_LIBC_FUNCTION(time_t, time, (time_t * tp)) {
struct timespec ts;
auto result = internal::clock_gettime(CLOCK_REALTIME, &ts);
if (!result.has_value()) {
>From 734a4f33e36211de4d39b41ce322f39b451164b2 Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Tue, 26 Nov 2024 14:20:28 -0800
Subject: [PATCH 4/9] [libc][windows] remove SEH
---
.../__support/time/windows/clock_gettime.cpp | 84 +++++++++----------
1 file changed, 40 insertions(+), 44 deletions(-)
diff --git a/libc/src/__support/time/windows/clock_gettime.cpp b/libc/src/__support/time/windows/clock_gettime.cpp
index f2be368352835f..379eae21b1d8d2 100644
--- a/libc/src/__support/time/windows/clock_gettime.cpp
+++ b/libc/src/__support/time/windows/clock_gettime.cpp
@@ -37,52 +37,48 @@ static long long get_ticks_per_second() {
ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
using namespace time_units;
ErrorOr<int> ret = 0;
- __try {
- switch (clockid) {
- default:
- ret = cpp::unexpected(EINVAL);
- break;
+ switch (clockid) {
+ default:
+ ret = cpp::unexpected(EINVAL);
+ break;
- case CLOCK_MONOTONIC: {
- // see
- // https://learn.microsoft.com/en-us/windows/win32/sysinfo/acquiring-high-resolution-time-stamps
- // Is the performance counter monotonic (non-decreasing)?
- // Yes. QPC does not go backward.
- UNINITIALIZED LARGE_INTEGER buffer;
- // On systems that run Windows XP or later, the function will always
- // succeed and will thus never return zero.
- ::QueryPerformanceCounter(&buffer);
- long long freq = get_ticks_per_second();
- long long ticks = buffer.QuadPart;
- long long tv_sec = ticks / freq;
- long long tv_nsec = (ticks % freq) * 1_s_ns / freq;
- ts->tv_sec = static_cast<decltype(ts->tv_sec)>(tv_sec);
- ts->tv_nsec = static_cast<decltype(ts->tv_nsec)>(tv_nsec);
- break;
- }
- case CLOCK_REALTIME: {
- // https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimepreciseasfiletime
- // GetSystemTimePreciseAsFileTime
- // This function is best suited for high-resolution time-of-day
- // measurements, or time stamps that are synchronized to UTC
- UNINITIALIZED FILETIME file_time;
- UNINITIALIZED ULARGE_INTEGER time;
- ::GetSystemTimePreciseAsFileTime(&file_time);
- time.LowPart = file_time.dwLowDateTime;
- time.HighPart = file_time.dwHighDateTime;
+ case CLOCK_MONOTONIC: {
+ // see
+ // https://learn.microsoft.com/en-us/windows/win32/sysinfo/acquiring-high-resolution-time-stamps
+ // Is the performance counter monotonic (non-decreasing)?
+ // Yes. QPC does not go backward.
+ UNINITIALIZED LARGE_INTEGER buffer;
+ // On systems that run Windows XP or later, the function will always
+ // succeed and will thus never return zero.
+ ::QueryPerformanceCounter(&buffer);
+ long long freq = get_ticks_per_second();
+ long long ticks = buffer.QuadPart;
+ long long tv_sec = ticks / freq;
+ long long tv_nsec = (ticks % freq) * 1_s_ns / freq;
+ ts->tv_sec = static_cast<decltype(ts->tv_sec)>(tv_sec);
+ ts->tv_nsec = static_cast<decltype(ts->tv_nsec)>(tv_nsec);
+ break;
+ }
+ case CLOCK_REALTIME: {
+ // https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimepreciseasfiletime
+ // GetSystemTimePreciseAsFileTime
+ // This function is best suited for high-resolution time-of-day
+ // measurements, or time stamps that are synchronized to UTC
+ UNINITIALIZED FILETIME file_time;
+ UNINITIALIZED ULARGE_INTEGER time;
+ ::GetSystemTimePreciseAsFileTime(&file_time);
+ time.LowPart = file_time.dwLowDateTime;
+ time.HighPart = file_time.dwHighDateTime;
- // adjust to POSIX epoch (from Jan 1, 1601 to Jan 1, 1970)
- constexpr unsigned long long HNS_PER_SEC = 1_s_ns / 100ULL;
- time.QuadPart -= (11644473600ULL * HNS_PER_SEC);
- unsigned long long tv_sec = time.QuadPart / HNS_PER_SEC;
- unsigned long long tv_nsec = (time.QuadPart % HNS_PER_SEC) * 100ULL;
- ts->tv_sec = static_cast<decltype(ts->tv_sec)>(tv_sec);
- ts->tv_nsec = static_cast<decltype(ts->tv_nsec)>(tv_nsec);
- break;
- }
- }
- } __except (EXCEPTION_EXECUTE_HANDLER) {
- ret = cpp::unexpected(EFAULT);
+ // adjust to POSIX epoch (from Jan 1, 1601 to Jan 1, 1970)
+ constexpr unsigned long long HNS_PER_SEC = 1_s_ns / 100ULL;
+ time.QuadPart -= (11644473600ULL * HNS_PER_SEC);
+ unsigned long long tv_sec = time.QuadPart / HNS_PER_SEC;
+ unsigned long long tv_nsec = (time.QuadPart % HNS_PER_SEC) * 100ULL;
+ ts->tv_sec = static_cast<decltype(ts->tv_sec)>(tv_sec);
+ ts->tv_nsec = static_cast<decltype(ts->tv_nsec)>(tv_nsec);
+ break;
+ }
}
return ret;
}
>From c7e61ba8c4fd6e83a36e5fa0a393891fbb718d3a Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Wed, 27 Nov 2024 06:36:44 -0800
Subject: [PATCH 5/9] adjust frequency caching
---
libc/src/__support/time/windows/clock_gettime.cpp | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/libc/src/__support/time/windows/clock_gettime.cpp b/libc/src/__support/time/windows/clock_gettime.cpp
index 379eae21b1d8d2..2bdbf740d34f15 100644
--- a/libc/src/__support/time/windows/clock_gettime.cpp
+++ b/libc/src/__support/time/windows/clock_gettime.cpp
@@ -23,15 +23,16 @@ namespace LIBC_NAMESPACE_DECL {
namespace internal {
static long long get_ticks_per_second() {
static cpp::Atomic<long long> frequency = 0;
- if (!frequency) {
+ auto freq = frequency.load(cpp::MemoryOrder::RELAXED);
+ if (!freq) {
UNINITIALIZED LARGE_INTEGER buffer;
// On systems that run Windows XP or later, the function will always
// succeed and will thus never return zero.
::QueryPerformanceFrequency(&buffer);
- frequency = buffer.QuadPart;
+ frequency.store(buffer.QuadPart, cpp::MemoryOrder::RELAXED);
return buffer.QuadPart;
}
- return frequency.load(cpp::MemoryOrder::RELAXED);
+ return freq;
}
ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
>From 7bf98bedc60742eabe867aa7eeced8fd1c13d99e Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Wed, 4 Dec 2024 07:37:47 -0800
Subject: [PATCH 6/9] address CRs
---
libc/hdr/time_macros.h | 6 +++
libc/hdr/types/clockid_t.h | 3 +-
.../src/__support/time/windows/CMakeLists.txt | 1 +
.../__support/time/windows/clock_gettime.cpp | 43 +++++++++++++------
libc/src/time/time.cpp | 6 +--
5 files changed, 41 insertions(+), 18 deletions(-)
diff --git a/libc/hdr/time_macros.h b/libc/hdr/time_macros.h
index dc36fe66f7a802..4488a24848c359 100644
--- a/libc/hdr/time_macros.h
+++ b/libc/hdr/time_macros.h
@@ -19,4 +19,10 @@
#endif // LLVM_LIBC_FULL_BUILD
+// TODO: For now, on windows, let's always include the extension header.
+// We will need to decide how to export this header.
+#ifdef _WIN32
+#include "include/llvm-libc-macros/windows/time-macros-ext.h"
+#endif // _WIN32
+
#endif // LLVM_LIBC_HDR_TIME_MACROS_H
diff --git a/libc/hdr/types/clockid_t.h b/libc/hdr/types/clockid_t.h
index 06fafc5b150612..729e580aba4384 100644
--- a/libc/hdr/types/clockid_t.h
+++ b/libc/hdr/types/clockid_t.h
@@ -9,7 +9,8 @@
#ifndef LLVM_LIBC_HDR_TYPES_CLOCKID_T_H
#define LLVM_LIBC_HDR_TYPES_CLOCKID_T_H
-#if defined(LIBC_FULL_BUILD) || defined(_MSC_VER)
+// TODO: we will need to decide how to export extension to windows.
+#if defined(LIBC_FULL_BUILD) || defined(_WIN32)
#include "include/llvm-libc-types/clockid_t.h"
diff --git a/libc/src/__support/time/windows/CMakeLists.txt b/libc/src/__support/time/windows/CMakeLists.txt
index 24b5fa7e086265..8406de838f6e45 100644
--- a/libc/src/__support/time/windows/CMakeLists.txt
+++ b/libc/src/__support/time/windows/CMakeLists.txt
@@ -13,4 +13,5 @@ add_object_library(
libc.src.__support.error_or
libc.src.__support.OSUtil.osutil
libc.src.__support.CPP.atomic
+ libc.src.__support.CPP.limits
)
diff --git a/libc/src/__support/time/windows/clock_gettime.cpp b/libc/src/__support/time/windows/clock_gettime.cpp
index 2bdbf740d34f15..c32a112e1db7a0 100644
--- a/libc/src/__support/time/windows/clock_gettime.cpp
+++ b/libc/src/__support/time/windows/clock_gettime.cpp
@@ -6,26 +6,29 @@
//
//===----------------------------------------------------------------------===//
-#include "src/__support/time/clock_gettime.h"
-#include "include/llvm-libc-macros/windows/time-macros-ext.h"
+#include "hdr/time_macros.h"
+
#include "src/__support/CPP/atomic.h"
#include "src/__support/CPP/bit.h"
+#include "src/__support/CPP/limits.h"
+#include "src/__support/macros/optimization.h"
+#include "src/__support/time/clock_gettime.h"
#include "src/__support/time/units.h"
-#include <Windows.h>
-#ifdef __clang__
-#define UNINITIALIZED [[clang::uninitialized]]
-#else
-#define UNINITIALIZED
-#endif
+#define WIN32_LEAN_AND_MEAN
+#define NOMINMAX
+#include <Windows.h>
namespace LIBC_NAMESPACE_DECL {
namespace internal {
static long long get_ticks_per_second() {
static cpp::Atomic<long long> frequency = 0;
+ // Relaxed ordering is enough. It is okay to record the frequency multiple
+ // times. The store operation itself is atomic and the value must propagate
+ // as required by cache coherence.
auto freq = frequency.load(cpp::MemoryOrder::RELAXED);
if (!freq) {
- UNINITIALIZED LARGE_INTEGER buffer;
+ [[clang::uninitialized]] LARGE_INTEGER buffer;
// On systems that run Windows XP or later, the function will always
// succeed and will thus never return zero.
::QueryPerformanceFrequency(&buffer);
@@ -37,6 +40,8 @@ static long long get_ticks_per_second() {
ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
using namespace time_units;
+ constexpr long long SEC_LIMIT =
+ cpp::numeric_limits<decltype(ts->tv_sec)>::max();
ErrorOr<int> ret = 0;
switch (clockid) {
default:
@@ -48,7 +53,7 @@ ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
// https://learn.microsoft.com/en-us/windows/win32/sysinfo/acquiring-high-resolution-time-stamps
// Is the performance counter monotonic (non-decreasing)?
// Yes. QPC does not go backward.
- UNINITIALIZED LARGE_INTEGER buffer;
+ [[clang::uninitialized]] LARGE_INTEGER buffer;
// On systems that run Windows XP or later, the function will always
// succeed and will thus never return zero.
::QueryPerformanceCounter(&buffer);
@@ -56,6 +61,10 @@ ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
long long ticks = buffer.QuadPart;
long long tv_sec = ticks / freq;
long long tv_nsec = (ticks % freq) * 1_s_ns / freq;
+ if (LIBC_UNLIKELY(tv_sec > SEC_LIMIT)) {
+ ret = cpp::unexpected(EOVERFLOW);
+ break;
+ }
ts->tv_sec = static_cast<decltype(ts->tv_sec)>(tv_sec);
ts->tv_nsec = static_cast<decltype(ts->tv_nsec)>(tv_nsec);
break;
@@ -65,17 +74,27 @@ ErrorOr<int> clock_gettime(clockid_t clockid, timespec *ts) {
// GetSystemTimePreciseAsFileTime
// This function is best suited for high-resolution time-of-day
// measurements, or time stamps that are synchronized to UTC
- UNINITIALIZED FILETIME file_time;
- UNINITIALIZED ULARGE_INTEGER time;
+ [[clang::uninitialized]] FILETIME file_time;
+ [[clang::uninitialized]] ULARGE_INTEGER time;
::GetSystemTimePreciseAsFileTime(&file_time);
time.LowPart = file_time.dwLowDateTime;
time.HighPart = file_time.dwHighDateTime;
// adjust to POSIX epoch (from Jan 1, 1601 to Jan 1, 1970)
constexpr unsigned long long HNS_PER_SEC = 1_s_ns / 100ULL;
+ constexpr unsigned long long POSIX_TIME_SHIFT =
+ (11644473600ULL * HNS_PER_SEC);
+ if (LIBC_UNLIKELY(POSIX_TIME_SHIFT > time.QuadPart)) {
+ ret = cpp::unexpected(EOVERFLOW);
+ break;
+ }
time.QuadPart -= (11644473600ULL * HNS_PER_SEC);
unsigned long long tv_sec = time.QuadPart / HNS_PER_SEC;
unsigned long long tv_nsec = (time.QuadPart % HNS_PER_SEC) * 100ULL;
+ if (LIBC_UNLIKELY(tv_sec > SEC_LIMIT)) {
+ ret = cpp::unexpected(EOVERFLOW);
+ break;
+ }
ts->tv_sec = static_cast<decltype(ts->tv_sec)>(tv_sec);
ts->tv_nsec = static_cast<decltype(ts->tv_nsec)>(tv_nsec);
break;
diff --git a/libc/src/time/time.cpp b/libc/src/time/time.cpp
index a233676e702998..ceded83b8e2e0e 100644
--- a/libc/src/time/time.cpp
+++ b/libc/src/time/time.cpp
@@ -13,12 +13,8 @@
#include "src/errno/libc_errno.h"
#include "src/time/time_func.h"
-#ifdef _MSC_VER
-#include "include/llvm-libc-macros/windows/time-macros-ext.h"
-#endif
-
namespace LIBC_NAMESPACE_DECL {
-LLVM_LIBC_FUNCTION(time_t, time, (time_t * tp)) {
+LLVM_LIBC_FUNCTION(time_t, time, (time_t *tp)) {
struct timespec ts;
auto result = internal::clock_gettime(CLOCK_REALTIME, &ts);
if (!result.has_value()) {
>From de9887c6e7f145d9faf7dc9ad80d8327b0d6a7ae Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Wed, 4 Dec 2024 08:01:10 -0800
Subject: [PATCH 7/9] adjust dependency
---
libc/hdr/CMakeLists.txt | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/libc/hdr/CMakeLists.txt b/libc/hdr/CMakeLists.txt
index 93da271f5e040b..5eb311f4bb2298 100644
--- a/libc/hdr/CMakeLists.txt
+++ b/libc/hdr/CMakeLists.txt
@@ -135,10 +135,18 @@ add_proxy_header_library(
libc.include.llvm-libc-macros.unistd_macros
)
+if (WIN32)
+ set(windows_addtional_time_macros libc.include.llvm-libc-macros.windows.time_macros_ext)
+else()
+ set(windows_addtional_time_macros "")
+endif()
+
add_proxy_header_library(
time_macros
HDRS
time_macros.h
+ DEPENDS
+ ${windows_addtional_time_macros}
FULL_BUILD_DEPENDS
libc.include.time
libc.include.llvm-libc-macros.time_macros
>From 717e609cbf62f541c0f093d5aff7dbc14956d33f Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Wed, 4 Dec 2024 08:02:46 -0800
Subject: [PATCH 8/9] adjust dependency
---
libc/test/src/time/CMakeLists.txt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libc/test/src/time/CMakeLists.txt b/libc/test/src/time/CMakeLists.txt
index 19f90869852251..d2a98677a55435 100644
--- a/libc/test/src/time/CMakeLists.txt
+++ b/libc/test/src/time/CMakeLists.txt
@@ -158,7 +158,7 @@ add_libc_unittest(
time_test.cpp
DEPENDS
libc.src.time.time
- libc.src.__support.time.windows.clock_gettime
+ libc.src.__support.time.clock_gettime
libc.src.errno.errno
)
>From b0844cc64ef05b3a448ccb111cc2a9740361225f Mon Sep 17 00:00:00 2001
From: Schrodinger ZHU Yifan <i at zhuyi.fan>
Date: Wed, 4 Dec 2024 08:05:57 -0800
Subject: [PATCH 9/9] fix timespec_get
---
libc/src/time/linux/timespec_get.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libc/src/time/linux/timespec_get.cpp b/libc/src/time/linux/timespec_get.cpp
index ba9f8eb2e4426b..cf5174523aa4f9 100644
--- a/libc/src/time/linux/timespec_get.cpp
+++ b/libc/src/time/linux/timespec_get.cpp
@@ -10,7 +10,7 @@
#include "hdr/time_macros.h"
#include "src/__support/common.h"
#include "src/__support/macros/config.h"
-#include "src/__support/time/linux/clock_gettime.h"
+#include "src/__support/time/clock_gettime.h"
#include "src/errno/libc_errno.h"
namespace LIBC_NAMESPACE_DECL {
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