[host/common] windows: provide delayExecution via nsleep

This change moves this platform specific sleep to `common` as the OS
agnostic `nsleep` function.

Ref PR #661

common/include/common/time.h

@@ -25,6 +25,13 @@
 
 #if defined(_WIN32)
 #include <windows.h>
+
+void windowsSetTimerResolution(void);
+NTSYSCALLAPI NTSTATUS NTAPI NtDelayExecution(
+  _In_ BOOLEAN Alertable,
+  _In_opt_ PLARGE_INTEGER DelayInterval
+);
+
 #else
 #include <time.h>
 #include <stdint.h>
@@ -49,6 +56,21 @@ static inline uint64_t microtime(void)
 #endif
 }
 
+static inline void nsleep(uint64_t ns)
+{
+#if defined(_WIN32)
+  LARGE_INTEGER interval = { .QuadPart = -(int64_t)(ns / 100LL) };
+  NtDelayExecution(FALSE, &interval);
+#else
+  const struct timespec ts =
+  {
+    .tv_sec  = ns / 1e9,
+    .tv_nsec = ns - ((ns / 1e9) * 1e9)
+  };
+  nanosleep(&ts, NULL);
+#endif
+}
+
 #if !defined(_WIN32)
 //FIXME: make win32 versions
 static inline uint64_t nanotime(void)
@@ -58,16 +80,6 @@ static inline uint64_t nanotime(void)
   return ((uint64_t)time.tv_sec * 1000000000LL) + time.tv_nsec;
 }
 
-static inline void nsleep(uint64_t ns)
-{
-  const struct timespec ts =
-  {
-    .tv_sec  = ns / 1e9,
-    .tv_nsec = ns - ((ns / 1e9) * 1e9)
-  };
-  nanosleep(&ts, NULL);
-}
-
 static inline void tsDiff(struct timespec *diff, const struct timespec *left,
               const struct timespec *right)
 {

common/src/platform/windows/CMakeLists.txt

@@ -8,6 +8,25 @@ include_directories(
 # allow use of functions for Windows 7 or later
 add_compile_definitions(WINVER=0x0601 _WIN32_WINNT=0x0601)
 
+if (MINGW)
+	# Build our own ntdll.dll import library
+	# This tricks MinGW into not linking stuff like memcpy from ntdll.dll instead of mscvrt.dll
+	if(NOT CMAKE_DLLTOOL)
+		# cmake older than 3.16 doesn't know how to find dlltool
+		find_program(CMAKE_DLLTOOL NAMES "x86_64-w64-mingw32-dlltool" "dlltool.exe" DOC "dlltool executable")
+	endif()
+	add_custom_command(OUTPUT "${PROJECT_BINARY_DIR}/ntdll.a"
+		COMMAND "${CMAKE_DLLTOOL}" -d "${PROJECT_SOURCE_DIR}/ntdll.def" -l "${PROJECT_BINARY_DIR}/ntdll.a"
+		MAIN_DEPENDENCY "${PROJECT_SOURCE_DIR}/ntdll.def"
+		COMMENT "Building import library ntdll.a"
+		VERBATIM
+	)
+	add_custom_target(ntdll_target DEPENDS "${PROJECT_BINARY_DIR}/ntdll.a")
+	add_library(ntdll STATIC IMPORTED GLOBAL)
+	add_dependencies(ntdll ntdll_target)
+	set_target_properties(ntdll PROPERTIES IMPORTED_LOCATION "${PROJECT_BINARY_DIR}/ntdll.a")
+endif()
+
 add_library(lg_common_platform_code STATIC
     debug.c
     crash.c
@@ -22,6 +41,7 @@ add_library(lg_common_platform_code STATIC
 target_link_libraries(lg_common_platform_code
 	lg_common
 	setupapi
+	ntdll
 )
 
 if (ENABLE_BACKTRACE)

common/src/platform/windows/ntdll.def

@@ -0,0 +1,7 @@
+; This file is used to trick MinGW to not like stuff like memcpy from ntdll.dll.
+; See CMakeLists.txt for how this is compiled.
+
+LIBRARY "ntdll.dll"
+EXPORTS
+NtDelayExecution
+NtSetTimerResolution

common/src/platform/windows/time.c

@@ -71,3 +71,16 @@ void lgTimerDestroy(LGTimer * timer)
 
   free(timer);
 }
+
+NTSYSCALLAPI NTSTATUS NTAPI NtSetTimerResolution(
+  _In_ ULONG DesiredTime,
+  _In_ BOOLEAN SetResolution,
+  _Out_ PULONG ActualTime
+);
+
+void windowsSetTimerResolution(void)
+{
+  ULONG actualResolution;
+  NtSetTimerResolution(1, true, &actualResolution);
+  DEBUG_INFO("System timer resolution: %.1f μs", actualResolution / 10.0);
+}