win: lazy-load [GS]etThreadDescription symbols

As said symbols are unavailable on Windows Server 2016.

Fixes: https://github.com/libuv/libuv/issues/4677

docs/src/threading.rst

@@ -146,6 +146,8 @@ Threads
     a thread name can be: Linux, IBM i (16), macOS (64), Windows (32767), and NetBSD (32), etc. `uv_thread_setname()`
     will truncate it in case `name` is larger than the limit of the platform.
 
+    Not supported on Windows Server 2016, returns `UV_ENOSYS`.
+
     .. versionadded:: 1.50.0
 
 .. c:function:: int uv_thread_getname(uv_thread_t* tid, char* name, size_t* size)
@@ -155,6 +157,8 @@ Threads
     The buffer should be large enough to hold the name of the thread plus the trailing NUL, or it will be truncated to fit
     with the trailing NUL.
 
+    Not supported on Windows Server 2016, returns `UV_ENOSYS`.
+
     .. versionadded:: 1.50.0
 
 .. c:function:: int uv_thread_setpriority(uv_thread_t tid, int priority)

src/win/thread.c

@@ -284,6 +284,9 @@ int uv_thread_setname(const char* name) {
   int err;
   char namebuf[UV_PTHREAD_MAX_NAMELEN_NP];
 
+  if (pSetThreadDescription == NULL)
+    return UV_ENOSYS;
+
   if (name == NULL)
     return UV_EINVAL;
 
@@ -295,7 +298,7 @@ int uv_thread_setname(const char* name) {
   if (err)
     return err;
 
-  hr = SetThreadDescription(GetCurrentThread(), namew);
+  hr = pSetThreadDescription(GetCurrentThread(), namew);
   uv__free(namew);
   if (FAILED(hr))
     return uv_translate_sys_error(HRESULT_CODE(hr));
@@ -312,6 +315,9 @@ int uv_thread_getname(uv_thread_t* tid, char* name, size_t size) {
   int r;
   DWORD exit_code;
 
+  if (pGetThreadDescription == NULL)
+    return UV_ENOSYS;
+
   if (name == NULL || size == 0)
     return UV_EINVAL;
 
@@ -324,7 +330,7 @@ int uv_thread_getname(uv_thread_t* tid, char* name, size_t size) {
 
   namew = NULL;
   thread_name = NULL;
-  hr = GetThreadDescription(*tid, &namew);
+  hr = pGetThreadDescription(*tid, &namew);
   if (FAILED(hr))
     return uv_translate_sys_error(HRESULT_CODE(hr));
 

src/win/winapi.c

@@ -35,6 +35,8 @@ sNtQueryVolumeInformationFile pNtQueryVolumeInformationFile;
 sNtQueryDirectoryFile pNtQueryDirectoryFile;
 sNtQuerySystemInformation pNtQuerySystemInformation;
 sNtQueryInformationProcess pNtQueryInformationProcess;
+sGetThreadDescription pGetThreadDescription;
+sSetThreadDescription pSetThreadDescription;
 
 /* Powrprof.dll function pointer */
 sPowerRegisterSuspendResumeNotification pPowerRegisterSuspendResumeNotification;
@@ -51,6 +53,7 @@ sGetFileInformationByName pGetFileInformationByName;
 void uv__winapi_init(void) {
   HMODULE ntdll_module;
   HMODULE powrprof_module;
+  HMODULE kernel32_module;
   HMODULE user32_module;
   HMODULE ws2_32_module;
   HMODULE api_win_core_file_module;
@@ -123,6 +126,14 @@ void uv__winapi_init(void) {
       GetProcAddress(powrprof_module, "PowerRegisterSuspendResumeNotification");
   }
 
+  kernel32_module = GetModuleHandleA("kernel32.dll");
+  if (kernel32_module != NULL) {
+    pGetThreadDescription = (sGetThreadDescription)
+      GetProcAddress(kernel32_module, "GetThreadDescription");
+    pSetThreadDescription = (sSetThreadDescription)
+      GetProcAddress(kernel32_module, "SetThreadDescription");
+  }
+
   user32_module = GetModuleHandleA("user32.dll");
   if (user32_module != NULL) {
     pSetWinEventHook = (sSetWinEventHook)

src/win/winapi.h

@@ -4829,12 +4829,12 @@ typedef int (WINAPI *uv_sGetHostNameW)
 extern uv_sGetHostNameW pGetHostNameW;
 
 /* processthreadsapi.h */
-#if defined(__MINGW32__)
-WINBASEAPI
-HRESULT WINAPI GetThreadDescription(HANDLE hThread,
-                                    PWSTR *ppszThreadDescription);
-WINBASEAPI
-HRESULT WINAPI SetThreadDescription(HANDLE hThread, PCWSTR lpThreadDescription);
-#endif
+typedef HRESULT (WINAPI *sGetThreadDescription)(HANDLE hThread,
+                                                PWSTR *ppszThreadDescription);
+typedef HRESULT (WINAPI *sSetThreadDescription)(HANDLE hThread,
+                                                PCWSTR lpThreadDescription);
+
+extern sGetThreadDescription pGetThreadDescription;
+extern sSetThreadDescription pSetThreadDescription;
 
 #endif /* UV_WIN_WINAPI_H_ */