[glib: 1/2] gthread-win32: Use SetThreadDescription Win32 API for setting thread name

[Philip Withnall <pwithnall src gnome org>]

commit 5763ddae3c6f3dbddf246741d2103a9b5ac546f4
Author: Seungha Yang <seungha centricular com>
Date:   Fri Jan 15 01:21:51 2021 +0900

    gthread-win32: Use SetThreadDescription Win32 API for setting thread name
    
    Since Windows 10 1607, we can make use of SetThreadDescription() API
    for setting thread name. Unlike previously used exception based
    method, this API will preserve configured thread name on dump file.

 glib/gthread-win32.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)
---
diff --git a/glib/gthread-win32.c b/glib/gthread-win32.c
index 30448fe43..66558df4a 100644
--- a/glib/gthread-win32.c
+++ b/glib/gthread-win32.c
@@ -597,10 +597,62 @@ SetThreadName (DWORD  dwThreadID,
 #endif
 }
 
+typedef HRESULT (WINAPI *pSetThreadDescription) (HANDLE hThread,
+                                                 PCWSTR lpThreadDescription);
+static pSetThreadDescription SetThreadDescriptionFunc = NULL;
+HMODULE kernel32_module = NULL;
+
+static gboolean
+g_thread_win32_load_library (void)
+{
+  /* FIXME: Add support for UWP app */
+#if !defined(G_WINAPI_ONLY_APP)
+  static volatile gsize _init_once = 0;
+  if (g_once_init_enter (&_init_once))
+    {
+      kernel32_module = LoadLibraryW (L"kernel32.dll");
+      if (kernel32_module)
+        {
+          SetThreadDescriptionFunc =
+              (pSetThreadDescription) GetProcAddress (kernel32_module,
+                                                      "SetThreadDescription");
+          if (!SetThreadDescriptionFunc)
+            FreeLibrary (kernel32_module);
+        }
+      g_once_init_leave (&_init_once, 1);
+    }
+#endif
+
+  return !!SetThreadDescriptionFunc;
+}
+
+static gboolean
+g_thread_win32_set_thread_desc (const gchar *name)
+{
+  HRESULT hr;
+  wchar_t *namew;
+
+  if (!g_thread_win32_load_library () || !name)
+    return FALSE;
+
+  namew = g_utf8_to_utf16 (name, -1, NULL, NULL, NULL);
+  if (!namew)
+    return FALSE;
+
+  hr = SetThreadDescriptionFunc (GetCurrentThread (), namew);
+
+  g_free (namew);
+  return SUCCEEDED (hr);
+}
+
 void
 g_system_thread_set_name (const gchar *name)
 {
-  SetThreadName ((DWORD) -1, name);
+  /* Prefer SetThreadDescription over exception based way if available,
+   * since thread description set by SetThreadDescription will be preserved
+   * in dump file */
+  if (!g_thread_win32_set_thread_desc (name))
+    SetThreadName ((DWORD) -1, name);
 }
 
 /* {{{1 Epilogue */