Simplify recording of main thread's ID on MS-Windows

* src/w32term.c (w32_initialize):
* src/w32console.c (initialize_w32_display):
* src/w32fns.c (globals_of_w32fns): Don't record the main thread
ID independently for each type of session (GUI, TTY, batch).
* src/w32term.c (w32_init_main_thread): New function, records the
main thread's thread ID.
* src/w32term.h: Add prototype for w32_init_main_thread.
* src/emacs.c (main) [WINDOWSNT]: Call w32_init_main_thread.

* src/emacs-module.c [WINDOWSNT]: Rename main_thread_id to
main_thread, for consistency with other threading libraries.  All
users changed.  Include w32term.h.
(check_main_thread) [WINDOWSNT]: Simplify the test: no need to
make sure the main thread is alive, as we hold a handle on it
opened by w32_init_main_thread.
(module_init) [WINDOWSNT]: Reuse the thread ID recorded by
w32_init_main_thread, instead of calling the requisite APIs once
more.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/emacs.c b/src/emacs.c
index ba71ceb84ce..c411da6a5da 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -760,6 +760,9 @@ main (int argc, char **argv)
      to have non-stub implementations of APIs we need to convert file
      names between UTF-8 and the system's ANSI codepage.  */
   maybe_load_unicows_dll ();
+  /* This has to be done before module_init is called below, so that
+     the latter could use the thread ID of the main thread.  */
+  w32_init_main_thread ();
 #endif
 #endif