Rename main_thread to main_thread_id and simplify

* src/emacs-module.c: Include syssignal.h, for main_thread_id.
[HAVE_PTHREAD]: Do not include pthread.h.
(main_thread): Remove.  All uses replaced by main_thread_id,
or by dwMainThreadId on NT.  Since the HAVE_PTHREAD code is now using
the main_thread_id established by sysdep.c, there is no need for a
separate copy of the main thread ID here.
(module_init): Remove.  All uses removed.
* src/sysdep.c (main_thread_id) [HAVE_PTHREAD]:
Rename from main_thread.  All uses changed.  Now extern.

src/emacs-module.c

@@ -28,6 +28,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "lisp.h"
 #include "dynlib.h"
 #include "coding.h"
+#include "syssignal.h"
 
 #include <intprops.h>
 #include <verify.h>
@@ -41,15 +42,9 @@ enum { module_has_cleanup = true };
 enum { module_has_cleanup = false };
 #endif
 
-/* Handle to the main thread.  Used to verify that modules call us in
-   the right thread.  */
-#ifdef HAVE_PTHREAD
-# include <pthread.h>
-static pthread_t main_thread;
-#elif defined WINDOWSNT
+#ifdef WINDOWSNT
 #include <windows.h>
 #include "w32term.h"
-static DWORD main_thread;
 #endif
 
 /* True if Lisp_Object and emacs_value have the same representation.
@@ -751,9 +746,9 @@ static void
 check_main_thread (void)
 {
 #ifdef HAVE_PTHREAD
-  eassert (pthread_equal (pthread_self (), main_thread));
+  eassert (pthread_equal (pthread_self (), main_thread_id));
 #elif defined WINDOWSNT
-  eassert (GetCurrentThreadId () == main_thread);
+  eassert (GetCurrentThreadId () == dwMainThreadId);
 #endif
 }
 
@@ -1062,20 +1057,3 @@ syms_of_module (void)
   DEFSYM (Qinternal__module_call, "internal--module-call");
   defsubr (&Sinternal_module_call);
 }
-
-/* Unlike syms_of_module, this initializer is called even from an
-   initialized (dumped) Emacs.  */
-
-void
-module_init (void)
-{
-  /* It is not guaranteed that dynamic initializers run in the main thread,
-     therefore detect the main thread here.  */
-#ifdef HAVE_PTHREAD
-  main_thread = pthread_self ();
-#elif defined WINDOWSNT
-  /* The 'main' function already recorded the main thread's thread ID,
-     so we need just to use it . */
-  main_thread = dwMainThreadId;
-#endif
-}

src/emacs.c

@@ -738,8 +738,6 @@ main (int argc, char **argv)
      non-ASCII file names during startup.  */
   w32_init_file_name_codepage ();
 #endif
-  /* 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
 
@@ -757,10 +755,6 @@ main (int argc, char **argv)
   init_standard_fds ();
   atexit (close_output_streams);
 
-#ifdef HAVE_MODULES
-  module_init ();
-#endif
-
   sort_args (argc, argv);
   argc = 0;
   while (argv[argc]) argc++;

src/lisp.h

@@ -3880,7 +3880,6 @@ extern bool let_shadows_global_binding_p (Lisp_Object symbol);
 extern Lisp_Object make_user_ptr (void (*finalizer) (void *), void *p);
 
 /* Defined in emacs-module.c.  */
-extern void module_init (void);
 extern void syms_of_module (void);
 #endif
 

src/sysdep.c

@@ -1612,7 +1612,7 @@ emacs_sigaction_init (struct sigaction *action, signal_handler_t handler)
 }
 
 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
-static pthread_t main_thread;
+pthread_t main_thread_id;
 #endif
 
 /* SIG has arrived at the current process.  Deliver it to the main
@@ -1636,13 +1636,13 @@ deliver_process_signal (int sig, signal_handler_t handler)
 
   bool on_main_thread = true;
 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
-  if (! pthread_equal (pthread_self (), main_thread))
+  if (! pthread_equal (pthread_self (), main_thread_id))
     {
       sigset_t blocked;
       sigemptyset (&blocked);
       sigaddset (&blocked, sig);
       pthread_sigmask (SIG_BLOCK, &blocked, 0);
-      pthread_kill (main_thread, sig);
+      pthread_kill (main_thread_id, sig);
       on_main_thread = false;
     }
 #endif
@@ -1668,12 +1668,12 @@ deliver_thread_signal (int sig, signal_handler_t handler)
   int old_errno = errno;
 
 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
-  if (! pthread_equal (pthread_self (), main_thread))
+  if (! pthread_equal (pthread_self (), main_thread_id))
     {
       thread_backtrace_npointers
 	= backtrace (thread_backtrace_buffer, BACKTRACE_LIMIT_MAX);
       sigaction (sig, &process_fatal_action, 0);
-      pthread_kill (main_thread, sig);
+      pthread_kill (main_thread_id, sig);
 
       /* Avoid further damage while the main thread is exiting.  */
       while (1)
@@ -1796,7 +1796,7 @@ handle_sigsegv (int sig, siginfo_t *siginfo, void *arg)
   bool fatal = gc_in_progress;
 
 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
-  if (!fatal && !pthread_equal (pthread_self (), main_thread))
+  if (!fatal && !pthread_equal (pthread_self (), main_thread_id))
     fatal = true;
 #endif
 
@@ -1888,7 +1888,7 @@ init_signals (bool dumping)
   sigemptyset (&empty_mask);
 
 #ifdef FORWARD_SIGNAL_TO_MAIN_THREAD
-  main_thread = pthread_self ();
+  main_thread_id = pthread_self ();
 #endif
 
 #if !HAVE_DECL_SYS_SIGLIST && !defined _sys_siglist

src/syssignal.h

@@ -32,6 +32,7 @@ extern void unblock_tty_out_signal (sigset_t const *);
 
 #ifdef HAVE_PTHREAD
 #include <pthread.h>
+extern pthread_t main_thread_id;
 /* If defined, asynchronous signals delivered to a non-main thread are
    forwarded to the main thread.  */
 #define FORWARD_SIGNAL_TO_MAIN_THREAD