Added C++ support in thread.h; don't use signals if not strictly

necessary, and when they are, use SIGKILL; when compiled with -DDEBUG,
only print debug messages when "THREADDEBUG" is set in the environment.

Include/pythread.h

 #ifndef _THREAD_H_included
 #define _THREAD_H_included
 
-#ifdef __STDC__
+#if defined(__STDC__) || defined(__cplusplus)
 #define _P(args)	args
 #else
 #define _P(args)	()
 #endif
 
+typedef void *type_lock;
+typedef void *type_sema;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void init_thread _P((void));
 int start_new_thread _P((void (*)(void *), void *));
 void exit_thread _P((void));
 void _exit_thread _P((void));
 
-typedef void *type_lock;
-
 type_lock allocate_lock _P((void));
 void free_lock _P((type_lock));
 int acquire_lock _P((type_lock, int));
@@ -21,8 +26,6 @@ int acquire_lock _P((type_lock, int));
 #define NOWAIT_LOCK	0
 void release_lock _P((type_lock));
 
-typedef void *type_sema;
-
 type_sema allocate_sema _P((int));
 void free_sema _P((type_sema));
 void down_sema _P((type_sema));
@@ -31,6 +34,10 @@ void up_sema _P((type_sema));
 void exit_prog _P((int));
 void _exit_prog _P((int));
 
+#ifdef __cplusplus
+}
+#endif
+
 #undef _P
 
 #endif

Include/thread.h

 #ifndef _THREAD_H_included
 #define _THREAD_H_included
 
-#ifdef __STDC__
+#if defined(__STDC__) || defined(__cplusplus)
 #define _P(args)	args
 #else
 #define _P(args)	()
 #endif
 
+typedef void *type_lock;
+typedef void *type_sema;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void init_thread _P((void));
 int start_new_thread _P((void (*)(void *), void *));
 void exit_thread _P((void));
 void _exit_thread _P((void));
 
-typedef void *type_lock;
-
 type_lock allocate_lock _P((void));
 void free_lock _P((type_lock));
 int acquire_lock _P((type_lock, int));
@@ -21,8 +26,6 @@ int acquire_lock _P((type_lock, int));
 #define NOWAIT_LOCK	0
 void release_lock _P((type_lock));
 
-typedef void *type_sema;
-
 type_sema allocate_sema _P((int));
 void free_sema _P((type_sema));
 void down_sema _P((type_sema));
@@ -31,6 +34,10 @@ void up_sema _P((type_sema));
 void exit_prog _P((int));
 void _exit_prog _P((int));
 
+#ifdef __cplusplus
+}
+#endif
+
 #undef _P
 
 #endif

Python/thread.c

 #include "thread.h"
 
 #ifdef DEBUG
-#define dprintf(args)	printf args
+static int thread_debug = 0;
+#define dprintf(args)	(thread_debug && printf args)
 #else
 #define dprintf(args)
 #endif
@@ -102,6 +103,9 @@ void init_thread _P0()
 	struct sigaction s;
 #endif
 
+#ifdef DEBUG
+	thread_debug = getenv("THREADDEBUG") != 0;
+#endif
 	dprintf(("init_thread called\n"));
 	if (initialized)
 		return;
@@ -112,7 +116,7 @@ void init_thread _P0()
 	atexit(maybe_exit);
 	s.sa_handler = exit_sig;
 	sigemptyset(&s.sa_mask);
-	sigaddset(&s.sa_mask, SIGUSR1);
+	/*sigaddset(&s.sa_mask, SIGUSR1);*/
 	s.sa_flags = 0;
 	sigaction(SIGUSR1, &s, 0);
 	prctl(PR_SETEXITSIG, SIGUSR1);
@@ -189,8 +193,12 @@ static void do_exit_thread _P1(no_cleanup, int no_cleanup)
 			int i;
 
 			/* notify other threads */
-			for (i = 0; i < maxpidindex; i++)
-				(void) kill(pidlist[i], SIGUSR1);
+			if (nthreads >= 0) {
+				dprintf(("kill other threads\n"));
+				for (i = 0; i < maxpidindex; i++)
+					(void) kill(pidlist[i], SIGKILL);
+				_exit(exit_status);
+			}
 		}
 		waiting_for_threads = 1;
 		ussetlock(wait_lock);
@@ -212,7 +220,8 @@ static void do_exit_thread _P1(no_cleanup, int no_cleanup)
 	if (waiting_for_threads) {
 		dprintf(("main thread is waiting\n"));
 		usunsetlock(wait_lock);
-	}
+	} else if (do_exit)
+		(void) kill(my_pid, SIGUSR1);
 	(void) usunsetlock(count_lock);
 	_exit(0);
 #endif
@@ -361,6 +370,8 @@ type_sema allocate_sema _P1(value, int value)
 #endif
 
 	dprintf(("allocate_sema called\n"));
+	if (!initialized)
+		init_thread();
 
 #ifdef __sgi
 	sema = usnewsema(shared_arena, value);