diff --git a/Include/ceval.h b/Include/ceval.h
index 2ddb7d0..d9708a2 100644
--- a/Include/ceval.h
+++ b/Include/ceval.h
@@ -22,10 +22,7 @@
 
 ******************************************************************/
 
-/* Interface to execute compiled code */
-/* This header depends on "compile.h" */
-
-object *eval_code PROTO((codeobject *, object *, object *, object *));
+/* Interface to random parts in ceval.c */
 
 object *call_object PROTO((object *, object *));
 
@@ -34,3 +31,70 @@
 
 void printtraceback PROTO((FILE *));
 void flushline PROTO((void));
+
+
+/* Interface for threads.
+
+   A module that plans to do a blocking system call (or something else
+   that lasts a long time and doesn't touch Python data) can allow other
+   threads to run as follows:
+
+	...preparations here...
+	BGN_SAVE
+	...blocking system call here...
+	END_SAVE
+	...interpretr result here...
+
+   The BGN_SAVE/END_SAVE pair expands to a {}-surrounded block.
+   To leave the block in the middle (e.g., with return), you must insert
+   a line containing RET_SAVE before the return, e.g.
+
+	if (...premature_exit...) {
+		RET_SAVE
+		err_errno(IOError);
+		return NULL;
+	}
+
+   An alternative is:
+
+	RET_SAVE
+	if (...premature_exit...) {
+		err_errno(IOError);
+		return NULL;
+	}
+	RES_SAVE
+
+   For convenience, that the value of 'errno' is restored across
+   END_SAVE and RET_SAVE.
+
+   WARNING: NEVER NEST CALLS TO BGN_SAVE AND END_SAVE!!!
+
+   The function init_save_thread() should be called only from
+   initthread() in "threadmodule.c".
+
+   Note that not yet all candidates have been converted to use this
+   mechanism!
+*/
+
+extern void init_save_thread PROTO((void));
+extern void *save_thread PROTO((void));
+extern void restore_thread PROTO((void *));
+
+#ifdef USE_THREAD
+
+#define BGN_SAVE { \
+			void *_save; \
+			_save = save_thread();
+#define RET_SAVE	restore_thread(_save);
+#define RES_SAVE	_save = save_thread();
+#define END_SAVE	restore_thread(_save); \
+		 }
+
+#else /* !USE_THREAD */
+
+#define BGN_SAVE {
+#define RET_SAVE
+#define RES_SAVE
+#define END_SAVE }
+
+#endif /* !USE_THREAD */
diff --git a/Include/eval.h b/Include/eval.h
new file mode 100644
index 0000000..da4bbde
--- /dev/null
+++ b/Include/eval.h
@@ -0,0 +1,27 @@
+/***********************************************************
+Copyright 1991, 1992 by Stichting Mathematisch Centrum, Amsterdam, The
+Netherlands.
+
+                        All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its 
+documentation for any purpose and without fee is hereby granted, 
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in 
+supporting documentation, and that the names of Stichting Mathematisch
+Centrum or CWI not be used in advertising or publicity pertaining to
+distribution of the software without specific, written prior permission.
+
+STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
+THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
+FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+******************************************************************/
+
+/* Interface to execute compiled code */
+
+object *eval_code PROTO((codeobject *, object *, object *, object *));
diff --git a/Modules/cdmodule.c b/Modules/cdmodule.c
index 332b54b..04451a1 100644
--- a/Modules/cdmodule.c
+++ b/Modules/cdmodule.c
@@ -30,7 +30,6 @@
 #include "allobjects.h"
 #include "import.h"
 #include "modsupport.h"
-#include "compile.h"
 #include "ceval.h"
 
 #define NCALLBACKS	8
diff --git a/Modules/cgen.py b/Modules/cgen.py
index d6e9c96..2775d3d 100644
--- a/Modules/cgen.py
+++ b/Modules/cgen.py
@@ -459,4 +459,8 @@
 print 'initgl()'
 print '{'
 print '\tinitmodule("gl", gl_methods);'
+print '\t/* Initialize GL and don\'t go in the background */'
+print '\tforeground();'
+print '\tnoport();'
+print '\twinopen("");'
 print '}'
diff --git a/Modules/flmodule.c b/Modules/flmodule.c
index d8c423c..bd5ff56 100644
--- a/Modules/flmodule.c
+++ b/Modules/flmodule.c
@@ -35,9 +35,7 @@
 #include "import.h"
 #include "modsupport.h"
 #include "structmember.h"
-
-/* #include "ceval.h" */
-extern object *call_object(object *, object *);
+#include "ceval.h"
 
 /* Generic Forms Objects */
 
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 8ae1758..367e21c 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -73,6 +73,7 @@
 
 #include "allobjects.h"
 #include "modsupport.h"
+#include "ceval.h"
 
 extern char *strerror PROTO((int));
 
@@ -128,9 +129,13 @@
 	int (*func) FPROTO((const char *));
 {
 	char *path1;
+	int res;
 	if (!getstrarg(args, &path1))
 		return NULL;
-	if ((*func)(path1) < 0)
+	BGN_SAVE
+	res = (*func)(path1);
+	END_SAVE
+	if (res < 0)
 		return posix_error();
 	INCREF(None);
 	return None;
@@ -142,9 +147,13 @@
 	int (*func) FPROTO((const char *, const char *));
 {
 	char *path1, *path2;
+	int res;
 	if (!getstrstrarg(args, &path1, &path2))
 		return NULL;
-	if ((*func)(path1, path2) < 0)
+	BGN_SAVE
+	res = (*func)(path1, path2);
+	END_SAVE
+	if (res < 0)
 		return posix_error();
 	INCREF(None);
 	return None;
@@ -157,9 +166,13 @@
 {
 	char *path;
 	int i;
+	int res;
 	if (!getstrintarg(args, &path, &i))
 		return NULL;
-	if ((*func)(path, i) < 0)
+	BGN_SAVE
+	res = (*func)(path, i);
+	END_SAVE
+	if (res < 0)
 		return posix_error();
 	INCREF(None);
 	return None;
@@ -174,9 +187,13 @@
 	struct stat st;
 	char *path;
 	object *v;
+	int res;
 	if (!getstrarg(args, &path))
 		return NULL;
-	if ((*statfunc)(path, &st) != 0)
+	BGN_SAVE
+	res = (*statfunc)(path, &st);
+	END_SAVE
+	if (res != 0)
 		return posix_error();
 	v = newtupleobject(10);
 	if (v == NULL)
@@ -227,10 +244,14 @@
 	object *args;
 {
 	char buf[1026];
+	char *res;
 	extern char *getcwd PROTO((char *, int));
 	if (!getnoarg(args))
 		return NULL;
-	if (getcwd(buf, sizeof buf) == NULL)
+	BGN_SAVE
+	res = getcwd(buf, sizeof buf);
+	END_SAVE
+	if (res == NULL)
 		return posix_error();
 	return newstringobject(buf);
 }
@@ -284,10 +305,14 @@
 	struct direct *ep;
 	if (!getstrarg(args, &name))
 		return NULL;
-	if ((dirp = opendir(name)) == NULL)
+	BGN_SAVE
+	if ((dirp = opendir(name)) == NULL) {
+		RET_SAVE
 		return posix_error();
+	}
 	if ((d = newlistobject(0)) == NULL) {
 		closedir(dirp);
+		RET_SAVE
 		return NULL;
 	}
 	while ((ep = readdir(dirp)) != NULL) {
@@ -306,6 +331,7 @@
 		DECREF(v);
 	}
 	closedir(dirp);
+	END_SAVE
 #endif /* !MSDOS */
 
 	return d;
@@ -368,11 +394,13 @@
 	object *args;
 {
 	char *command;
-	int sts;
+	long sts;
 	if (!getstrarg(args, &command))
 		return NULL;
+	BGN_SAVE
 	sts = system(command);
-	return newintobject((long)sts);
+	END_SAVE
+	return newintobject(sts);
 }
 
 #ifndef MSDOS
@@ -411,9 +439,13 @@
 	extern int uname PROTO((struct utsname *));
 	struct utsname u;
 	object *v;
+	int res;
 	if (!getnoarg(args))
 		return NULL;
-	if (uname(&u) < 0)
+	BGN_SAVE
+	res = uname(&u);
+	END_SAVE
+	if (res < 0)
 		return posix_error();
 	v = newtupleobject(5);
 	if (v == NULL)
@@ -443,6 +475,7 @@
 	object *args;
 {
 	char *path;
+	int res;
 
 #ifdef UTIME_STRUCT
 	struct utimbuf buf;
@@ -459,7 +492,10 @@
 
 	if (!getargs(args, "(s(ll))", &path, &ATIME, &MTIME))
 		return NULL;
-	if (utime(path, UTIME_ARG) < 0)
+	BGN_SAVE
+	res = utime(path, UTIME_ARG);
+	END_SAVE
+	if (res < 0)
 		return posix_error();
 	INCREF(None);
 	return None;
@@ -648,7 +684,9 @@
 	FILE *fp;
 	if (!getargs(args, "(ss)", &name, &mode))
 		return NULL;
+	BGN_SAVE
 	fp = popen(name, mode);
+	END_SAVE
 	if (fp == NULL)
 		return posix_error();
 	/* From now on, ignore SIGPIPE and let the error checking
@@ -664,8 +702,11 @@
 {
 	object *v;
 	int pid, sts;
-	if (args == NULL)
+	if (args == NULL) {
+		BGN_SAVE
 		pid = wait(&sts);
+		END_SAVE
+	}
 	else {
 #ifdef NO_WAITPID
 		err_setstr(PosixError,
@@ -674,7 +715,9 @@
 		int options;
 		if (!getintintarg(args, &pid, &options))
 			return NULL;
+		BGN_SAVE
 		pid = waitpid(pid, &sts, options);
+		END_SAVE
 #endif
 	}
 	if (pid == -1)
@@ -719,7 +762,9 @@
 	int n;
 	if (!getstrarg(args, &path))
 		return NULL;
+	BGN_SAVE
 	n = readlink(path, buf, (int) sizeof buf);
+	END_SAVE
 	if (n < 0)
 		return posix_error();
 	return newsizedstringobject(buf, n);
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index 8afd208..3a5644b 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -26,7 +26,6 @@
 
 #include "allobjects.h"
 #include "modsupport.h"
-#include "compile.h"
 #include "ceval.h"
 
 #include "myselect.h"
@@ -154,7 +153,9 @@
     if ( omax > max ) max = omax;
     if ( emax > max ) max = emax;
 
+    BGN_SAVE
     n = select(max, &ifdset, &ofdset, &efdset, tvp);
+    END_SAVE
 
     if ( n < 0 ) {
 	err_errno(SelectError);
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 839d46e..ab8c6b5 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -24,8 +24,6 @@
 
 /* Socket module */
 
-/* XXX Ought to fix getStr*arg calls to use getargs(args, "s#", ...) */
-
 /*
 This module provides an interface to Berkeley socket IPC.
 
@@ -72,6 +70,7 @@
 
 #include "allobjects.h"
 #include "modsupport.h"
+#include "ceval.h"
 
 #include "myselect.h" /* Implies <sys/types.h>, <sys/time.h>, <sys/param.h> */
 
@@ -171,7 +170,9 @@
 			((long) d3 << 8) | ((long) d4 << 0));
 		return 4;
 	}
+	BGN_SAVE
 	hp = gethostbyname(name);
+	END_SAVE
 	if (hp == NULL) {
 		err_setstr(SocketError, "host not found");
 		return -1;
@@ -256,16 +257,16 @@
 	case AF_UNIX:
 	{
 		static struct sockaddr_un addr;
-		object *path;
+		char *path;
 		int len;
-		if (!getStrarg(args, &path))
+		if (!getargs(args, "s#", &path, &len))
 			return 0;
-		if ((len = getstringsize(path)) > sizeof addr.sun_path) {
+		if (len > sizeof addr.sun_path) {
 			err_setstr(SocketError, "AF_UNIX path too long");
 			return 0;
 		}
 		addr.sun_family = AF_UNIX;
-		memcpy(addr.sun_path, getstringvalue(path), len);
+		memcpy(addr.sun_path, path, len);
 		*addr_ret = (struct sockaddr *) &addr;
 		*len_ret = len + sizeof addr.sun_family;
 		return 1;
@@ -274,11 +275,11 @@
 	case AF_INET:
 	{
 		static struct sockaddr_in addr;
-		object *host;
+		char *host;
 		int port;
-		if (!getStrintarg(args, &host, &port))
+		if (!getargs(args, "(si)", &host, &port))
 			return 0;
-		if (setipaddr(getstringvalue(host), &addr) < 0)
+		if (setipaddr(host, &addr) < 0)
 			return 0;
 		addr.sin_family = AF_INET;
 		addr.sin_port = htons(port);
@@ -344,7 +345,9 @@
 		return NULL;
 	if (!getsockaddrlen(s, &addrlen))
 		return NULL;
+	BGN_SAVE
 	newfd = accept(s->sock_fd, (struct sockaddr *) addrbuf, &addrlen);
+	END_SAVE
 	if (newfd < 0)
 		return socket_error();
 	/* Create the new object with unspecified family,
@@ -370,7 +373,7 @@
 {
 	int flag;
 	int res;
-	if (!getintarg(args, &flag))
+	if (!getargs(args, "i", &flag))
 		return NULL;
 	res = setsockopt(s->sock_fd, SOL_SOCKET, SO_BROADCAST,
 			 &flag, sizeof flag);
@@ -461,9 +464,13 @@
 {
 	struct sockaddr *addr;
 	int addrlen;
+	int res;
 	if (!getsockaddrarg(s, args, &addr, &addrlen))
 		return NULL;
-	if (bind(s->sock_fd, addr, addrlen) < 0)
+	BGN_SAVE
+	res = bind(s->sock_fd, addr, addrlen);
+	END_SAVE
+	if (res < 0)
 		return socket_error();
 	INCREF(None);
 	return None;
@@ -481,7 +488,9 @@
 {
 	if (!getnoarg(args))
 		return NULL;
+	BGN_SAVE
 	(void) close(s->sock_fd);
+	END_SAVE
 	s->sock_fd = -1;
 	INCREF(None);
 	return None;
@@ -497,9 +506,13 @@
 {
 	struct sockaddr *addr;
 	int addrlen;
+	int res;
 	if (!getsockaddrarg(s, args, &addr, &addrlen))
 		return NULL;
-	if (connect(s->sock_fd, addr, addrlen) < 0)
+	BGN_SAVE
+	res = connect(s->sock_fd, addr, addrlen);
+	END_SAVE
+	if (res < 0)
 		return socket_error();
 	INCREF(None);
 	return None;
@@ -527,9 +540,13 @@
 	object *args;
 {
 	int backlog;
+	int res;
 	if (!getintarg(args, &backlog))
 		return NULL;
-	if (listen(s->sock_fd, backlog) < 0)
+	BGN_SAVE
+	res = listen(s->sock_fd, backlog);
+	END_SAVE
+	if (res < 0)
 		return socket_error();
 	INCREF(None);
 	return None;
@@ -549,15 +566,15 @@
 	object *args;
 {
 	extern int fclose PROTO((FILE *));
-	object *mode;
+	char *mode;
 	int fd;
 	FILE *fp;
-	if (!getStrarg(args, &mode))
+	if (!getargs(args, "s", &mode))
 		return NULL;
 	if ((fd = dup(s->sock_fd)) < 0 ||
-	    (fp = fdopen(fd, getstringvalue(mode))) == NULL)
+	    (fp = fdopen(fd, mode)) == NULL)
 		return socket_error();
-	return newopenfileobject(fp, "<socket>", getstringvalue(mode), fclose);
+	return newopenfileobject(fp, "<socket>", mode, fclose);
 }
 
 
@@ -579,7 +596,9 @@
 	buf = newsizedstringobject((char *) 0, len);
 	if (buf == NULL)
 		return NULL;
+	BGN_SAVE
 	n = recv(s->sock_fd, getstringvalue(buf), len, flags);
+	END_SAVE
 	if (n < 0)
 		return socket_error();
 	if (resizestring(&buf, n) < 0)
@@ -600,10 +619,13 @@
 	int addrlen, len, n;
 	if (!getintarg(args, &len))
 		return NULL;
+	if (!getsockaddrlen(s, &addrlen))
+		return NULL;
 	buf = newsizedstringobject((char *) 0, len);
-	addrlen = sizeof addrbuf;
+	BGN_SAVE
 	n = recvfrom(s->sock_fd, getstringvalue(buf), len, 0,
 		     addrbuf, &addrlen);
+	END_SAVE
 	if (n < 0)
 		return socket_error();
 	if (resizestring(&buf, n) < 0)
@@ -620,16 +642,17 @@
 	sockobject *s;
 	object *args;
 {
-	object *buf;
+	char *buf;
 	int len, n, flags;
-	if (!getStrintarg(args, &buf, &flags)) {
+	if (!getargs(args, "(s#i)", &buf, &len, &flags)) {
 		err_clear();
-		if (!getStrarg(args, &buf))
+		if (!getargs(args, "s#", &buf, &len))
 			return NULL;
 		flags = 0;
 	}
-	len = getstringsize(buf);
-	n = send(s->sock_fd, getstringvalue(buf), len, flags);
+	BGN_SAVE
+	n = send(s->sock_fd, buf, len, flags);
+	END_SAVE
 	if (n < 0)
 		return socket_error();
 	INCREF(None);
@@ -644,19 +667,20 @@
 	sockobject *s;
 	object *args;
 {
-	object *buf;
+	object *addro;
+	char *buf;
 	struct sockaddr *addr;
 	int addrlen, len, n;
 	if (args == NULL || !is_tupleobject(args) || gettuplesize(args) != 2) {
 		err_badarg();
 		return NULL;
 	}
-	if (!getStrarg(gettupleitem(args, 0), &buf) ||
-	    !getsockaddrarg(s, gettupleitem(args, 1), &addr, &addrlen))
+	if (!getargs(args, "(s#O)", &buf, &len, &addro) ||
+	    !getsockaddrarg(s, addro, &addr, &addrlen))
 		return NULL;
-	len = getstringsize(buf);
-	n = sendto(s->sock_fd, getstringvalue(buf), len, 0,
-		   addr, addrlen);
+	BGN_SAVE
+	n = sendto(s->sock_fd, buf, len, 0, addr, addrlen);
+	END_SAVE
 	if (n < 0)
 		return socket_error();
 	INCREF(None);
@@ -672,9 +696,13 @@
 	object *args;
 {
 	int how;
+	int res;
 	if (!getintarg(args, &how))
 		return NULL;
-	if (shutdown(s->sock_fd, how) < 0)
+	BGN_SAVE
+	res = shutdown(s->sock_fd, how);
+	END_SAVE
+	if (res < 0)
 		return socket_error();
 	INCREF(None);
 	return None;
@@ -758,13 +786,19 @@
 	object *args;
 {
 	char buf[1024];
+	int res;
 	if (!getnoarg(args))
 		return NULL;
-	if (gethostname(buf, (int) sizeof buf - 1) < 0)
+	BGN_SAVE
+	res = gethostname(buf, (int) sizeof buf - 1);
+	END_SAVE
+	if (res < 0)
 		return socket_error();
 	buf[sizeof buf - 1] = '\0';
 	return newstringobject(buf);
 }
+
+
 /* Python interface to gethostbyname(name). */
 
 /*ARGSUSED*/
@@ -775,9 +809,9 @@
 {
 	object *name;
 	struct sockaddr_in addrbuf;
-	if (!getStrarg(args, &name))
+	if (!getargs(args, "s", &name))
 		return NULL;
-	if (setipaddr(getstringvalue(name), &addrbuf) < 0)
+	if (setipaddr(name, &addrbuf) < 0)
 		return NULL;
 	return makeipaddr(&addrbuf);
 }
@@ -793,11 +827,13 @@
 	object *self;
 	object *args;
 {
-	object *name, *proto;
+	char *name, *proto;
 	struct servent *sp;
-	if (!getStrStrarg(args, &name, &proto))
+	if (!getargs(args, "(ss)", &name, &proto))
 		return NULL;
-	sp = getservbyname(getstringvalue(name), getstringvalue(proto));
+	BGN_SAVE
+	sp = getservbyname(name, proto);
+	END_SAVE
 	if (sp == NULL) {
 		err_setstr(SocketError, "service/proto not found");
 		return NULL;
@@ -827,7 +863,9 @@
 			return NULL;
 		proto = 0;
 	}
+	BGN_SAVE
 	fd = socket(family, type, proto);
+	END_SAVE
 	if (fd < 0)
 		return socket_error();
 	s = newsockobject(fd, family, type, proto);
diff --git a/Modules/stdwinmodule.c b/Modules/stdwinmodule.c
index 537777e..e33610d 100644
--- a/Modules/stdwinmodule.c
+++ b/Modules/stdwinmodule.c
@@ -63,11 +63,29 @@
 */
 
 #include "allobjects.h"
-
 #include "modsupport.h"
+#include "ceval.h"
 
 #include "stdwin.h"
 
+#ifdef USE_THREAD
+
+#include "thread.h"
+
+static type_lock StdwinLock; /* Lock held when interpreter not locked */
+
+#define BGN_STDWIN BGN_SAVE acquire_lock(StdwinLock, 1);
+#define RET_STDWIN release_lock(StdwinLock); RET_SAVE
+#define END_STDWIN release_lock(StdwinLock); END_SAVE
+
+#else
+
+#define BGN_STDWIN BGN_SAVE
+#define RET_STDWIN RET_SAVE
+#define END_STDWIN END_SAVE
+
+#endif
+
 static object *StdwinError; /* Exception stdwin.error */
 
 /* Window and menu object types declared here because of forward references */
@@ -1727,14 +1745,17 @@
 		return NULL;
 	}
  again:
+	BGN_STDWIN
 	if (poll) {
 		if (!wpollevent(&e)) {
+			RET_STDWIN
 			INCREF(None);
 			return None;
 		}
 	}
 	else
 		wgetevent(&e);
+	END_STDWIN
 	if (e.type == WE_COMMAND && e.u.command == WC_CANCEL) {
 		/* Turn keyboard interrupts into exceptions */
 		err_set(KeyboardInterrupt);
@@ -1919,7 +1940,9 @@
 		return NULL;
 	strncpy(buf, dflt, sizeof buf);
 	buf[sizeof buf - 1] = '\0';
+	BGN_STDWIN
 	ret = waskfile(prompt, buf, sizeof buf, new);
+	END_STDWIN
 	if (!ret) {
 		err_set(KeyboardInterrupt);
 		return NULL;
@@ -1936,7 +1959,9 @@
 	int new, ret;
 	if (!getstrintarg(args, &prompt, &new))
 		return NULL;
+	BGN_STDWIN
 	ret = waskync(prompt, new);
+	END_STDWIN
 	if (ret < 0) {
 		err_set(KeyboardInterrupt);
 		return NULL;
@@ -1956,7 +1981,9 @@
 		return NULL;
 	strncpy(buf, dflt, sizeof buf);
 	buf[sizeof buf - 1] = '\0';
+	BGN_STDWIN
 	ret = waskstr(prompt, buf, sizeof buf);
+	END_STDWIN
 	if (!ret) {
 		err_set(KeyboardInterrupt);
 		return NULL;
@@ -1972,7 +1999,9 @@
 	char *msg;
 	if (!getstrarg(args, &msg))
 		return NULL;
+	BGN_STDWIN
 	wmessage(msg);
+	END_STDWIN
 	INCREF(None);
 	return None;
 }
@@ -2185,4 +2214,9 @@
 	StdwinError = newstringobject("stdwin.error");
 	if (StdwinError == NULL || dictinsert(d, "error", StdwinError) != 0)
 		fatal("can't define stdwin.error");
+#ifdef USE_THREAD
+	StdwinLock = allocate_lock();
+	if (StdwinLock == NULL)
+		fatal("can't allocate stdwin lock");
+#endif
 }
diff --git a/Modules/threadmodule.c b/Modules/threadmodule.c
index c4de295..6ab7ea8 100644
--- a/Modules/threadmodule.c
+++ b/Modules/threadmodule.c
@@ -27,15 +27,10 @@
 
 #include "allobjects.h"
 #include "modsupport.h"
-#include "compile.h"
 #include "ceval.h"
 
 #include "thread.h"
 
-extern void init_save_thread PROTO((void));
-extern void* save_thread PROTO((void));
-extern void restore_thread PROTO((void *));
-
 object *ThreadError;
 
 
@@ -83,7 +78,6 @@
 	lockobject *self;
 	object *args;
 {
-	void *save;
 	int i;
 
 	if (args != NULL) {
@@ -93,11 +87,9 @@
 	else
 		i = 1;
 
-	save = save_thread();
-
+	BGN_SAVE
 	i = acquire_lock(self->lock_lock, i);
-
-	restore_thread(save);
+	END_SAVE
 
 	if (args == NULL) {
 		INCREF(None);
@@ -193,8 +185,6 @@
 	if (res == NULL) {
 		fprintf(stderr, "Unhandled exception in thread:\n");
 		print_error(); /* From pythonmain.c */
-		fprintf(stderr, "Exiting the entire program\n");
-		goaway(1);
 	}
 	(void) save_thread();
 	exit_thread();
@@ -251,7 +241,7 @@
 {
 	if (!getnoarg(args))
 		return NULL;
-	return newlockobject();
+	return (object *) newlockobject();
 }
 
 static struct methodlist thread_methods[] = {
diff --git a/Modules/timemodule.c b/Modules/timemodule.c
index 5a278a9bd..4d13611 100644
--- a/Modules/timemodule.c
+++ b/Modules/timemodule.c
@@ -25,8 +25,8 @@
 /* Time module */
 
 #include "allobjects.h"
-
 #include "modsupport.h"
+#include "ceval.h"
 
 #include "sigtype.h"
 
@@ -104,14 +104,13 @@
 	object *self;
 	object *args;
 {
-	void *save, *save_thread(), restore_thread();
-	int secs;
+	long secs;
 	SIGTYPE (*sigsave)() = 0; /* Initialized to shut lint up */
-	if (!getintarg(args, &secs))
+	if (!getargs(args, "l", &secs))
 		return NULL;
-	save = save_thread();
+	BGN_SAVE
 	if (setjmp(sleep_intr)) {
-		restore_thread(save);
+		RET_SAVE
 		signal(SIGINT, sigsave);
 		err_set(KeyboardInterrupt);
 		return NULL;
@@ -119,8 +118,12 @@
 	sigsave = signal(SIGINT, SIG_IGN);
 	if (sigsave != (SIGTYPE (*)()) SIG_IGN)
 		signal(SIGINT, sleep_catcher);
-	sleep(secs);
-	restore_thread(save);
+#ifdef BSD_TIME
+	longsleep(secs);
+#else
+	sleep((int)secs);
+#endif
+	END_SAVE
 	signal(SIGINT, sigsave);
 	INCREF(None);
 	return None;
@@ -151,14 +154,13 @@
 	object *self;
 	object *args;
 {
-	void *save, *save_thread(), restore_thread();
 	long msecs;
 	SIGTYPE (*sigsave)();
 	if (!getlongarg(args, &msecs))
 		return NULL;
-	save = save_thread();
+	BGN_SAVE
 	if (setjmp(sleep_intr)) {
-		restore_thread(save);
+		RET_SAVE
 		signal(SIGINT, sigsave);
 		err_set(KeyboardInterrupt);
 		return NULL;
@@ -167,7 +169,7 @@
 	if (sigsave != (SIGTYPE (*)()) SIG_IGN)
 		signal(SIGINT, sleep_catcher);
 	millisleep(msecs);
-	restore_thread(save);
+	END_SAVE
 	signal(SIGINT, sigsave);
 	INCREF(None);
 	return None;
@@ -249,12 +251,12 @@
 #define MacTicks	(* (long *)0x16A)
 
 #ifdef THINK_C_3_0
-sleep(msecs)
-	int msecs;
+sleep(secs)
+	int secs;
 {
 	register long deadline;
 	
-	deadline = MacTicks + msecs * 60;
+	deadline = MacTicks + mecs * 60;
 	while (MacTicks < deadline) {
 		if (intrcheck())
 			sleep_catcher(SIGINT);
@@ -295,7 +297,6 @@
 	if (gettimeofday(&t, &tz) != 0)
 		return -1;
 	return t.tv_sec*1000 + t.tv_usec/1000;
-	
 }
 
 millisleep(msecs)
@@ -307,6 +308,15 @@
 	(void) select(0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &t);
 }
 
+longsleep(secs)
+	long secs;
+{
+	struct timeval t;
+	t.tv_sec = secs;
+	t.tv_usec = 0;
+	(void) select(0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &t);
+}
+
 #endif /* BSD_TIME */
 
 
diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index 99f4e5e..e649792 100644
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -26,6 +26,7 @@
 
 #include "allobjects.h"
 #include "modsupport.h"
+#include "ceval.h"
 
 #define BUF(v) GETSTRINGVALUE((stringobject *)v)
 
@@ -93,7 +94,11 @@
 	}
 	else
 #endif
-	f->f_fp = fopen(name, mode);
+	{
+		BGN_SAVE
+		f->f_fp = fopen(name, mode);
+		END_SAVE
+	}
 	if (f->f_fp == NULL) {
 		err_errno(IOError);
 		DECREF(f);
@@ -115,8 +120,11 @@
 file_dealloc(f)
 	fileobject *f;
 {
-	if (f->f_fp != NULL && f->f_close != NULL)
+	if (f->f_fp != NULL && f->f_close != NULL) {
+		BGN_SAVE
 		(*f->f_close)(f->f_fp);
+		END_SAVE
+	}
 	if (f->f_name != NULL)
 		DECREF(f->f_name);
 	if (f->f_mode != NULL)
@@ -162,10 +170,13 @@
 	int sts = 0;
 	if (!getnoarg(args))
 		return NULL;
-	errno = 0;
 	if (f->f_fp != NULL) {
-		if (f->f_close != NULL)
+		if (f->f_close != NULL) {
+			BGN_SAVE
+			errno = 0;
 			sts = (*f->f_close)(f->f_fp);
+			END_SAVE
+		}
 		f->f_fp = NULL;
 	}
 	if (sts == EOF)
@@ -183,6 +194,7 @@
 {
 	long offset;
 	int whence;
+	int ret;
 	
 	if (f->f_fp == NULL)
 		return err_closed();
@@ -192,8 +204,11 @@
 		if (!getargs(args, "(li)", &offset, &whence))
 			return NULL;
 	}
+	BGN_SAVE
 	errno = 0;
-	if (fseek(f->f_fp, offset, whence) != 0) {
+	ret = fseek(f->f_fp, offset, whence);
+	END_SAVE
+	if (ret != 0) {
 		err_errno(IOError);
 		clearerr(f->f_fp);
 		return NULL;
@@ -212,8 +227,10 @@
 		return err_closed();
 	if (!getnoarg(args))
 		return NULL;
+	BGN_SAVE
 	errno = 0;
 	offset = ftell(f->f_fp);
+	END_SAVE
 	if (offset == -1L) {
 		err_errno(IOError);
 		clearerr(f->f_fp);
@@ -239,12 +256,17 @@
 	fileobject *f;
 	object *args;
 {
+	int res;
+	
 	if (f->f_fp == NULL)
 		return err_closed();
 	if (!getnoarg(args))
 		return NULL;
+	BGN_SAVE
 	errno = 0;
-	if (fflush(f->f_fp) != 0) {
+	res = fflush(f->f_fp);
+	END_SAVE
+	if (res != 0) {
 		err_errno(IOError);
 		clearerr(f->f_fp);
 		return NULL;
@@ -258,11 +280,15 @@
 	fileobject *f;
 	object *args;
 {
+	long res;
 	if (f->f_fp == NULL)
 		return err_closed();
 	if (!getnoarg(args))
 		return NULL;
-	return newintobject((long)isatty((int)fileno(f->f_fp)));
+	BGN_SAVE
+	res = isatty((int)fileno(f->f_fp));
+	END_SAVE
+	return newintobject(res);
 }
 
 static object *
@@ -290,6 +316,7 @@
 	if (v == NULL)
 		return NULL;
 	n1 = 0;
+	BGN_SAVE
 	for (;;) {
 		n3 = fread(BUF(v)+n1, 1, n2-n1, f->f_fp);
 		/* XXX Error check? */
@@ -300,10 +327,13 @@
 			break;
 		if (n == 0) {
 			n2 = n1 + BUFSIZ;
+			RET_SAVE
 			if (resizestring(&v, n2) < 0)
 				return NULL;
+			RES_SAVE
 		}
 	}
+	END_SAVE
 	if (n1 != n2)
 		resizestring(&v, n1);
 	return v;
@@ -321,7 +351,6 @@
 	fileobject *f;
 	int n;
 {
-	void *save, *save_thread(), restore_thread();
 	register FILE *fp;
 	register int c;
 	register char *buf, *end;
@@ -336,18 +365,18 @@
 	buf = BUF(v);
 	end = buf + n2;
 
-	save = save_thread();
+	BGN_SAVE
 	for (;;) {
 		if ((c = getc(fp)) == EOF) {
 			clearerr(fp);
 			if (intrcheck()) {
-				restore_thread(save);
+				RET_SAVE
 				DECREF(v);
 				err_set(KeyboardInterrupt);
 				return NULL;
 			}
 			if (n < 0 && buf == BUF(v)) {
-				restore_thread(save);
+				RET_SAVE
 				DECREF(v);
 				err_setstr(EOFError,
 					   "EOF when reading a line");
@@ -365,15 +394,15 @@
 				break;
 			n1 = n2;
 			n2 += 1000;
-			restore_thread(save);
+			RET_SAVE
 			if (resizestring(&v, n2) < 0)
 				return NULL;
-			save = save_thread();
+			RES_SAVE
 			buf = BUF(v) + n1;
 			end = BUF(v) + n2;
 		}
 	}
-	restore_thread(save);
+	END_SAVE
 
 	n1 = buf - BUF(v);
 	if (n1 != n2)
@@ -464,8 +493,10 @@
 	if (!getargs(args, "s#", &s, &n))
 		return NULL;
 	f->f_softspace = 0;
+	BGN_SAVE
 	errno = 0;
 	n2 = fwrite(s, 1, n, f->f_fp);
+	END_SAVE
 	if (n2 != n) {
 		err_errno(IOError);
 		clearerr(f->f_fp);
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 996c289..0f51735 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -26,8 +26,7 @@
 
 #include "allobjects.h"
 #include "modsupport.h"
-#include "compile.h" /* Needed by ceval.h */
-#include "ceval.h" /* For call_object() */
+#include "ceval.h"
 
 object *
 newlistobject(size)
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index d6ae46f..ca5043d 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -33,7 +33,6 @@
 #include "bltinmodule.h"
 #include "import.h"
 #include "pythonrun.h"
-#include "compile.h" /* For ceval.h */
 #include "ceval.h"
 #include "modsupport.h"
 
@@ -218,13 +217,17 @@
 		    "execfile arguments must be filename[,dict[,dict]]");
 		return NULL;
 	}
+	BGN_SAVE
 	fp = fopen(getstringvalue(str), "r");
+	END_SAVE
 	if (fp == NULL) {
 		err_setstr(IOError, "execfile cannot open the file argument");
 		return NULL;
 	}
 	w = run_file(fp, getstringvalue(str), file_input, globals, locals);
+	BGN_SAVE
 	fclose(fp);
+	END_SAVE
 	return w;
 }
 
@@ -324,9 +327,11 @@
 	}
 	m = add_module("__main__");
 	d = getmoduledict(m);
+	BGN_SAVE
 	while ((c = getc(in)) != EOF && (c == ' ' || c == '\t'))
 		;
 	ungetc(c, in);
+	END_SAVE
 	return run_file(in, "<stdin>", expr_input, d, d);
 }
 
diff --git a/Python/ceval.c b/Python/ceval.c
index 32c52c7..252b1dc 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -30,6 +30,7 @@
 #include "sysmodule.h"
 #include "compile.h"
 #include "frameobject.h"
+#include "eval.h"
 #include "ceval.h"
 #include "opcode.h"
 #include "bltinmodule.h"
@@ -83,48 +84,28 @@
 
 static frameobject *current_frame;
 
-
-/* Interface for threads.
-
-   A module that plans to do a blocking system call (or something else
-   that lasts a long time and doesn't touch Python data) can allow other
-   threads to run as follows:
-
-	void *x;
-
-	...preparations here...
-	x = save_thread();
-	...blocking system call here...
-	restore_thread(x);
-	...interpretr result here...
-
-   For convenience, that the value of 'errno' is restored across the
-   the call to restore_thread().
-
-   The function init_save_thread() should be called only from
-   initthread() in "threadmodule.c".
-
-   Note that not yet all candidates have been converted to use this
-   mechanism!
-*/
-
 #ifdef USE_THREAD
+
 #include <errno.h>
 #include "thread.h"
+
 static type_lock interpreter_lock;
 
 void
 init_save_thread()
 {
-#ifdef USE_THREAD
 	if (interpreter_lock)
 		fatal("2nd call to init_save_thread");
 	interpreter_lock = allocate_lock();
 	acquire_lock(interpreter_lock, 1);
-#endif
 }
+
 #endif
 
+/* Functions save_thread and restore_thread are always defined so
+   dynamically loaded modules needn't be compiled separately for use
+   with and without threads: */
+
 void *
 save_thread()
 {
diff --git a/Python/import.c b/Python/import.c
index 5667c77..44f6d7b 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -35,7 +35,7 @@
 #include "pythonrun.h"
 #include "marshal.h"
 #include "compile.h"
-#include "ceval.h"
+#include "eval.h"
 #include "osdefs.h"
 
 extern int verbose; /* Defined in pythonmain.c */
diff --git a/Python/pythonmain.c b/Python/pythonmain.c
index 0f76bfd..4344cde 100644
--- a/Python/pythonmain.c
+++ b/Python/pythonmain.c
@@ -26,8 +26,6 @@
 
 #include "allobjects.h"
 
-extern char *getpythonpath();
-
 extern int debugging; /* Needed by parser.c */
 extern int verbose; /* Needed by import.c */
 
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 2a68f24..c8921da 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -33,14 +33,11 @@
 #include "errcode.h"
 #include "sysmodule.h"
 #include "compile.h"
+#include "eval.h"
 #include "ceval.h"
 #include "pythonrun.h"
 #include "import.h"
 
-#ifdef USE_THREAD
-extern void *save_thread();
-#endif
-
 extern char *getpythonpath();
 
 extern grammar gram; /* From graminit.c */
@@ -127,7 +124,6 @@
 	FILE *fp;
 	char *filename;
 {
-	void *save, *save_thread(), restore_thread();
 	object *m, *d, *v, *w;
 	node *n;
 	char *ps1, *ps2;
@@ -150,9 +146,9 @@
 		w = NULL;
 		ps2 = "";
 	}
-	save = save_thread();
+	BGN_SAVE
 	err = parsefile(fp, filename, &gram, single_input, ps1, ps2, &n);
-	restore_thread(save);
+	END_SAVE
 	XDECREF(v);
 	XDECREF(w);
 	if (err == E_EOF)
@@ -330,8 +326,12 @@
 	int start;
 	node **n_ret;
 {
-	return parsefile(fp, filename, &gram, start,
+	int ret;
+	BGN_SAVE
+	ret = parsefile(fp, filename, &gram, start,
 				(char *)0, (char *)0, n_ret);
+	END_SAVE
+	return ret;
 }
 
 /* Simplified interface to parsestring */
@@ -366,6 +366,18 @@
 	int sts;
 {
 	flushline();
+
+#ifdef USE_THREAD
+
+	/* Other threads may still be active, so skip most of the
+	   cleanup actions usually done (these are mostly for
+	   debugging anyway). */
+	
+	(void *) save_thread();
+	donecalls();
+	exit_prog(sts);
+	
+#else /* USE_THREAD */
 	
 	/* XXX Call doneimport() before donecalls(), since donecalls()
 	   calls wdone(), and doneimport() may close windows */
@@ -384,12 +396,8 @@
 	}
 #endif /* TRACE_REFS */
 
-#ifdef USE_THREAD
-	(void) save_thread();
-	exit_prog(sts);
-#else
 	exit(sts);
-#endif
+#endif /* USE_THREAD */
 	/*NOTREACHED*/
 }
 
diff --git a/Python/thread.c b/Python/thread.c
index 1f0633a..4aa06cf 100644
--- a/Python/thread.c
+++ b/Python/thread.c
@@ -17,7 +17,7 @@
 #include <lwp/lwp.h>
 #include <lwp/stackdep.h>
 
-#define STACKSIZE	1000	/* stacksize for a thread */
+#define STACKSIZE	16000	/* stacksize for a thread */
 #define NSTACKS		2	/* # stacks to be put in cache initialy */
 
 struct lock {
@@ -90,7 +90,7 @@
 		exit(0);
 #ifdef __sgi
 	exiting = 1;
-	exit(0);
+	_exit(0);
 #endif
 #ifdef SOLARIS
 	thread_exit();
@@ -113,7 +113,7 @@
 #ifdef DEBUG
 		printf("exiting in exit_sig\n");
 #endif
-		exit(exit_status);
+		_exit(exit_status);
 	}
 }
 #endif
@@ -255,7 +255,7 @@
 	exiting = 1;
 	do_exit = 1;
 	exit_status = status;
-	exit(status);
+	_exit(status);
 #endif
 #ifdef sun
 	pod_exit(status);