Use unlocked stdio more systematically

This can improve performance significantly on stdio-bottlenecked code.
E.g., make-docfile is 3x faster on my Fedora 25 x86-64 desktop.
* admin/merge-gnulib (GNULIB_MODULES): Add unlocked-io.
* lib-src/ebrowse.c, lib-src/emacsclient.c, lib-src/etags.c:
* lib-src/hexl.c, lib-src/make-docfile.c, lib-src/movemail.c:
* lib-src/profile.c, lib-src/update-game-score.c:
Include unlocked-io.h instead of stdio.h, since these programs are
single-threaded.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/unlocked-io.h, m4/unlocked-io.m4: New files, copied from Gnulib.
* src/charset.c, src/cm.c, src/emacs.c, src/image.c, src/keyboard.c:
* src/lread.c, src/term.c:
Include sysstdio.h, possibly instead of stdio.h, to define
the unlocked functions if the system does not provide them.
* src/charset.c, src/lread.c (getc_unlocked):
Remove, since sysstdio.h now defines it if needed.
* src/cm.c (cmputc, cmcheckmagic):
* src/dispnew.c (update_frame, update_frame_with_menu)
(update_frame_1, Fsend_string_to_terminal, Fding, bitch_at_user):
* src/emacs.c (main, Fdump_emacs):
* src/fileio.c (Fdo_auto_save, Fset_binary_mode):
* src/image.c (slurp_file, png_read_from_file, png_load_body)
(our_stdio_fill_input_buffer):
* src/keyboard.c (record_char, kbd_buffer_get_event, handle_interrupt):
* src/lread.c (readbyte_from_file):
* src/minibuf.c (read_minibuf_noninteractive):
* src/print.c (printchar_to_stream, strout)
(Fredirect_debugging_output):
* src/sysdep.c (reset_sys_modes, procfs_ttyname)
(procfs_get_total_memory):
* src/term.c (tty_ring_bell, tty_send_additional_strings)
(tty_set_terminal_modes, tty_reset_terminal_modes)
(tty_update_end, tty_clear_end_of_line, tty_write_glyphs)
(tty_write_glyphs_with_face, tty_insert_glyphs)
(tty_menu_activate):
* src/xfaces.c (Fx_load_color_file):
Use unlocked stdio when it should be safe.
* src/sysstdio.h (clearerr_unlocked, feof_unlocked, ferror_unlocked)
(fflush_unlocked, fgets_unlocked, fputc_unlocked, fputs_unlocked)
(fread_unlocked, fwrite_unlocked, getc_unlocked, getchar_unlocked)
(putc_unlocked, putchar_unloced): Provide substitutes if not declared.

27 files changed, 341 insertions, 116 deletions

diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index d4bbf17cb3d..85921ba1ba6 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -40,7 +40,7 @@ GNULIB_MODULES='
   sig2str socklen stat-time std-gnu11 stdalign stddef stdio
   stpcpy strftime strtoimax symlink sys_stat
   sys_time time time_r time_rz timegm timer-time timespec-add timespec-sub
-  update-copyright utimens
+  update-copyright unlocked-io utimens
   vla warnings
 '
 
diff --git a/lib-src/ebrowse.c b/lib-src/ebrowse.c
index 51d181997b1..e77b7c94cca 100644
--- a/lib-src/ebrowse.c
+++ b/lib-src/ebrowse.c
@@ -20,21 +20,21 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include <stddef.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
 #include <assert.h>
 #include <getopt.h>
 
+#include <flexmember.h>
+#include <min-max.h>
+#include <unlocked-io.h>
+
 /* The SunOS compiler doesn't have SEEK_END.  */
 #ifndef SEEK_END
 #define SEEK_END 2
 #endif
 
-#include <flexmember.h>
-#include <min-max.h>
-
 /* Files are read in chunks of this number of bytes.  */
 
 enum { READ_CHUNK_SIZE = 100 * 1024 };
diff --git a/lib-src/emacsclient.c b/lib-src/emacsclient.c
index 8828b7652de..f1d4e8976da 100644
--- a/lib-src/emacsclient.c
+++ b/lib-src/emacsclient.c
@@ -73,7 +73,6 @@ char *w32_getenv (const char *);
 
 #include <stdarg.h>
 #include <ctype.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <getopt.h>
@@ -84,6 +83,8 @@ char *w32_getenv (const char *);
 #include <signal.h>
 #include <errno.h>
 
+#include <unlocked-io.h>
+
 #ifndef VERSION
 #define VERSION "unspecified"
 #endif
diff --git a/lib-src/etags.c b/lib-src/etags.c
index 6f280d8ab40..e5ff7bd10fc 100644
--- a/lib-src/etags.c
+++ b/lib-src/etags.c
@@ -123,6 +123,7 @@ char pot_etags_version[] = "@(#) pot revision number is 17.38.1.4";
 #include <errno.h>
 #include <fcntl.h>
 #include <binary-io.h>
+#include <unlocked-io.h>
 #include <c-ctype.h>
 #include <c-strcase.h>
 
diff --git a/lib-src/hexl.c b/lib-src/hexl.c
index 319ce8bc890..d949af08902 100644
--- a/lib-src/hexl.c
+++ b/lib-src/hexl.c
@@ -22,11 +22,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 
 #include <inttypes.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <binary-io.h>
+#include <unlocked-io.h>
 
 static char *progname;
 
diff --git a/lib-src/make-docfile.c b/lib-src/make-docfile.c
index 9470bd635f5..6b2cc110403 100644
--- a/lib-src/make-docfile.c
+++ b/lib-src/make-docfile.c
@@ -39,10 +39,14 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+#include <binary-io.h>
+#include <intprops.h>
+#include <min-max.h>
+#include <unlocked-io.h>
+
 #ifdef WINDOWSNT
 /* Defined to be sys_fopen in ms-w32.h, but only #ifdef emacs, so this
    is really just insurance.  */
@@ -50,10 +54,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <direct.h>
 #endif /* WINDOWSNT */
 
-#include <binary-io.h>
-#include <intprops.h>
-#include <min-max.h>
-
 #ifdef DOS_NT
 /* Defined to be sys_chdir in ms-w32.h, but only #ifdef emacs, so this
    is really just insurance.
diff --git a/lib-src/movemail.c b/lib-src/movemail.c
index cd12c48ed36..e5ca0b16611 100644
--- a/lib-src/movemail.c
+++ b/lib-src/movemail.c
@@ -59,7 +59,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/file.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
 #include <time.h>
@@ -69,6 +68,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <fcntl.h>
 #include <signal.h>
 #include <string.h>
+
+#include <unlocked-io.h>
+
 #include "syswait.h"
 #ifdef MAIL_USE_POP
 #include "pop.h"
diff --git a/lib-src/profile.c b/lib-src/profile.c
index 253f00e2d80..f4ab45c1718 100644
--- a/lib-src/profile.c
+++ b/lib-src/profile.c
@@ -34,11 +34,11 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 
 #include <inttypes.h>
-#include <stdio.h>
 #include <stdlib.h>
 
 #include <intprops.h>
 #include <systime.h>
+#include <unlocked-io.h>
 
 static struct timespec TV1;
 static int watch_not_started = 1; /* flag */
diff --git a/lib-src/update-game-score.c b/lib-src/update-game-score.c
index 5edc8e79569..942aeeb399d 100644
--- a/lib-src/update-game-score.c
+++ b/lib-src/update-game-score.c
@@ -39,7 +39,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <limits.h>
 #include <string.h>
 #include <stdlib.h>
-#include <stdio.h>
 #include <time.h>
 #include <pwd.h>
 #include <ctype.h>
@@ -47,6 +46,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/stat.h>
 #include <getopt.h>
 
+#include <unlocked-io.h>
+
 #ifdef WINDOWSNT
 #include "ntlib.h"
 #endif
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 509089e6391..fd0f9e5c780 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=close --avoid=dup --avoid=fchdir --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=setenv --avoid=sigprocmask --avoid=stat --avoid=stdarg --avoid=stdbool --avoid=threadlib --avoid=tzset --avoid=unsetenv --avoid=utime --avoid=utime-h --gnu-make --makefile-name=gnulib.mk.in --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt binary-io byteswap c-ctype c-strcase careadlinkat close-stream count-leading-zeros count-one-bits count-trailing-zeros crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 diffseq dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode filevercmp flexmember fstatat fsync getloadavg getopt-gnu gettime gettimeofday gitlog-to-changelog ignore-value intprops largefile lstat manywarnings memrchr minmax mkostemp mktime pipe2 pselect pthread_sigmask putenv qcopy-acl readlink readlinkat sig2str socklen stat-time std-gnu11 stdalign stddef stdio stpcpy strftime strtoimax symlink sys_stat sys_time time time_r time_rz timegm timer-time timespec-add timespec-sub update-copyright utimens vla warnings
+# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=close --avoid=dup --avoid=fchdir --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=setenv --avoid=sigprocmask --avoid=stat --avoid=stdarg --avoid=stdbool --avoid=threadlib --avoid=tzset --avoid=unsetenv --avoid=utime --avoid=utime-h --gnu-make --makefile-name=gnulib.mk.in --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt binary-io byteswap c-ctype c-strcase careadlinkat close-stream count-leading-zeros count-one-bits count-trailing-zeros crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 diffseq dtoastr dtotimespec dup2 environ execinfo faccessat fcntl fcntl-h fdatasync fdopendir filemode filevercmp flexmember fstatat fsync getloadavg getopt-gnu gettime gettimeofday gitlog-to-changelog ignore-value intprops largefile lstat manywarnings memrchr minmax mkostemp mktime pipe2 pselect pthread_sigmask putenv qcopy-acl readlink readlinkat sig2str socklen stat-time std-gnu11 stdalign stddef stdio stpcpy strftime strtoimax symlink sys_stat sys_time time time_r time_rz timegm timer-time timespec-add timespec-sub unlocked-io update-copyright utimens vla warnings
 
 
 MOSTLYCLEANFILES += core *.stackdump
@@ -2996,6 +2996,15 @@ EXTRA_DIST += unistd.in.h
 endif
 ## end   gnulib module unistd
 
+## begin gnulib module unlocked-io
+ifeq (,$(OMIT_GNULIB_MODULE_unlocked-io))
+
+
+EXTRA_DIST += unlocked-io.h
+
+endif
+## end   gnulib module unlocked-io
+
 ## begin gnulib module update-copyright
 ifeq (,$(OMIT_GNULIB_MODULE_update-copyright))
 
diff --git a/lib/unlocked-io.h b/lib/unlocked-io.h
new file mode 100644
index 00000000000..aaf60a0fb4e
--- /dev/null
+++ b/lib/unlocked-io.h
@@ -0,0 +1,136 @@
+/* Prefer faster, non-thread-safe stdio functions if available.
+
+   Copyright (C) 2001-2004, 2009-2017 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Jim Meyering.  */
+
+#ifndef UNLOCKED_IO_H
+# define UNLOCKED_IO_H 1
+
+/* These are wrappers for functions/macros from the GNU C library, and
+   from other C libraries supporting POSIX's optional thread-safe functions.
+
+   The standard I/O functions are thread-safe.  These *_unlocked ones are
+   more efficient but not thread-safe.  That they're not thread-safe is
+   fine since all of the applications in this package are single threaded.
+
+   Also, some code that is shared with the GNU C library may invoke
+   the *_unlocked functions directly.  On hosts that lack those
+   functions, invoke the non-thread-safe versions instead.  */
+
+# include <stdio.h>
+
+# if HAVE_DECL_CLEARERR_UNLOCKED
+#  undef clearerr
+#  define clearerr(x) clearerr_unlocked (x)
+# else
+#  define clearerr_unlocked(x) clearerr (x)
+# endif
+
+# if HAVE_DECL_FEOF_UNLOCKED
+#  undef feof
+#  define feof(x) feof_unlocked (x)
+# else
+#  define feof_unlocked(x) feof (x)
+# endif
+
+# if HAVE_DECL_FERROR_UNLOCKED
+#  undef ferror
+#  define ferror(x) ferror_unlocked (x)
+# else
+#  define ferror_unlocked(x) ferror (x)
+# endif
+
+# if HAVE_DECL_FFLUSH_UNLOCKED
+#  undef fflush
+#  define fflush(x) fflush_unlocked (x)
+# else
+#  define fflush_unlocked(x) fflush (x)
+# endif
+
+# if HAVE_DECL_FGETS_UNLOCKED
+#  undef fgets
+#  define fgets(x,y,z) fgets_unlocked (x,y,z)
+# else
+#  define fgets_unlocked(x,y,z) fgets (x,y,z)
+# endif
+
+# if HAVE_DECL_FPUTC_UNLOCKED
+#  undef fputc
+#  define fputc(x,y) fputc_unlocked (x,y)
+# else
+#  define fputc_unlocked(x,y) fputc (x,y)
+# endif
+
+# if HAVE_DECL_FPUTS_UNLOCKED
+#  undef fputs
+#  define fputs(x,y) fputs_unlocked (x,y)
+# else
+#  define fputs_unlocked(x,y) fputs (x,y)
+# endif
+
+# if HAVE_DECL_FREAD_UNLOCKED
+#  undef fread
+#  define fread(w,x,y,z) fread_unlocked (w,x,y,z)
+# else
+#  define fread_unlocked(w,x,y,z) fread (w,x,y,z)
+# endif
+
+# if HAVE_DECL_FWRITE_UNLOCKED
+#  undef fwrite
+#  define fwrite(w,x,y,z) fwrite_unlocked (w,x,y,z)
+# else
+#  define fwrite_unlocked(w,x,y,z) fwrite (w,x,y,z)
+# endif
+
+# if HAVE_DECL_GETC_UNLOCKED
+#  undef getc
+#  define getc(x) getc_unlocked (x)
+# else
+#  define getc_unlocked(x) getc (x)
+# endif
+
+# if HAVE_DECL_GETCHAR_UNLOCKED
+#  undef getchar
+#  define getchar() getchar_unlocked ()
+# else
+#  define getchar_unlocked() getchar ()
+# endif
+
+# if HAVE_DECL_PUTC_UNLOCKED
+#  undef putc
+#  define putc(x,y) putc_unlocked (x,y)
+# else
+#  define putc_unlocked(x,y) putc (x,y)
+# endif
+
+# if HAVE_DECL_PUTCHAR_UNLOCKED
+#  undef putchar
+#  define putchar(x) putchar_unlocked (x)
+# else
+#  define putchar_unlocked(x) putchar (x)
+# endif
+
+# undef flockfile
+# define flockfile(x) ((void) 0)
+
+# undef ftrylockfile
+# define ftrylockfile(x) 0
+
+# undef funlockfile
+# define funlockfile(x) ((void) 0)
+
+#endif /* UNLOCKED_IO_H */
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 1ac58e871cc..107645df4fd 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -158,6 +158,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module timespec-sub:
   # Code from module u64:
   # Code from module unistd:
+  # Code from module unlocked-io:
   # Code from module update-copyright:
   # Code from module utimens:
   # Code from module vararrays:
@@ -399,6 +400,7 @@ AC_DEFUN([gl_INIT],
   gl_TIMER_TIME
   gl_TIMESPEC
   gl_UNISTD_H
+  gl_FUNC_GLIBC_UNLOCKED_IO
   gl_UTIMENS
   AC_C_VARARRAYS
   gl_gnulib_enabled_260941c0e5dc67ec9e87d1fb321c300b=false
@@ -940,6 +942,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/u64.h
   lib/unistd.c
   lib/unistd.in.h
+  lib/unlocked-io.h
   lib/utimens.c
   lib/utimens.h
   lib/verify.h
@@ -1044,6 +1047,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/timespec.m4
   m4/tm_gmtoff.m4
   m4/unistd_h.m4
+  m4/unlocked-io.m4
   m4/utimens.m4
   m4/utimes.m4
   m4/vararrays.m4
diff --git a/m4/unlocked-io.m4 b/m4/unlocked-io.m4
new file mode 100644
index 00000000000..448ccac2f0e
--- /dev/null
+++ b/m4/unlocked-io.m4
@@ -0,0 +1,41 @@
+# unlocked-io.m4 serial 15
+
+# Copyright (C) 1998-2006, 2009-2017 Free Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl From Jim Meyering.
+dnl
+dnl See if the glibc *_unlocked I/O macros or functions are available.
+dnl Use only those *_unlocked macros or functions that are declared
+dnl (because some of them were declared in Solaris 2.5.1 but were removed
+dnl in Solaris 2.6, whereas we want binaries built on Solaris 2.5.1 to run
+dnl on Solaris 2.6).
+
+AC_DEFUN([gl_FUNC_GLIBC_UNLOCKED_IO],
+[
+  AC_DEFINE([USE_UNLOCKED_IO], [1],
+    [Define to 1 if you want getc etc. to use unlocked I/O if available.
+     Unlocked I/O can improve performance in unithreaded apps,
+     but it is not safe for multithreaded apps.])
+
+  dnl Persuade glibc and Solaris <stdio.h> to declare
+  dnl fgets_unlocked(), fputs_unlocked() etc.
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  AC_CHECK_DECLS_ONCE([clearerr_unlocked])
+  AC_CHECK_DECLS_ONCE([feof_unlocked])
+  AC_CHECK_DECLS_ONCE([ferror_unlocked])
+  AC_CHECK_DECLS_ONCE([fflush_unlocked])
+  AC_CHECK_DECLS_ONCE([fgets_unlocked])
+  AC_CHECK_DECLS_ONCE([fputc_unlocked])
+  AC_CHECK_DECLS_ONCE([fputs_unlocked])
+  AC_CHECK_DECLS_ONCE([fread_unlocked])
+  AC_CHECK_DECLS_ONCE([fwrite_unlocked])
+  AC_CHECK_DECLS_ONCE([getc_unlocked])
+  AC_CHECK_DECLS_ONCE([getchar_unlocked])
+  AC_CHECK_DECLS_ONCE([putc_unlocked])
+  AC_CHECK_DECLS_ONCE([putchar_unlocked])
+])
diff --git a/src/charset.c b/src/charset.c
index 9d15375dd79..d0840f7d2a9 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -29,7 +29,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 
 #include <errno.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <limits.h>
@@ -40,6 +39,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "charset.h"
 #include "coding.h"
 #include "buffer.h"
+#include "sysstdio.h"
 
 /*** GENERAL NOTES on CODED CHARACTER SETS (CHARSETS) ***
 
@@ -198,10 +198,6 @@ static struct
 
 #define GET_TEMP_CHARSET_WORK_DECODER(CODE)	\
   (temp_charset_work->table.decoder[(CODE)])
-
-#ifndef HAVE_GETC_UNLOCKED
-#define getc_unlocked getc
-#endif
 
 
 /* Set to 1 to warn that a charset map is loaded and thus a buffer
diff --git a/src/cm.c b/src/cm.c
index efa50b0f58d..9a90f37445c 100644
--- a/src/cm.c
+++ b/src/cm.c
@@ -19,10 +19,10 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 
 #include <config.h>
-#include <stdio.h>
 
 #include "lisp.h"
 #include "cm.h"
+#include "sysstdio.h"
 #include "termchar.h"
 #include "tparam.h"
 
@@ -45,8 +45,8 @@ int
 cmputc (int c)
 {
   if (current_tty->termscript)
-    putc (c & 0177, current_tty->termscript);
-  putc (c & 0177, current_tty->output);
+    putc_unlocked (c & 0177, current_tty->termscript);
+  putc_unlocked (c & 0177, current_tty->output);
   return c;
 }
 
@@ -117,11 +117,11 @@ cmcheckmagic (struct tty_display_info *tty)
       if (!MagicWrap (tty) || curY (tty) >= FrameRows (tty) - 1)
 	emacs_abort ();
       if (tty->termscript)
-	putc ('\r', tty->termscript);
-      putc ('\r', tty->output);
+	putc_unlocked ('\r', tty->termscript);
+      putc_unlocked ('\r', tty->output);
       if (tty->termscript)
-	putc ('\n', tty->termscript);
-      putc ('\n', tty->output);
+	putc_unlocked ('\n', tty->termscript);
+      putc_unlocked ('\n', tty->output);
       curX (tty) = 0;
       curY (tty)++;
     }
diff --git a/src/dispnew.c b/src/dispnew.c
index 27c69bde831..925e44d9804 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -3126,9 +3126,9 @@ update_frame (struct frame *f, bool force_p, bool inhibit_hairy_id_p)
       if (FRAME_TERMCAP_P (f) || FRAME_MSDOS_P (f))
         {
           if (FRAME_TTY (f)->termscript)
-            fflush (FRAME_TTY (f)->termscript);
+	    fflush_unlocked (FRAME_TTY (f)->termscript);
 	  if (FRAME_TERMCAP_P (f))
-	    fflush (FRAME_TTY (f)->output);
+	    fflush_unlocked (FRAME_TTY (f)->output);
         }
 
       /* Check window matrices for lost pointers.  */
@@ -3181,8 +3181,8 @@ update_frame_with_menu (struct frame *f, int row, int col)
   update_end (f);
 
   if (FRAME_TTY (f)->termscript)
-    fflush (FRAME_TTY (f)->termscript);
-  fflush (FRAME_TTY (f)->output);
+    fflush_unlocked (FRAME_TTY (f)->termscript);
+  fflush_unlocked (FRAME_TTY (f)->output);
   /* Check window matrices for lost pointers.  */
 #if GLYPH_DEBUG
 #if 0
@@ -4531,7 +4531,7 @@ update_frame_1 (struct frame *f, bool force_p, bool inhibit_id_p,
 		  ptrdiff_t outq = __fpending (display_output);
 		  if (outq > 900
 		      || (outq > 20 && ((i - 1) % preempt_count == 0)))
-		    fflush (display_output);
+		    fflush_unlocked (display_output);
 		}
 	    }
 
@@ -5615,13 +5615,13 @@ when TERMINAL is nil.  */)
 
       if (tty->termscript)
 	{
-	  fwrite (SDATA (string), 1, SBYTES (string), tty->termscript);
-	  fflush (tty->termscript);
+	  fwrite_unlocked (SDATA (string), 1, SBYTES (string), tty->termscript);
+	  fflush_unlocked (tty->termscript);
 	}
       out = tty->output;
     }
-  fwrite (SDATA (string), 1, SBYTES (string), out);
-  fflush (out);
+  fwrite_unlocked (SDATA (string), 1, SBYTES (string), out);
+  fflush_unlocked (out);
   unblock_input ();
   return Qnil;
 }
@@ -5636,7 +5636,7 @@ terminate any keyboard macro currently executing.  */)
   if (!NILP (arg))
     {
       if (noninteractive)
-	putchar (07);
+	putchar_unlocked (07);
       else
 	ring_bell (XFRAME (selected_frame));
     }
@@ -5650,7 +5650,7 @@ void
 bitch_at_user (void)
 {
   if (noninteractive)
-    putchar (07);
+    putchar_unlocked (07);
   else if (!INTERACTIVE)  /* Stop executing a keyboard macro.  */
     {
       const char *msg
diff --git a/src/emacs.c b/src/emacs.c
index da8df1bf1c7..0fec7167588 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -23,7 +23,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <errno.h>
 #include <fcntl.h>
-#include <stdio.h>
 #include <stdlib.h>
 
 #include <sys/file.h>
@@ -33,6 +32,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #define MAIN_PROGRAM
 #include "lisp.h"
+#include "sysstdio.h"
 
 #ifdef WINDOWSNT
 #include <fcntl.h>
@@ -885,7 +885,7 @@ main (int argc, char **argv)
     }
 #endif /* HAVE_SETRLIMIT and RLIMIT_STACK and not CYGWIN */
 
-  clearerr (stdin);
+  clearerr_unlocked (stdin);
 
   emacs_backtrace (-1);
 
@@ -983,7 +983,7 @@ main (int argc, char **argv)
       int i;
       printf ("Usage: %s [OPTION-OR-FILENAME]...\n", argv[0]);
       for (i = 0; i < ARRAYELTS (usage_message); i++)
-	fputs (usage_message[i], stdout);
+	fputs_unlocked (usage_message[i], stdout);
       exit (0);
     }
 
@@ -2197,7 +2197,7 @@ You must run Emacs in batch mode in order to dump it.  */)
   }
 #endif
 
-  fflush (stdout);
+  fflush_unlocked (stdout);
   /* Tell malloc where start of impure now is.  */
   /* Also arrange for warnings when nearly out of space.  */
 #if !defined SYSTEM_MALLOC && !defined HYBRID_MALLOC
diff --git a/src/fileio.c b/src/fileio.c
index cb070029a9b..a57d50b24e0 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -5643,14 +5643,12 @@ A non-nil CURRENT-ONLY argument means save only current buffer.  */)
 	  {
 	    block_input ();
 	    if (!NILP (BVAR (b, filename)))
-	      {
-		fwrite (SDATA (BVAR (b, filename)), 1,
-			SBYTES (BVAR (b, filename)), stream);
-	      }
-	    putc ('\n', stream);
-	    fwrite (SDATA (BVAR (b, auto_save_file_name)), 1,
-		    SBYTES (BVAR (b, auto_save_file_name)), stream);
-	    putc ('\n', stream);
+	      fwrite_unlocked (SDATA (BVAR (b, filename)), 1,
+			       SBYTES (BVAR (b, filename)), stream);
+	    putc_unlocked ('\n', stream);
+	    fwrite_unlocked (SDATA (BVAR (b, auto_save_file_name)), 1,
+			     SBYTES (BVAR (b, auto_save_file_name)), stream);
+	    putc_unlocked ('\n', stream);
 	    unblock_input ();
 	  }
 
@@ -5841,7 +5839,7 @@ effect except for flushing STREAM's data.  */)
 
   binmode = NILP (mode) ? O_TEXT : O_BINARY;
   if (fp != stdin)
-    fflush (fp);
+    fflush_unlocked (fp);
 
   return (set_binary_mode (fileno (fp), binmode) == O_BINARY) ? Qt : Qnil;
 }
diff --git a/src/image.c b/src/image.c
index aedec7954ee..07c4769e9e3 100644
--- a/src/image.c
+++ b/src/image.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 
 #include <fcntl.h>
-#include <stdio.h>
 #include <unistd.h>
 
 /* Include this before including <setjmp.h> to work around bugs with
@@ -41,6 +40,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "buffer.h"
 #include "dispextern.h"
 #include "blockinput.h"
+#include "sysstdio.h"
 #include "systime.h"
 #include <epaths.h>
 #include "coding.h"
@@ -2361,7 +2361,7 @@ slurp_file (int fd, ptrdiff_t *size)
 	     This can happen if the file grows as we read it.  */
 	  ptrdiff_t buflen = st.st_size;
 	  buf = xmalloc (buflen + 1);
-	  if (fread (buf, 1, buflen + 1, fp) == buflen)
+	  if (fread_unlocked (buf, 1, buflen + 1, fp) == buflen)
 	    *size = buflen;
 	  else
 	    {
@@ -5890,7 +5890,7 @@ png_read_from_file (png_structp png_ptr, png_bytep data, png_size_t length)
 {
   FILE *fp = png_get_io_ptr (png_ptr);
 
-  if (fread (data, 1, length, fp) < length)
+  if (fread_unlocked (data, 1, length, fp) < length)
     png_error (png_ptr, "Read error");
 }
 
@@ -5959,7 +5959,7 @@ png_load_body (struct frame *f, struct image *img, struct png_load_context *c)
 	}
 
       /* Check PNG signature.  */
-      if (fread (sig, 1, sizeof sig, fp) != sizeof sig
+      if (fread_unlocked (sig, 1, sizeof sig, fp) != sizeof sig
 	  || png_sig_cmp (sig, 0, sizeof sig))
 	{
 	  fclose (fp);
@@ -6598,7 +6598,8 @@ our_stdio_fill_input_buffer (j_decompress_ptr cinfo)
     {
       ptrdiff_t bytes;
 
-      bytes = fread (src->buffer, 1, JPEG_STDIO_BUFFER_SIZE, src->file);
+      bytes = fread_unlocked (src->buffer, 1, JPEG_STDIO_BUFFER_SIZE,
+			      src->file);
       if (bytes > 0)
         src->mgr.bytes_in_buffer = bytes;
       else
diff --git a/src/keyboard.c b/src/keyboard.c
index 55486c6d9ab..3442b18409a 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -39,6 +39,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "intervals.h"
 #include "keymap.h"
 #include "blockinput.h"
+#include "sysstdio.h"
 #include "systime.h"
 #include "atimer.h"
 #include "process.h"
@@ -3290,7 +3291,7 @@ record_char (Lisp_Object c)
       if (INTEGERP (c))
 	{
 	  if (XUINT (c) < 0x100)
-	    putc (XUINT (c), dribble);
+	    putc_unlocked (XUINT (c), dribble);
 	  else
 	    fprintf (dribble, " 0x%"pI"x", XUINT (c));
 	}
@@ -3303,15 +3304,15 @@ record_char (Lisp_Object c)
 
 	  if (SYMBOLP (dribblee))
 	    {
-	      putc ('<', dribble);
-	      fwrite (SDATA (SYMBOL_NAME (dribblee)), sizeof (char),
-		      SBYTES (SYMBOL_NAME (dribblee)),
-		      dribble);
-	      putc ('>', dribble);
+	      putc_unlocked ('<', dribble);
+	      fwrite_unlocked (SDATA (SYMBOL_NAME (dribblee)), sizeof (char),
+			       SBYTES (SYMBOL_NAME (dribblee)),
+			       dribble);
+	      putc_unlocked ('>', dribble);
 	    }
 	}
 
-      fflush (dribble);
+      fflush_unlocked (dribble);
       unblock_input ();
     }
 }
@@ -3769,7 +3770,7 @@ kbd_buffer_get_event (KBOARD **kbp,
 	 detaching from the terminal.  */
       || (IS_DAEMON && DAEMON_RUNNING))
     {
-      int c = getchar ();
+      int c = getchar_unlocked ();
       XSETINT (obj, c);
       *kbp = current_kboard;
       return obj;
@@ -10377,7 +10378,7 @@ handle_interrupt (bool in_signal_handler)
 	  sigemptyset (&blocked);
 	  sigaddset (&blocked, SIGINT);
 	  pthread_sigmask (SIG_BLOCK, &blocked, 0);
-	  fflush (stdout);
+	  fflush_unlocked (stdout);
 	}
 
       reset_all_sys_modes ();
diff --git a/src/lread.c b/src/lread.c
index 8716b86e9bf..182f96223a5 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -72,10 +72,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define file_tell ftell
 #endif
 
-#ifndef HAVE_GETC_UNLOCKED
-#define getc_unlocked getc
-#endif
-
 /* The objects or placeholders read with the #n=object form.
 
    A hash table maps a number to either a placeholder (while the
@@ -474,16 +470,15 @@ readbyte_from_file (int c, Lisp_Object readcharfun)
     }
 
   block_input ();
-  c = getc_unlocked (instream);
 
   /* Interrupted reads have been observed while reading over the network.  */
-  while (c == EOF && ferror (instream) && errno == EINTR)
+  while ((c = getc_unlocked (instream)) == EOF && errno == EINTR
+	 && ferror_unlocked (instream))
     {
       unblock_input ();
       maybe_quit ();
       block_input ();
-      clearerr (instream);
-      c = getc_unlocked (instream);
+      clearerr_unlocked (instream);
     }
 
   unblock_input ();
diff --git a/src/minibuf.c b/src/minibuf.c
index 1bbe276776e..835992fa79d 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include <errno.h>
-#include <stdio.h>
 
 #include <binary-io.h>
 
@@ -31,6 +30,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "frame.h"
 #include "window.h"
 #include "keymap.h"
+#include "sysstdio.h"
 #include "systty.h"
 
 /* List of buffers for use as minibuffers.
@@ -209,15 +209,15 @@ read_minibuf_noninteractive (Lisp_Object map, Lisp_Object initial,
       suppress_echo_on_tty (STDIN_FILENO);
     }
 
-  fwrite (SDATA (prompt), 1, SBYTES (prompt), stdout);
-  fflush (stdout);
+  fwrite_unlocked (SDATA (prompt), 1, SBYTES (prompt), stdout);
+  fflush_unlocked (stdout);
 
   val = Qnil;
   size = 100;
   len = 0;
   line = xmalloc (size);
 
-  while ((c = getchar ()) != '\n' && c != '\r')
+  while ((c = getchar_unlocked ()) != '\n' && c != '\r')
     {
       if (c == EOF)
 	{
diff --git a/src/print.c b/src/print.c
index aaec5b04956..6bf8af9ef93 100644
--- a/src/print.c
+++ b/src/print.c
@@ -228,7 +228,7 @@ printchar_to_stream (unsigned int ch, FILE *stream)
     {
       if (ASCII_CHAR_P (ch))
 	{
-	  putc (ch, stream);
+	  putc_unlocked (ch, stream);
 #ifdef WINDOWSNT
 	  /* Send the output to a debugger (nothing happens if there
 	     isn't one).  */
@@ -246,7 +246,7 @@ printchar_to_stream (unsigned int ch, FILE *stream)
 	  if (encode_p)
 	    encoded_ch = code_convert_string_norecord (encoded_ch,
 						       coding_system, true);
-	  fwrite (SSDATA (encoded_ch), 1, SBYTES (encoded_ch), stream);
+	  fwrite_unlocked (SSDATA (encoded_ch), 1, SBYTES (encoded_ch), stream);
 #ifdef WINDOWSNT
 	  if (print_output_debug_flag && stream == stderr)
 	    OutputDebugString (SSDATA (encoded_ch));
@@ -298,7 +298,7 @@ printchar (unsigned int ch, Lisp_Object fun)
 	  if (DISP_TABLE_P (Vstandard_display_table))
 	    printchar_to_stream (ch, stdout);
 	  else
-	    fwrite (str, 1, len, stdout);
+	    fwrite_unlocked (str, 1, len, stdout);
 	  noninteractive_need_newline = 1;
 	}
       else
@@ -350,7 +350,7 @@ strout (const char *ptr, ptrdiff_t size, ptrdiff_t size_byte,
 	    }
 	}
       else
-	fwrite (ptr, 1, size_byte, stdout);
+	fwrite_unlocked (ptr, 1, size_byte, stdout);
 
       noninteractive_need_newline = 1;
     }
@@ -801,7 +801,7 @@ append to existing target file.  */)
 	report_file_error ("Cannot open debugging output stream", file);
     }
 
-  fflush (stderr);
+  fflush_unlocked (stderr);
   if (dup2 (fd, STDERR_FILENO) < 0)
     report_file_error ("dup2", file);
   if (fd != stderr_dup)
diff --git a/src/sysdep.c b/src/sysdep.c
index 70f4a9dd7ea..b52236769e0 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -1408,7 +1408,7 @@ reset_sys_modes (struct tty_display_info *tty_out)
 {
   if (noninteractive)
     {
-      fflush (stdout);
+      fflush_unlocked (stdout);
       return;
     }
   if (!tty_out->term_initted)
@@ -1428,17 +1428,14 @@ reset_sys_modes (struct tty_display_info *tty_out)
     }
   else
     {			/* have to do it the hard way */
-      int i;
       tty_turn_off_insert (tty_out);
 
-      for (i = cursorX (tty_out); i < FrameCols (tty_out) - 1; i++)
-        {
-          fputc (' ', tty_out->output);
-        }
+      for (int i = cursorX (tty_out); i < FrameCols (tty_out) - 1; i++)
+	fputc_unlocked (' ', tty_out->output);
     }
 
   cmgoto (tty_out, FrameRows (tty_out) - 1, 0);
-  fflush (tty_out->output);
+  fflush_unlocked (tty_out->output);
 
   if (tty_out->terminal->reset_terminal_modes_hook)
     tty_out->terminal->reset_terminal_modes_hook (tty_out->terminal);
@@ -3079,7 +3076,7 @@ procfs_ttyname (int rdev)
       char minor[25];	/* 2 32-bit numbers + dash */
       char *endp;
 
-      for (; !feof (fdev) && !ferror (fdev); name[0] = 0)
+      for (; !feof_unlocked (fdev) && !ferror_unlocked (fdev); name[0] = 0)
 	{
 	  if (fscanf (fdev, "%*s %s %u %s %*s\n", name, &major, minor) >= 3
 	      && major == MAJOR (rdev))
@@ -3129,7 +3126,7 @@ procfs_get_total_memory (void)
 	    break;
 
 	  case 0:
-	    while ((c = getc (fmem)) != EOF && c != '\n')
+	    while ((c = getc_unlocked (fmem)) != EOF && c != '\n')
 	      continue;
 	    done = c == EOF;
 	    break;
diff --git a/src/sysstdio.h b/src/sysstdio.h
index 45ee33f5580..7fbcefcdad9 100644
--- a/src/sysstdio.h
+++ b/src/sysstdio.h
@@ -33,4 +33,45 @@ extern FILE *emacs_fopen (char const *, char const *);
 # define FOPEN_TEXT ""
 #endif
 
+/* These are compatible with unlocked-io.h, if both files are included.  */
+#if !HAVE_DECL_CLEARERR_UNLOCKED
+# define clearerr_unlocked(x) clearerr (x)
+#endif
+#if !HAVE_DECL_FEOF_UNLOCKED
+# define feof_unlocked(x) feof (x)
+#endif
+#if !HAVE_DECL_FERROR_UNLOCKED
+# define ferror_unlocked(x) ferror (x)
+#endif
+#if !HAVE_DECL_FFLUSH_UNLOCKED
+# define fflush_unlocked(x) fflush (x)
+#endif
+#if !HAVE_DECL_FGETS_UNLOCKED
+# define fgets_unlocked(x,y,z) fgets (x,y,z)
+#endif
+#if !HAVE_DECL_FPUTC_UNLOCKED
+# define fputc_unlocked(x,y) fputc (x,y)
+#endif
+#if !HAVE_DECL_FPUTS_UNLOCKED
+# define fputs_unlocked(x,y) fputs (x,y)
+#endif
+#if !HAVE_DECL_FREAD_UNLOCKED
+# define fread_unlocked(w,x,y,z) fread (w,x,y,z)
+#endif
+#if !HAVE_DECL_FWRITE_UNLOCKED
+# define fwrite_unlocked(w,x,y,z) fwrite (w,x,y,z)
+#endif
+#if !HAVE_DECL_GETC_UNLOCKED
+# define getc_unlocked(x) getc (x)
+#endif
+#if !HAVE_DECL_GETCHAR_UNLOCKED
+# define getchar_unlocked() getchar ()
+#endif
+#if !HAVE_DECL_PUTC_UNLOCKED
+# define putc_unlocked(x,y) putc (x,y)
+#endif
+#if !HAVE_DECL_PUTCHAR_UNLOCKED
+# define putchar_unlocked(x) putchar (x)
+#endif
+
 #endif /* EMACS_SYSSTDIO_H */
diff --git a/src/term.c b/src/term.c
index 8770aff8a92..3d7f4ada0b9 100644
--- a/src/term.c
+++ b/src/term.c
@@ -22,7 +22,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <errno.h>
 #include <fcntl.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <sys/file.h>
 #include <sys/time.h>
@@ -45,6 +44,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "keymap.h"
 #include "blockinput.h"
 #include "syssignal.h"
+#include "sysstdio.h"
 #ifdef MSDOS
 #include "msdos.h"
 static int been_here = -1;
@@ -146,7 +146,7 @@ tty_ring_bell (struct frame *f)
       OUTPUT (tty, (tty->TS_visible_bell && visible_bell
                     ? tty->TS_visible_bell
                     : tty->TS_bell));
-      fflush (tty->output);
+      fflush_unlocked (tty->output);
     }
 }
 
@@ -167,9 +167,10 @@ tty_send_additional_strings (struct terminal *terminal, Lisp_Object sym)
       Lisp_Object string = XCAR (extra_codes);
       if (STRINGP (string))
         {
-          fwrite (SDATA (string), 1, SBYTES (string), tty->output);
+	  fwrite_unlocked (SDATA (string), 1, SBYTES (string), tty->output);
           if (tty->termscript)
-            fwrite (SDATA (string), 1, SBYTES (string), tty->termscript);
+	    fwrite_unlocked (SDATA (string), 1, SBYTES (string),
+			     tty->termscript);
         }
     }
 }
@@ -197,7 +198,7 @@ tty_set_terminal_modes (struct terminal *terminal)
       OUTPUT_IF (tty, tty->TS_keypad_mode);
       losecursor (tty);
       tty_send_additional_strings (terminal, Qtty_mode_set_strings);
-      fflush (tty->output);
+      fflush_unlocked (tty->output);
     }
 }
 
@@ -220,7 +221,7 @@ tty_reset_terminal_modes (struct terminal *terminal)
       /* Output raw CR so kernel can track the cursor hpos.  */
       current_tty = tty;
       cmputc ('\r');
-      fflush (tty->output);
+      fflush_unlocked (tty->output);
     }
 }
 
@@ -235,7 +236,7 @@ tty_update_end (struct frame *f)
     tty_show_cursor (tty);
   tty_turn_off_insert (tty);
   tty_background_highlight (tty);
-  fflush (tty->output);
+  fflush_unlocked (tty->output);
 }
 
 /* The implementation of set_terminal_window for termcap frames. */
@@ -497,8 +498,8 @@ tty_clear_end_of_line (struct frame *f, int first_unused_hpos)
       for (i = curX (tty); i < first_unused_hpos; i++)
 	{
 	  if (tty->termscript)
-	    fputc (' ', tty->termscript);
-	  fputc (' ', tty->output);
+	    fputc_unlocked (' ', tty->termscript);
+	  fputc_unlocked (' ', tty->output);
 	}
       cmplus (tty, first_unused_hpos - curX (tty));
     }
@@ -771,11 +772,11 @@ tty_write_glyphs (struct frame *f, struct glyph *string, int len)
       if (coding->produced > 0)
 	{
 	  block_input ();
-	  fwrite (conversion_buffer, 1, coding->produced, tty->output);
-	  if (ferror (tty->output))
-	    clearerr (tty->output);
+	  fwrite_unlocked (conversion_buffer, 1, coding->produced, tty->output);
+	  clearerr_unlocked (tty->output);
 	  if (tty->termscript)
-	    fwrite (conversion_buffer, 1, coding->produced, tty->termscript);
+	    fwrite_unlocked (conversion_buffer, 1, coding->produced,
+			     tty->termscript);
 	  unblock_input ();
 	}
       string += n;
@@ -832,11 +833,11 @@ tty_write_glyphs_with_face (register struct frame *f, register struct glyph *str
   if (coding->produced > 0)
     {
       block_input ();
-      fwrite (conversion_buffer, 1, coding->produced, tty->output);
-      if (ferror (tty->output))
-	clearerr (tty->output);
+      fwrite_unlocked (conversion_buffer, 1, coding->produced, tty->output);
+      clearerr_unlocked (tty->output);
       if (tty->termscript)
-	fwrite (conversion_buffer, 1, coding->produced, tty->termscript);
+	fwrite_unlocked (conversion_buffer, 1, coding->produced,
+			 tty->termscript);
       unblock_input ();
     }
 
@@ -918,11 +919,11 @@ tty_insert_glyphs (struct frame *f, struct glyph *start, int len)
       if (coding->produced > 0)
 	{
 	  block_input ();
-	  fwrite (conversion_buffer, 1, coding->produced, tty->output);
-	  if (ferror (tty->output))
-	    clearerr (tty->output);
+	  fwrite_unlocked (conversion_buffer, 1, coding->produced, tty->output);
+	  clearerr_unlocked (tty->output);
 	  if (tty->termscript)
-	    fwrite (conversion_buffer, 1, coding->produced, tty->termscript);
+	    fwrite_unlocked (conversion_buffer, 1, coding->produced,
+			     tty->termscript);
 	  unblock_input ();
 	}
 
@@ -3327,7 +3328,7 @@ tty_menu_activate (tty_menu *menu, int *pane, int *selidx,
 	 which calls tty_show_cursor.  Re-hide it, so it doesn't show
 	 through the menus.  */
       tty_hide_cursor (tty);
-      fflush (tty->output);
+      fflush_unlocked (tty->output);
     }
 
   sf->mouse_moved = 0;
@@ -3335,7 +3336,7 @@ tty_menu_activate (tty_menu *menu, int *pane, int *selidx,
   while (statecount--)
     free_saved_screen (state[statecount].screen_behind);
   tty_show_cursor (tty);	/* Turn cursor back on.  */
-  fflush (tty->output);
+  fflush_unlocked (tty->output);
 
 /* Clean up any mouse events that are waiting inside Emacs event queue.
      These events are likely to be generated before the menu was even
diff --git a/src/xfaces.c b/src/xfaces.c
index 4714b7b3cb8..86bb9b0b496 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -6232,7 +6232,7 @@ where R,G,B are numbers between 0 and 255 and name is an arbitrary string.  */)
       int red, green, blue;
       int num;
 
-      while (fgets (buf, sizeof (buf), fp) != NULL) {
+      while (fgets_unlocked (buf, sizeof (buf), fp) != NULL) {
 	if (sscanf (buf, "%d %d %d %n", &red, &green, &blue, &num) == 3)
 	  {
 #ifdef HAVE_NTGUI