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.

2 files changed, 45 insertions, 0 deletions

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])
+])