From 07d4b44bca1eb9c476d0f296c10066068882d334 Mon Sep 17 00:00:00 2001 From: Grisha Levit Date: Mon, 5 Feb 2024 20:37:52 -0500 Subject: [PATCH] use unlocked stdio functions Bash makes many calls to stdio functions that may have unlocked_stdio(3) equivalents. Since the locking functionality provided by the regular versions is only useful in multi-threaded applications, it probably makes sense for Bash to use the *_unlocked versions where available. E.g. in situations where execution time is dominated by putchar(3) calls, using putchar_unlocked(3) can offer an ~2X speedup: $ fun() { printf -v X "%$((1<<24))s" && time printf "$X"; } $ export -f fun $ bash.old -c fun >/dev/null real 0m0.720s user 0m0.669s sys 0m0.048s $ bash.new -c fun >/dev/null real 0m0.370s user 0m0.301s sys 0m0.067s This patch is basically an adoption of the unlocked-io module from Gnulib. m4/unlocked-io.m4 - BASH_FUNC_UNLOCKED_IO: new AC_DEFUN, adapted from Gnulib config.h.in - HAVE_DECL_*_UNLOCKED: for checking by BASH_FUNC_UNLOCKED_IO configure.ac - include m4/unlocked-io.m4, use BASH_FUNC_UNLOCKED_IO include/unlocked-io.h - clearerr, feof, ferror, fflush, fgets, fputc, fputs, fread, fwrite, getc, getchar, putc, putchar: replace with *_unlocked versions if available. Adopted from Gnulib. general.h - include unlocked-io.h --- config.h.in | 16 +++++ configure.ac | 2 + general.h | 1 + include/unlocked-io.h | 138 ++++++++++++++++++++++++++++++++++++++++++ m4/unlocked-io.m4 | 31 ++++++++++ 5 files changed, 188 insertions(+) create mode 100644 include/unlocked-io.h create mode 100644 m4/unlocked-io.m4 diff --git a/config.h.in b/config.h.in index f0c8be79..93536427 100644 --- a/config.h.in +++ b/config.h.in @@ -510,6 +510,22 @@ #undef HAVE_DECL_STRTOULL #undef HAVE_DECL_STRTOUMAX +/* These are checked with BASH_FUNC_UNLOCKED_IO */ + +#undef HAVE_DECL_CLEARERR_UNLOCKED +#undef HAVE_DECL_FEOF_UNLOCKED +#undef HAVE_DECL_FERROR_UNLOCKED +#undef HAVE_DECL_FFLUSH_UNLOCKED +#undef HAVE_DECL_FGETS_UNLOCKED +#undef HAVE_DECL_FPUTC_UNLOCKED +#undef HAVE_DECL_FPUTS_UNLOCKED +#undef HAVE_DECL_FREAD_UNLOCKED +#undef HAVE_DECL_FWRITE_UNLOCKED +#undef HAVE_DECL_GETC_UNLOCKED +#undef HAVE_DECL_GETCHAR_UNLOCKED +#undef HAVE_DECL_PUTC_UNLOCKED +#undef HAVE_DECL_PUTCHAR_UNLOCKED + /* Characteristics of system calls and C library functions. */ /* Define if the `getpgrp' function takes no argument. */ diff --git a/configure.ac b/configure.ac index c25a8088..29add098 100644 --- a/configure.ac +++ b/configure.ac @@ -717,6 +717,7 @@ m4_include([m4/stat-time.m4]) m4_include([m4/timespec.m4]) m4_include([m4/strtoimax.m4]) +m4_include([m4/unlocked-io.m4]) dnl include files for gettext @@ -1092,6 +1093,7 @@ BASH_FUNC_SNPRINTF BASH_FUNC_VSNPRINTF BASH_FUNC_STRTOIMAX +BASH_FUNC_UNLOCKED_IO dnl If putenv or unsetenv is not present, set the right define so the dnl prototype and declaration in lib/sh/getenv.c will be standard-conformant diff --git a/general.h b/general.h index ecbc8877..6f7a3aaa 100644 --- a/general.h +++ b/general.h @@ -43,6 +43,7 @@ # include #endif +#include "unlocked-io.h" #include "xmalloc.h" /* Hardly used anymore */ diff --git a/include/unlocked-io.h b/include/unlocked-io.h new file mode 100644 index 00000000..659e7986 --- /dev/null +++ b/include/unlocked-io.h @@ -0,0 +1,138 @@ +/* Prefer faster, non-thread-safe stdio functions if available. + + Copyright (C) 2001-2004, 2009-2024 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 . */ + +/* Written by Jim Meyering. */ + +/* Adapted from gnulib:lib/unlocked-io.h */ + +#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 + +# if HAVE_DECL_CLEARERR_UNLOCKED || defined clearerr_unlocked +# undef clearerr +# define clearerr(x) clearerr_unlocked (x) +# else +# define clearerr_unlocked(x) clearerr (x) +# endif + +# if HAVE_DECL_FEOF_UNLOCKED || defined feof_unlocked +# undef feof +# define feof(x) feof_unlocked (x) +# else +# define feof_unlocked(x) feof (x) +# endif + +# if HAVE_DECL_FERROR_UNLOCKED || defined ferror_unlocked +# undef ferror +# define ferror(x) ferror_unlocked (x) +# else +# define ferror_unlocked(x) ferror (x) +# endif + +# if HAVE_DECL_FFLUSH_UNLOCKED || defined fflush_unlocked +# undef fflush +# define fflush(x) fflush_unlocked (x) +# else +# define fflush_unlocked(x) fflush (x) +# endif + +# if HAVE_DECL_FGETS_UNLOCKED || defined 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 || defined 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 || defined 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 || defined 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 || defined 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 || defined getc_unlocked +# undef getc +# define getc(x) getc_unlocked (x) +# else +# define getc_unlocked(x) getc (x) +# endif + +# if HAVE_DECL_GETCHAR_UNLOCKED || defined getchar_unlocked +# undef getchar +# define getchar() getchar_unlocked () +# else +# define getchar_unlocked() getchar () +# endif + +# if HAVE_DECL_PUTC_UNLOCKED || defined 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 || defined 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/unlocked-io.m4 b/m4/unlocked-io.m4 new file mode 100644 index 00000000..ff14f349 --- /dev/null +++ b/m4/unlocked-io.m4 @@ -0,0 +1,31 @@ +# unlocked-io.m4 serial 16 + +# Copyright (C) 1998-2006, 2009-2024 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 Adapted from gnulib:m4/unlocked-io.m4 +AC_DEFUN([BASH_FUNC_UNLOCKED_IO], +[ + dnl Persuade glibc and Solaris to declare + dnl fgets_unlocked(), fputs_unlocked() etc. + AC_REQUIRE([AC_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]) +]) -- 2.43.0