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5e9dc714ca
As the Autoconf documentation says, "These days portable programs [...] should not rely on `HAVE_RESTARTABLE_SYSCALLS', since nowadays whether a system call is restartable is a dynamic issue, not a configuration-time issue." In other words, if we ever rely on HAVE_RESTARTABLE_SYSCALLS, we are at the mercy of any code that Guile happens to be linked with, because that code could install a signal handler without the SA_RESTART flag, and then a Guile system call could unexpectedly return EINTR. The readline part of this goes back to this problem report: excellent example of the above paragraph. It was noted during the discussion that undefining HAVE_RESTARTABLE_SYSCALLS would fix the problem, but that solution wasn't adopted - I guess because Guile was still using cooperative threads then (not pthreads) and so there was a significant concern (whether founded or not) that not using restartable syscalls (where available) could lead to a loss of performance. Now Guile's default mode of operation is with pthreads, where we already don't assume that HAVE_RESTARTABLE_SYSCALLS is reliable, so there is no possible further performance loss. And in any case we really have no choice, if we want correct operation. * configure.in (AC_SYS_RESTARTABLE_SYSCALLS): Removed. * doc/ref/posix.texi (Signals): Remove statement that Guile always sets SA_RESTART flag. * guile-readline/configure.in (GUILE_SIGWINCH_SA_RESTART_CLEARED): Remove this setting, together with its test code. (HAVE_RL_PRE_INPUT_HOOK): Remove this setting and its code, as no longer needed. * guile-readline/readline.c (sigwinch_enable_restart): Removed. (scm_init_readline): Remove setting of rl_pre_input_hook. * libguile/_scm.h (SCM_SYSCALL): Remove the definition that relies on HAVE_RESTARTABLE_SYSCALLS. * libguile/scmsigs.c (scm_sigaction_for_thread): Don't always set the SA_RESTART flag if available. Update docstring accordingly. (scm_init_scmsigs): Remove code that sets SA_RESTART flag for all signals.
164 lines
5.6 KiB
C
164 lines
5.6 KiB
C
/* classes: h_files */
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#ifndef SCM__SCM_H
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#define SCM__SCM_H
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/* Copyright (C) 1995,1996,2000,2001, 2002, 2006, 2008 Free Software Foundation, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**********************************************************************
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This file is Guile's central private header.
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When included by other files, this file should preceed any include
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other than __scm.h. See __scm.h for details regarding the purpose of
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and differences between _scm.h and __scm.h.
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**********************************************************************/
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#if defined(__ia64) && !defined(__ia64__)
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# define __ia64__
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#endif
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#if HAVE_CONFIG_H
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# include <config.h>
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#endif
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/* Undefine HAVE_STRUCT_TIMESPEC, because the libguile C code doesn't
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need it anymore, and because on MinGW:
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- the definition of struct timespec is provided (if at all) by
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pthread.h
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- pthread.h will _not_ define struct timespec if
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HAVE_STRUCT_TIMESPEC is 1, because then it thinks that it doesn't
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need to.
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The libguile C code doesn't need HAVE_STRUCT_TIMESPEC anymore,
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because the value of HAVE_STRUCT_TIMESPEC has already been
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incorporated in how scm_t_timespec is defined (in scmconfig.h), and
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the rest of the libguile C code now just uses scm_t_timespec.
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*/
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#ifdef HAVE_STRUCT_TIMESPEC
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#undef HAVE_STRUCT_TIMESPEC
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#endif
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#include <errno.h>
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#include "libguile/__scm.h"
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/* Include headers for those files central to the implementation. The
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rest should be explicitly #included in the C files themselves. */
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#include "libguile/error.h" /* Everyone signals errors. */
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#include "libguile/print.h" /* Everyone needs to print. */
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#include "libguile/pairs.h" /* Everyone conses. */
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#include "libguile/list.h" /* Everyone makes lists. */
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#include "libguile/gc.h" /* Everyone allocates. */
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#include "libguile/gsubr.h" /* Everyone defines global functions. */
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#include "libguile/procs.h" /* Same. */
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#include "libguile/numbers.h" /* Everyone deals with fixnums. */
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#include "libguile/symbols.h" /* For length, chars, values, miscellany. */
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#include "libguile/boolean.h" /* Everyone wonders about the truth. */
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#include "libguile/threads.h" /* You are not alone. */
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#include "libguile/snarf.h" /* Everyone snarfs. */
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#include "libguile/variable.h"
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#include "libguile/modules.h"
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#include "libguile/inline.h"
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#ifndef SCM_SYSCALL
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#ifdef vms
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# ifndef __GNUC__
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# include <ssdef.h>
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# define SCM_SYSCALL(line) do{errno = 0;line;} \
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while(EVMSERR==errno && (vaxc$errno>>3)==(SS$_CONTROLC>>3))
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# endif /* ndef __GNUC__ */
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#endif /* def vms */
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#endif /* ndef SCM_SYSCALL */
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#ifndef SCM_SYSCALL
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# ifdef EINTR
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# if (EINTR > 0)
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# define SCM_SYSCALL(line) do{errno = 0;line;}while(EINTR==errno)
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# endif /* (EINTR > 0) */
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# endif /* def EINTR */
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#endif /* ndef SCM_SYSCALL */
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#ifndef SCM_SYSCALL
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# define SCM_SYSCALL(line) line;
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#endif /* ndef SCM_SYSCALL */
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#ifndef min
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#define min(A, B) ((A) <= (B) ? (A) : (B))
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#endif
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#ifndef max
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#define max(A, B) ((A) >= (B) ? (A) : (B))
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#endif
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#if GUILE_USE_64_CALLS && HAVE_STAT64
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#define CHOOSE_LARGEFILE(foo,foo64) foo64
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#else
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#define CHOOSE_LARGEFILE(foo,foo64) foo
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#endif
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/* These names are a bit long, but they make it clear what they represent. */
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#if SCM_HAVE_STRUCT_DIRENT64 == 1
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# define dirent_or_dirent64 CHOOSE_LARGEFILE(dirent,dirent64)
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#else
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# define dirent_or_dirent64 dirent
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#endif
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#define fstat_or_fstat64 CHOOSE_LARGEFILE(fstat,fstat64)
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#define ftruncate_or_ftruncate64 CHOOSE_LARGEFILE(ftruncate,ftruncate64)
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#define lseek_or_lseek64 CHOOSE_LARGEFILE(lseek,lseek64)
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#define lstat_or_lstat64 CHOOSE_LARGEFILE(lstat,lstat64)
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#define off_t_or_off64_t CHOOSE_LARGEFILE(off_t,off64_t)
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#define open_or_open64 CHOOSE_LARGEFILE(open,open64)
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#define readdir_or_readdir64 CHOOSE_LARGEFILE(readdir,readdir64)
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#if SCM_HAVE_READDIR64_R == 1
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# define readdir_r_or_readdir64_r CHOOSE_LARGEFILE(readdir_r,readdir64_r)
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#else
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# define readdir_r_or_readdir64_r readdir_r
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#endif
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#define stat_or_stat64 CHOOSE_LARGEFILE(stat,stat64)
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#define truncate_or_truncate64 CHOOSE_LARGEFILE(truncate,truncate64)
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#define scm_from_off_t_or_off64_t CHOOSE_LARGEFILE(scm_from_off_t,scm_from_int64)
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#define scm_from_ino_t_or_ino64_t CHOOSE_LARGEFILE(scm_from_ulong,scm_from_uint64)
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#define scm_from_blkcnt_t_or_blkcnt64_t CHOOSE_LARGEFILE(scm_from_ulong,scm_from_uint64)
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#define scm_to_off_t_or_off64_t CHOOSE_LARGEFILE(scm_to_off_t,scm_to_int64)
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#if SIZEOF_OFF_T == 4
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# define scm_to_off_t scm_to_int32
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# define scm_from_off_t scm_from_int32
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#elif SIZEOF_OFF_T == 8
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# define scm_to_off_t scm_to_int64
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# define scm_from_off_t scm_from_int64
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#else
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# error sizeof(off_t) is not 4 or 8.
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#endif
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#define scm_to_off64_t scm_to_int64
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#define scm_from_off64_t scm_from_int64
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#endif /* SCM__SCM_H */
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/*
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Local Variables:
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c-file-style: "gnu"
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End:
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*/
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