Remove support for Unix systems without the POSIX signal APIs.

Remove configure's checks for HAVE_POSIX_SIGNALS, HAVE_SIGPROCMASK, and
HAVE_SIGSETJMP.  These APIs are required by the Single Unix Spec v2
(POSIX 1997), which we generally consider to define our minimum required
set of Unix APIs.  Moreover, no buildfarm member has reported not having
them since 2012 or before, which means that even if the code is still live
somewhere, it's untested --- and we've made plenty of signal-handling
changes of late.  So just take these APIs as given and save the cycles for
configure probes for them.

However, we can't remove as much C code as I'd hoped, because the Windows
port evidently still uses the non-POSIX code paths for signal masking.
Since we're largely emulating these BSD-style APIs for Windows anyway, it
might be a good thing to switch over to POSIX-like notation and thereby
remove a few more #ifdefs.  But I'm not in a position to code or test that.
In the meantime, we can at least make things a bit more transparent by
testing for WIN32 explicitly in these places.
This commit is contained in:
Tom Lane 2015-08-31 12:55:59 -04:00
parent 8f7d044ba8
commit a65e086453
11 changed files with 27 additions and 200 deletions

View File

@ -170,33 +170,6 @@ AC_DEFUN([PGAC_STRUCT_ADDRINFO],
])])# PGAC_STRUCT_ADDRINFO
# PGAC_FUNC_POSIX_SIGNALS
# -----------------------
# Check to see if the machine has the POSIX signal interface. Define
# HAVE_POSIX_SIGNALS if so. Also set the output variable HAVE_POSIX_SIGNALS
# to yes or no.
#
# Note that this test only compiles a test program, it doesn't check
# whether the routines actually work. If that becomes a problem, make
# a fancier check.
AC_DEFUN([PGAC_FUNC_POSIX_SIGNALS],
[AC_CACHE_CHECK(for POSIX signal interface, pgac_cv_func_posix_signals,
[AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <signal.h>
],
[struct sigaction act, oact;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_RESTART;
sigaction(0, &act, &oact);])],
[pgac_cv_func_posix_signals=yes],
[pgac_cv_func_posix_signals=no])])
if test x"$pgac_cv_func_posix_signals" = xyes ; then
AC_DEFINE(HAVE_POSIX_SIGNALS, 1,
[Define to 1 if you have the POSIX signal interface.])
fi
HAVE_POSIX_SIGNALS=$pgac_cv_func_posix_signals
AC_SUBST(HAVE_POSIX_SIGNALS)])# PGAC_FUNC_POSIX_SIGNALS
# PGAC_FUNC_SNPRINTF_LONG_LONG_INT_MODIFIER
# ---------------------------------------
# Determine which length modifier snprintf uses for long long int. We

83
configure vendored
View File

@ -649,7 +649,6 @@ XGETTEXT
MSGMERGE
MSGFMT_FLAGS
MSGFMT
HAVE_POSIX_SIGNALS
PG_CRC32C_OBJS
CFLAGS_SSE42
have_win32_dbghelp
@ -12289,7 +12288,7 @@ fi
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
@ -13048,38 +13047,6 @@ esac
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for sigsetjmp" >&5
$as_echo_n "checking for sigsetjmp... " >&6; }
if ${pgac_cv_func_sigsetjmp+:} false; then :
$as_echo_n "(cached) " >&6
else
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
#include <setjmp.h>
int
main ()
{
sigjmp_buf x; sigsetjmp(x, 1);
;
return 0;
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
pgac_cv_func_sigsetjmp=yes
else
pgac_cv_func_sigsetjmp=no
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_func_sigsetjmp" >&5
$as_echo "$pgac_cv_func_sigsetjmp" >&6; }
if test x"$pgac_cv_func_sigsetjmp" = x"yes"; then
$as_echo "#define HAVE_SIGSETJMP 1" >>confdefs.h
fi
ac_fn_c_check_decl "$LINENO" "sys_siglist" "ac_cv_have_decl_sys_siglist" "#include <signal.h>
/* NetBSD declares sys_siglist in unistd.h. */
#ifdef HAVE_UNISTD_H
@ -14635,54 +14602,6 @@ fi
# Check that POSIX signals are available if thread safety is enabled.
if test "$PORTNAME" != "win32"
then
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for POSIX signal interface" >&5
$as_echo_n "checking for POSIX signal interface... " >&6; }
if ${pgac_cv_func_posix_signals+:} false; then :
$as_echo_n "(cached) " >&6
else
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
#include <signal.h>
int
main ()
{
struct sigaction act, oact;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_RESTART;
sigaction(0, &act, &oact);
;
return 0;
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
pgac_cv_func_posix_signals=yes
else
pgac_cv_func_posix_signals=no
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_func_posix_signals" >&5
$as_echo "$pgac_cv_func_posix_signals" >&6; }
if test x"$pgac_cv_func_posix_signals" = xyes ; then
$as_echo "#define HAVE_POSIX_SIGNALS 1" >>confdefs.h
fi
HAVE_POSIX_SIGNALS=$pgac_cv_func_posix_signals
if test "$pgac_cv_func_posix_signals" != yes -a "$enable_thread_safety" = yes; then
as_fn_error $? "
Thread-safety requires POSIX signals, which are not supported by this
operating system; use --disable-thread-safety to disable thread safety." "$LINENO" 5
fi
fi
# Select semaphore implementation type.
if test "$PORTNAME" != "win32"; then
if test x"$USE_NAMED_POSIX_SEMAPHORES" = x"1" ; then

View File

@ -1406,7 +1406,7 @@ PGAC_FUNC_GETTIMEOFDAY_1ARG
LIBS_including_readline="$LIBS"
LIBS=`echo "$LIBS" | sed -e 's/-ledit//g' -e 's/-lreadline//g'`
AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat pthread_is_threaded_np readlink setproctitle setsid shm_open symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
AC_REPLACE_FUNCS(fseeko)
case $host_os in
@ -1596,18 +1596,6 @@ if test "$PORTNAME" = "cygwin"; then
AC_LIBOBJ(dirmod)
fi
dnl Cannot use AC_CHECK_FUNC because sigsetjmp may be a macro
dnl (especially on GNU libc)
dnl See also comments in c.h.
AC_CACHE_CHECK([for sigsetjmp], pgac_cv_func_sigsetjmp,
[AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <setjmp.h>],
[sigjmp_buf x; sigsetjmp(x, 1);])],
[pgac_cv_func_sigsetjmp=yes],
[pgac_cv_func_sigsetjmp=no])])
if test x"$pgac_cv_func_sigsetjmp" = x"yes"; then
AC_DEFINE(HAVE_SIGSETJMP, 1, [Define to 1 if you have sigsetjmp().])
fi
AC_CHECK_DECLS([sys_siglist], [], [],
[#include <signal.h>
/* NetBSD declares sys_siglist in unistd.h. */
@ -1932,18 +1920,6 @@ fi
AC_SUBST(PG_CRC32C_OBJS)
# Check that POSIX signals are available if thread safety is enabled.
if test "$PORTNAME" != "win32"
then
PGAC_FUNC_POSIX_SIGNALS
if test "$pgac_cv_func_posix_signals" != yes -a "$enable_thread_safety" = yes; then
AC_MSG_ERROR([
Thread-safety requires POSIX signals, which are not supported by this
operating system; use --disable-thread-safety to disable thread safety.])
fi
fi
# Select semaphore implementation type.
if test "$PORTNAME" != "win32"; then
if test x"$USE_NAMED_POSIX_SEMAPHORES" = x"1" ; then

View File

@ -432,9 +432,6 @@ host_cpu = @host_cpu@
# Make HAVE_IPV6 available for initdb script creation
HAVE_IPV6= @HAVE_IPV6@
# The HP-UX port makefile, for one, needs access to this symbol
HAVE_POSIX_SIGNALS= @HAVE_POSIX_SIGNALS@
# This is mainly for use on FreeBSD, where we have both a.out and elf
# systems now. May be applicable to other systems to?
ELF_SYSTEM= @ELF_SYS@

View File

@ -18,7 +18,7 @@
#include "libpq/pqsignal.h"
#ifdef HAVE_SIGPROCMASK
#ifndef WIN32
sigset_t UnBlockSig,
BlockSig,
StartupBlockSig;
@ -45,7 +45,7 @@ int UnBlockSig,
void
pqinitmask(void)
{
#ifdef HAVE_SIGPROCMASK
#ifndef WIN32
sigemptyset(&UnBlockSig);
@ -101,7 +101,7 @@ pqinitmask(void)
#ifdef SIGALRM
sigdelset(&StartupBlockSig, SIGALRM);
#endif
#else
#else /* WIN32 */
/* Set the signals we want. */
UnBlockSig = 0;
BlockSig = sigmask(SIGQUIT) |

View File

@ -1051,9 +1051,9 @@ extern int vsnprintf(char *str, size_t count, const char *fmt, va_list args);
/*
* When there is no sigsetjmp, its functionality is provided by plain
* setjmp. Incidentally, nothing provides setjmp's functionality in
* that case.
* that case. We now support the case only on Windows.
*/
#ifndef HAVE_SIGSETJMP
#ifdef WIN32
#define sigjmp_buf jmp_buf
#define sigsetjmp(x,y) setjmp(x)
#define siglongjmp longjmp

View File

@ -15,27 +15,27 @@
#include <signal.h>
#ifdef HAVE_SIGPROCMASK
#ifndef WIN32
extern sigset_t UnBlockSig,
BlockSig,
StartupBlockSig;
#define PG_SETMASK(mask) sigprocmask(SIG_SETMASK, mask, NULL)
#else /* not HAVE_SIGPROCMASK */
#else /* WIN32 */
/*
* Windows doesn't provide the POSIX signal API, so we use something
* approximating the old BSD signal API.
*/
extern int UnBlockSig,
BlockSig,
StartupBlockSig;
#ifndef WIN32
#define PG_SETMASK(mask) sigsetmask(*((int*)(mask)))
#else
#define PG_SETMASK(mask) pqsigsetmask(*((int*)(mask)))
int pqsigsetmask(int mask);
#endif
extern int pqsigsetmask(int mask);
#define PG_SETMASK(mask) pqsigsetmask(*(mask))
#define sigaddset(set, signum) (*(set) |= (sigmask(signum)))
#define sigdelset(set, signum) (*(set) &= ~(sigmask(signum)))
#endif /* not HAVE_SIGPROCMASK */
#endif /* WIN32 */
extern void pqinitmask(void);

View File

@ -379,9 +379,6 @@
/* Define to 1 if you have the `posix_fadvise' function. */
#undef HAVE_POSIX_FADVISE
/* Define to 1 if you have the POSIX signal interface. */
#undef HAVE_POSIX_SIGNALS
/* Define to 1 if the assembler supports PPC's LWARX mutex hint bit. */
#undef HAVE_PPC_LWARX_MUTEX_HINT
@ -443,12 +440,6 @@
/* Define to 1 if you have the `shm_open' function. */
#undef HAVE_SHM_OPEN
/* Define to 1 if you have the `sigprocmask' function. */
#undef HAVE_SIGPROCMASK
/* Define to 1 if you have sigsetjmp(). */
#undef HAVE_SIGSETJMP
/* Define to 1 if you have the `snprintf' function. */
#undef HAVE_SNPRINTF

View File

@ -264,9 +264,6 @@
/* Define to 1 if you have the <poll.h> header file. */
/* #undef HAVE_POLL_H */
/* Define to 1 if you have the POSIX signal interface. */
/* #undef HAVE_POSIX_SIGNALS */
/* Define to 1 if you have the `pstat' function. */
/* #undef HAVE_PSTAT */
@ -316,12 +313,6 @@
/* Define to 1 if you have the `setsid' function. */
/* #undef HAVE_SETSID */
/* Define to 1 if you have the `sigprocmask' function. */
/* #undef HAVE_SIGPROCMASK */
/* Define to 1 if you have sigsetjmp(). */
/* #undef HAVE_SIGSETJMP */
/* Define to 1 if you have the `snprintf' function. */
/* #undef HAVE_SNPRINTF */

View File

@ -1,10 +1,3 @@
# If we don't have POSIX signals, we need to use the libBSD signal routines.
# (HPUX 9 and early HPUX 10 releases don't have POSIX signals.) Link in
# libBSD only in that case.
ifeq ($(HAVE_POSIX_SIGNALS), no)
LIBS := -lBSD $(LIBS)
endif
# Using X/Open Networking Interfaces requires to link with libxnet.
# Without specifying this, bind(), getpeername() and so on don't work
# correctly in the LP64 data model.

View File

@ -11,30 +11,17 @@
* IDENTIFICATION
* src/port/pqsignal.c
*
* A NOTE ABOUT SIGNAL HANDLING ACROSS THE VARIOUS PLATFORMS.
*
* pg_config.h defines the macro HAVE_POSIX_SIGNALS for some platforms and
* not for others. We use that here to decide how to handle signalling.
*
* Ultrix and SunOS provide BSD signal(2) semantics by default.
*
* SVID2 and POSIX signal(2) semantics differ from BSD signal(2)
* semantics. We can use the POSIX sigaction(2) on systems that
* allow us to request restartable signals (SA_RESTART).
*
* Some systems don't allow restartable signals at all unless we
* link to a special BSD library.
*
* We devoutly hope that there aren't any Unix-oid systems that provide
* neither POSIX signals nor BSD signals. The alternative is to do
* signal-handler reinstallation, which doesn't work well at all.
* We now assume that all Unix-oid systems have POSIX sigaction(2)
* with support for restartable signals (SA_RESTART). We used to also
* support BSD-style signal(2), but there really shouldn't be anything
* out there anymore that doesn't have the POSIX API.
*
* Windows, of course, is resolutely in a class by itself. In the backend,
* we don't use this file at all; src/backend/port/win32/signal.c provides
* pqsignal() for the backend environment. Frontend programs can use
* this version of pqsignal() if they wish, but beware that Windows
* requires signal-handler reinstallation, because indeed it provides
* neither POSIX signals nor BSD signals :-(
* this version of pqsignal() if they wish, but beware that this does
* not provide restartable signals on Windows.
*
* ------------------------------------------------------------------------
*/
@ -52,9 +39,7 @@
pqsigfunc
pqsignal(int signo, pqsigfunc func)
{
#if !defined(HAVE_POSIX_SIGNALS)
return signal(signo, func);
#else
#ifndef WIN32
struct sigaction act,
oact;
@ -68,7 +53,9 @@ pqsignal(int signo, pqsigfunc func)
if (sigaction(signo, &act, &oact) < 0)
return SIG_ERR;
return oact.sa_handler;
#endif /* !HAVE_POSIX_SIGNALS */
#else /* WIN32 */
return signal(signo, func);
#endif
}
#endif /* !defined(WIN32) || defined(FRONTEND) */