From a65e086453e0dea5cdd7f9fe9dc6c34d8bfc0f2c Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 31 Aug 2015 12:55:59 -0400 Subject: [PATCH] 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. --- config/c-library.m4 | 27 ------------ configure | 83 +---------------------------------- configure.in | 26 +---------- src/Makefile.global.in | 3 -- src/backend/libpq/pqsignal.c | 6 +-- src/include/c.h | 4 +- src/include/libpq/pqsignal.h | 18 ++++---- src/include/pg_config.h.in | 9 ---- src/include/pg_config.h.win32 | 9 ---- src/makefiles/Makefile.hpux | 7 --- src/port/pqsignal.c | 35 +++++---------- 11 files changed, 27 insertions(+), 200 deletions(-) diff --git a/config/c-library.m4 b/config/c-library.m4 index 7b1d9f4063..1d28c454ba 100644 --- a/config/c-library.m4 +++ b/config/c-library.m4 @@ -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 -], -[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 diff --git a/configure b/configure index 0376a7ca91..99ef10f0f7 100755 --- a/configure +++ b/configure @@ -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 -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 /* 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 - -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 diff --git a/configure.in b/configure.in index 5f16530fca..4143451c40 100644 --- a/configure.in +++ b/configure.in @@ -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 ], - [sigjmp_buf x; sigsetjmp(x, 1);])], - [pgac_cv_func_sigsetjmp=yes], - [pgac_cv_func_sigsetjmp=no])]) -if test x"$pgac_cv_func_sigsetjmp" = x"yes"; then - AC_DEFINE(HAVE_SIGSETJMP, 1, [Define to 1 if you have sigsetjmp().]) -fi - AC_CHECK_DECLS([sys_siglist], [], [], [#include /* NetBSD declares sys_siglist in unistd.h. */ @@ -1932,18 +1920,6 @@ fi AC_SUBST(PG_CRC32C_OBJS) -# Check that POSIX signals are available if thread safety is enabled. -if test "$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 diff --git a/src/Makefile.global.in b/src/Makefile.global.in index 39a7879bb6..6871c3c614 100644 --- a/src/Makefile.global.in +++ b/src/Makefile.global.in @@ -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@ diff --git a/src/backend/libpq/pqsignal.c b/src/backend/libpq/pqsignal.c index 5f17d76581..b19c4539f3 100644 --- a/src/backend/libpq/pqsignal.c +++ b/src/backend/libpq/pqsignal.c @@ -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) | diff --git a/src/include/c.h b/src/include/c.h index f5da4676c6..8163b000df 100644 --- a/src/include/c.h +++ b/src/include/c.h @@ -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 diff --git a/src/include/libpq/pqsignal.h b/src/include/libpq/pqsignal.h index 4b85342f32..3364247531 100644 --- a/src/include/libpq/pqsignal.h +++ b/src/include/libpq/pqsignal.h @@ -15,27 +15,27 @@ #include -#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); diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in index 1dcc9a9ee7..dda73a8b4c 100644 --- a/src/include/pg_config.h.in +++ b/src/include/pg_config.h.in @@ -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 diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32 index bf69ef5bde..6f7a773c5b 100644 --- a/src/include/pg_config.h.win32 +++ b/src/include/pg_config.h.win32 @@ -264,9 +264,6 @@ /* Define to 1 if you have the 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 */ diff --git a/src/makefiles/Makefile.hpux b/src/makefiles/Makefile.hpux index 1917d61b43..97bd0ba6d9 100644 --- a/src/makefiles/Makefile.hpux +++ b/src/makefiles/Makefile.hpux @@ -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. diff --git a/src/port/pqsignal.c b/src/port/pqsignal.c index f475b58acd..3e538d8c98 100644 --- a/src/port/pqsignal.c +++ b/src/port/pqsignal.c @@ -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) */