From a038288139470e7a32c1e711fcfdbd64212e87e4 Mon Sep 17 00:00:00 2001 From: "jan.nijtmans" Date: Mon, 22 Jul 2013 10:57:44 +0000 Subject: Use pthread_atfork() when available. --- unix/configure | 209 +++++++++++++++++++++++++++------------------------- unix/configure.in | 7 +- unix/tclUnixNotfy.c | 90 +++++++++++++++++++++- 3 files changed, 202 insertions(+), 104 deletions(-) diff --git a/unix/configure b/unix/configure index 6faa7d8..ee194b7 100755 --- a/unix/configure +++ b/unix/configure @@ -16759,6 +16759,113 @@ done #-------------------------------------------------------------------- +# Check for support of pthread_atfork function +#-------------------------------------------------------------------- + + +for ac_func in pthread_atfork +do +as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh` +echo "$as_me:$LINENO: checking for $ac_func" >&5 +echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6 +if eval "test \"\${$as_ac_var+set}\" = set"; then + echo $ECHO_N "(cached) $ECHO_C" >&6 +else + cat >conftest.$ac_ext <<_ACEOF +/* confdefs.h. */ +_ACEOF +cat confdefs.h >>conftest.$ac_ext +cat >>conftest.$ac_ext <<_ACEOF +/* end confdefs.h. */ +/* Define $ac_func to an innocuous variant, in case declares $ac_func. + For example, HP-UX 11i declares gettimeofday. */ +#define $ac_func innocuous_$ac_func + +/* System header to define __stub macros and hopefully few prototypes, + which can conflict with char $ac_func (); below. + Prefer to if __STDC__ is defined, since + exists even on freestanding compilers. */ + +#ifdef __STDC__ +# include +#else +# include +#endif + +#undef $ac_func + +/* Override any gcc2 internal prototype to avoid an error. */ +#ifdef __cplusplus +extern "C" +{ +#endif +/* We use char because int might match the return type of a gcc2 + builtin and then its argument prototype would still apply. */ +char $ac_func (); +/* The GNU C library defines this for functions which it implements + to always fail with ENOSYS. Some functions are actually named + something starting with __ and the normal name is an alias. */ +#if defined (__stub_$ac_func) || defined (__stub___$ac_func) +choke me +#else +char (*f) () = $ac_func; +#endif +#ifdef __cplusplus +} +#endif + +int +main () +{ +return f != $ac_func; + ; + return 0; +} +_ACEOF +rm -f conftest.$ac_objext conftest$ac_exeext +if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5 + (eval $ac_link) 2>conftest.er1 + ac_status=$? + grep -v '^ *+' conftest.er1 >conftest.err + rm -f conftest.er1 + cat conftest.err >&5 + echo "$as_me:$LINENO: \$? = $ac_status" >&5 + (exit $ac_status); } && + { ac_try='test -z "$ac_c_werror_flag" + || test ! -s conftest.err' + { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5 + (eval $ac_try) 2>&5 + ac_status=$? + echo "$as_me:$LINENO: \$? = $ac_status" >&5 + (exit $ac_status); }; } && + { ac_try='test -s conftest$ac_exeext' + { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5 + (eval $ac_try) 2>&5 + ac_status=$? + echo "$as_me:$LINENO: \$? = $ac_status" >&5 + (exit $ac_status); }; }; then + eval "$as_ac_var=yes" +else + echo "$as_me: failed program was:" >&5 +sed 's/^/| /' conftest.$ac_ext >&5 + +eval "$as_ac_var=no" +fi +rm -f conftest.err conftest.$ac_objext \ + conftest$ac_exeext conftest.$ac_ext +fi +echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5 +echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6 +if test `eval echo '${'$as_ac_var'}'` = yes; then + cat >>confdefs.h <<_ACEOF +#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1 +_ACEOF + +fi +done + + +#-------------------------------------------------------------------- # Check for support of isnan() function or macro #-------------------------------------------------------------------- @@ -17439,108 +17546,6 @@ _ACEOF fi done - -for ac_func in pthread_atfork -do -as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh` -echo "$as_me:$LINENO: checking for $ac_func" >&5 -echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6 -if eval "test \"\${$as_ac_var+set}\" = set"; then - echo $ECHO_N "(cached) $ECHO_C" >&6 -else - cat >conftest.$ac_ext <<_ACEOF -/* confdefs.h. */ -_ACEOF -cat confdefs.h >>conftest.$ac_ext -cat >>conftest.$ac_ext <<_ACEOF -/* end confdefs.h. */ -/* Define $ac_func to an innocuous variant, in case declares $ac_func. - For example, HP-UX 11i declares gettimeofday. */ -#define $ac_func innocuous_$ac_func - -/* System header to define __stub macros and hopefully few prototypes, - which can conflict with char $ac_func (); below. - Prefer to if __STDC__ is defined, since - exists even on freestanding compilers. */ - -#ifdef __STDC__ -# include -#else -# include -#endif - -#undef $ac_func - -/* Override any gcc2 internal prototype to avoid an error. */ -#ifdef __cplusplus -extern "C" -{ -#endif -/* We use char because int might match the return type of a gcc2 - builtin and then its argument prototype would still apply. */ -char $ac_func (); -/* The GNU C library defines this for functions which it implements - to always fail with ENOSYS. Some functions are actually named - something starting with __ and the normal name is an alias. */ -#if defined (__stub_$ac_func) || defined (__stub___$ac_func) -choke me -#else -char (*f) () = $ac_func; -#endif -#ifdef __cplusplus -} -#endif - -int -main () -{ -return f != $ac_func; - ; - return 0; -} -_ACEOF -rm -f conftest.$ac_objext conftest$ac_exeext -if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5 - (eval $ac_link) 2>conftest.er1 - ac_status=$? - grep -v '^ *+' conftest.er1 >conftest.err - rm -f conftest.er1 - cat conftest.err >&5 - echo "$as_me:$LINENO: \$? = $ac_status" >&5 - (exit $ac_status); } && - { ac_try='test -z "$ac_c_werror_flag" - || test ! -s conftest.err' - { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5 - (eval $ac_try) 2>&5 - ac_status=$? - echo "$as_me:$LINENO: \$? = $ac_status" >&5 - (exit $ac_status); }; } && - { ac_try='test -s conftest$ac_exeext' - { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5 - (eval $ac_try) 2>&5 - ac_status=$? - echo "$as_me:$LINENO: \$? = $ac_status" >&5 - (exit $ac_status); }; }; then - eval "$as_ac_var=yes" -else - echo "$as_me: failed program was:" >&5 -sed 's/^/| /' conftest.$ac_ext >&5 - -eval "$as_ac_var=no" -fi -rm -f conftest.err conftest.$ac_objext \ - conftest$ac_exeext conftest.$ac_ext -fi -echo "$as_me:$LINENO: result: `eval echo '${'$as_ac_var'}'`" >&5 -echo "${ECHO_T}`eval echo '${'$as_ac_var'}'`" >&6 -if test `eval echo '${'$as_ac_var'}'` = yes; then - cat >>confdefs.h <<_ACEOF -#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1 -_ACEOF - -fi -done - fi cat >>confdefs.h <<\_ACEOF diff --git a/unix/configure.in b/unix/configure.in index e22a7d3..f47b882 100644 --- a/unix/configure.in +++ b/unix/configure.in @@ -491,6 +491,12 @@ SC_ENABLE_LANGINFO AC_CHECK_FUNCS(chflags) #-------------------------------------------------------------------- +# Check for support of pthread_atfork function +#-------------------------------------------------------------------- + +AC_CHECK_FUNCS(pthread_atfork) + +#-------------------------------------------------------------------- # Check for support of isnan() function or macro #-------------------------------------------------------------------- @@ -513,7 +519,6 @@ if test "`uname -s`" = "Darwin" ; then if test $tcl_corefoundation = yes; then AC_CHECK_HEADERS(libkern/OSAtomic.h) AC_CHECK_FUNCS(OSSpinLockLock) - AC_CHECK_FUNCS(pthread_atfork) fi AC_DEFINE(USE_VFORK, 1, [Should we use vfork() instead of fork()?]) AC_DEFINE(TCL_DEFAULT_ENCODING, "utf-8", diff --git a/unix/tclUnixNotfy.c b/unix/tclUnixNotfy.c index 6e8b5fa..f414c3f 100644 --- a/unix/tclUnixNotfy.c +++ b/unix/tclUnixNotfy.c @@ -202,7 +202,13 @@ static Tcl_ThreadId notifierThread; #ifdef TCL_THREADS static void NotifierThreadProc(ClientData clientData); -#endif +#ifdef HAVE_PTHREAD_ATFORK +static int atForkInit = 0; +static void AtForkPrepare(void); +static void AtForkParent(void); +static void AtForkChild(void); +#endif /* HAVE_PTHREAD_ATFORK */ +#endif /* TCL_THREADS */ static int FileHandlerEventProc(Tcl_Event *evPtr, int flags); /* @@ -276,6 +282,21 @@ Tcl_InitNotifier(void) */ Tcl_MutexLock(¬ifierMutex); +#ifdef HAVE_PTHREAD_ATFORK + /* + * Install pthread_atfork handlers to reinitialize the notifier in the + * child of a fork. + */ + + if (!atForkInit) { + int result = pthread_atfork(AtForkPrepare, AtForkParent, AtForkChild); + + if (result) { + Tcl_Panic("Tcl_InitNotifier: pthread_atfork failed"); + } + atForkInit = 1; + } +#endif /* * Check if my process id changed, e.g. I was forked * In this case, restart the notifier thread and close the @@ -1251,6 +1272,73 @@ NotifierThreadProc( TclpThreadExit (0); } + +#ifdef HAVE_PTHREAD_ATFORK +/* + *---------------------------------------------------------------------- + * + * AtForkPrepare -- + * + * Lock the notifier in preparation for a fork. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static void +AtForkPrepare(void) +{ +} + +/* + *---------------------------------------------------------------------- + * + * AtForkParent -- + * + * Unlock the notifier in the parent after a fork. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static void +AtForkParent(void) +{ +} + +/* + *---------------------------------------------------------------------- + * + * AtForkChild -- + * + * Unlock and reinstall the notifier in the child after a fork. + * + * Results: + * None. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static void +AtForkChild(void) +{ + Tcl_InitNotifier(); +} +#endif /* HAVE_PTHREAD_ATFORK */ + #endif /* TCL_THREADS */ #endif /* HAVE_COREFOUNDATION */ -- cgit v0.12