+2008-01-08 Jakub Jelinek <jakub@redhat.com>
+
+ * futex.m4: New file.
+
2007-12-06 Richard Sandiford <rsandifo@nildram.co.uk>
* mt-sde (CFLAGS_FOR_TARGET, CXXFLAGS_FOR_TARGET): Use +=, not =.
--- /dev/null
+dnl ----------------------------------------------------------------------
+dnl This whole bit snagged from libgomp.
+
+dnl
+dnl GCC_LINUX_FUTEX
+dnl (SHELL-CODE_HANDLER)
+dnl
+AC_DEFUN([GCC_LINUX_FUTEX],[dnl
+GCC_ENABLE(linux-futex,default, ,[use the Linux futex system call],
+ permit yes|no|default)
+case "$target" in
+ *-linux*)
+ case "$enable_linux_futex" in
+ default)
+ # If headers don't have gettid/futex syscalls definition, then
+ # default to no, otherwise there will be compile time failures.
+ # Otherwise, default to yes. If we don't detect we are
+ # compiled/linked against NPTL and not cross-compiling, check
+ # if programs are run by default against NPTL and if not, issue
+ # a warning.
+ enable_linux_futex=no
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [#include <sys/syscall.h>
+ int lk;],
+ [syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);])],
+ [save_LIBS="$LIBS"
+ LIBS="-lpthread $LIBS"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [#ifndef _GNU_SOURCE
+ #define _GNU_SOURCE 1
+ #endif
+ #include <pthread.h>
+ pthread_t th; void *status;],
+ [pthread_tryjoin_np (th, &status);])],[enable_linux_futex=yes],
+ [if test x$cross_compiling = xno; then
+ if getconf GNU_LIBPTHREAD_VERSION 2>/dev/null \
+ | LC_ALL=C grep -i NPTL > /dev/null 2>/dev/null; then :; else
+ AC_MSG_WARN([The kernel might not support futex or gettid syscalls.
+If so, please configure with --disable-linux-futex])
+ fi
+ fi
+ enable_linux_futex=yes])
+ LIBS="$save_LIBS"])
+ ;;
+ yes)
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [#include <sys/syscall.h>
+ int lk;],
+ [syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);])],[],
+ [AC_MSG_ERROR([SYS_gettid and SYS_futex required for --enable-linux-futex])])
+ ;;
+ esac
+ ;;
+ *)
+ enable_linux_futex=no
+ ;;
+esac
+if test x$enable_linux_futex = xyes; then
+ $1
+fi
+])
+2008-01-08 Jakub Jelinek <jakub@redhat.com>
+
+ * configure.ac: Move futex checking into ../config/futex.m4.
+ * configure: Rebuilt.
+ * aclocal.m4: Rebuilt.
+ * Makefile.in: Rebuilt.
+
+ * configure.tgt: Rename have_tls to gcc_cv_have_tls to match
+ 2007-10-15 ../config/tls.m4 change.
+
2007-12-19 Jakub Jelinek <jakub@redhat.com>
PR c++/34513
$(top_srcdir)/../config/lead-dot.m4 \
$(top_srcdir)/../config/multi.m4 \
$(top_srcdir)/../config/stdint.m4 \
- $(top_srcdir)/../config/tls.m4 $(top_srcdir)/../ltoptions.m4 \
+ $(top_srcdir)/../config/tls.m4 \
+ $(top_srcdir)/../config/futex.m4 $(top_srcdir)/../ltoptions.m4 \
$(top_srcdir)/../ltsugar.m4 $(top_srcdir)/../ltversion.m4 \
$(top_srcdir)/../lt~obsolete.m4 $(top_srcdir)/acinclude.m4 \
$(top_srcdir)/../libtool.m4 $(top_srcdir)/configure.ac
m4_include([../config/multi.m4])
m4_include([../config/stdint.m4])
m4_include([../config/tls.m4])
+m4_include([../config/futex.m4])
m4_include([../ltoptions.m4])
m4_include([../ltsugar.m4])
m4_include([../ltversion.m4])
--enable-version-specific-runtime-libs
Specify that runtime libraries should be installed
in a compiler-specific directory [default=no]
- --enable-linux-futex Use the Linux futex system call
- [default=default]
--enable-generated-files-in-srcdir
put copies of generated files in source dir intended
for creating source tarballs for users without
--disable-libtool-lock avoid locking (might break parallel builds)
--enable-maintainer-mode enable make rules and dependencies not useful
(and sometimes confusing) to the casual installer
+ --enable-linux-futex use the Linux futex system call
+ [default=default]
--enable-tls Use thread-local storage [default=yes]
--enable-symvers=STYLE enables symbol versioning of the shared library
[default=yes]
echo "$as_me:$LINENO: result: $enable_version_specific_runtime_libs" >&5
echo "${ECHO_T}$enable_version_specific_runtime_libs" >&6
-echo "$as_me:$LINENO: checking for --enable-linux-futex" >&5
-echo $ECHO_N "checking for --enable-linux-futex... $ECHO_C" >&6
- # Check whether --enable-linux-futex or --disable-linux-futex was given.
-if test "${enable_linux_futex+set}" = set; then
- enableval="$enable_linux_futex"
-
- case "$enableval" in
- yes|no|default) ;;
- *) { { echo "$as_me:$LINENO: error: Unknown argument to enable/disable linux-futex" >&5
-echo "$as_me: error: Unknown argument to enable/disable linux-futex" >&2;}
- { (exit 1); exit 1; }; } ;;
- esac
-
-else
- enable_linux_futex=default
-fi;
-
-echo "$as_me:$LINENO: result: $enable_linux_futex" >&5
-echo "${ECHO_T}$enable_linux_futex" >&6
-
# We would like our source tree to be readonly. However when releases or
# pre-releases are generated, the flex/bison generated files as well as the
# various formats of manuals need to be included along with the rest of the
_ACEOF
;;
+esac
+
+ # Check whether --enable-linux-futex or --disable-linux-futex was given.
+if test "${enable_linux_futex+set}" = set; then
+ enableval="$enable_linux_futex"
+
+ case "$enableval" in
+ yes|no|default) ;;
+ *) { { echo "$as_me:$LINENO: error: Unknown argument to enable/disable linux-futex" >&5
+echo "$as_me: error: Unknown argument to enable/disable linux-futex" >&2;}
+ { (exit 1); exit 1; }; } ;;
+ esac
+
+else
+ enable_linux_futex=default
+fi;
+
+case "$target" in
*-linux*)
case "$enable_linux_futex" in
default)
ac_status=$?
echo "$as_me:$LINENO: \$? = $ac_status" >&5
(exit $ac_status); }; }; then
- cat >conftest.$ac_ext <<_ACEOF
+ save_LIBS="$LIBS"
+ LIBS="-lpthread $LIBS"
+ cat >conftest.$ac_ext <<_ACEOF
/* confdefs.h. */
_ACEOF
cat confdefs.h >>conftest.$ac_ext
if test x$cross_compiling = xno; then
if getconf GNU_LIBPTHREAD_VERSION 2>/dev/null \
- | LC_ALL=C grep -i NPTL > /dev/null 2>/dev/null; then
+ | LC_ALL=C grep -i NPTL > /dev/null 2>/dev/null; then :; else
{ echo "$as_me:$LINENO: WARNING: The kernel might not support futex or gettid syscalls.
If so, please configure with --disable-linux-futex" >&5
echo "$as_me: WARNING: The kernel might not support futex or gettid syscalls.
fi
rm -f conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
+ LIBS="$save_LIBS"
else
echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5
rm -f conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
;;
- yes)
+ yes)
cat >conftest.$ac_ext <<_ACEOF
/* confdefs.h. */
_ACEOF
;;
esac
;;
+ *)
+ enable_linux_futex=no
+ ;;
esac
+if test x$enable_linux_futex = xyes; then
+ :
+fi
+
# Check for pthread_{,attr_}[sg]etaffinity_np.
cat >conftest.$ac_ext <<_ACEOF
permit yes|no)
AC_MSG_RESULT($enable_version_specific_runtime_libs)
-AC_MSG_CHECKING([for --enable-linux-futex])
-LIBGOMP_ENABLE(linux-futex, default, ,
- [Use the Linux futex system call],
- permit yes|no|default)
-AC_MSG_RESULT($enable_linux_futex)
-
# We would like our source tree to be readonly. However when releases or
# pre-releases are generated, the flex/bison generated files as well as the
# various formats of manuals need to be included along with the rest of the
AC_DEFINE(HAVE_BROKEN_POSIX_SEMAPHORES, 1,
Define if the POSIX Semaphores do not work on your system.)
;;
- *-linux*)
- case "$enable_linux_futex" in
- default)
- # If headers don't have gettid/futex syscalls definition, then
- # default to no, otherwise there will be compile time failures.
- # Otherwise, default to yes. If we don't detect we are
- # compiled/linked against NPTL and not cross-compiling, check
- # if programs are run by default against NPTL and if not, issue
- # a warning.
- enable_linux_futex=no
- AC_LINK_IFELSE(
- [AC_LANG_PROGRAM(
- [#include <sys/syscall.h>
- int lk;],
- [syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);])],
- [AC_LINK_IFELSE(
- [AC_LANG_PROGRAM(
- [#ifndef _GNU_SOURCE
- #define _GNU_SOURCE 1
- #endif
- #include <pthread.h>
- pthread_t th; void *status;],
- [pthread_tryjoin_np (th, &status);])],[enable_linux_futex=yes],
- [if test x$cross_compiling = xno; then
- if getconf GNU_LIBPTHREAD_VERSION 2>/dev/null \
- | LC_ALL=C grep -i NPTL > /dev/null 2>/dev/null; then
- AC_MSG_WARN([The kernel might not support futex or gettid syscalls.
-If so, please configure with --disable-linux-futex])
- fi
- fi
- enable_linux_futex=yes])])
- ;;
- yes)
- AC_LINK_IFELSE(
- [AC_LANG_PROGRAM(
- [#include <sys/syscall.h>
- int lk;],
- [syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);])],[],
- [AC_MSG_ERROR([SYS_gettid and SYS_futex required for --enable-linux-futex])])
- ;;
- esac
- ;;
esac
+GCC_LINUX_FUTEX(:)
+
# Check for pthread_{,attr_}[sg]etaffinity_np.
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
# XLDFLAGS Add extra link flags to use.
# Optimize TLS usage by avoiding the overhead of dynamic allocation.
-if test $have_tls = yes ; then
+if test $gcc_cv_have_tls = yes ; then
case "${target}" in
*-*-linux*)
+2008-01-08 Jakub Jelinek <jakub@redhat.com>
+
+ * configure.ac (--enable-linux-futex): Add new configure option.
+ (HAVE_LINUX_FUTEX): New AC_DEFINE.
+ * Makefile.in: Rebuilt.
+ * aclocal.m4: Rebuilt.
+ * configure: Rebuilt.
+ * config.h.in: Rebuilt.
+ * config/cpu/generic/cxxabi_tweaks.h (_GLIBCXX_GUARD_BIT,
+ _GLIBCXX_GUARD_PENDING_BIT, _GLIBCXX_GUARD_WAITING_BIT): Define.
+ * config/cpu/arm/cxxabi_tweaks.h (_GLIBCXX_GUARD_BIT,
+ _GLIBCXX_GUARD_PENDING_BIT, _GLIBCXX_GUARD_WAITING_BIT): Define.
+ * libsupc++/guard.cc: Include climits and syscall.h.
+ (_GLIBCXX_USE_FUTEX): Define if futex syscall and atomic builtins
+ are supported.
+ (_GLIBCXX_FUTEX_WAIT, _GLIBCXX_FUTEX_WAKE): Likewise.
+ (__guard_test_bit): New static inline.
+ (__cxa_guard_acquire, __cxa_guard_release, __cxa_guard_abort): Use
+ atomic builtins and futex syscall if _GLIBCXX_USE_FUTEX.
+
2008-01-07 Paolo Carlini <pcarlini@suse.de>
PR libstdc++/34680
$(top_srcdir)/../config/multi.m4 \
$(top_srcdir)/../config/no-executables.m4 \
$(top_srcdir)/../config/unwind_ipinfo.m4 \
+ $(top_srcdir)/../config/futex.m4 \
$(top_srcdir)/../libtool.m4 $(top_srcdir)/../ltoptions.m4 \
$(top_srcdir)/../ltsugar.m4 $(top_srcdir)/../ltversion.m4 \
$(top_srcdir)/crossconfig.m4 $(top_srcdir)/linkage.m4 \
m4_include([../config/multi.m4])
m4_include([../config/no-executables.m4])
m4_include([../config/unwind_ipinfo.m4])
+m4_include([../config/futex.m4])
m4_include([../libtool.m4])
m4_include([../ltoptions.m4])
m4_include([../ltsugar.m4])
/* Only used in build directory testsuite_hooks.h. */
#undef HAVE_LIMIT_VMEM
+/* Define if futex syscall is available. */
+#undef HAVE_LINUX_FUTEX
+
/* Define to 1 if you have the <locale.h> header file. */
#undef HAVE_LOCALE_H
// Control various target specific ABI tweaks. ARM version.
-// Copyright (C) 2004, 2006 Free Software Foundation, Inc.
+// Copyright (C) 2004, 2006, 2008 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// guard variable. */
#define _GLIBCXX_GUARD_TEST(x) ((*(x) & 1) != 0)
#define _GLIBCXX_GUARD_SET(x) *(x) = 1
+#define _GLIBCXX_GUARD_BIT 1
+#define _GLIBCXX_GUARD_PENDING_BIT __guard_test_bit (1, 1)
+#define _GLIBCXX_GUARD_WAITING_BIT __guard_test_bit (2, 1)
typedef int __guard;
// We also want the element size in array cookies.
// The generic ABI uses the first byte of a 64-bit guard variable.
#define _GLIBCXX_GUARD_TEST(x) (*(char *) (x) != 0)
#define _GLIBCXX_GUARD_SET(x) *(char *) (x) = 1
+#define _GLIBCXX_GUARD_BIT __guard_test_bit (0, 1)
+#define _GLIBCXX_GUARD_PENDING_BIT __guard_test_bit (1, 1)
+#define _GLIBCXX_GUARD_WAITING_BIT __guard_test_bit (2, 1)
__extension__ typedef int __guard __attribute__((mode (__DI__)));
// __cxa_vec_ctor has void return type.
// Control various target specific ABI tweaks. Generic version.
-// Copyright (C) 2004, 2006 Free Software Foundation, Inc.
+// Copyright (C) 2004, 2006, 2008 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// The generic ABI uses the first byte of a 64-bit guard variable.
#define _GLIBCXX_GUARD_TEST(x) (*(char *) (x) != 0)
#define _GLIBCXX_GUARD_SET(x) *(char *) (x) = 1
+#define _GLIBCXX_GUARD_BIT __guard_test_bit (0, 1)
+#define _GLIBCXX_GUARD_PENDING_BIT __guard_test_bit (1, 1)
+#define _GLIBCXX_GUARD_WAITING_BIT __guard_test_bit (2, 1)
__extension__ typedef int __guard __attribute__((mode (__DI__)));
// __cxa_vec_ctor has void return type.
memory [default=no]
--enable-tls Use thread-local storage [default=yes]
--disable-rpath do not hardcode runtime library paths
+ --enable-linux-futex use the Linux futex system call
+ [default=default]
--enable-symvers=STYLE enables symbol versioning of the shared library
[default=yes]
--enable-visibility enables visibility safe usage [default=yes]
#define HAVE_GETIPINFO 1
_ACEOF
+fi
+
+ # Check whether --enable-linux-futex or --disable-linux-futex was given.
+if test "${enable_linux_futex+set}" = set; then
+ enableval="$enable_linux_futex"
+
+ case "$enableval" in
+ yes|no|default) ;;
+ *) { { echo "$as_me:$LINENO: error: Unknown argument to enable/disable linux-futex" >&5
+echo "$as_me: error: Unknown argument to enable/disable linux-futex" >&2;}
+ { (exit 1); exit 1; }; } ;;
+ esac
+
+else
+ enable_linux_futex=default
+fi;
+
+case "$target" in
+ *-linux*)
+ case "$enable_linux_futex" in
+ default)
+ # If headers don't have gettid/futex syscalls definition, then
+ # default to no, otherwise there will be compile time failures.
+ # Otherwise, default to yes. If we don't detect we are
+ # compiled/linked against NPTL and not cross-compiling, check
+ # if programs are run by default against NPTL and if not, issue
+ # a warning.
+ enable_linux_futex=no
+ if test x$gcc_no_link = xyes; then
+ { { echo "$as_me:$LINENO: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&5
+echo "$as_me: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&2;}
+ { (exit 1); exit 1; }; }
+fi
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h. */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h. */
+#include <sys/syscall.h>
+ int lk;
+int
+main ()
+{
+syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);
+ ;
+ 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 $ac_status); }; }; then
+ save_LIBS="$LIBS"
+ LIBS="-lpthread $LIBS"
+ if test x$gcc_no_link = xyes; then
+ { { echo "$as_me:$LINENO: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&5
+echo "$as_me: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&2;}
+ { (exit 1); exit 1; }; }
+fi
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h. */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h. */
+#ifndef _GNU_SOURCE
+ #define _GNU_SOURCE 1
+ #endif
+ #include <pthread.h>
+ pthread_t th; void *status;
+int
+main ()
+{
+pthread_tryjoin_np (th, &status);
+ ;
+ 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 $ac_status); }; }; then
+ enable_linux_futex=yes
+else
+ echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+if test x$cross_compiling = xno; then
+ if getconf GNU_LIBPTHREAD_VERSION 2>/dev/null \
+ | LC_ALL=C grep -i NPTL > /dev/null 2>/dev/null; then :; else
+ { echo "$as_me:$LINENO: WARNING: The kernel might not support futex or gettid syscalls.
+If so, please configure with --disable-linux-futex" >&5
+echo "$as_me: WARNING: The kernel might not support futex or gettid syscalls.
+If so, please configure with --disable-linux-futex" >&2;}
+ fi
+ fi
+ enable_linux_futex=yes
fi
+rm -f conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+ LIBS="$save_LIBS"
+else
+ echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+fi
+rm -f conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+ ;;
+ yes)
+ if test x$gcc_no_link = xyes; then
+ { { echo "$as_me:$LINENO: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&5
+echo "$as_me: error: Link tests are not allowed after GCC_NO_EXECUTABLES." >&2;}
+ { (exit 1); exit 1; }; }
+fi
+cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h. */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h. */
+#include <sys/syscall.h>
+ int lk;
+int
+main ()
+{
+syscall (SYS_gettid); syscall (SYS_futex, &lk, 0, 0, 0);
+ ;
+ return 0;
+}
+_ACEOF
+rm -f conftest.$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 $ac_status); }; }; then
+ :
+else
+ echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+{ { echo "$as_me:$LINENO: error: SYS_gettid and SYS_futex required for --enable-linux-futex" >&5
+echo "$as_me: error: SYS_gettid and SYS_futex required for --enable-linux-futex" >&2;}
+ { (exit 1); exit 1; }; }
+fi
+rm -f conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+ ;;
+ esac
+ ;;
+ *)
+ enable_linux_futex=no
+ ;;
+esac
+if test x$enable_linux_futex = xyes; then
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_LINUX_FUTEX 1
+_ACEOF
+
+fi
+
# This depends on GLIBCXX CHECK_LINKER_FEATURES, but without it assumes no.
# Assume we have _Unwind_GetIPInfo for cross-compiles.
AC_DEFINE(HAVE_GETIPINFO)
-
fi
+GCC_LINUX_FUTEX([AC_DEFINE(HAVE_LINUX_FUTEX, 1, [Define if futex syscall is available.])])
+
# This depends on GLIBCXX CHECK_LINKER_FEATURES, but without it assumes no.
GLIBCXX_ENABLE_SYMVERS([yes])
GLIBCXX_ENABLE_VISIBILITY([yes])
#include <new>
#include <ext/atomicity.h>
#include <ext/concurrence.h>
+#if defined(__GTHREADS) && defined(__GTHREAD_HAS_COND) \
+ && defined(_GLIBCXX_ATOMIC_BUILTINS) && defined(_GLIBCXX_HAVE_LINUX_FUTEX)
+# include <climits>
+# include <syscall.h>
+# define _GLIBCXX_USE_FUTEX
+# define _GLIBCXX_FUTEX_WAIT 0
+# define _GLIBCXX_FUTEX_WAKE 1
+#endif
// The IA64/generic ABI uses the first byte of the guard variable.
// The ARM EABI uses the least significant bit.
// Thread-safe static local initialization support.
#ifdef __GTHREADS
+# ifndef _GLIBCXX_USE_FUTEX
namespace
{
// A single mutex controlling all static initializations.
}
};
}
+# endif
-#ifdef __GTHREAD_HAS_COND
+# if defined(__GTHREAD_HAS_COND) && !defined(_GLIBCXX_USE_FUTEX)
namespace
{
// A single conditional variable controlling all static initializations.
return *static_cond;
}
}
-#endif
+# endif
-#ifndef _GLIBCXX_GUARD_TEST_AND_ACQUIRE
+# ifndef _GLIBCXX_GUARD_TEST_AND_ACQUIRE
inline bool
__test_and_acquire (__cxxabiv1::__guard *g)
{
_GLIBCXX_READ_MEM_BARRIER;
return b;
}
-#define _GLIBCXX_GUARD_TEST_AND_ACQUIRE(G) __test_and_acquire (G)
-#endif
+# define _GLIBCXX_GUARD_TEST_AND_ACQUIRE(G) __test_and_acquire (G)
+# endif
-#ifndef _GLIBCXX_GUARD_SET_AND_RELEASE
+# ifndef _GLIBCXX_GUARD_SET_AND_RELEASE
inline void
__set_and_release (__cxxabiv1::__guard *g)
{
_GLIBCXX_WRITE_MEM_BARRIER;
_GLIBCXX_GUARD_SET (g);
}
-#define _GLIBCXX_GUARD_SET_AND_RELEASE(G) __set_and_release (G)
-#endif
+# define _GLIBCXX_GUARD_SET_AND_RELEASE(G) __set_and_release (G)
+# endif
#else /* !__GTHREADS */
-#undef _GLIBCXX_GUARD_TEST_AND_ACQUIRE
-#undef _GLIBCXX_GUARD_SET_AND_RELEASE
-#define _GLIBCXX_GUARD_SET_AND_RELEASE(G) _GLIBCXX_GUARD_SET (G)
+# undef _GLIBCXX_GUARD_TEST_AND_ACQUIRE
+# undef _GLIBCXX_GUARD_SET_AND_RELEASE
+# define _GLIBCXX_GUARD_SET_AND_RELEASE(G) _GLIBCXX_GUARD_SET (G)
#endif /* __GTHREADS */
// headers define a symbol __GTHREAD_HAS_COND for platforms that support POSIX
// like conditional variables. For platforms that do not support conditional
// variables, we need to fall back to the old code.
+
+// If _GLIBCXX_USE_FUTEX, no global mutex or conditional variable is used,
+// only atomic operations are used together with futex syscall.
+// Valid values of the first integer in guard are:
+// 0 No thread encountered the guarded init
+// yet or it has been aborted.
+// _GLIBCXX_GUARD_BIT The guarded static var has been successfully
+// initialized.
+// _GLIBCXX_GUARD_PENDING_BIT The guarded static var is being initialized
+// and no other thread is waiting for its
+// initialization.
+// (_GLIBCXX_GUARD_PENDING_BIT The guarded static var is being initialized
+// | _GLIBCXX_GUARD_WAITING_BIT) and some other threads are waiting until
+// it is initialized.
+
namespace __cxxabiv1
{
+#ifdef _GLIBCXX_USE_FUTEX
+ namespace
+ {
+ static inline int __guard_test_bit (const int __byte, const int __val)
+ {
+ union { int __i; char __c[sizeof (int)]; } __u = { 0 };
+ __u.__c[__byte] = __val;
+ return __u.__i;
+ }
+ }
+#endif
+
static inline int
init_in_progress_flag(__guard* g)
{ return ((char *)g)[1]; }
return 0;
if (init_in_progress_flag(g))
- throw_recursive_init_exception();
+ throw_recursive_init_exception();
set_init_in_progress_flag(g, 1);
return 1;
if (_GLIBCXX_GUARD_TEST_AND_ACQUIRE (g))
return 0;
+# ifdef _GLIBCXX_USE_FUTEX
+ // If __sync_* and futex syscall are supported, don't use any global
+ // mutex.
+ if (__gthread_active_p ())
+ {
+ int *gi = (int *) (void *) g;
+ const int guard_bit = _GLIBCXX_GUARD_BIT;
+ const int pending_bit = _GLIBCXX_GUARD_PENDING_BIT;
+ const int waiting_bit = _GLIBCXX_GUARD_WAITING_BIT;
+
+ while (1)
+ {
+ int old = __sync_val_compare_and_swap (gi, 0, pending_bit);
+ if (old == 0)
+ return 1; // This thread should do the initialization.
+
+ if (old == guard_bit)
+ return 0; // Already initialized.
+
+ if (old == pending_bit)
+ {
+ int newv = old | waiting_bit;
+ if (__sync_val_compare_and_swap (gi, old, newv) != old)
+ continue;
+
+ old = newv;
+ }
+
+ syscall (SYS_futex, gi, _GLIBCXX_FUTEX_WAIT, old, 0);
+ }
+ }
+# else
if (__gthread_active_p ())
{
mutex_wrapper mw;
while (1) // When this loop is executing, mutex is locked.
{
-#ifdef __GTHREAD_HAS_COND
- // The static is allready initialized.
+# ifdef __GTHREAD_HAS_COND
+ // The static is already initialized.
if (_GLIBCXX_GUARD_TEST(g))
return 0; // The mutex will be unlocked via wrapper
set_init_in_progress_flag(g, 1);
return 1; // The mutex will be unlocked via wrapper.
}
-#else
+# else
// This provides compatibility with older systems not supporting
// POSIX like conditional variables.
if (acquire(g))
return 1; // The mutex still locked.
}
return 0; // The mutex will be unlocked via wrapper.
-#endif
+# endif
}
}
+# endif
#endif
return acquire (g);
extern "C"
void __cxa_guard_abort (__guard *g)
{
-#ifdef __GTHREAD_HAS_COND
+#ifdef _GLIBCXX_USE_FUTEX
+ // If __sync_* and futex syscall are supported, don't use any global
+ // mutex.
+ if (__gthread_active_p ())
+ {
+ int *gi = (int *) (void *) g;
+ const int waiting_bit = _GLIBCXX_GUARD_WAITING_BIT;
+ int old = __sync_lock_test_and_set (gi, 0);
+
+ if ((old & waiting_bit) != 0)
+ syscall (SYS_futex, gi, _GLIBCXX_FUTEX_WAKE, INT_MAX);
+ return;
+ }
+#elif defined(__GTHREAD_HAS_COND)
if (__gthread_active_p())
{
mutex_wrapper mw;
extern "C"
void __cxa_guard_release (__guard *g)
{
-#ifdef __GTHREAD_HAS_COND
+#ifdef _GLIBCXX_USE_FUTEX
+ // If __sync_* and futex syscall are supported, don't use any global
+ // mutex.
+ if (__gthread_active_p ())
+ {
+ int *gi = (int *) (void *) g;
+ const int guard_bit = _GLIBCXX_GUARD_BIT;
+ const int waiting_bit = _GLIBCXX_GUARD_WAITING_BIT;
+ int old = __sync_lock_test_and_set (gi, guard_bit);
+
+ if ((old & waiting_bit) != 0)
+ syscall (SYS_futex, gi, _GLIBCXX_FUTEX_WAKE, INT_MAX);
+ return;
+ }
+#elif defined(__GTHREAD_HAS_COND)
if (__gthread_active_p())
{
mutex_wrapper mw;
git://gcc.gnu.org / gcc.git / commitdiff