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authorJonathan Wakely <jwakely@redhat.com>2023-05-09 09:30:48 +0100
committerJonathan Wakely <jwakely@redhat.com>2023-05-16 09:59:01 +0100
commit3b7cb33033fbe6af6c1c4ef014f7353479d1dd6b (patch)
tree5fa4d0e49ee40aaed8bfe46325a6cf8406eb554b
parent45efdda3ff6c92f948881298031779f81aad0886 (diff)
downloadgcc-3b7cb33033fbe6af6c1c4ef014f7353479d1dd6b.tar.gz
libstdc++: Do not use pthread_mutex_clocklock with ThreadSanitizer
As noted in https://github.com/llvm/llvm-project/issues/62623 there are no tsan interceptors for some of the new POSIX-1:202x APIs added by https://austingroupbugs.net/view.php?id=1216 so tsan gives false positive warnings for try_lock_for on timed mutexes. Disable the uses of the new pthread_mutex_clocklock API when tsan is active. This changes the semantics of the try_lock_for functions, because it can change which clock is used for the wait. This means those functions might be affected by system clock adjustments when tsan is used, when they would not be affected otherwise. Reviewed-by: Thomas Rodgers <trodgers@redhat.com> Reviewed-by: Mike Crowe <mac@mcrowe.com> libstdc++-v3/ChangeLog: * acinclude.m4 (GLIBCXX_CHECK_PTHREAD_MUTEX_CLOCKLOCK): Define _GLIBCXX_USE_PTHREAD_MUTEX_CLOCKLOCK in terms of _GLIBCXX_TSAN. * configure: Regenerate.
-rw-r--r--libstdc++-v3/acinclude.m42
-rwxr-xr-xlibstdc++-v3/configure2
2 files changed, 2 insertions, 2 deletions
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 42a8e7a775e..0ce3b8b5b31 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -4314,7 +4314,7 @@ AC_DEFUN([GLIBCXX_CHECK_PTHREAD_MUTEX_CLOCKLOCK], [
[glibcxx_cv_PTHREAD_MUTEX_CLOCKLOCK=no])
])
if test $glibcxx_cv_PTHREAD_MUTEX_CLOCKLOCK = yes; then
- AC_DEFINE(_GLIBCXX_USE_PTHREAD_MUTEX_CLOCKLOCK, 1, [Define if pthread_mutex_clocklock is available in <pthread.h>.])
+ AC_DEFINE(_GLIBCXX_USE_PTHREAD_MUTEX_CLOCKLOCK, (_GLIBCXX_TSAN==0), [Define if pthread_mutex_clocklock is available in <pthread.h>.])
fi
CXXFLAGS="$ac_save_CXXFLAGS"
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index d4286b67a73..c1faebd54f2 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -21364,7 +21364,7 @@ fi
$as_echo "$glibcxx_cv_PTHREAD_MUTEX_CLOCKLOCK" >&6; }
if test $glibcxx_cv_PTHREAD_MUTEX_CLOCKLOCK = yes; then
-$as_echo "#define _GLIBCXX_USE_PTHREAD_MUTEX_CLOCKLOCK 1" >>confdefs.h
+$as_echo "#define _GLIBCXX_USE_PTHREAD_MUTEX_CLOCKLOCK (_GLIBCXX_TSAN==0)" >>confdefs.h
fi