From: Jimmy Guo Date: Fri, 18 Dec 2009 09:41:03 +0000 (+0000) Subject: re PR libstdc++/40088 (Creating a std::ostringstream object locks a global mutex) X-Git-Tag: releases/gcc-4.5.0~1582 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4ef8972563c56304859db4bb3571f96004408a9f;p=thirdparty%2Fgcc.git re PR libstdc++/40088 (Creating a std::ostringstream object locks a global mutex) 2009-12-18 Jimmy Guo PR libstdc++/40088 * src/locale_init.cc (locale::locale()): Optimize the common case where _S_global still points to _S_classic. From-SVN: r155342 --- diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index d6b934c38db8..2077dc14ec70 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,9 @@ +2009-12-18 Jimmy Guo + + PR libstdc++/40088 + * src/locale_init.cc (locale::locale()): Optimize the common case + where _S_global still points to _S_classic. + 2009-12-17 Dave Korn PR target/42377 diff --git a/libstdc++-v3/include/std/condition_variable b/libstdc++-v3/include/std/condition_variable index f87eb1b8d1a0..f5e4db15c2a2 100644 --- a/libstdc++-v3/include/std/condition_variable +++ b/libstdc++-v3/include/std/condition_variable @@ -50,6 +50,9 @@ namespace std * @{ */ + /// cv_status + enum class cv_status { no_timeout, timeout }; + /// condition_variable class condition_variable { @@ -84,13 +87,13 @@ namespace std } template - bool + cv_status wait_until(unique_lock& __lock, const chrono::time_point<__clock_t, _Duration>& __atime) { return __wait_until_impl(__lock, __atime); } template - bool + cv_status wait_until(unique_lock& __lock, const chrono::time_point<_Clock, _Duration>& __atime) { @@ -110,14 +113,14 @@ namespace std _Predicate __p) { while (!__p()) - if (!wait_until(__lock, __atime)) + if (wait_until(__lock, __atime) == cv_status::timeout) return __p(); return true; } template - bool + cv_status wait_for(unique_lock& __lock, const chrono::duration<_Rep, _Period>& __rtime) { return wait_until(__lock, __clock_t::now() + __rtime); } @@ -135,7 +138,7 @@ namespace std private: template - bool + cv_status __wait_until_impl(unique_lock& __lock, const chrono::time_point<_Clock, _Duration>& __atime) { @@ -154,7 +157,8 @@ namespace std __gthread_cond_timedwait(&_M_cond, __lock.mutex()->native_handle(), &__ts); - return _Clock::now() < __atime; + return (_Clock::now() < __atime + ? cv_status::no_timeout : cv_status::timeout); } }; @@ -189,7 +193,7 @@ namespace std wait(_Lock& __lock, _Predicate __p); template - bool + cv_status wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __atime); @@ -201,7 +205,7 @@ namespace std _Predicate __p); template - bool + cv_status wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __rtime); template_M_add_reference(); + + // Checked locking to optimize the common case where _S_global + // still points to _S_classic (locale::_S_initialize_once()): + // - If they are the same, just increment the reference count and + // we are done. This effectively constructs a C locale object + // identical to the static c_locale. + // - Otherwise, _S_global can and may be destroyed due to + // locale::global() call on another thread, in which case we + // fall back to lock protected access to both _S_global and + // its reference count. _M_impl = _S_global; + if (_M_impl == _S_classic) + _M_impl->_M_add_reference(); + else + { + __gnu_cxx::__scoped_lock sentry(get_locale_mutex()); + _S_global->_M_add_reference(); + _M_impl = _S_global; + } } locale diff --git a/libstdc++-v3/testsuite/30_threads/condition_variable/cons/assign_neg.cc b/libstdc++-v3/testsuite/30_threads/condition_variable/cons/assign_neg.cc index 04e492b3f43b..9e9ad8a7b03c 100644 --- a/libstdc++-v3/testsuite/30_threads/condition_variable/cons/assign_neg.cc +++ b/libstdc++-v3/testsuite/30_threads/condition_variable/cons/assign_neg.cc @@ -32,4 +32,4 @@ void test01() } // { dg-error "used here" "" { target *-*-* } 31 } -// { dg-error "deleted function" "" { target *-*-* } 67 } +// { dg-error "deleted function" "" { target *-*-* } 70 } diff --git a/libstdc++-v3/testsuite/30_threads/condition_variable/cons/copy_neg.cc b/libstdc++-v3/testsuite/30_threads/condition_variable/cons/copy_neg.cc index 0d066282f1f3..5765351554e1 100644 --- a/libstdc++-v3/testsuite/30_threads/condition_variable/cons/copy_neg.cc +++ b/libstdc++-v3/testsuite/30_threads/condition_variable/cons/copy_neg.cc @@ -31,4 +31,4 @@ void test01() } // { dg-error "used here" "" { target *-*-* } 30 } -// { dg-error "deleted function" "" { target *-*-* } 66 } +// { dg-error "deleted function" "" { target *-*-* } 69 } diff --git a/libstdc++-v3/testsuite/30_threads/condition_variable/members/1.cc b/libstdc++-v3/testsuite/30_threads/condition_variable/members/1.cc index 4dea137064f0..127960a625db 100644 --- a/libstdc++-v3/testsuite/30_threads/condition_variable/members/1.cc +++ b/libstdc++-v3/testsuite/30_threads/condition_variable/members/1.cc @@ -40,8 +40,8 @@ int main() std::unique_lock l(m); auto then = std::chrono::system_clock::now(); - bool result = c1.wait_for(l, ms); - VERIFY( !result ); + std::cv_status result = c1.wait_for(l, ms); + VERIFY( result == std::cv_status::timeout ); VERIFY( (std::chrono::system_clock::now() - then) >= ms ); VERIFY( l.owns_lock() ); } diff --git a/libstdc++-v3/testsuite/30_threads/condition_variable/members/2.cc b/libstdc++-v3/testsuite/30_threads/condition_variable/members/2.cc index fe176668aa01..ab2e8776b842 100644 --- a/libstdc++-v3/testsuite/30_threads/condition_variable/members/2.cc +++ b/libstdc++-v3/testsuite/30_threads/condition_variable/members/2.cc @@ -40,8 +40,8 @@ int main() std::unique_lock l(m); auto then = std::chrono::monotonic_clock::now(); - bool result = c1.wait_until(l, then + ms); - VERIFY( !result ); + std::cv_status result = c1.wait_until(l, then + ms); + VERIFY( result == std::cv_status::timeout ); VERIFY( (std::chrono::monotonic_clock::now() - then) >= ms ); VERIFY( l.owns_lock() ); } diff --git a/libstdc++-v3/testsuite/30_threads/condition_variable_any/cons/assign_neg.cc b/libstdc++-v3/testsuite/30_threads/condition_variable_any/cons/assign_neg.cc index 473f32639b34..14990a292348 100644 --- a/libstdc++-v3/testsuite/30_threads/condition_variable_any/cons/assign_neg.cc +++ b/libstdc++-v3/testsuite/30_threads/condition_variable_any/cons/assign_neg.cc @@ -32,4 +32,4 @@ void test01() } // { dg-error "used here" "" { target *-*-* } 31 } -// { dg-error "deleted function" "" { target *-*-* } 175 } +// { dg-error "deleted function" "" { target *-*-* } 179 } diff --git a/libstdc++-v3/testsuite/30_threads/condition_variable_any/cons/copy_neg.cc b/libstdc++-v3/testsuite/30_threads/condition_variable_any/cons/copy_neg.cc index 1d06c2ded3c3..1a48a9e627cf 100644 --- a/libstdc++-v3/testsuite/30_threads/condition_variable_any/cons/copy_neg.cc +++ b/libstdc++-v3/testsuite/30_threads/condition_variable_any/cons/copy_neg.cc @@ -31,4 +31,4 @@ void test01() } // { dg-error "used here" "" { target *-*-* } 30 } -// { dg-error "deleted function" "" { target *-*-* } 174 } +// { dg-error "deleted function" "" { target *-*-* } 178 }