@@ -36,7 +36,12 @@
#else
#include <chrono>
-#include <mutex> // unique_lock
+#include <mutex>
+#include <ext/concurrence.h>
+#include <bits/alloc_traits.h>
+#include <bits/allocator.h>
+#include <bits/unique_ptr.h>
+#include <bits/shared_ptr.h>
#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
@@ -165,13 +170,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
};
+ inline namespace _V2 {
+
/// condition_variable_any
// Like above, but mutex is not required to have try_lock.
class condition_variable_any
{
typedef chrono::system_clock __clock_t;
condition_variable _M_cond;
- mutex _M_mutex;
+ shared_ptr<mutex> _M_mutex;
// scoped unlock - unlocks in ctor, re-locks in dtor
template<typename _Lock>
@@ -194,9 +201,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
};
public:
-
- condition_variable_any() noexcept;
- ~condition_variable_any() noexcept;
+ condition_variable_any() : _M_mutex(std::make_shared<mutex>()) { }
+ ~condition_variable_any() = default;
condition_variable_any(const condition_variable_any&) = delete;
condition_variable_any& operator=(const condition_variable_any&) = delete;
@@ -204,14 +210,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void
notify_one() noexcept
{
- lock_guard<mutex> __lock(_M_mutex);
+ lock_guard<mutex> __lock(*_M_mutex);
_M_cond.notify_one();
}
void
notify_all() noexcept
{
- lock_guard<mutex> __lock(_M_mutex);
+ lock_guard<mutex> __lock(*_M_mutex);
_M_cond.notify_all();
}
@@ -219,10 +225,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void
wait(_Lock& __lock)
{
- unique_lock<mutex> __my_lock(_M_mutex);
+ shared_ptr<mutex> __mutex = _M_mutex;
+ unique_lock<mutex> __my_lock(*__mutex);
_Unlock<_Lock> __unlock(__lock);
- // _M_mutex must be unlocked before re-locking __lock so move
- // ownership of _M_mutex lock to an object with shorter lifetime.
+ // *__mutex must be unlocked before re-locking __lock so move
+ // ownership of *__mutex lock to an object with shorter lifetime.
unique_lock<mutex> __my_lock2(std::move(__my_lock));
_M_cond.wait(__my_lock2);
}
@@ -241,10 +248,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
wait_until(_Lock& __lock,
const chrono::time_point<_Clock, _Duration>& __atime)
{
- unique_lock<mutex> __my_lock(_M_mutex);
+ shared_ptr<mutex> __mutex = _M_mutex;
+ unique_lock<mutex> __my_lock(*__mutex);
_Unlock<_Lock> __unlock(__lock);
- // _M_mutex must be unlocked before re-locking __lock so move
- // ownership of _M_mutex lock to an object with shorter lifetime.
+ // *__mutex must be unlocked before re-locking __lock so move
+ // ownership of *__mutex lock to an object with shorter lifetime.
unique_lock<mutex> __my_lock2(std::move(__my_lock));
return _M_cond.wait_until(__my_lock2, __atime);
}
@@ -275,6 +283,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); }
};
+ } // end inline namespace
+
// @} group condition_variables
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
@@ -51,7 +51,8 @@ cxx11_sources = \
compatibility-c++0x.cc \
compatibility-atomic-c++0x.cc \
compatibility-thread-c++0x.cc \
- compatibility-chrono.cc
+ compatibility-chrono.cc \
+ compatibility-condvar.cc
libstdc___la_SOURCES = $(cxx98_sources) $(cxx11_sources)
@@ -103,6 +104,11 @@ compatibility-chrono.lo: compatibility-chrono.cc
compatibility-chrono.o: compatibility-chrono.cc
$(CXXCOMPILE) -std=gnu++11 -c $<
+compatibility-condvar.lo: compatibility-condvar.cc
+ $(LTCXXCOMPILE) -std=gnu++11 -c $<
+compatibility-condvar.o: compatibility-condvar.cc
+ $(CXXCOMPILE) -std=gnu++11 -c $<
+
# A note on compatibility and static libraries.
#
# static lib == linked against only this version, should not need compat
@@ -93,7 +93,8 @@ am__DEPENDENCIES_1 =
am__objects_2 = compatibility.lo compatibility-debug_list.lo \
compatibility-debug_list-2.lo $(am__objects_1)
am__objects_3 = compatibility-c++0x.lo compatibility-atomic-c++0x.lo \
- compatibility-thread-c++0x.lo compatibility-chrono.lo
+ compatibility-thread-c++0x.lo compatibility-chrono.lo \
+ compatibility-condvar.lo
am_libstdc___la_OBJECTS = $(am__objects_2) $(am__objects_3)
libstdc___la_OBJECTS = $(am_libstdc___la_OBJECTS)
DEFAULT_INCLUDES = -I.@am__isrc@ -I$(top_builddir)
@@ -352,7 +353,8 @@ cxx11_sources = \
compatibility-c++0x.cc \
compatibility-atomic-c++0x.cc \
compatibility-thread-c++0x.cc \
- compatibility-chrono.cc
+ compatibility-chrono.cc \
+ compatibility-condvar.cc
libstdc___la_SOURCES = $(cxx98_sources) $(cxx11_sources)
libstdc___la_LIBADD = \
@@ -854,6 +856,11 @@ compatibility-chrono.lo: compatibility-chrono.cc
compatibility-chrono.o: compatibility-chrono.cc
$(CXXCOMPILE) -std=gnu++11 -c $<
+compatibility-condvar.lo: compatibility-condvar.cc
+ $(LTCXXCOMPILE) -std=gnu++11 -c $<
+compatibility-condvar.o: compatibility-condvar.cc
+ $(CXXCOMPILE) -std=gnu++11 -c $<
+
# Symbol versioning for shared libraries.
@ENABLE_SYMVERS_TRUE@libstdc++-symbols.ver: ${glibcxx_srcdir}/$(SYMVER_FILE) \
@ENABLE_SYMVERS_TRUE@ $(port_specific_symbol_files)
new file mode 100644
@@ -0,0 +1,57 @@
+// Compatibility symbols for previous versions, C++0x bits -*- C++ -*-
+
+// Copyright (C) 2013 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
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+#include <bits/c++config.h>
+
+#if __cplusplus < 201103L
+# error "compatibility-condvar-c++0x.cc must be compiled with -std=gnu++11"
+#endif
+
+#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
+
+#define condition_variable_any condition_variable_anyXX
+#include <condition_variable>
+#undef condition_variable_any
+
+// XXX GLIBCXX_ABI Deprecated
+// gcc-4.9.0
+// std::condition_variable_any replaced with std::_V2::condition_variable_any
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+ class condition_variable_any
+ {
+ condition_variable _M_cond;
+ mutex _M_mutex;
+
+ public:
+ condition_variable_any() noexcept;
+ ~condition_variable_any() noexcept;
+ };
+ condition_variable_any::condition_variable_any() noexcept = default;
+ condition_variable_any::~condition_variable_any() noexcept = default;
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace std
+
+#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
@@ -77,10 +77,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__throw_system_error(__e);
}
- condition_variable_any::condition_variable_any() noexcept = default;
-
- condition_variable_any::~condition_variable_any() noexcept = default;
-
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
In order to conform to [thread.condition.condvarany]/5 and fix this PR we need an ABI change to std::condition_variable_any, so that its internal mutex can outlive the condition_variable_any while there are threads blocked on the mutex, which this patch does by using a shared_ptr to hold the mutex and making waiting threads share ownership of that mutex. The ABI change is handled similarly to the recent chrono::steady_clock changes, using an inline namespace for the new versions and continuing to export the old version from the library for compatibility with old code. Any thoughts or suggestions on improving this before I commit it to trunk? I can no longer reproduce the valgrind errors, except by hacking in changes to std::mutex to cause races, so I haven't been able to write a test case that fails without this change, but I believe it's still necessary for correctness. PR libstdc++/54352 * include/std/condition_variable (condition_variable_any): Move into inline namespace _V2 and replace mutex member with shared_ptr<mutex>. * src/c++11/condition_variable.cc (condition_variable_any): Move definitions to ... * src/c++11/compatibility-condvar.cc (condition_variable_any): Here. * src/Makefile.am: Add new source file. * src/Makefile.in: Regenerate. commit 60d115e1b9631adf1476a77c71224257a7c5ca7d Author: Jonathan Wakely <jwakely.gcc@gmail.com> Date: Sun Jun 16 12:38:32 2013 +0100 PR libstdc++/54352 * include/std/condition_variable (condition_variable_any): Move into inline namespace _V2 and replace mutex member with shared_ptr<mutex>. * src/c++11/condition_variable.cc (condition_variable_any): Move definitions to ... * src/c++11/compatibility-condvar.cc (condition_variable_any): Here. * src/Makefile.am: Add new source file. * src/Makefile.in: Regenerate.