On 18/01/15 13:19 +0000, Jonathan Wakely wrote:
On 17/01/15 19:51 -0700, Sandra Loosemore wrote:
On 01/17/2015 03:58 PM, Jonathan Wakely wrote:
My fault, this additional chunk is needed alongside the patch I sent
earlier:
--- a/libstdc++-v3/include/bits/atomic_futex.h
+++ b/libstdc++-v3/include/bits/atomic_futex.h
@@ -35,7 +35,7 @@
#include <bits/c++config.h>
#include <atomic>
#include <chrono>
-#if !defined(_GLIBCXX_HAVE_LINUX_FUTEX)
+#if ! (defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1)
#include <mutex>
#include <condition_variable>
#endif
What I sent earlier causes your target to use std::mutex and
std::condition_variable, but without the bit above the headers aren't
included.
Still no joy:
/scratch/sandra/arm-fsf2/src/gcc-mainline/libstdc++-v3/src/c++11/futex.cc:45:3:
error: '__atomic_futex_unsigned_base' has not been declared
__atomic_futex_unsigned_base::_M_futex_wait_until(unsigned *__addr,
^
/scratch/sandra/arm-fsf2/src/gcc-mainline/libstdc++-v3/src/c++11/futex.cc:88:3:
error: '__atomic_futex_unsigned_base' has not been declared
__atomic_futex_unsigned_base::_M_futex_notify_all(unsigned* __addr)
^
futex.cc needs the same change ...
diff --git a/libstdc++-v3/src/c++11/futex.cc b/libstdc++-v3/src/c++11/futex.cc
index ad766c8..f24b44e 100644
--- a/libstdc++-v3/src/c++11/futex.cc
+++ b/libstdc++-v3/src/c++11/futex.cc
@@ -23,7 +23,7 @@
// <http://www.gnu.org/licenses/>.
#include <bits/c++config.h>
-#if defined(_GLIBCXX_HAVE_LINUX_FUTEX)
+#if defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1
#include <bits/atomic_futex.h>
#include <chrono>
#include <climits>
I've committed the attached after succesfully building
arm-none-linux-gnueabi with it and testing on x86_64-linux.
(The other changes in the patch are just whitespace and making the
member variables private.)
commit 07fcc71b616a253ed34b8b6f83e7f8cf6ea08a7a
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Sun Jan 18 14:34:52 2015 +0000
* src/c++11/futex.cc: Fix order of includes and preprocessor condition.
diff --git a/libstdc++-v3/src/c++11/futex.cc b/libstdc++-v3/src/c++11/futex.cc
index f24b44e..1336779 100644
--- a/libstdc++-v3/src/c++11/futex.cc
+++ b/libstdc++-v3/src/c++11/futex.cc
@@ -22,9 +22,8 @@
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
-#include <bits/c++config.h>
-#if defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1
#include <bits/atomic_futex.h>
+#if defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1
#include <chrono>
#include <climits>
#include <syscall.h>
commit c0b71ac062080887ae2bc072c9db21118155ae22
Author: redi <redi@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Sun Jan 18 14:25:22 2015 +0000
* include/bits/atomic_futex.h: Use mutex and condition_variable when
atomic int is not lock-free. Make member variables private.
* src/c++11/futex.cc: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@219815 138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/libstdc++-v3/include/bits/atomic_futex.h b/libstdc++-v3/include/bits/atomic_futex.h
index 2673604..51b9c7e 100644
--- a/libstdc++-v3/include/bits/atomic_futex.h
+++ b/libstdc++-v3/include/bits/atomic_futex.h
@@ -35,7 +35,7 @@
#include <bits/c++config.h>
#include <atomic>
#include <chrono>
-#if !defined(_GLIBCXX_HAVE_LINUX_FUTEX)
+#if ! (defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1)
#include <mutex>
#include <condition_variable>
#endif
@@ -49,7 +49,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
_GLIBCXX_BEGIN_NAMESPACE_VERSION
#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
-#if defined(_GLIBCXX_HAVE_LINUX_FUTEX)
+#if defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1
struct __atomic_futex_unsigned_base
{
// Returns false iff a timeout occurred.
@@ -62,16 +62,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
};
template <unsigned _Waiter_bit = 0x80000000>
- struct __atomic_futex_unsigned : __atomic_futex_unsigned_base
+ class __atomic_futex_unsigned : __atomic_futex_unsigned_base
{
typedef chrono::system_clock __clock_t;
- // XXX We expect this to be lock-free, and having the payload at offset 0.
-#if ATOMIC_INT_LOCK_FREE < 2
-# error We require lock-free atomic operations on int
-#endif
+ // This must be lock-free and at offset 0.
atomic<unsigned> _M_data;
+ public:
+ explicit
__atomic_futex_unsigned(unsigned __data) : _M_data(__data)
{ }
@@ -82,7 +81,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
private:
-
// If a timeout occurs, returns a current value after the timeout;
// otherwise, returns the operand's value if equal is true or a different
// value if equal is false.
@@ -165,26 +163,27 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Returns false iff a timeout occurred.
template<typename _Rep, typename _Period>
- _GLIBCXX_ALWAYS_INLINE bool
- _M_load_when_equal_for(unsigned __val, memory_order __mo,
- const chrono::duration<_Rep, _Period>& __rtime)
- {
- return _M_load_when_equal_until(__val, __mo, __clock_t::now() + __rtime);
- }
+ _GLIBCXX_ALWAYS_INLINE bool
+ _M_load_when_equal_for(unsigned __val, memory_order __mo,
+ const chrono::duration<_Rep, _Period>& __rtime)
+ {
+ return _M_load_when_equal_until(__val, __mo,
+ __clock_t::now() + __rtime);
+ }
// Returns false iff a timeout occurred.
template<typename _Clock, typename _Duration>
- _GLIBCXX_ALWAYS_INLINE bool
- _M_load_when_equal_until(unsigned __val, memory_order __mo,
- const chrono::time_point<_Clock, _Duration>& __atime)
- {
- // DR 887 - Sync unknown clock to known clock.
- const typename _Clock::time_point __c_entry = _Clock::now();
- const __clock_t::time_point __s_entry = __clock_t::now();
- const auto __delta = __atime - __c_entry;
- const auto __s_atime = __s_entry + __delta;
- return _M_load_when_equal_until(__val, __mo, __s_atime);
- }
+ _GLIBCXX_ALWAYS_INLINE bool
+ _M_load_when_equal_until(unsigned __val, memory_order __mo,
+ const chrono::time_point<_Clock, _Duration>& __atime)
+ {
+ // DR 887 - Sync unknown clock to known clock.
+ const typename _Clock::time_point __c_entry = _Clock::now();
+ const __clock_t::time_point __s_entry = __clock_t::now();
+ const auto __delta = __atime - __c_entry;
+ const auto __s_atime = __s_entry + __delta;
+ return _M_load_when_equal_until(__val, __mo, __s_atime);
+ }
// Returns false iff a timeout occurred.
template<typename _Duration>
@@ -207,16 +206,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
if (_M_data.exchange(__val, __mo) & _Waiter_bit)
_M_futex_notify_all(__futex);
}
-
};
-#else // !_GLIBCXX_HAVE_LINUX_FUTEX
+#else // ! (_GLIBCXX_HAVE_LINUX_FUTEX && ATOMIC_INT_LOCK_FREE > 1)
// If futexes are not available, use a mutex and a condvar to wait.
// Because we access the data only within critical sections, all accesses
// are sequentially consistent; thus, we satisfy any provided memory_order.
template <unsigned _Waiter_bit = 0x80000000>
- struct __atomic_futex_unsigned
+ class __atomic_futex_unsigned
{
typedef chrono::system_clock __clock_t;
@@ -224,6 +222,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
mutex _M_mutex;
condition_variable _M_condvar;
+ public:
+ explicit
__atomic_futex_unsigned(unsigned __data) : _M_data(__data)
{ }
@@ -252,24 +252,24 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Rep, typename _Period>
- _GLIBCXX_ALWAYS_INLINE bool
- _M_load_when_equal_for(unsigned __val, memory_order __mo,
- const chrono::duration<_Rep, _Period>& __rtime)
- {
- unique_lock<mutex> __lock(_M_mutex);
- return _M_condvar.wait_for(__lock, __rtime,
- [&] { return _M_data == __val;});
- }
+ _GLIBCXX_ALWAYS_INLINE bool
+ _M_load_when_equal_for(unsigned __val, memory_order __mo,
+ const chrono::duration<_Rep, _Period>& __rtime)
+ {
+ unique_lock<mutex> __lock(_M_mutex);
+ return _M_condvar.wait_for(__lock, __rtime,
+ [&] { return _M_data == __val;});
+ }
template<typename _Clock, typename _Duration>
- _GLIBCXX_ALWAYS_INLINE bool
- _M_load_when_equal_until(unsigned __val, memory_order __mo,
- const chrono::time_point<_Clock, _Duration>& __atime)
- {
- unique_lock<mutex> __lock(_M_mutex);
- return _M_condvar.wait_until(__lock, __atime,
- [&] { return _M_data == __val;});
- }
+ _GLIBCXX_ALWAYS_INLINE bool
+ _M_load_when_equal_until(unsigned __val, memory_order __mo,
+ const chrono::time_point<_Clock, _Duration>& __atime)
+ {
+ unique_lock<mutex> __lock(_M_mutex);
+ return _M_condvar.wait_until(__lock, __atime,
+ [&] { return _M_data == __val;});
+ }
_GLIBCXX_ALWAYS_INLINE void
_M_store_notify_all(unsigned __val, memory_order __mo)
@@ -278,10 +278,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_data = __val;
_M_condvar.notify_all();
}
-
};
-#endif // _GLIBCXX_HAVE_LINUX_FUTEX
+#endif // _GLIBCXX_HAVE_LINUX_FUTEX && ATOMIC_INT_LOCK_FREE > 1
#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
_GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/src/c++11/futex.cc b/libstdc++-v3/src/c++11/futex.cc
index ad766c8..f24b44e 100644
--- a/libstdc++-v3/src/c++11/futex.cc
+++ b/libstdc++-v3/src/c++11/futex.cc
@@ -23,7 +23,7 @@
// <http://www.gnu.org/licenses/>.
#include <bits/c++config.h>
-#if defined(_GLIBCXX_HAVE_LINUX_FUTEX)
+#if defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1
#include <bits/atomic_futex.h>
#include <chrono>
#include <climits>
