On 11/05/20 09:11 +0100, Jonathan Wakely wrote:
On 08/05/20 17:05 +0200, Ulrich Drepper via Libstdc++ wrote:
This is not yet implemented. Here is a patch.
2020-05-08 Ulrich Drepper <drep...@redhat.com>
* include/bits/atomic_base.h (atomic_flag): Implement test
memeber function.
* include/std/version: Define __cpp_lib_atomic_flag_test.
* testsuite/29_atomics/atomic_flag/test/explicit.cc: New file.
* testsuite/29_atomics/atomic_flag/test/implicit.cc: New file.
libatomic does not have a function 'test' so I implemented it with
__atomic_load (which takes care of memory ordering) and then compare
with the set-value.
The code generated at least for x86-64 looks good, it's a
straight-forward load, nothing else.
Thanks, looks good for master.
The tests weren't running by default, and the new members weren't const.
Fixed like so, tested powerpc64le-linux, committed to master.
commit 17412a74c531a21595311df5428f26552e82dfa8
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Fri Jun 12 10:22:05 2020 +0100
libstdc++: Make std::atomic_flag::test members const
Also fix the tests so they run without an explicit -std=gnu++2a in the
RUNTESTFLAGS, and test the new function on const-qualified objects.
* include/bits/atomic_base.h (atomic_flag::test): Add missing
const qualifiers.
* testsuite/29_atomics/atomic_flag/test/explicit.cc: Add
dg-options and verify results of test function.
* testsuite/29_atomics/atomic_flag/test/implicit.cc: Likewise.
diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h
index 01f77a0f372..ebcfeb4d51a 100644
--- a/libstdc++-v3/include/bits/atomic_base.h
+++ b/libstdc++-v3/include/bits/atomic_base.h
@@ -212,7 +212,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#define __cpp_lib_atomic_flag_test 201907L
_GLIBCXX_ALWAYS_INLINE bool
- test(memory_order __m = memory_order_seq_cst) noexcept
+ test(memory_order __m = memory_order_seq_cst) const noexcept
{
__atomic_flag_data_type __v;
__atomic_load(&_M_i, &__v, int(__m));
@@ -220,7 +220,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
_GLIBCXX_ALWAYS_INLINE bool
- test(memory_order __m = memory_order_seq_cst) volatile noexcept
+ test(memory_order __m = memory_order_seq_cst) const volatile noexcept
{
__atomic_flag_data_type __v;
__atomic_load(&_M_i, &__v, int(__m));
diff --git a/libstdc++-v3/testsuite/29_atomics/atomic_flag/test/explicit.cc b/libstdc++-v3/testsuite/29_atomics/atomic_flag/test/explicit.cc
index 539656ba583..4f2a10d6d40 100644
--- a/libstdc++-v3/testsuite/29_atomics/atomic_flag/test/explicit.cc
+++ b/libstdc++-v3/testsuite/29_atomics/atomic_flag/test/explicit.cc
@@ -1,3 +1,4 @@
+// { dg-options "-std=gnu++2a" }
// { dg-do run { target c++2a } }
// { dg-require-thread-fence "" }
@@ -19,14 +20,21 @@
// <http://www.gnu.org/licenses/>.
#include <atomic>
+#include <testsuite_hooks.h>
int main()
{
using namespace std;
- atomic_flag af = ATOMIC_FLAG_INIT;
- if (af.test(memory_order_acquire))
- af.clear(memory_order_release);
+ atomic_flag af0 = ATOMIC_FLAG_INIT;
+ VERIFY( ! af0.test(memory_order_acquire) );
- return 0;
+ atomic_flag af{true};
+ const atomic_flag& caf = af;
+
+ VERIFY( af.test(memory_order_acquire) );
+ VERIFY( caf.test(memory_order_acquire) );
+ af.clear(memory_order_release);
+ VERIFY( ! af.test(memory_order_acquire) );
+ VERIFY( ! caf.test(memory_order_acquire) );
}
diff --git a/libstdc++-v3/testsuite/29_atomics/atomic_flag/test/implicit.cc b/libstdc++-v3/testsuite/29_atomics/atomic_flag/test/implicit.cc
index 11d29ac0b9e..3889f32b98a 100644
--- a/libstdc++-v3/testsuite/29_atomics/atomic_flag/test/implicit.cc
+++ b/libstdc++-v3/testsuite/29_atomics/atomic_flag/test/implicit.cc
@@ -1,3 +1,4 @@
+// { dg-options "-std=gnu++2a" }
// { dg-do run { target c++2a } }
// { dg-require-thread-fence "" }
@@ -19,14 +20,21 @@
// <http://www.gnu.org/licenses/>.
#include <atomic>
+#include <testsuite_hooks.h>
int main()
{
using namespace std;
- atomic_flag af = ATOMIC_FLAG_INIT;
- if (af.test())
- af.clear();
+ atomic_flag af0 = ATOMIC_FLAG_INIT;
+ VERIFY( ! af0.test(memory_order_acquire) );
- return 0;
+ atomic_flag af{true};
+ const atomic_flag& caf = af;
+
+ VERIFY( af.test() );
+ VERIFY( caf.test() );
+ af.clear();
+ VERIFY( ! af.test() );
+ VERIFY( ! caf.test() );
}
