import quincy beta 17.1.0

[ceph.git] / ceph / src / boost / boost / atomic / detail / wait_ops_emulated.hpp

diff --git a/ceph/src/boost/boost/atomic/detail/wait_ops_emulated.hpp b/ceph/src/boost/boost/atomic/detail/wait_ops_emulated.hpp
new file mode 100644 (file)
index 0000000..75c0354
--- /dev/null
+++ b/ceph/src/boost/boost/atomic/detail/wait_ops_emulated.hpp
@@ -0,0 +1,97 @@
+/*
+ * Distributed under the Boost Software License, Version 1.0.
+ * (See accompanying file LICENSE_1_0.txt or copy at
+ * http://www.boost.org/LICENSE_1_0.txt)
+ *
+ * Copyright (c) 2020 Andrey Semashev
+ */
+/*!
+ * \file   atomic/detail/wait_ops_emulated.hpp
+ *
+ * This header contains emulated (lock-based) implementation of the waiting and notifying atomic operations.
+ */
+
+#ifndef BOOST_ATOMIC_DETAIL_WAIT_OPS_EMULATED_HPP_INCLUDED_
+#define BOOST_ATOMIC_DETAIL_WAIT_OPS_EMULATED_HPP_INCLUDED_
+
+#include <cstddef>
+#include <boost/static_assert.hpp>
+#include <boost/memory_order.hpp>
+#include <boost/atomic/detail/config.hpp>
+#include <boost/atomic/detail/lock_pool.hpp>
+#include <boost/atomic/detail/wait_operations_fwd.hpp>
+#include <boost/atomic/detail/header.hpp>
+
+#ifdef BOOST_HAS_PRAGMA_ONCE
+#pragma once
+#endif
+
+namespace boost {
+namespace atomics {
+namespace detail {
+
+//! Emulated implementation of waiting and notifying operations
+template< typename Base >
+struct wait_operations_emulated :
+    public Base
+{
+    typedef Base base_type;
+    typedef typename base_type::storage_type storage_type;
+    typedef lock_pool::scoped_lock< base_type::storage_alignment, true > scoped_lock;
+    typedef lock_pool::scoped_wait_state< base_type::storage_alignment > scoped_wait_state;
+
+    static BOOST_CONSTEXPR_OR_CONST bool always_has_native_wait_notify = false;
+
+    static BOOST_FORCEINLINE bool has_native_wait_notify(storage_type const volatile&) BOOST_NOEXCEPT
+    {
+        return false;
+    }
+
+    static
+#if defined(BOOST_MSVC) && BOOST_MSVC < 1500
+    // In some cases, when this function is inlined, MSVC-8 (VS2005) x64 generates broken code that returns a bogus value from this function.
+    BOOST_NOINLINE
+#endif
+    storage_type wait(storage_type const volatile& storage, storage_type old_val, memory_order) BOOST_NOEXCEPT
+    {
+        BOOST_STATIC_ASSERT_MSG(!base_type::is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object");
+        storage_type const& s = const_cast< storage_type const& >(storage);
+        scoped_wait_state wait_state(&storage);
+        storage_type new_val = s;
+        while (new_val == old_val)
+        {
+            wait_state.wait();
+            new_val = s;
+        }
+
+        return new_val;
+    }
+
+    static void notify_one(storage_type volatile& storage) BOOST_NOEXCEPT
+    {
+        BOOST_STATIC_ASSERT_MSG(!base_type::is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object");
+        scoped_lock lock(&storage);
+        lock_pool::notify_one(lock.get_lock_state(), &storage);
+    }
+
+    static void notify_all(storage_type volatile& storage) BOOST_NOEXCEPT
+    {
+        BOOST_STATIC_ASSERT_MSG(!base_type::is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object");
+        scoped_lock lock(&storage);
+        lock_pool::notify_all(lock.get_lock_state(), &storage);
+    }
+};
+
+template< typename Base, std::size_t Size, bool Interprocess >
+struct wait_operations< Base, Size, false, Interprocess > :
+    public wait_operations_emulated< Base >
+{
+};
+
+} // namespace detail
+} // namespace atomics
+} // namespace boost
+
+#include <boost/atomic/detail/footer.hpp>
+
+#endif // BOOST_ATOMIC_DETAIL_WAIT_OPS_EMULATED_HPP_INCLUDED_