uhd: Removed atomic.hpp from public API

atomic.hpp defines a spin lock and a lockfree mutex. There is no reason
to have standard constructs in the public API, where we're contractually
obligated to not touch them. Thus, moving them into the internal API
space.

2 files changed, 76 insertions, 2 deletions

diff --git a/host/lib/include/CMakeLists.txt b/host/lib/include/CMakeLists.txt
index 5eea68f80..a688f4ea9 100644
--- a/host/lib/include/CMakeLists.txt
+++ b/host/lib/include/CMakeLists.txt
@@ -1,7 +1,7 @@
 #
-# Copyright 2017 Ettus Research, a National Instruments Company
+# Copyright 2017 Ettus Research (National Instruments Corp.)
 #
-# SPDX-License-Identifier: GPL-3.0
+# SPDX-License-Identifier: GPL-3.0+
 #
 
 INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})
diff --git a/host/lib/include/uhd/utils/atomic.hpp b/host/lib/include/uhd/utils/atomic.hpp
new file mode 100644
index 000000000..86b1dddda
--- /dev/null
+++ b/host/lib/include/uhd/utils/atomic.hpp
@@ -0,0 +1,74 @@
+//
+// Copyright 2012-2013,2016-2017 Ettus Research LLC
+// Copyright 2018 Ettus Research, a National Instruments Company
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#ifndef INCLUDED_UHD_UTILS_ATOMIC_HPP
+#define INCLUDED_UHD_UTILS_ATOMIC_HPP
+
+#include <uhd/config.hpp>
+#include <uhd/utils/system_time.hpp>
+#include <uhd/types/time_spec.hpp>
+#include <boost/thread/thread.hpp>
+#include <atomic>
+
+namespace uhd{
+
+    /*! DEPRECATED -- Will be removed in coming versions of UHD.
+     *
+     * Spin-wait on a condition with a timeout.
+     * \param cond an atomic variable to compare
+     * \param value compare to atomic for true/false
+     * \param timeout the timeout in seconds
+     * \return true for cond == value, false for timeout
+     */
+    template<typename T>
+    UHD_INLINE bool spin_wait_with_timeout(
+        std::atomic<T> &cond,
+        const T value,
+        const double timeout
+    ){
+        if (cond == value) return true;
+        const time_spec_t exit_time = uhd::get_system_time() + time_spec_t(timeout);
+        while (cond != value) {
+            if (uhd::get_system_time() > exit_time) {
+                return false;
+            }
+            boost::this_thread::interruption_point();
+            boost::this_thread::yield();
+        }
+        return true;
+    }
+
+    /*! DEPRECATED -- Will be removed in coming versions of UHD.
+     *
+     * Claimer class to provide synchronization for multi-thread access.
+     * Claiming enables buffer classes to be used with a buffer queue.
+     */
+    class simple_claimer{
+    public:
+        simple_claimer(void){
+            this->release();
+        }
+
+        UHD_INLINE void release(void){
+            _locked = false;
+        }
+
+        UHD_INLINE bool claim_with_wait(const double timeout){
+            if (spin_wait_with_timeout(_locked, false, timeout)){
+                _locked = true;
+                return true;
+            }
+            return false;
+        }
+
+    private:
+        std::atomic<bool> _locked;
+    };
+
+} //namespace uhd
+
+#endif /* INCLUDED_UHD_UTILS_ATOMIC_HPP */