1 files changed, 36 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/utils/thread_utils/barrier.cpp b/comm/third_party/botan/src/lib/utils/thread_utils/barrier.cpp
new file mode 100644
index 0000000000..c05c22121e
--- /dev/null
+++ b/comm/third_party/botan/src/lib/utils/thread_utils/barrier.cpp
@@ -0,0 +1,36 @@
+/*
+* Barrier
+* (C) 2016 Joel Low
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/internal/barrier.h>
+
+namespace Botan {
+
+void Barrier::wait(size_t delta)
+    {
+    std::lock_guard<std::mutex> lock(m_mutex);
+    m_value += delta;
+    }
+
+void Barrier::sync()
+    {
+    std::unique_lock<std::mutex> lock(m_mutex);
+
+    if(m_value > 1)
+        {
+        --m_value;
+        const size_t current_syncs = m_syncs;
+        m_cond.wait(lock, [this, &current_syncs] { return m_syncs != current_syncs; });
+        }
+    else
+        {
+        m_value = 0;
+        ++m_syncs;
+        m_cond.notify_all();
+        }
+    }
+
+}