1 files changed, 42 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/utils/thread_utils/barrier.h b/comm/third_party/botan/src/lib/utils/thread_utils/barrier.h
new file mode 100644
index 0000000000..749da92a77
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+++ b/comm/third_party/botan/src/lib/utils/thread_utils/barrier.h
@@ -0,0 +1,42 @@
+/*
+* Barrier
+* (C) 2016 Joel Low
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_UTIL_BARRIER_H_
+#define BOTAN_UTIL_BARRIER_H_
+
+#include <mutex>
+#include <condition_variable>
+
+namespace Botan {
+
+/**
+Barrier implements a barrier synchronization primitive. wait() will
+indicate how many threads to synchronize; each thread needing
+synchronization should call sync(). When sync() returns, the barrier
+is reset to zero, and the m_syncs counter is incremented. m_syncs is a
+counter to ensure that wait() can be called after a sync() even if the
+previously sleeping threads have not awoken.)
+*/
+class Barrier final
+   {
+   public:
+      explicit Barrier(int value = 0) : m_value(value), m_syncs(0) {}
+
+      void wait(size_t delta);
+
+      void sync();
+
+   private:
+      size_t m_value;
+      size_t m_syncs;
+      std::mutex m_mutex;
+      std::condition_variable m_cond;
+   };
+
+}
+
+#endif