// Protocol Buffers - Google's data interchange format
// Copyright 2014 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
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// this software without specific prior written permission.
//
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#ifndef GOOGLE_PROTOBUF_ATOMIC_SEQUENCE_NUM_H_
#define GOOGLE_PROTOBUF_ATOMIC_SEQUENCE_NUM_H_

#include <google/protobuf/stubs/atomicops.h>

namespace google {
namespace protobuf {
namespace internal {

class SequenceNumber {
 public:
  SequenceNumber() : word_(0) {}

  AtomicWord GetNext() {
    return NoBarrier_AtomicIncrement(&word_, 1) - 1;
  }
 private:
  AtomicWord word_;
};

}  // namespace internal
}  // namespace protobuf
}  // namespace google

#endif  // GOOGLE_PROTOBUF_ATOMIC_SEQUENCE_NUM_H_
