internal/ceres/scoped_thread_token.h

// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2017 Google Inc. All rights reserved.
// http://ceres-solver.org/
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// Author: yp@photonscore.de (Yury Prokazov)

#ifndef CERES_INTERNAL_SCOPED_THREAD_TOKEN_H_
#define CERES_INTERNAL_SCOPED_THREAD_TOKEN_H_

#include "ceres/internal/export.h"
#include "ceres/thread_token_provider.h"

namespace ceres::internal {

// Helper class for ThreadTokenProvider. This object acquires a token in its
// constructor and puts that token back with destruction.
class CERES_NO_EXPORT ScopedThreadToken {
 public:
  explicit ScopedThreadToken(ThreadTokenProvider* provider)
      : provider_(provider), token_(provider->Acquire()) {}

  ~ScopedThreadToken() { provider_->Release(token_); }
  ScopedThreadToken(ScopedThreadToken&) = delete;
  ScopedThreadToken& operator=(ScopedThreadToken&) = delete;

  int token() const { return token_; }

 private:
  ThreadTokenProvider* provider_;
  int token_;
};

}  // namespace ceres::internal

#endif  // CERES_INTERNAL_SCOPED_THREAD_TOKEN_H_