chromium/third_party/abseil-cpp/absl/random/internal/pool_urbg.h

// Copyright 2017 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef ABSL_RANDOM_INTERNAL_POOL_URBG_H_
#define ABSL_RANDOM_INTERNAL_POOL_URBG_H_

#include <cinttypes>
#include <limits>

#include "absl/random/internal/traits.h"
#include "absl/types/span.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace random_internal {

// RandenPool is a thread-safe random number generator [random.req.urbg] that
// uses an underlying pool of Randen generators to generate values.  Each thread
// has affinity to one instance of the underlying pool generators.  Concurrent
// access is guarded by a spin-lock.
template <typename T>
class RandenPool { … };

extern template class RandenPool<uint8_t>;
extern template class RandenPool<uint16_t>;
extern template class RandenPool<uint32_t>;
extern template class RandenPool<uint64_t>;

// PoolURBG uses an underlying pool of random generators to implement a
// thread-compatible [random.req.urbg] interface with an internal cache of
// values.
template <typename T, size_t kBufferSize>
class PoolURBG { … };

}  // namespace random_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_RANDOM_INTERNAL_POOL_URBG_H_