mirror of https://github.com/facebook/rocksdb.git
41 lines
1.1 KiB
C++
41 lines
1.1 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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// This source code is also licensed under the GPLv2 license found in the
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// COPYING file in the root directory of this source tree.
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//
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#include "util/random.h"
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#include <stdint.h>
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#include <string.h>
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#include <thread>
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#include <utility>
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#include "port/likely.h"
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#include "util/thread_local.h"
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#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
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#define STORAGE_DECL static __thread
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#else
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#define STORAGE_DECL static
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#endif
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namespace rocksdb {
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Random* Random::GetTLSInstance() {
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STORAGE_DECL Random* tls_instance;
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STORAGE_DECL std::aligned_storage<sizeof(Random)>::type tls_instance_bytes;
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auto rv = tls_instance;
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if (UNLIKELY(rv == nullptr)) {
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size_t seed = std::hash<std::thread::id>()(std::this_thread::get_id());
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rv = new (&tls_instance_bytes) Random((uint32_t)seed);
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tls_instance = rv;
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}
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return rv;
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}
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} // namespace rocksdb
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