1 files changed, 38 insertions, 0 deletions
diff --git a/src/rocksdb/util/random.cc b/src/rocksdb/util/random.cc
new file mode 100644
index 000000000..38c36defd
--- /dev/null
+++ b/src/rocksdb/util/random.cc
@@ -0,0 +1,38 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+//
+
+#include "util/random.h"
+
+#include <stdint.h>
+#include <string.h>
+#include <thread>
+#include <utility>
+
+#include "port/likely.h"
+#include "util/thread_local.h"
+
+#ifdef ROCKSDB_SUPPORT_THREAD_LOCAL
+#define STORAGE_DECL static __thread
+#else
+#define STORAGE_DECL static
+#endif
+
+namespace ROCKSDB_NAMESPACE {
+
+Random* Random::GetTLSInstance() {
+  STORAGE_DECL Random* tls_instance;
+  STORAGE_DECL std::aligned_storage<sizeof(Random)>::type tls_instance_bytes;
+
+  auto rv = tls_instance;
+  if (UNLIKELY(rv == nullptr)) {
+    size_t seed = std::hash<std::thread::id>()(std::this_thread::get_id());
+    rv = new (&tls_instance_bytes) Random((uint32_t)seed);
+    tls_instance = rv;
+  }
+  return rv;
+}
+
+}  // namespace ROCKSDB_NAMESPACE