2 * Copyright 2017-present Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 #include <folly/synchronization/ParkingLot.h>
19 namespace parking_lot_detail {
21 Bucket& Bucket::bucketFor(uint64_t key) {
22 constexpr size_t const kNumBuckets = kIsMobile ? 256 : 4096;
24 // Statically allocating this lets us use this in allocation-sensitive
25 // contexts. This relies on the assumption that std::mutex won't dynamically
26 // allocate memory, which we assume to be the case on Linux and iOS.
27 static Indestructible<std::array<Bucket, kNumBuckets>> gBuckets;
28 return (*gBuckets)[key % kNumBuckets];
31 std::atomic<uint64_t> idallocator{0};
33 } // namespace parking_lot_detail