1 | /* |
2 | * Copyright 2014-present Facebook, Inc. |
3 | * |
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 |
7 | * |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * |
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. |
15 | */ |
16 | |
17 | #include <folly/synchronization/LifoSem.h> |
18 | |
19 | /// Raw node storage is preallocated in a contiguous memory segment, |
20 | /// but we use an anonymous mmap so the physical memory used (RSS) will |
21 | /// only reflect the maximum number of waiters that actually existed |
22 | /// concurrently. For blocked threads the max node count is limited by the |
23 | /// number of threads, so we can conservatively estimate that this will be |
24 | /// < 10k. For LifoEventSem, however, we could potentially have many more. |
25 | /// |
26 | /// On a 64-bit architecture each LifoSemRawNode takes 16 bytes. We make |
27 | /// the pool 1 million entries. |
28 | |
29 | LIFOSEM_DECLARE_POOL(std::atomic, 1000000) |
30 | |
31 | namespace folly { |
32 | |
33 | ShutdownSemError::ShutdownSemError(const std::string& msg) |
34 | : std::runtime_error(msg) {} |
35 | |
36 | ShutdownSemError::~ShutdownSemError() noexcept {} |
37 | |
38 | } // namespace folly |
39 | |