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2f48a02b44
Recursive mutexes now go as fast as normal mutexes. The tradeoff is they are no longer safe to use in signal handlers. However you can still have signal safe mutexes if you set your mutex to both recursive and pshared. You can also make functions that use recursive mutexes signal safe using sigprocmask to ensure recursion doesn't happen due to any signal handler The impact of this change is that, on Windows, many functions which edit the file descriptor table rely on recursive mutexes, e.g. open(). If you develop your app so it uses pread() and pwrite() then your app should go very fast when performing a heavily multithreaded and contended workload For example, when scaling to 40+ cores, *NSYNC mutexes can go as much as 1000x faster (in CPU time) than the naive recursive lock implementation. Now recursive will use *NSYNC under the hood when it's possible to do so
27 lines
2.1 KiB
C
27 lines
2.1 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│ vi: set noet ft=c ts=8 sw=8 fenc=utf-8 :vi │
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2016 Google Inc. │
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│ │
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│ Licensed under the Apache License, Version 2.0 (the "License"); │
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│ you may not use this file except in compliance with the License. │
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│ You may obtain a copy of the License at │
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│ │
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│ http://www.apache.org/licenses/LICENSE-2.0 │
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│ │
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│ Unless required by applicable law or agreed to in writing, software │
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│ distributed under the License is distributed on an "AS IS" BASIS, │
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│ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. │
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│ See the License for the specific language governing permissions and │
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│ limitations under the License. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "third_party/nsync/testing/mu_wait_test.inc"
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int main (int argc, char *argv[]) {
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testing_base tb = testing_new (argc, argv, 0);
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TEST_RUN (tb, test_mu_producer_consumer0);
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TEST_RUN (tb, test_mu_producer_consumer3);
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TEST_RUN (tb, test_mu_producer_consumer4);
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TEST_RUN (tb, test_mu_producer_consumer5);
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return (testing_base_exit (tb));
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}
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