1 // Copyright 2010-2021 Google LLC
2 // Licensed under the Apache License, Version 2.0 (the "License");
3 // you may not use this file except in compliance with the License.
4 // You may obtain a copy of the License at
5 //
6 //     http://www.apache.org/licenses/LICENSE-2.0
7 //
8 // Unless required by applicable law or agreed to in writing, software
9 // distributed under the License is distributed on an "AS IS" BASIS,
10 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11 // See the License for the specific language governing permissions and
12 // limitations under the License.
13 
14 #include "ortools/util/sigint.h"
15 
16 #include <csignal>
17 
18 #include "ortools/base/logging.h"
19 
20 namespace operations_research {
21 
Register(const std::function<void ()> & f)22 void SigintHandler::Register(const std::function<void()>& f) {
23   handler_ = [this, f]() -> void {
24     ++num_sigint_calls_;
25     if (num_sigint_calls_ >= 3) {
26       LOG(INFO) << "^C pressed " << num_sigint_calls_
27                 << " times. Forcing termination.";
28       exit(EXIT_FAILURE);
29     }
30     LOG(INFO) << "^C pressed " << num_sigint_calls_ << " times. "
31               << "Interrupting the solver. Press 3 times to force termination.";
32     if (num_sigint_calls_ == 1) f();
33   };
34   signal(SIGINT, &ControlCHandler);
35 }
36 
37 // This method will be called by the system after the SIGINT signal.
38 // The parameter is the signal received.
ControlCHandler(int sig)39 void SigintHandler::ControlCHandler(int sig) { handler_(); }
40 
41 // Unregister the SIGINT handler.
~SigintHandler()42 SigintHandler::~SigintHandler() { signal(SIGINT, SIG_DFL); }
43 
44 thread_local std::function<void()> SigintHandler::handler_;
45 
46 }  // namespace operations_research
47