1 // 2 // detail/posix_signal_blocker.hpp 3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com) 6 // 7 // Distributed under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 9 // 10 11 #ifndef BOOST_ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP 12 #define BOOST_ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP 13 14 #if defined(_MSC_VER) && (_MSC_VER >= 1200) 15 # pragma once 16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) 17 18 #include <boost/asio/detail/config.hpp> 19 20 #if defined(BOOST_ASIO_HAS_PTHREADS) 21 22 #include <csignal> 23 #include <pthread.h> 24 #include <signal.h> 25 #include <boost/asio/detail/noncopyable.hpp> 26 27 #include <boost/asio/detail/push_options.hpp> 28 29 namespace boost { 30 namespace asio { 31 namespace detail { 32 33 class posix_signal_blocker 34 : private noncopyable 35 { 36 public: 37 // Constructor blocks all signals for the calling thread. posix_signal_blocker()38 posix_signal_blocker() 39 : blocked_(false) 40 { 41 sigset_t new_mask; 42 sigfillset(&new_mask); 43 blocked_ = (pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask_) == 0); 44 } 45 46 // Destructor restores the previous signal mask. ~posix_signal_blocker()47 ~posix_signal_blocker() 48 { 49 if (blocked_) 50 pthread_sigmask(SIG_SETMASK, &old_mask_, 0); 51 } 52 53 // Block all signals for the calling thread. block()54 void block() 55 { 56 if (!blocked_) 57 { 58 sigset_t new_mask; 59 sigfillset(&new_mask); 60 blocked_ = (pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask_) == 0); 61 } 62 } 63 64 // Restore the previous signal mask. unblock()65 void unblock() 66 { 67 if (blocked_) 68 blocked_ = (pthread_sigmask(SIG_SETMASK, &old_mask_, 0) != 0); 69 } 70 71 private: 72 // Have signals been blocked. 73 bool blocked_; 74 75 // The previous signal mask. 76 sigset_t old_mask_; 77 }; 78 79 } // namespace detail 80 } // namespace asio 81 } // namespace boost 82 83 #include <boost/asio/detail/pop_options.hpp> 84 85 #endif // defined(BOOST_ASIO_HAS_PTHREADS) 86 87 #endif // BOOST_ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP 88