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 ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP 12 #define ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP 13 14 15 #include "asio/detail/config.hpp" 16 17 #if defined(ASIO_HAS_PTHREADS) 18 19 #include <csignal> 20 #include <pthread.h> 21 #include <signal.h> 22 #include "asio/detail/noncopyable.hpp" 23 24 #include "asio/detail/push_options.hpp" 25 26 namespace asio { 27 namespace detail { 28 29 class posix_signal_blocker 30 : private noncopyable 31 { 32 public: 33 // Constructor blocks all signals for the calling thread. 34 posix_signal_blocker() 35 : blocked_(false) 36 { 37 sigset_t new_mask; 38 sigfillset(&new_mask); 39 blocked_ = (pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask_) == 0); 40 } 41 42 // Destructor restores the previous signal mask. 43 ~posix_signal_blocker() 44 { 45 if (blocked_) 46 pthread_sigmask(SIG_SETMASK, &old_mask_, 0); 47 } 48 49 // Block all signals for the calling thread. 50 void block() 51 { 52 if (!blocked_) 53 { 54 sigset_t new_mask; 55 sigfillset(&new_mask); 56 blocked_ = (pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask_) == 0); 57 } 58 } 59 60 // Restore the previous signal mask. 61 void unblock() 62 { 63 if (blocked_) 64 blocked_ = (pthread_sigmask(SIG_SETMASK, &old_mask_, 0) != 0); 65 } 66 67 private: 68 // Have signals been blocked. 69 bool blocked_; 70 71 // The previous signal mask. 72 sigset_t old_mask_; 73 }; 74 75 } // namespace detail 76 } // namespace asio 77 78 #include "asio/detail/pop_options.hpp" 79 80 #endif // defined(ASIO_HAS_PTHREADS) 81 82 #endif // ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP 83
