ceph/src/boost/boost/asio/detail/posix_signal_blocker.hpp

   1 //
   2 // detail/posix_signal_blocker.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2019 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.
  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.
  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.
  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.
  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