Initial Commit

include/asio/detail/posix_signal_blocker.hpp

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+//
+// detail/posix_signal_blocker.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2025 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP
+#define ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_PTHREADS)
+
+#include <csignal>
+#include <pthread.h>
+#include <signal.h>
+#include "asio/detail/noncopyable.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class posix_signal_blocker
+  : private noncopyable
+{
+public:
+  // Constructor blocks all signals for the calling thread.
+  posix_signal_blocker()
+    : blocked_(false)
+  {
+    sigset_t new_mask;
+    sigfillset(&new_mask);
+    blocked_ = (pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask_) == 0);
+  }
+
+  // Destructor restores the previous signal mask.
+  ~posix_signal_blocker()
+  {
+    if (blocked_)
+      pthread_sigmask(SIG_SETMASK, &old_mask_, 0);
+  }
+
+  // Block all signals for the calling thread.
+  void block()
+  {
+    if (!blocked_)
+    {
+      sigset_t new_mask;
+      sigfillset(&new_mask);
+      blocked_ = (pthread_sigmask(SIG_BLOCK, &new_mask, &old_mask_) == 0);
+    }
+  }
+
+  // Restore the previous signal mask.
+  void unblock()
+  {
+    if (blocked_)
+      blocked_ = (pthread_sigmask(SIG_SETMASK, &old_mask_, 0) != 0);
+  }
+
+private:
+  // Have signals been blocked.
+  bool blocked_;
+
+  // The previous signal mask.
+  sigset_t old_mask_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_PTHREADS)
+
+#endif // ASIO_DETAIL_POSIX_SIGNAL_BLOCKER_HPP