1 files changed, 80 insertions, 0 deletions
diff --git a/src/signaler.hpp b/src/signaler.hpp
new file mode 100644
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--- /dev/null
+++ b/src/signaler.hpp
@@ -0,0 +1,80 @@
+/*
+    Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_SIGNALER_HPP_INCLUDED__
+#define __ZMQ_SIGNALER_HPP_INCLUDED__
+
+#ifdef HAVE_FORK
+#include <unistd.h>
+#endif
+
+#include "fd.hpp"
+
+namespace zmq
+{
+
+    //  This is a cross-platform equivalent to signal_fd. However, as opposed
+    //  to signal_fd there can be at most one signal in the signaler at any
+    //  given moment. Attempt to send a signal before receiving the previous
+    //  one will result in undefined behaviour.
+
+    class signaler_t
+    {
+    public:
+
+        signaler_t ();
+        ~signaler_t ();
+
+        fd_t get_fd ();
+        void send ();
+        int wait (int timeout_);
+        void recv ();
+
+#ifdef HAVE_FORK
+        // close the file descriptors in a forked child process so that they
+        // do not interfere with the context in the parent process.
+        void forked();
+#endif
+
+    private:
+
+        //  Creates a pair of filedescriptors that will be used
+        //  to pass the signals.
+        static int make_fdpair (fd_t *r_, fd_t *w_);
+
+        //  Underlying write & read file descriptor
+        //  Will be -1 if we exceeded number of available handles
+        fd_t w;
+        fd_t r;
+
+        //  Disable copying of signaler_t object.
+        signaler_t (const signaler_t&);
+        const signaler_t &operator = (const signaler_t&);
+
+#ifdef HAVE_FORK
+        // the process that created this context. Used to detect forking.
+        pid_t pid;
+        // idempotent close of file descriptors that is safe to use by destructor
+        // and forked().
+        void close_internal();
+#endif
+    };
+}
+
+#endif