ceph/src/boost/boost/process/spawn.hpp

   1 // Copyright (c) 2006, 2007 Julio M. Merino Vidal
   2 // Copyright (c) 2008 Ilya Sokolov, Boris Schaeling
   3 // Copyright (c) 2009 Boris Schaeling
   4 // Copyright (c) 2010 Felipe Tanus, Boris Schaeling
   5 // Copyright (c) 2011, 2012 Jeff Flinn, Boris Schaeling
   6 // Copyright (c) 2016 Klemens D. Morgenstern
   7 //
   8 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   9 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  10
  11 /**
  12  * \file boost/process/spawn.hpp
  13  *
  14  * Defines the spawn function.
  15  */
  16
  17 #ifndef BOOST_PROCESS_SPAWN_HPP
  18 #define BOOST_PROCESS_SPAWN_HPP
  19
  20 #include <boost/process/detail/config.hpp>
  21 #include <boost/process/detail/child_decl.hpp>
  22 #include <boost/process/detail/execute_impl.hpp>
  23 #include <boost/process/detail/async_handler.hpp>
  24
  25 #if defined(BOOST_POSIX_API)
  26 #include <boost/process/posix.hpp>
  27 #endif
  28
  29 namespace boost {
  30
  31 namespace process {
  32
  33 namespace detail {
  34
  35 }
  36
  37 /** Launch a process and detach it. Returns no handle.
  38
  39 This function starts a process and immediately detaches it. It thereby prevents the system from creating a zombie process,
  40 but will also cause the system to be unable to wait for the child to exit.
  41
  42 \note This will set `SIGCHLD` to `SIGIGN` on posix.
  43
  44 \warning This function does not allow asynchronous operations, since it cannot wait for the end of the process.
  45 It will fail to compile if a reference to `boost::asio::io_context` is passed.
  46
  47  */
  48 template<typename ...Args>
  49 inline void spawn(Args && ...args)
  50 {
  51     typedef typename ::boost::process::detail::has_async_handler<Args...>::type
  52             has_async;
  53
  54
  55     static_assert(
  56             !has_async::value,
  57             "Spawn cannot wait for exit, so async properties cannot be used");
  58
  59     auto c = ::boost::process::detail::execute_impl(
  60 #if defined(BOOST_POSIX_API)
  61             ::boost::process::posix::sig.ign(),
  62 #endif
  63              std::forward<Args>(args)...);
  64     c.detach();
  65 }
  66
  67 }}
  68 #endif
  69