detail/posix/wait_group.hpp

0001 // Copyright (c) 2006, 2007 Julio M. Merino Vidal
0002 // Copyright (c) 2008 Ilya Sokolov, Boris Schaeling
0003 // Copyright (c) 2009 Boris Schaeling
0004 // Copyright (c) 2010 Felipe Tanus, Boris Schaeling
0005 // Copyright (c) 2011, 2012 Jeff Flinn, Boris Schaeling
0006 //
0007 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0008 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0009
0010 #ifndef BOOST_PROCESS_DETAIL_POSIX_WAIT_GROUP_HPP
0011 #define BOOST_PROCESS_DETAIL_POSIX_WAIT_GROUP_HPP
0012
0013 #include <boost/process/detail/config.hpp>
0014 #include <boost/process/detail/posix/group_handle.hpp>
0015 #include <chrono>
0016 #include <system_error>
0017 #include <sys/types.h>
0018 #include <sys/wait.h>
0019 #include <unistd.h>
0020
0021 namespace boost { namespace process { namespace detail { namespace posix {
0022
0023 inline void wait(const group_handle &p, std::error_code &ec) noexcept
0024 {
0025     pid_t ret;
0026     siginfo_t  status;
0027
0028     do
0029     {
0030         ret = ::waitpid(-p.grp, &status.si_status, 0);
0031         if (ret == -1)
0032         {
0033             ec = get_last_error();
0034             return;
0035         }
0036
0037         //ECHILD --> no child processes left.
0038         ret = ::waitid(P_PGID, p.grp, &status, WEXITED | WNOHANG);
0039     }
0040     while ((ret != -1) || (errno != ECHILD));
0041
0042     if (errno != ECHILD)
0043         ec = boost::process::detail::get_last_error();
0044     else
0045         ec.clear();
0046 }
0047
0048 inline void wait(const group_handle &p) noexcept
0049 {
0050     std::error_code ec;
0051     wait(p, ec);
0052     boost::process::detail::throw_error(ec, "waitpid(2) failed in wait");
0053 }
0054
0055 template< class Clock, class Duration >
0056 inline bool wait_until(
0057         const group_handle &p,
0058         const std::chrono::time_point<Clock, Duration>& time_out,
0059         std::error_code & ec) noexcept
0060 {
0061
0062     ::siginfo_t siginfo;
0063
0064     bool timed_out = false;
0065     int ret;
0066
0067     ::timespec sleep_interval;
0068     sleep_interval.tv_sec = 0;
0069     sleep_interval.tv_nsec = 100000000;
0070
0071
0072     while (!(timed_out = (Clock::now() > time_out)))
0073     {
0074         ret = ::waitid(P_PGID, p.grp, &siginfo, WEXITED | WSTOPPED | WNOHANG);
0075         if (ret == -1)
0076         {
0077             if ((errno == ECHILD) || (errno == ESRCH))
0078             {
0079                 ec.clear();
0080                 return true;
0081             }
0082             ec = boost::process::detail::get_last_error();
0083             return false;
0084         }
0085         //we can wait, because unlike in the wait_for_exit, we have no race condition regarding eh exit code.
0086         ::nanosleep(&sleep_interval, nullptr);
0087     }
0088     return !timed_out;
0089 }
0090
0091 template< class Clock, class Duration >
0092 inline bool wait_until(
0093         const group_handle &p,
0094         const std::chrono::time_point<Clock, Duration>& time_out) noexcept
0095 {
0096     std::error_code ec;
0097     bool b = wait_until(p, time_out, ec);
0098     boost::process::detail::throw_error(ec, "waitpid(2) failed in wait_until");
0099     return b;
0100 }
0101
0102 template< class Rep, class Period >
0103 inline bool wait_for(
0104         const group_handle &p,
0105         const std::chrono::duration<Rep, Period>& rel_time,
0106         std::error_code & ec) noexcept
0107 {
0108     return wait_until(p, std::chrono::steady_clock::now() + rel_time, ec);
0109 }
0110
0111 template< class Rep, class Period >
0112 inline bool wait_for(
0113         const group_handle &p,
0114         const std::chrono::duration<Rep, Period>& rel_time) noexcept
0115 {
0116     std::error_code ec;
0117     bool b = wait_for(p, rel_time, ec);
0118     boost::process::detail::throw_error(ec, "waitpid(2) failed in wait_for");
0119     return b;
0120 }
0121
0122 }}}}
0123
0124 #endif