整理

include/boost/process/v2/posix/pipe_fork_launcher.hpp

@@ -0,0 +1,185 @@
+// Copyright (c) 2022 Klemens D. Morgenstern
+//
+// 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 BOOST_PROCESS_V2_POSIX_PIPE_FORK_LAUNCHER_HPP
+#define BOOST_PROCESS_V2_POSIX_PIPE_FORK_LAUNCHER_HPP
+
+#include <boost/process/v2/posix/default_launcher.hpp>
+
+#include <unistd.h>
+
+BOOST_PROCESS_V2_BEGIN_NAMESPACE
+
+namespace posix
+{
+
+/// A launcher using `pipe_fork`. Default on FreeBSD
+struct pipe_fork_launcher : default_launcher
+{
+    /// The file descriptor of the subprocess. Set after fork.
+    pipe_fork_launcher() = default;
+
+    template<typename ExecutionContext, typename Args, typename ... Inits>
+    auto operator()(ExecutionContext & context,
+                    const typename std::enable_if<is_convertible<
+                            ExecutionContext&, net::execution_context&>::value,
+                            filesystem::path >::type & executable,
+                    Args && args,
+                    Inits && ... inits ) -> basic_process<typename ExecutionContext::executor_type>
+    {
+        error_code ec;
+        auto proc =  (*this)(context, ec, executable, std::forward<Args>(args), std::forward<Inits>(inits)...);
+
+        if (ec)
+            v2::detail::throw_error(ec, "pipe_fork_launcher");
+
+        return proc;
+    }
+
+
+    template<typename ExecutionContext, typename Args, typename ... Inits>
+    auto operator()(ExecutionContext & context,
+                    error_code & ec,
+                    const typename std::enable_if<is_convertible<
+                            ExecutionContext&, net::execution_context&>::value,
+                            filesystem::path >::type & executable,
+                    Args && args,
+                    Inits && ... inits ) -> basic_process<typename ExecutionContext::executor_type>
+    {
+        return (*this)(context.get_executor(), ec, executable, std::forward<Args>(args), std::forward<Inits>(inits)...);
+    }
+
+    template<typename Executor, typename Args, typename ... Inits>
+    auto operator()(Executor exec,
+                    const typename std::enable_if<
+                            net::execution::is_executor<Executor>::value ||
+                            net::is_executor<Executor>::value,
+                            filesystem::path >::type & executable,
+                    Args && args,
+                    Inits && ... inits ) -> basic_process<Executor>
+    {
+        error_code ec;
+        auto proc =  (*this)(std::move(exec), ec, executable, std::forward<Args>(args), std::forward<Inits>(inits)...);
+
+        if (ec)
+            v2::detail::throw_error(ec, "pipe_fork_launcher");
+
+        return proc;
+    }
+
+    template<typename Executor, typename Args, typename ... Inits>
+    auto operator()(Executor exec,
+                    error_code & ec,
+                    const typename std::enable_if<
+                            net::execution::is_executor<Executor>::value ||
+                            net::is_executor<Executor>::value,
+                            filesystem::path >::type & executable,
+                    Args && args,
+                    Inits && ... inits ) -> basic_process<Executor>
+    {
+        auto argv = this->build_argv_(executable, std::forward<Args>(args));
+        int fd = -1;
+        {
+            pipe_guard pg, pg_wait;
+            if (::pipe(pg.p))
+            {
+                BOOST_PROCESS_V2_ASSIGN_EC(ec, errno, system_category());
+                return basic_process<Executor>{exec};
+            }
+            if (::fcntl(pg.p[1], F_SETFD, FD_CLOEXEC))
+            {
+                BOOST_PROCESS_V2_ASSIGN_EC(ec, errno, system_category());
+                return basic_process<Executor>{exec};
+            }
+            if (::pipe(pg_wait.p))
+            {
+              BOOST_PROCESS_V2_ASSIGN_EC(ec, errno, system_category());
+              return basic_process<Executor>{exec};
+            }
+            if (::fcntl(pg_wait.p[1], F_SETFD, FD_CLOEXEC))
+            {
+                BOOST_PROCESS_V2_ASSIGN_EC(ec, errno, system_category());
+                return basic_process<Executor>{exec};
+            }
+            ec = detail::on_setup(*this, executable, argv, inits ...);
+            if (ec)
+            {
+                detail::on_error(*this, executable, argv, ec, inits...);
+                return basic_process<Executor>(exec);
+            }
+            fd_whitelist.push_back(pg.p[1]);
+            fd_whitelist.push_back(pg_wait.p[1]);
+
+            auto & ctx = net::query(
+                    exec, net::execution::context);
+            ctx.notify_fork(net::execution_context::fork_prepare);
+            pid = ::fork();
+            if (pid == -1)
+            {
+                ctx.notify_fork(net::execution_context::fork_parent);
+                detail::on_fork_error(*this, executable, argv, ec, inits...);
+                detail::on_error(*this, executable, argv, ec, inits...);
+
+                BOOST_PROCESS_V2_ASSIGN_EC(ec, errno, system_category());
+                return basic_process<Executor>{exec};
+            }
+            else if (pid == 0)
+            {
+                ctx.notify_fork(net::execution_context::fork_child);
+                ::close(pg.p[0]);
+
+                ec = detail::on_exec_setup(*this, executable, argv, inits...);
+                if (!ec)
+                {
+                    close_all_fds(ec);
+                }                
+                if (!ec)
+                    ::execve(executable.c_str(), const_cast<char * const *>(argv), const_cast<char * const *>(env));
+
+                default_launcher::ignore_unused(::write(pg.p[1], &errno, sizeof(int)));
+                BOOST_PROCESS_V2_ASSIGN_EC(ec, errno, system_category());
+                detail::on_exec_error(*this, executable, argv, ec, inits...);
+                ::_exit(EXIT_FAILURE);
+                return basic_process<Executor>{exec};
+            }
+            ctx.notify_fork(net::execution_context::fork_parent);
+            ::close(pg.p[1]);
+            pg.p[1] = -1;
+            ::close(pg_wait.p[1]);
+            pg_wait.p[1] = -1;
+            int child_error{0};
+            int count = -1;
+            while ((count = ::read(pg.p[0], &child_error, sizeof(child_error))) == -1)
+            {
+                int err = errno;
+                if ((err != EAGAIN) && (err != EINTR))
+                {
+                    BOOST_PROCESS_V2_ASSIGN_EC(ec, err, system_category());
+                    break;
+                }
+            }
+            if (count != 0)
+                BOOST_PROCESS_V2_ASSIGN_EC(ec, child_error, system_category());
+
+            if (ec)
+            {
+                detail::on_error(*this, executable, argv, ec, inits...);
+                return basic_process<Executor>{exec};
+            }
+            std::swap(fd, pg_wait.p[0]);
+        }
+
+        basic_process<Executor> proc(exec, pid, fd);
+        detail::on_success(*this, executable, argv, ec, inits...);
+        return proc;
+    }
+};
+
+
+}
+
+BOOST_PROCESS_V2_END_NAMESPACE
+
+
+#endif //BOOST_PROCESS_V2_POSIX_PIPE_FORK_LAUNCHER_HPP