--- /dev/null
+/*
+ * Copyright © 2013 Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program 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/>.
+ *
+ * Authored by: Thomas Voß <thomas.voss@canonical.com>
+ */
+
+#include <core/posix/exit.h>
+#include <core/posix/fork.h>
+
+#ifndef ANDROID
+#include "backtrace.h"
+#endif
+
+#include <iomanip>
+#include <iostream>
+#include <system_error>
+
+#include <unistd.h>
+
+namespace
+{
+void redirect_stream_to_fd(int fd, int stream)
+{
+ auto rc = ::dup2(fd, stream);
+ if (rc == -1)
+ throw std::system_error(errno, std::system_category());
+}
+
+void print_backtrace(std::ostream& out, const std::string& line_prefix)
+{
+#ifndef ANDROID
+ core::posix::backtrace::visit_with_handler([&out, line_prefix](const core::posix::backtrace::Frame& frame)
+ {
+ out << line_prefix << std::dec << std::setw(2) << frame.depth() << "@" << std::hex << std::setw(14) << frame.frame_pointer() << ": "
+ << (frame.symbol().is_cxx() ? frame.symbol().demangled() : frame.symbol().raw()) << std::endl;
+ return true;
+ });
+#endif
+}
+}
+
+namespace core
+{
+namespace posix
+{
+
+bool is_child(pid_t pid) { return pid == 0; }
+
+ChildProcess fork(const std::function<posix::exit::Status()>& main,
+ const StandardStream& flags)
+{
+ ChildProcess::Pipe stdin_pipe{ChildProcess::Pipe::invalid()};
+ ChildProcess::Pipe stdout_pipe{ChildProcess::Pipe::invalid()};
+ ChildProcess::Pipe stderr_pipe{ChildProcess::Pipe::invalid()};
+
+ if ((flags & StandardStream::stdin) != StandardStream::empty)
+ stdin_pipe = ChildProcess::Pipe();
+ if ((flags & StandardStream::stdout) != StandardStream::empty)
+ stdout_pipe = ChildProcess::Pipe();
+ if ((flags & StandardStream::stderr) != StandardStream::empty)
+ stderr_pipe = ChildProcess::Pipe();
+
+ pid_t pid = ::fork();
+
+ if (pid == -1)
+ throw std::system_error(errno, std::system_category());
+
+ if (is_child(pid))
+ {
+ posix::exit::Status result = posix::exit::Status::failure;
+
+ try
+ {
+ stdin_pipe.close_write_fd();
+ stdout_pipe.close_read_fd();
+ stderr_pipe.close_read_fd();
+ // We replace stdin and stdout of the child process first:
+ if ((flags & StandardStream::stdin) != StandardStream::empty)
+ redirect_stream_to_fd(stdin_pipe.read_fd(), STDIN_FILENO);
+ if ((flags & StandardStream::stdout) != StandardStream::empty)
+ redirect_stream_to_fd(stdout_pipe.write_fd(), STDOUT_FILENO);
+ if ((flags & StandardStream::stderr) != StandardStream::empty)
+ redirect_stream_to_fd(stderr_pipe.write_fd(), STDERR_FILENO);
+
+ result = main();
+ } catch(const std::exception& e)
+ {
+ std::cerr << "core::posix::fork(): An unhandled std::exception occured in the child process:" << std::endl
+ << " what(): " << e.what() << std::endl;
+ print_backtrace(std::cerr, " ");
+ } catch(...)
+ {
+ std::cerr << "core::posix::fork(): An unhandled exception occured in the child process." << std::endl;
+ print_backtrace(std::cerr, " ");
+ }
+
+ // We have to ensure that we exit here. Otherwise, we run into
+ // all sorts of weird issues.
+ ::exit(static_cast<int>(result));
+ }
+
+ // We are in the parent process, and create a process object
+ // corresponding to the newly forked process.
+ stdin_pipe.close_read_fd();
+ stdout_pipe.close_write_fd();
+ stderr_pipe.close_write_fd();
+
+ return ChildProcess(pid,
+ stdin_pipe,
+ stdout_pipe,
+ stderr_pipe);
+}
+
+ChildProcess vfork(const std::function<posix::exit::Status()>& main,
+ const StandardStream& flags)
+{
+ ChildProcess::Pipe stdin_pipe, stdout_pipe, stderr_pipe;
+
+ pid_t pid = ::vfork();
+
+ if (pid == -1)
+ throw std::system_error(errno, std::system_category());
+
+ if (is_child(pid))
+ {
+ posix::exit::Status result = posix::exit::Status::failure;
+
+ try
+ {
+ // We replace stdin and stdout of the child process first:
+ stdin_pipe.close_write_fd();
+ stdout_pipe.close_read_fd();
+ stderr_pipe.close_read_fd();
+ // We replace stdin and stdout of the child process first:
+ if ((flags & StandardStream::stdin) != StandardStream::empty)
+ redirect_stream_to_fd(stdin_pipe.read_fd(), STDIN_FILENO);
+ if ((flags & StandardStream::stdout) != StandardStream::empty)
+ redirect_stream_to_fd(stdout_pipe.write_fd(), STDOUT_FILENO);
+ if ((flags & StandardStream::stderr) != StandardStream::empty)
+ redirect_stream_to_fd(stderr_pipe.write_fd(), STDERR_FILENO);
+
+ result = main();
+ } catch(const std::exception& e)
+ {
+ std::cerr << "core::posix::fork(): An unhandled std::exception occured in the child process:" << std::endl
+ << " what(): " << e.what() << std::endl;
+ print_backtrace(std::cerr, " ");
+ } catch(...)
+ {
+ std::cerr << "core::posix::fork(): An unhandled exception occured in the child process." << std::endl;
+ print_backtrace(std::cerr, " ");
+ }
+
+ // We have to ensure that we exit here. Otherwise, we run into
+ // all sorts of weird issues.
+ ::exit(static_cast<int>(result));
+ }
+
+ // We are in the parent process, and create a process object
+ // corresponding to the newly forked process.
+ // Close the parent's pipe end
+ stdin_pipe.close_read_fd();
+ stdout_pipe.close_write_fd();
+ stderr_pipe.close_write_fd();
+
+ return ChildProcess(pid,
+ stdin_pipe,
+ stdout_pipe,
+ stderr_pipe);
+}
+}
+}
Code Review / iec.git / blobdiff