| /* Utility for handling interrupted syscalls by signals. |
| |
| Copyright (C) 2020 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| 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 General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #ifndef GDBSUPPORT_EINTR_H |
| #define GDBSUPPORT_EINTR_H |
| |
| #include <cerrno> |
| |
| namespace gdb |
| { |
| /* Repeat a system call interrupted with a signal. |
| |
| A utility for handling interrupted syscalls, which return with error |
| and set the errno to EINTR. The interrupted syscalls can be repeated, |
| until successful completion. This utility avoids wrapping code with |
| manual checks for such errors which are highly repetitive. |
| |
| For example, with: |
| |
| ssize_t ret; |
| do |
| { |
| errno = 0; |
| ret = ::write (pipe[1], "+", 1); |
| } |
| while (ret == -1 && errno == EINTR); |
| |
| You could wrap it by writing the wrapped form: |
| |
| ssize_t ret = gdb::handle_eintr<ssize_t> (-1, ::write, pipe[1], "+", 1); |
| |
| The RET typename specifies the return type of the wrapped system call, which |
| is typically int or ssize_t. The R argument specifies the failure value |
| indicating the interrupted syscall when calling the F function with |
| the A... arguments. */ |
| |
| template <typename Ret, typename Fun, typename... Args> |
| inline Ret handle_eintr (const Ret &R, const Fun &F, const Args &... A) |
| { |
| Ret ret; |
| do |
| { |
| errno = 0; |
| ret = F (A...); |
| } |
| while (ret == R && errno == EINTR); |
| return ret; |
| } |
| } |
| |
| #endif /* GDBSUPPORT_EINTR_H */ |