67 lines
2 KiB
C++
67 lines
2 KiB
C++
/* Utility for handling interrupted syscalls by signals.
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Copyright (C) 2020 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#ifndef GDBSUPPORT_EINTR_H
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#define GDBSUPPORT_EINTR_H
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#include <cerrno>
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namespace gdb
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{
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/* Repeat a system call interrupted with a signal.
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A utility for handling interrupted syscalls, which return with error
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and set the errno to EINTR. The interrupted syscalls can be repeated,
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until successful completion. This utility avoids wrapping code with
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manual checks for such errors which are highly repetitive.
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For example, with:
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ssize_t ret;
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do
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{
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errno = 0;
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ret = ::write (pipe[1], "+", 1);
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}
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while (ret == -1 && errno == EINTR);
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You could wrap it by writing the wrapped form:
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ssize_t ret = gdb::handle_eintr<ssize_t> (-1, ::write, pipe[1], "+", 1);
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The RET typename specifies the return type of the wrapped system call, which
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is typically int or ssize_t. The R argument specifies the failure value
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indicating the interrupted syscall when calling the F function with
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the A... arguments. */
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template <typename Ret, typename Fun, typename... Args>
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inline Ret handle_eintr (const Ret &R, const Fun &F, const Args &... A)
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{
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Ret ret;
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do
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{
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errno = 0;
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ret = F (A...);
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}
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while (ret == R && errno == EINTR);
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return ret;
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}
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}
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#endif /* GDBSUPPORT_EINTR_H */
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