775b7e41f4
* seastar d59fcef...b924495 (2): > build: Fix protobuf generation rules > Merge "Restructure files" from Jesse Includes fixup patch from Jesse: " Update Seastar `#include`s to reflect restructure All Seastar header files are now prefixed with "seastar" and the configure script reflects the new locations of files. Signed-off-by: Jesse Haber-Kucharsky <jhaberku@scylladb.com> Message-Id: <5d22d964a7735696fb6bb7606ed88f35dde31413.1542731639.git.jhaberku@scylladb.com> "
83 lines
2.3 KiB
C++
83 lines
2.3 KiB
C++
/*
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* Copyright (C) 2014 ScyllaDB
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*/
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/*
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* This file is part of Scylla.
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*
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* Scylla is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero 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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*
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* Scylla 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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*
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* You should have received a copy of the GNU General Public License
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* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <seastar/core/reactor.hh>
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#include <seastar/core/posix.hh>
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#include <unistd.h>
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#include <fcntl.h>
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#include "file_lock.hh"
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class utils::file_lock::impl {
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public:
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impl(sstring path)
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: _path(std::move(path)), _fd(
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file_desc::open(_path, O_RDWR | O_CREAT | O_CLOEXEC,
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S_IRWXU)) {
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if (::lockf(_fd.get(), F_TLOCK, 0) != 0) {
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throw std::system_error(errno, std::system_category(), "Could not acquire lock: " + _path);
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}
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}
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impl(impl&&) = default;
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~impl() {
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if (!_path.empty()) {
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::unlink(_path.c_str());
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}
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assert(_fd.get() != -1);
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auto r = ::lockf(_fd.get(), F_ULOCK, 0);
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assert(r == 0);
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}
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sstring
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_path;
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file_desc
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_fd;
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};
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utils::file_lock::file_lock(sstring path)
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: _impl(std::make_unique<impl>(std::move(path)))
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{}
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utils::file_lock::file_lock(file_lock&& f) noexcept
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: _impl(std::move(f._impl))
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{}
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utils::file_lock::~file_lock()
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{}
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sstring utils::file_lock::path() const {
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return _impl ? _impl->_path : "";
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}
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future<utils::file_lock> utils::file_lock::acquire(sstring path) {
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// meh. not really any future stuff here. but pretend, for the
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// day when a future version of lock etc is added.
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try {
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return make_ready_future<file_lock>(file_lock(path));
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} catch (...) {
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return make_exception_future<utils::file_lock>(std::current_exception());
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}
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}
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std::ostream& utils::operator<<(std::ostream& out, const file_lock& f) {
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return out << "file lock '" << f.path() << "'";
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}
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