75bc702ae8
The lock itself is only used by utils/directories code Signed-off-by: Pavel Emelyanov <xemul@scylladb.com> Closes scylladb/scylladb#17051
65 lines
1.6 KiB
C++
65 lines
1.6 KiB
C++
/*
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* Copyright (C) 2014-present ScyllaDB
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*/
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/*
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* SPDX-License-Identifier: AGPL-3.0-or-later
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*/
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#include <seastar/core/seastar.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(fs::path path)
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: _path(std::move(path)), _fd(
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file_desc::open(_path.native(), 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(),
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"Could not acquire lock: " + _path.native());
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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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fs::path _path;
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file_desc _fd;
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};
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utils::file_lock::file_lock(fs::path 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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fs::path 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(fs::path 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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