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37 lines
1.1 KiB
C++
37 lines
1.1 KiB
C++
/*
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* Copyright (C) 2019-present ScyllaDB
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*/
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/*
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* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.1
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*/
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#pragma once
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#include <seastar/core/semaphore.hh>
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#include <seastar/core/shared_ptr.hh>
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class service_permit {
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seastar::lw_shared_ptr<seastar::semaphore_units<>> _permit;
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service_permit(seastar::semaphore_units<>&& u) : _permit(seastar::make_lw_shared<seastar::semaphore_units<>>(std::move(u))) {}
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friend service_permit make_service_permit(seastar::semaphore_units<>&& permit);
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friend service_permit empty_service_permit();
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public:
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size_t count() const { return _permit ? _permit->count() : 0; };
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// Merge additional semaphore units into this permit.
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// Used to grow the permit after the actual resource cost is known.
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void adopt(seastar::semaphore_units<>&& units) {
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if (_permit) {
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_permit->adopt(std::move(units));
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}
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}
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};
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inline service_permit make_service_permit(seastar::semaphore_units<>&& permit) {
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return service_permit(std::move(permit));
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}
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inline service_permit empty_service_permit() {
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return make_service_permit(seastar::semaphore_units<>());
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}
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