ee36358a60
these unused includes are identified by clang-include-cleaner. after auditing the source files, all of the reports have been confirmed. please note, since we have `using seastar::shared_ptr` in `seastarx.h`, this renders `#include <seastar/core/shared_ptr.hh>` unnecessary if we don't need the full definition of `seastar::shared_ptr`. so, in this change, all the unused includes are removed. but there are some headers which are actually used, while still being identified by this tool. these includes are marked with "IWYU pragma: keep". Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
69 lines
2.0 KiB
C++
69 lines
2.0 KiB
C++
/*
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* Copyright (C) 2018-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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#pragma once
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#include "db/view/view_update_backlog.hh"
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#include "utils/error_injection.hh"
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#include <seastar/core/cacheline.hh>
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#include <seastar/core/future.hh>
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#include <seastar/core/lowres_clock.hh>
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#include <seastar/util/bool_class.hh>
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#include <atomic>
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#include <chrono>
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namespace db::view {
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/**
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* An atomic view update backlog representation, safe to update from multiple shards.
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* It is legal for a stale current max value to be returned.
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*/
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class node_update_backlog {
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using clock = seastar::lowres_clock;
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using need_publishing = seastar::bool_class<class need_publishing_tag>;
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struct per_shard_backlog {
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// Multiply by 2 to defeat the prefetcher
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alignas(seastar::cache_line_size * 2) std::atomic<update_backlog> backlog = update_backlog::no_backlog();
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need_publishing need_publishing = need_publishing::no;
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update_backlog load() const {
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return backlog.load(std::memory_order_relaxed);
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}
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};
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std::vector<per_shard_backlog> _backlogs;
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std::chrono::milliseconds _interval;
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std::atomic<clock::time_point> _last_update;
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std::atomic<update_backlog> _max;
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public:
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explicit node_update_backlog(size_t shards, std::chrono::milliseconds interval)
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: _backlogs(shards)
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, _interval(interval)
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, _last_update(clock::now() - _interval)
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, _max(update_backlog::no_backlog()) {
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if (utils::get_local_injector().enter("update_backlog_immediately")) {
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_interval = std::chrono::milliseconds(0);
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_last_update = clock::now();
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}
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}
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update_backlog fetch();
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void add(update_backlog backlog);
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update_backlog fetch_shard(unsigned shard);
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seastar::future<std::optional<update_backlog>> fetch_if_changed();
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// Exposed for testing only.
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update_backlog load() const {
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return _max.load(std::memory_order_relaxed);
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}
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};
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}
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