The `compaction_strategy_state` class holds strategy specific state via a `std::variant` containing different state types. When a compaction strategy performs compaction, it retrieves a reference to its state from the `compaction_strategy_state` object. If the table's compaction strategy is ALTERed while a compaction is in progress, the `compaction_strategy_state` object gets replaced, destroying the old state. This leaves the ongoing compaction holding a dangling reference, resulting in a use after free. Fix this by using `seastar::shared_ptr` for the state variant alternatives(`leveled_compaction_strategy_state_ptr` and `time_window_compaction_strategy_state_ptr`). The compaction strategies now hold a copy of the shared_ptr, ensuring the state remains valid for the duration of the compaction even if the strategy is altered. The `compaction_strategy_state` itself is still passed by reference and only the variant alternatives use shared_ptrs. This allows ongoing compactions to retain ownership of the state independently of the wrapper's lifetime. Fixes #25913 Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
40 lines
928 B
C++
40 lines
928 B
C++
/*
|
|
* Copyright (C) 2023-present ScyllaDB
|
|
*/
|
|
|
|
/*
|
|
* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "time_window_compaction_strategy.hh"
|
|
#include "leveled_compaction_strategy.hh"
|
|
#include <utility>
|
|
#include <variant>
|
|
|
|
namespace compaction {
|
|
|
|
class compaction_strategy_state {
|
|
public:
|
|
struct default_empty_state {};
|
|
using states_variant = std::variant<default_empty_state, leveled_compaction_strategy_state_ptr, time_window_compaction_strategy_state_ptr>;
|
|
private:
|
|
states_variant _state;
|
|
public:
|
|
explicit compaction_strategy_state(states_variant state) : _state(std::move(state)) {
|
|
}
|
|
|
|
template <typename StateType>
|
|
requires requires (StateType st) {
|
|
{ states_variant{} = st };
|
|
}
|
|
StateType& get() noexcept {
|
|
return std::get<StateType>(_state);
|
|
}
|
|
|
|
static compaction_strategy_state make(const compaction_strategy& cs);
|
|
};
|
|
|
|
}
|