foundationdb/flow/IndexedSet.actor.h

76 lines
2.4 KiB
C++

/*
* IndexedSet.actor.h
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2022 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
// When actually compiled (NO_INTELLISENSE), include the generated version of this file. In intellisense use the source
// version.
#if defined(NO_INTELLISENSE) && !defined(FLOW_INDEXEDSET_ACTOR_G_H)
#define FLOW_INDEXEDSET_ACTOR_G_H
#include "flow/IndexedSet.actor.g.h"
#elif !defined(FLOW_INDEXEDSET_ACTOR_H)
#define FLOW_INDEXEDSET_ACTOR_H
#include "flow/flow.h"
#include "flow/Platform.h"
#include "flow/actorcompiler.h" // This must be the last #include.
ACTOR template <class Node>
[[flow_allow_discard]] Future<Void> ISFreeNodes(std::vector<Node*> toFree, bool synchronous) {
// Frees the forest of nodes in the 'toFree' vector.
// If 'synchronous' is true, then there can be no waits.
state int eraseCount = 0;
// Freeing many items from a large tree is bound by the memory latency to
// fetch each node from main memory. This code does a largely depth first
// traversal of the forest to be destroyed (using a stack) but prefetches
// each node and puts it on a short queue before actually processing it, so
// that several memory transactions can be outstanding simultaneously.
state Deque<Node*> prefetchQueue;
while (!prefetchQueue.empty() || !toFree.empty()) {
while (prefetchQueue.size() < 10 && !toFree.empty()) {
_mm_prefetch((const char*)toFree.back(), _MM_HINT_T0);
prefetchQueue.push_back(toFree.back());
toFree.pop_back();
}
auto n = prefetchQueue.front();
prefetchQueue.pop_front();
if (n->child[0])
toFree.push_back(n->child[0]);
if (n->child[1])
toFree.push_back(n->child[1]);
n->child[0] = n->child[1] = 0;
delete n;
++eraseCount;
if (!synchronous && eraseCount % 1000 == 0)
wait(yield());
}
return Void();
}
#include "flow/unactorcompiler.h"
#endif