mirror of https://github.com/facebook/rocksdb.git
91 lines
2.5 KiB
C++
91 lines
2.5 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
|
|
// This source code is licensed under the BSD-style license found in the
|
|
// LICENSE file in the root directory of this source tree. An additional grant
|
|
// of patent rights can be found in the PATENTS file in the same directory.
|
|
// This source code is also licensed under the GPLv2 license found in the
|
|
// COPYING file in the root directory of this source tree.
|
|
|
|
#include "db/flush_scheduler.h"
|
|
|
|
#include <cassert>
|
|
|
|
#include "db/column_family.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
void FlushScheduler::ScheduleFlush(ColumnFamilyData* cfd) {
|
|
#ifndef NDEBUG
|
|
std::lock_guard<std::mutex> lock(checking_mutex_);
|
|
assert(checking_set_.count(cfd) == 0);
|
|
checking_set_.insert(cfd);
|
|
#endif // NDEBUG
|
|
cfd->Ref();
|
|
// Suppress false positive clang analyzer warnings.
|
|
#ifndef __clang_analyzer__
|
|
Node* node = new Node{cfd, head_.load(std::memory_order_relaxed)};
|
|
while (!head_.compare_exchange_strong(
|
|
node->next, node, std::memory_order_relaxed, std::memory_order_relaxed)) {
|
|
// failing CAS updates the first param, so we are already set for
|
|
// retry. TakeNextColumnFamily won't happen until after another
|
|
// inter-thread synchronization, so we don't even need release
|
|
// semantics for this CAS
|
|
}
|
|
#endif // __clang_analyzer__
|
|
}
|
|
|
|
ColumnFamilyData* FlushScheduler::TakeNextColumnFamily() {
|
|
#ifndef NDEBUG
|
|
std::lock_guard<std::mutex> lock(checking_mutex_);
|
|
#endif // NDEBUG
|
|
while (true) {
|
|
if (head_.load(std::memory_order_relaxed) == nullptr) {
|
|
return nullptr;
|
|
}
|
|
|
|
// dequeue the head
|
|
Node* node = head_.load(std::memory_order_relaxed);
|
|
head_.store(node->next, std::memory_order_relaxed);
|
|
ColumnFamilyData* cfd = node->column_family;
|
|
delete node;
|
|
|
|
#ifndef NDEBUG
|
|
auto iter = checking_set_.find(cfd);
|
|
assert(iter != checking_set_.end());
|
|
checking_set_.erase(iter);
|
|
#endif // NDEBUG
|
|
|
|
if (!cfd->IsDropped()) {
|
|
// success
|
|
return cfd;
|
|
}
|
|
|
|
// no longer relevant, retry
|
|
if (cfd->Unref()) {
|
|
delete cfd;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool FlushScheduler::Empty() {
|
|
#ifndef NDEBUG
|
|
std::lock_guard<std::mutex> lock(checking_mutex_);
|
|
#endif // NDEBUG
|
|
auto rv = head_.load(std::memory_order_relaxed) == nullptr;
|
|
#ifndef NDEBUG
|
|
assert(rv == checking_set_.empty());
|
|
#endif // NDEBUG
|
|
return rv;
|
|
}
|
|
|
|
void FlushScheduler::Clear() {
|
|
ColumnFamilyData* cfd;
|
|
while ((cfd = TakeNextColumnFamily()) != nullptr) {
|
|
if (cfd->Unref()) {
|
|
delete cfd;
|
|
}
|
|
}
|
|
assert(head_.load(std::memory_order_relaxed) == nullptr);
|
|
}
|
|
|
|
} // namespace rocksdb
|