ClickHouse/libs/libzkutil/include/zkutil/Lock.h
2016-07-14 14:42:51 +03:00

81 lines
2.0 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#pragma once
#include <zkutil/ZooKeeperHolder.h>
#include <common/logger_useful.h>
#include <DB/Common/Exception.h>
namespace zkutil
{
class Lock
{
public:
/// lock_prefix - относительный путь до блокировки в ZK. Начинается со слеша
/// lock_name - имя ноды блокировки в ZK
Lock(
zkutil::ZooKeeperHolderPtr zookeeper_holder_,
const std::string & lock_prefix_,
const std::string & lock_name_,
const std::string & lock_message_ = "",
bool create_parent_path_ = false)
:
zookeeper_holder(zookeeper_holder_),
lock_path(lock_prefix_ + "/" + lock_name_),
lock_message(lock_message_),
log(&Logger::get("zkutil::Lock"))
{
auto zookeeper = zookeeper_holder->getZooKeeper();
if (create_parent_path_)
zookeeper->createAncestors(lock_prefix_);
zookeeper->createIfNotExists(lock_prefix_, "");
}
Lock(const Lock &) = delete;
Lock(Lock && lock) = default;
Lock & operator=(const Lock &) = delete;
~Lock()
{
try
{
unlock();
}
catch (const zkutil::KeeperException & e)
{
DB::tryLogCurrentException(__PRETTY_FUNCTION__);
}
}
enum Status
{
UNLOCKED,
LOCKED_BY_ME,
LOCKED_BY_OTHER,
END
};
std::string status2String(Status status);
/// проверяет создана ли эфемерная нода и кто ее владелец.
Status tryCheck() const;
void unlock();
void unlockOrMoveIfFailed(std::vector<zkutil::Lock> & failed_to_unlock_locks);
bool tryLock();
/// путь к ноде блокировки в zookeeper
const std::string & getPath() { return lock_path; }
private:
zkutil::ZooKeeperHolderPtr zookeeper_holder;
/// пока храним указатель на хендлер, никто не может переиницализировать сессию с zookeeper
using ZooKeeperHandler = zkutil::ZooKeeperHolder::UnstorableZookeeperHandler;
std::unique_ptr<ZooKeeperHandler> locked;
std::string lock_path;
std::string lock_message;
Logger * log;
};
}