1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
#include <Common/ZooKeeper/ZooKeeperLock.h>
#include <Common/logger_useful.h>
#include <Common/ErrorCodes.h>
#include <filesystem>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
}
}
namespace fs = std::filesystem;
namespace zkutil
{
ZooKeeperLock::ZooKeeperLock(
const ZooKeeperPtr & zookeeper_,
const std::string & lock_prefix_,
const std::string & lock_name_,
const std::string & lock_message_)
: zookeeper(zookeeper_)
, lock_path(fs::path(lock_prefix_) / lock_name_)
, lock_message(lock_message_)
, log(&Poco::Logger::get("zkutil::Lock"))
{
zookeeper->createIfNotExists(lock_prefix_, "");
}
ZooKeeperLock::~ZooKeeperLock()
{
try
{
unlock();
}
catch (...)
{
DB::tryLogCurrentException(__PRETTY_FUNCTION__);
}
}
bool ZooKeeperLock::isLocked() const
{
return locked;
}
const std::string & ZooKeeperLock::getLockPath() const
{
return lock_path;
}
void ZooKeeperLock::unlock()
{
if (!locked)
return;
locked = false;
if (zookeeper->expired())
{
LOG_WARNING(log, "Lock is lost, because session was expired. Path: {}, message: {}", lock_path, lock_message);
return;
}
Coordination::Stat stat;
/// NOTE It will throw if session expired after we checked it above
bool result = zookeeper->exists(lock_path, &stat);
if (result && stat.ephemeralOwner == zookeeper->getClientID())
zookeeper->remove(lock_path, -1);
else if (result)
throw DB::Exception(DB::ErrorCodes::LOGICAL_ERROR, "Lock is lost, it has another owner. Path: {}, message: {}, owner: {}, our id: {}",
lock_path, lock_message, stat.ephemeralOwner, zookeeper->getClientID());
else
throw DB::Exception(DB::ErrorCodes::LOGICAL_ERROR, "Lock is lost, node does not exist. Path: {}, message: {}", lock_path, lock_message);
}
bool ZooKeeperLock::tryLock()
{
Coordination::Error code = zookeeper->tryCreate(lock_path, lock_message, zkutil::CreateMode::Ephemeral);
if (code == Coordination::Error::ZOK)
{
locked = true;
}
else if (code != Coordination::Error::ZNODEEXISTS)
{
throw Coordination::Exception(code);
}
return locked;
}
std::unique_ptr<ZooKeeperLock> createSimpleZooKeeperLock(
const ZooKeeperPtr & zookeeper, const String & lock_prefix, const String & lock_name, const String & lock_message)
{
return std::make_unique<ZooKeeperLock>(zookeeper, lock_prefix, lock_name, lock_message);
}
}
|
