io.mongock.driver.core.lock

Class DefaultLockManager

java.lang.Object

io.mongock.driver.core.lock.DefaultLockManager

All Implemented Interfaces:

LockManager, Closeable, AutoCloseable

@NotThreadSafe
public class DefaultLockManager
extends Object
implements LockManager

This class is responsible of managing the lock at high level. It provides 3 main methods which are for acquiring, ensuring(doesn't acquires the lock, just refresh the expiration time if required) and releasing the lock.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DefaultLockManager.DefaultLockManagerBuilder

Constructor Summary

Constructors

Constructor and Description
DefaultLockManager(LockRepository repository, TimeService timeUtils, long lockAcquiredForMillis, long lockQuitTryingAfterMillis, long lockTryFrequencyMillis, long lockRefreshMarginMillis) Constructor takes some bean injections

Method Summary

Modifier and Type	Method and Description
void	acquireLockDefault() Tries to acquire the default lock regardless who is the current owner.
static DefaultLockManager.DefaultLockManagerBuilder	builder()
void	close() Required when lock managing is done.
void	ensureLockDefault() Tries to refresh the default lock when the current LockChecker has the lock or , when the lock is expired, is the last owner
long	getLockTryFrequency()
long	getMillisUntilRefreshRequired()
String	getOwner()
protected void	initialize() idempotent operation that - Starts the acquisition timer - Initializes and run the lock daemon.
boolean	isLockHeld()
void	releaseLockDefault() Release the default lock when is acquired by the current LockChecker.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.mongock.driver.api.lock.LockManager

getDefaultKey

Constructor Detail

DefaultLockManager

public DefaultLockManager(LockRepository repository,
                          TimeService timeUtils,
                          long lockAcquiredForMillis,
                          long lockQuitTryingAfterMillis,
                          long lockTryFrequencyMillis,
                          long lockRefreshMarginMillis)

Constructor takes some bean injections

Parameters:

repository - lock repository

timeUtils - time utils service

Method Detail

builder

public static DefaultLockManager.DefaultLockManagerBuilder builder()

acquireLockDefault

public void acquireLockDefault()
                        throws LockCheckException

Tries to acquire the default lock regardless who is the current owner.

If the lock is already acquired by the current LockChecker or is expired, will be updated

In case the lock is acquired by another LockChecker, it will wait until the current lock is expired and will try to acquire it again. This will be repeated as many times as (maxTries - 1)

Specified by:

acquireLockDefault in interface LockManager

Throws:

LockCheckException - if the lock cannot be acquired

ensureLockDefault

public void ensureLockDefault()
                       throws LockCheckException

Tries to refresh the default lock when the current LockChecker has the lock or , when the lock is expired, is the last owner

Notice that it does not try to acquire when is acquired by another LockChecker

Specified by:

ensureLockDefault in interface LockManager

Throws:

LockCheckException - if, in case of needed, the lock cannot be refreshed

releaseLockDefault

public void releaseLockDefault()

Release the default lock when is acquired by the current LockChecker.

When the lock is not acquired by the current LockChecker, it won't make any change. Does not throw any exception neither.

Idempotent operation.

Specified by:

releaseLockDefault in interface LockManager

close

public void close()

Required when lock managing is done. Responsible for: - Release the lock in database (not critical. It will be expired eventually ) - Cancel the lock daemon (CRITICAL. Otherwise it will keep refreshing the lock making other Mongock process starved)

Specified by:

close in interface LockManager

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

getLockTryFrequency

public long getLockTryFrequency()

Specified by:

getLockTryFrequency in interface LockManager

getOwner

public String getOwner()

Specified by:

getOwner in interface LockManager

isLockHeld

public boolean isLockHeld()

Specified by:

isLockHeld in interface LockManager

getMillisUntilRefreshRequired

public long getMillisUntilRefreshRequired()

Specified by:

getMillisUntilRefreshRequired in interface LockManager

initialize

protected void initialize()

idempotent operation that - Starts the acquisition timer - Initializes and run the lock daemon.