Class UpdateRowLockHandler

Namespace

Quartz.Impl.AdoJobStore

Assembly

Quartz.dll

Provide thread/resource locking in order to protect resources from being altered by multiple threads at the same time using a db row update.

public class UpdateRowLockHandler : DbLockHandler, ILockHandler

Inheritance

object

DbLockHandler

UpdateRowLockHandler

Implements

ILockHandler

Derived

SqlServerMemoryOptimizedUpdateRowLockHandler

Inherited Members

DbLockHandler.Initialize(LockHandlerContext)

DbLockHandler.AcquireLock(Guid, ConnectionAndTransactionHolder, SchedulerLock, CancellationToken)

DbLockHandler.ReleaseLock(Guid, SchedulerLock, CancellationToken)

DbLockHandler.RequiresConnection

DbLockHandler.LockSql

DbLockHandler.InsertSql

DbLockHandler.SchedulerName

DbLockHandler.TablePrefix

DbLockHandler.TimeProvider

DbLockHandler.PrepareCommand(ConnectionAndTransactionHolder, string)

DbLockHandler.AddCommandParameter(DbCommand, string, object)

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

Note: This lock handler is useful for databases that do not support row locking via "SELECT FOR UPDATE" or SQL Server's type syntax.

As of Quartz.NET 2.0 version there is no need to use this implementation for SQL Server databases.

Constructors

UpdateRowLockHandler(IDbProvider)

Initializes a new instance of the UpdateRowLockHandler class.

public UpdateRowLockHandler(IDbProvider provider)

Parameters

provider IDbProvider

UpdateRowLockHandler(string, string?, string, string, IDbProvider)

Initializes a new instance of the UpdateRowLockHandler class for a derived handler that spells its own statements — a dialect whose UPDATE needs a hint, for instance.

protected UpdateRowLockHandler(string tablePrefix, string? schedulerName, string updateForLockSql, string insertLockSql, IDbProvider dbProvider)

Parameters

tablePrefix string

The table prefix the store was configured with.

schedulerName string

The scheduler whose lock rows these are.

updateForLockSql string

The statement that takes the lock.

insertLockSql string

The statement that creates the lock row.

dbProvider IDbProvider

The database the statements run against.

Fields

InsertLock

The statement that inserts the lock row when it does not exist yet.

protected const string InsertLock = "INSERT INTO {0}LOCKS(SCHED_NAME, LOCK_NAME) VALUES (@schedulerName, @lockName)"

Field Value

string

UpdateForLock

The statement that takes the lock by updating its row.

protected const string UpdateForLock = "UPDATE {0}LOCKS SET LOCK_NAME = LOCK_NAME WHERE SCHED_NAME = @schedulerName AND LOCK_NAME = @lockName"

Field Value

string

Properties

RetryCount

How many times a contended lock attempt is retried before it fails.

protected virtual int RetryCount { get; }

Property Value

int

RetryPeriod

Sleep between attempts, defaults to 1 second.

[TimeSpanParseRule(TimeSpanParseRule.Milliseconds)]
public TimeSpan RetryPeriod { get; init; }

Property Value

TimeSpan

Remarks

It was a literal TimeSpan.FromSeconds(1) in the retry loop, which meant this handler ignored quartz.jobStore.lockHandler.retryPeriod while its sibling SelectForUpdateLockHandler honoured it. Init-only for the same reason as there: the value is fixed for the life of the handler, and the property bridge writes it by reflection, which an init accessor does not stop.

Methods

ExecuteSql(Guid, ConnectionAndTransactionHolder, string, string, string, CancellationToken)

Execute the SQL that will lock the proper database row.

protected override ValueTask ExecuteSql(Guid requestorId, ConnectionAndTransactionHolder conn, string lockName, string expandedSql, string expandedInsertSql, CancellationToken cancellationToken = default)

Parameters

requestorId Guid

conn ConnectionAndTransactionHolder

lockName string

expandedSql string

expandedInsertSql string

cancellationToken CancellationToken

Returns

ValueTask