/// <summary>
/// Releases a mutex on the DB server.
/// </summary>
/// <param name="lockName">Unique name for the lock</param>
/// <param name="owner">The owner of the lock. Partial support in different db servers.</param>
/// <param name="dbPrincipal">The user that has permissions to the lock.</param>
/// <returns><value>true</value> if the lock was release, <value>false</value> if failed, not exists or timed out.</returns>
public virtual bool ReleaseLock(string lockName, SqlMutexOwner owner = SqlMutexOwner.Session, string dbPrincipal = null)
{
throw new NotImplementedException(@"ReleaseLock");
}
/// <summary>
/// Creates a mutex on the DB server.
/// </summary>
/// <param name="lockName">Unique name for the lock</param>
/// <param name="owner">The owner of the lock. Partial support in different db servers.</param>
/// <param name="timeout">Timeout</param>
/// <param name="dbPrincipal">The user that has permissions to the lock.</param>
/// <returns><value>true</value> if the lock was acquired, <value>false</value> if failed or timed out.</returns>
public virtual bool GetLock(string lockName, TimeSpan timeout, SqlMutexOwner owner = SqlMutexOwner.Session, string dbPrincipal = null)
{
throw new NotImplementedException(@"GetLock");
}
public override bool ReleaseLock(string lockName, SqlMutexOwner owner = SqlMutexOwner.Session, string dbPrincipal = null)
{
string ownerString = "Session";
switch (owner)
{
case SqlMutexOwner.Transaction:
ownerString = "Transaction";
break;
}
SqlCommand sqlCommand = new SqlCommand("sp_releaseapplock", _Connection);
sqlCommand.CommandType = CommandType.StoredProcedure;
sqlCommand.Parameters.AddWithValue("Resource", lockName);
sqlCommand.Parameters.AddWithValue("LockOwner", ownerString);
sqlCommand.Parameters.AddWithValue("DbPrincipal", dbPrincipal ?? "public");
SqlParameter returnValue = sqlCommand.Parameters.Add("ReturnValue", SqlDbType.Int);
returnValue.Direction = ParameterDirection.ReturnValue;
sqlCommand.ExecuteNonQuery();
if (Convert.ToInt32(returnValue.Value) < 0)
{
return false;
}
return true;
}
public override bool GetLock(string lockName, TimeSpan timeout, SqlMutexOwner owner = SqlMutexOwner.Session, string dbPrincipal = null)
{
string ownerString = "Session";
switch (owner)
{
case SqlMutexOwner.Transaction:
ownerString = "Transaction";
break;
}
SqlCommand sqlCommand = new SqlCommand("sp_getapplock", _Connection);
sqlCommand.CommandType = CommandType.StoredProcedure;
sqlCommand.CommandTimeout = (int)Math.Ceiling(timeout.TotalSeconds);
sqlCommand.Parameters.AddWithValue("Resource", lockName);
sqlCommand.Parameters.AddWithValue("LockOwner", ownerString);
sqlCommand.Parameters.AddWithValue("LockMode", "Exclusive");
sqlCommand.Parameters.AddWithValue("LockTimeout", (Int32)timeout.TotalMilliseconds);
sqlCommand.Parameters.AddWithValue("DbPrincipal", dbPrincipal ?? "public");
SqlParameter returnValue = sqlCommand.Parameters.Add("ReturnValue", SqlDbType.Int);
returnValue.Direction = ParameterDirection.ReturnValue;
sqlCommand.ExecuteNonQuery();
if (Convert.ToInt32(returnValue.Value) < 0)
{
return false;
}
return true;
}
public override bool ReleaseLock(string lockName, SqlMutexOwner owner = SqlMutexOwner.Session, string dbPrincipal = null)
{
object sqlLock = ExecuteScalar(@"SELECT RELEASE_LOCK('" + EscapeString(lockName) + "')");
if (sqlLock == null ||
sqlLock == DBNull.Value ||
(sqlLock is System.Data.SqlTypes.INullable && ((System.Data.SqlTypes.INullable)sqlLock).IsNull) ||
Convert.ToInt32(sqlLock) != 1)
{
return false;
}
return true;
}
public override bool GetLock(string lockName, TimeSpan timeout, SqlMutexOwner owner = SqlMutexOwner.Session, string dbPrincipal = null)
{
object sqlLock = ExecuteScalar(string.Format("SELECT GET_LOCK('{0}', {1})",
EscapeString(lockName), (timeout == TimeSpan.MaxValue ? "-1" : timeout.TotalSeconds.ToString(CultureInfo.InvariantCulture))));
if (sqlLock == null ||
sqlLock == DBNull.Value ||
(sqlLock is System.Data.SqlTypes.INullable && ((System.Data.SqlTypes.INullable)sqlLock).IsNull) ||
Convert.ToInt32(sqlLock) != 1)
{
return false;
}
return true;
}
