DbTxn::set_timeout()

#include <db_cxx.h>
 
u_int32_t
DbTxn::set_timeout(db_timeout_t timeout, u_int32_t flags);

The DbTxn::set_timeout() method sets timeout values for locks or transactions for the specified transaction.

Timeouts are checked whenever a thread of control blocks on a lock or when deadlock detection is performed. In the case of DB_SET_LOCK_TIMEOUT, the timeout is for any single lock request. In the case of DB_SET_TXN_TIMEOUT, the timeout is for the life of the transaction. As timeouts are only checked when the lock request first blocks or when deadlock detection is performed, the accuracy of the timeout depends on how often deadlock detection is performed.

Timeout values may be specified for the database environment as a whole. Also, the database environment must enable the locking subsystem before timeout values can be specified. See DbEnv::set_timeout() for more information.

The DbTxn::set_timeout() method configures operations performed on the underlying transaction, not only operations performed using the specified DbTxn handle.

The DbTxn::set_timeout() method may be called at any time during the life of the application.

The DbTxn::set_timeout() method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success.

Parameters

timeout

The timeout parameter is specified as an unsigned 32-bit number of microseconds, limiting the maximum timeout to roughly 71 minutes. A value of 0 disables timeouts for the transaction.

flags

The flags parameter must be set to one of the following values:

  • DB_SET_LOCK_TIMEOUT

    Set the timeout value for locks in this transaction.

  • DB_SET_TXN_TIMEOUT

    Set the timeout value for this transaction.

Errors

The DbTxn::set_timeout() method may fail and throw a DbException exception, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:

EINVAL

An invalid flag value or parameter was specified.

Class

DbEnv, DbTxn

See Also

Transaction Subsystem and Related Methods