DB_ENV->set_timeout

API Ref

#include <db.h>

int DB_ENV->set_timeout(DB_ENV *dbenv, db_timeout_t timeout, u_int32_t flags);

int DB_ENV->get_timeout(DB_ENV *dbenv, db_timeout_t *timeoutp, u_int32_t flag);


Description: DB_ENV->set_timeout

The DB_ENV->set_timeout method sets timeout values for locks or transactions in the database environment.

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 lock is one requested explicitly through the Lock subsystem interfaces. In the case of DB_SET_TXN_TIMEOUT, the lock is one requested on behalf of a transaction. In either case, it may be a lock requested by the database access methods underlying the application.) 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 specified for the database environment may be overridden on a per-lock or per-transaction basis. See DB_ENV->lock_vec and DB_TXN->set_timeout for more information.

The DB_ENV->set_timeout method configures a database environment, not only operations performed using the specified DB_ENV handle.

The DB_ENV->set_timeout method may be called at any time during the life of the application.

The DB_ENV->set_timeout method returns a non-zero error value on failure and 0 on success.

Parameters

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 database environment.

The database environment's lock timeout value may also be set using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "set_lock_timeout", one or more whitespace characters, and the lock timeout value. Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.

DB_SET_TXN_TIMEOUT
Set the timeout value for transactions in this database environment.

The database environment's transaction timeout value may also be set using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "set_txn_timeout", one or more whitespace characters, and the transaction timeout value. Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.

timeout
The timeout parameter is the timeout value. It must be specified as an unsigned 32-bit number of microseconds, limiting the maximum timeout to roughly 71 minutes.

Errors

The DB_ENV->set_timeout method may fail and return one of the following non-zero errors:

EINVAL
An invalid flag value or parameter was specified.

Description: DB_ENV->get_timeout

The DB_ENV->get_timeout method returns a timeout value, in microseconds.

The DB_ENV->get_timeout method may be called at any time during the life of the application.

The DB_ENV->get_timeout method returns a non-zero error value on failure and 0 on success.

Parameters

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

DB_SET_LOCK_TIMEOUT
Return the timeout value for locks in this database environment.

DB_SET_TXN_TIMEOUT
Return the timeout value for transactions in this database environment.

timeoutp
The timeoutp parameter references memory into which the timeout value of the specified flag parameter is copied.

Class

DB_ENV

See Also

Database Environments and Related Methods

APIRef

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