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Berkeley DB: DbEnv.set_tas_spins
DbEnv.set_tas_spins
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import com.sleepycat.db.*;
static int
DbEnv.set_tas_spins(u_int32_t tas_spins);
throws DbException;
Description
Specify that test-and-set mutexes should spin tas_spins times
without blocking. The value defaults to 1 on uniprocessor systems and
to 50 times the number of processors on multiprocessor systems.
The DbEnv.set_tas_spins interface affects the entire application, not a single
database or database environment.
Although the DbEnv.set_tas_spins interface may be used to configure Berkeley DB at any time
during the life of the application, it should normally be called before
making any calls to the db_env_create or db_create methods.
The DbEnv.set_tas_spins method throws an exception that encapsulates a non-zero error value on
failure.
The database environment's test-and-set spin count 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_tas_spins", one or more whitespace characters,
and the number of spins. Because the DB_CONFIG file is read when the database
environment is opened, it will silently overrule configuration done
before that time.
Errors
The DbEnv.set_tas_spins method may fail and throw an exception encapsulating a non-zero error for the following conditions:
- EINVAL
- An invalid flag value or parameter was specified.
The DbEnv.set_tas_spins method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbEnv.set_tas_spins method may fail and throw
a DbRunRecoveryException, in which case all subsequent Berkeley DB calls
will fail in the same way.
Class
DbEnv
See Also
DbEnv.close,
DbEnv.get_version_string,
DbEnv.open,
DbEnv.remove,
DbEnv.set_cachesize,
DbEnv.set_data_dir,
DbEnv.set_errcall,
DbEnv.set_error_stream,
DbEnv.set_errpfx,
DbEnv.set_feedback,
DbEnv.set_flags,
DbEnv.set_mutexlocks,
DbEnv.set_pageyield,
DbEnv.set_panicstate,
DbEnv.set_recovery_init,
DbEnv.set_rpc_server,
DbEnv.set_region_init,
DbEnv.set_shm_key,
DbEnv.set_tas_spins,
DbEnv.set_tmp_dir,
DbEnv.set_verbose,
and DbEnv.strerror.
Copyright Sleepycat Software
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