DB_ENV->mutex_alloc
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#include <db.h>
int
DB_ENV->mutex_alloc(DB_ENV *dbenv, u_int32_t flags, db_mutex_t *mutexp);
Description: DB_ENV->mutex_alloc
The DB_ENV->mutex_alloc method allocates a mutex and returns a reference to
it into the memory specified by mutexp.
The DB_ENV->mutex_alloc method may not be called before the DB_ENV->open method has
been called.
The DB_ENV->mutex_alloc method
returns a non-zero error value on failure
and 0 on success.
Parameters
- flags
- The flags parameter must be set to 0 or
the following value:
- DB_MUTEX_SELF_BLOCK
- The mutex must be self-blocking. That is, if a thread of control locks
the mutex and then attempts to lock the mutex again, the thread of
control will block until another thread of control releases the original
lock on the mutex, allowing the original thread of control to lock the
mutex the second time. Attempting to re-acquire a mutex for which the
DB_MUTEX_SELF_BLOCK flag was not specified will result in
undefined behavior.
- mutexp
- The mutexp parameter references memory into which
the mutex reference is copied.
Errors
The DB_ENV->mutex_alloc method
may fail and return one of the following non-zero errors:
- EINVAL
- An
invalid flag value or parameter was specified.
Class
DB_ENV
See Also
Database Environments and Related Methods
Copyright (c) 1996-2005 Sleepycat Software, Inc. - All rights reserved.