DB_ENV->lock_stat
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#include <db.h>
int
DB_ENV->lock_stat(DB_ENV *env, DB_LOCK_STAT **statp, u_int32_t flags);
int
DB_ENV->lock_stat_print(DB_ENV *env, u_int32_t flags);
Description: DB_ENV->lock_stat
The DB_ENV->lock_stat method returns the locking subsystem statistics.
The DB_ENV->lock_stat method creates a statistical structure of type
DB_LOCK_STAT and copies a pointer to it into a user-specified memory
location.
Statistical structures are stored in allocated memory. If application-specific allocation
routines have been declared (see DB_ENV->set_alloc for more
information), they are used to allocate the memory; otherwise, the
standard C library malloc(3) is used. The caller is
responsible for deallocating the memory. To deallocate the memory, free
the memory reference; references inside the returned memory need not be
individually freed.
The following DB_LOCK_STAT fields will be filled in:
- u_int32_t st_id;
- The last allocated locker ID.
- u_int32_t st_cur_maxid;
- The current maximum unused locker ID.
- u_int32_t st_nmodes;
- The number of lock modes.
- u_int32_t st_maxlocks;
- The maximum number of locks possible.
- u_int32_t st_maxlockers;
- The maximum number of lockers possible.
- u_int32_t st_maxobjects;
- The maximum number of lock objects possible.
- u_int32_t st_nlocks;
- The number of current locks.
- u_int32_t st_maxnlocks;
- The maximum number of locks at any one time.
- u_int32_t st_nlockers;
- The number of current lockers.
- u_int32_t st_maxnlockers;
- The maximum number of lockers at any one time.
- u_int32_t st_nobjects;
- The number of current lock objects.
- u_int32_t st_maxnobjects;
- The maximum number of lock objects at any one time.
- u_int32_t st_nrequests;
- The total number of locks requested.
- u_int32_t st_nreleases;
- The total number of locks released.
- u_int32_t st_nupgrade;
- The total number of locks upgraded.
- u_int32_t st_ndowngrade;
- The total number of locks downgraded.
- u_int32_t st_lock_wait;
- The number of lock requests not immediately available due to conflicts,
for which the thread of control waited.
- u_int32_t st_lock_nowait;
- The number of lock requests not immediately available due to conflicts,
for which the thread of control did not wait.
- u_int32_t st_ndeadlocks;
- The number of deadlocks.
- u_int32_t st_locktimeout;
- Lock timeout value.
- u_int32_t st_nlocktimeouts;
- The number of lock requests that have timed out.
- u_int32_t st_txntimeout;
- Transaction timeout value.
- u_int32_t st_ntxntimeouts;
- The number of transactions that have timed out. This value is also a
component of st_ndeadlocks, the total number of deadlocks
detected.
- roff_t st_regsize;
- The size of the lock region, in bytes.
- u_int32_t st_region_wait;
- The number of times that a thread of control was forced to wait before
obtaining the lock region mutex.
- u_int32_t st_region_nowait;
- The number of times that a thread of control was able to obtain
the lock region mutex without waiting.
The DB_ENV->lock_stat 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_STAT_CLEAR
- Reset statistics after returning their values.
- statp
- The statp parameter references memory into which
a pointer to the allocated statistics structure is copied.
Errors
The DB_ENV->lock_stat method
may fail and return one of the following non-zero errors:
- EINVAL
- An
invalid flag value or parameter was specified.
Description: DB_ENV->lock_stat_print
The DB_ENV->lock_stat_print method prints diagnostic information to the output
channel described by the DB_ENV->set_msgfile method.
The DB_ENV->lock_stat_print method may not be called before the DB_ENV->open method has
been called.
The DB_ENV->lock_stat_print method
returns a non-zero error value on failure
and 0 on success.
Parameters
- flags
- The flags parameter must be set by bitwise inclusively OR'ing together one or more
of the following values:
- DB_STAT_ALL
- Display all available information.
- DB_STAT_LOCK_CONF
- Display the lock conflict matrix.
- DB_STAT_LOCK_LOCKERS
- Display the lockers within hash chains.
- DB_STAT_LOCK_OBJECTS
- Display the lock objects within hash chains.
- DB_STAT_LOCK_PARAMS
- Display the locking subsystem parameters.
Class
DB_ENV, DB_LOCK
See Also
Locking Subsystem and Related Methods
Copyright (c) 1996-2005 Sleepycat Software, Inc. - All rights reserved.