diff options
Diffstat (limited to 'lib/tdb/include/tdb.h')
| -rw-r--r-- | lib/tdb/include/tdb.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/lib/tdb/include/tdb.h b/lib/tdb/include/tdb.h index a34f089e66..5ea5e6048c 100644 --- a/lib/tdb/include/tdb.h +++ b/lib/tdb/include/tdb.h @@ -80,6 +80,9 @@ extern "C" { #define TDB_ALLOW_NESTING 512 /** Allow transactions to nest */ #define TDB_DISALLOW_NESTING 1024 /** Disallow transactions to nest */ #define TDB_INCOMPATIBLE_HASH 2048 /** Better hashing: can't be opened by tdb < 1.2.6. */ +#define TDB_MUTEX_LOCKING 4096 /** optimized locking using robust mutexes if supported, + only with tdb >= 1.3.0 and TDB_CLEAR_IF_FIRST + after checking tdb_runtime_check_for_robust_mutexes() */ /** The tdb error codes */ enum TDB_ERROR {TDB_SUCCESS=0, TDB_ERR_CORRUPT, TDB_ERR_IO, TDB_ERR_LOCK, @@ -143,6 +146,11 @@ struct tdb_logging_context { * default 5.\n * TDB_ALLOW_NESTING - Allow transactions to nest.\n * TDB_DISALLOW_NESTING - Disallow transactions to nest.\n + * TDB_INCOMPATIBLE_HASH - Better hashing: can't be opened by tdb < 1.2.6.\n + * TDB_MUTEX_LOCKING - Optimized locking using robust mutexes if supported, + * can't be opened by tdb < 1.3.0. + * Only valid in combination with TDB_CLEAR_IF_FIRST + * after checking tdb_runtime_check_for_robust_mutexes()\n * * @param[in] open_flags Flags for the open(2) function. * @@ -179,6 +187,11 @@ struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags, * default 5.\n * TDB_ALLOW_NESTING - Allow transactions to nest.\n * TDB_DISALLOW_NESTING - Disallow transactions to nest.\n + * TDB_INCOMPATIBLE_HASH - Better hashing: can't be opened by tdb < 1.2.6.\n + * TDB_MUTEX_LOCKING - Optimized locking using robust mutexes if supported, + * can't be opened by tdb < 1.3.0. + * Only valid in combination with TDB_CLEAR_IF_FIRST + * after checking tdb_runtime_check_for_robust_mutexes()\n * * @param[in] open_flags Flags for the open(2) function. * @@ -842,6 +855,27 @@ int tdb_rescue(struct tdb_context *tdb, void (*walk) (TDB_DATA key, TDB_DATA data, void *private_data), void *private_data); +/** + * @brief Check if support for TDB_MUTEX_LOCKING is available at runtime. + * + * On some systems the API for pthread_mutexattr_setrobust() is not available. + * On other systems there are some bugs in the interaction between glibc and + * the linux kernel. + * + * This function provides a runtime check if robust mutexes are really + * available. + * + * This needs to be called and return true before TDB_MUTEX_LOCKING + * can be used at runtime. + * + * @note This calls fork(), but the SIGCHILD handling should be transparent. + * + * @return true if supported, false otherwise. + * + * @see TDB_MUTEX_LOCKING + */ +bool tdb_runtime_check_for_robust_mutexes(void); + /* @} ******************************************************************/ /* Low level locking functions: use with care */ |