diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/my_pthread.h | 70 |
1 files changed, 58 insertions, 12 deletions
diff --git a/include/my_pthread.h b/include/my_pthread.h index 0e421f678b0..0b55c70b0fa 100644 --- a/include/my_pthread.h +++ b/include/my_pthread.h @@ -600,30 +600,76 @@ int my_pthread_fastmutex_lock(my_pthread_fastmutex_t *mp); #define my_rwlock_init(A,B) rwlock_init((A),USYNC_THREAD,0) #else /* Use our own version of read/write locks */ -typedef struct _my_rw_lock_t { - pthread_mutex_t lock; /* lock for structure */ - pthread_cond_t readers; /* waiting readers */ - pthread_cond_t writers; /* waiting writers */ - int state; /* -1:writer,0:free,>0:readers */ - int waiters; /* number of waiting writers */ -} my_rw_lock_t; - +#define NEED_MY_RW_LOCK 1 #define rw_lock_t my_rw_lock_t +#define my_rwlock_init(A,B) my_rw_init((A), 0) #define rw_rdlock(A) my_rw_rdlock((A)) #define rw_wrlock(A) my_rw_wrlock((A)) #define rw_tryrdlock(A) my_rw_tryrdlock((A)) #define rw_trywrlock(A) my_rw_trywrlock((A)) #define rw_unlock(A) my_rw_unlock((A)) -#define rwlock_destroy(A) my_rwlock_destroy((A)) +#define rwlock_destroy(A) my_rw_destroy((A)) +#endif /* USE_MUTEX_INSTEAD_OF_RW_LOCKS */ -extern int my_rwlock_init(my_rw_lock_t *, void *); -extern int my_rwlock_destroy(my_rw_lock_t *); + +/* + Portable read-write locks which prefer readers. + + Required by some algorithms in order to provide correctness. +*/ + +#if defined(HAVE_PTHREAD_RWLOCK_RDLOCK) && defined(HAVE_PTHREAD_RWLOCKATTR_SETKIND_NP) +/* + On systems which have a way to specify that readers should + be preferred through attribute mechanism (e.g. Linux) we use + system implementation of read/write locks. +*/ +#define rw_pr_lock_t pthread_rwlock_t +extern int rw_pr_init(rw_pr_lock_t *); +#define rw_pr_rdlock(A) pthread_rwlock_rdlock(A) +#define rw_pr_wrlock(A) pthread_rwlock_wrlock(A) +#define rw_pr_tryrdlock(A) pthread_rwlock_tryrdlock(A) +#define rw_pr_trywrlock(A) pthread_rwlock_trywrlock(A) +#define rw_pr_unlock(A) pthread_rwlock_unlock(A) +#define rw_pr_destroy(A) pthread_rwlock_destroy(A) +#else +/* Otherwise we have to use our own implementation of read/write locks. */ +#define NEED_MY_RW_LOCK 1 +struct st_my_rw_lock_t; +#define rw_pr_lock_t my_rw_lock_t +extern int rw_pr_init(struct st_my_rw_lock_t *); +#define rw_pr_rdlock(A) my_rw_rdlock((A)) +#define rw_pr_wrlock(A) my_rw_wrlock((A)) +#define rw_pr_tryrdlock(A) my_rw_tryrdlock((A)) +#define rw_pr_trywrlock(A) my_rw_trywrlock((A)) +#define rw_pr_unlock(A) my_rw_unlock((A)) +#define rw_pr_destroy(A) my_rw_destroy((A)) +#endif /* defined(HAVE_PTHREAD_RWLOCK_RDLOCK) && defined(HAVE_PTHREAD_RWLOCKATTR_SETKIND_NP) */ + + +#ifdef NEED_MY_RW_LOCK +/* + On systems which don't support native read/write locks, or don't support + read/write locks which prefer readers we have to use own implementation. +*/ +typedef struct st_my_rw_lock_t { + pthread_mutex_t lock; /* lock for structure */ + pthread_cond_t readers; /* waiting readers */ + pthread_cond_t writers; /* waiting writers */ + int state; /* -1:writer,0:free,>0:readers */ + int waiters; /* number of waiting writers */ + my_bool prefer_readers; +} my_rw_lock_t; + +extern int my_rw_init(my_rw_lock_t *, my_bool *); +extern int my_rw_destroy(my_rw_lock_t *); extern int my_rw_rdlock(my_rw_lock_t *); extern int my_rw_wrlock(my_rw_lock_t *); extern int my_rw_unlock(my_rw_lock_t *); extern int my_rw_tryrdlock(my_rw_lock_t *); extern int my_rw_trywrlock(my_rw_lock_t *); -#endif /* USE_MUTEX_INSTEAD_OF_RW_LOCKS */ +#endif /* NEED_MY_RW_LOCK */ + #define GETHOSTBYADDR_BUFF_SIZE 2048 |