Many threads can acquire the same read/write lock if they acquire a shared read lock on the read/write lock object. Only one thread can acquire an exclusive write lock on a read/write lock object. When an exclusive write lock is held, no other threads are allowed to hold any lock.

pthread_rwlockattr_destroy()--Destroy Read/Write Lock Attribute

pthread_rwlockattr_getpshared()--Get Pshared Read/Write Lock Attribute

pthread_rwlockattr_init()--Initialize Read/Write Lock Attribute

pthread_rwlockattr_setpshared()--Set Pshared Read/Write Lock Attribute

pthread_rwlock_destroy()--Destroy a Read/Write Lock

pthread_rwlock_init()--Initialize a Read/Write Lock

pthread_rwlock_rdlock()--Get a Shared Read Lock

pthread_rwlock_timedrdlock_np()--Get a Shared Read Lock with Time-out

pthread_rwlock_timedwrlock_np()--Get an Exclusive Write Lock with Time-out

pthread_rwlock_tryrdlock()--Get a Shared Read Lock with No Wait

pthread_rwlock_trywrlock()--Get an Exclusive Write Lock with No Wait

pthread_rwlock_unlock()--Unlock an Exclusive Write or Shared Read Lock

pthread_rwlock_wrlock()--Get an Exclusive Write Lock