Multithreaded Programming Guide

rw_wrlock Syntax

#include <synch.h>  (or #include <thread.h>)

int rw_wrlock(rwlock_t *rwlp);

When the read-write lock is already locked for reading or writing, the calling thread blocks until all read locks and write locks are released. Only one thread at a time can hold a write lock on a read-write lock. For POSIX threads, see pthread_rwlock_wrlock Syntax.