Professional Multicore Programming: Design and Implementation for C++ Developers

Name

NAME

pthread_rwlock_rdlock, pthread_rwlock_tryrdlock — lock a read-write lock object for reading

SYNOPSIS

THR #include <pthread.h>

    int pthread_rwlock_rdlock(pthread_rwlock_t  *rwlock);
    int pthread_rwlock_tryrdlock(pthread_rwlock_t  *rwlock);

DESCRIPTION

The pthread_rwlock_rdlock() function shall apply a read lock to the read-write lock referenced by rwlock. The calling thread acquires the read lock if a writer does not hold the lock and there are no writers blocked on the lock.

TPS If the Thread Execution Scheduling option is supported, and the threads involved in the lock are executing with the scheduling policies SCHED_FIFO or SCHED_RR, the calling thread shall not acquire the lock if a writer holds the lock or if writers of higher or equal priority are blocked on the lock; otherwise, the calling thread shall acquire the lock.

TPS TSP If the Threads Execution Scheduling option is supported, and the threads involved in the lock are executing with the SCHED_SPORADIC scheduling policy, the calling thread shall not acquire the lock if a writer holds the lock or if writers of higher or equal priority are blocked on the lock; otherwise, the calling thread shall acquire the lock.

If the Thread Execution Scheduling option is not supported, it is implementation-defined whether the calling thread acquires the lock when a writer does not hold the lock and there are writers blocked on the lock. If a writer holds the lock, the calling thread shall not acquire the read lock. If the read lock is ...