pthread_rwlock_rdlock may fail if the maximum number of read locks (implementation defined) for the lock has been exceeded.

如果超过了最大读锁数量（由实现定义），pthread_rwlock_rdlock 可能会失败。

youdao

Conversely, if an exclusive lock was able to be acquired, concurrent applications would not be able to access the file and could fail with a lock time-out.

相反地，如果能够获得互斥型锁，那么并发应用程序就无法访问文件，并因为锁超时失败。

youdao

And you should never unlock a mutex that you don't hold a lock for (otherwise, the pthread_mutex_unlock call will fail with a non-zero EPERM return value).

并且绝对不要对您未保持锁的互斥对象进行解锁操作(否则，pthread _ mutex_unlock调用将失败并带一个非零的eperm返回值)。

youdao