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。
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)。
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。
A lock can fail, for example, if files on the target volume are currently opened by other programs.
锁定会有失败的情况，例如，当目标卷上的文件正被其他的程序打开。
Custom options include painted and metal-clad finishes, electric lock and power-fail options, and unique configurations.
用户自定义选项包括喷漆和覆金属面，电子锁和发生电源故障后的选择以及一些独特的配置。
Custom options include painted and metal-clad finishes, electric lock and power-fail options, and unique configurations.
用户自定义选项包括喷漆和覆金属面，电子锁和发生电源故障后的选择以及一些独特的配置。
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