如果一个 fd 正在关闭而其他函数正在阻塞它怎么办？
What if an fd is being closed while other function is blocking on it?
根据pipe的手册页：
If a process attempts to read from an empty pipe, then read(2) will
block until data is available. If a process attempts to write to a
full pipe (see below), then write(2) blocks until sufficient data has
been read from the pipe to allow the write to complete. Nonblocking
I/O is possible by using the fcntl(2) F_SETFL operation to enable the
O_NONBLOCK open file status flag.
我有这样一个问题：
前提是管道缓冲区为空；
读取在管道上阻塞；
现在关闭写端，读端会自动解封吗？
是的，read 将被解锁并且 return EOF (0)。
根据pipe的手册页：
If a process attempts to read from an empty pipe, then read(2) will
block until data is available. If a process attempts to write to a
full pipe (see below), then write(2) blocks until sufficient data has
been read from the pipe to allow the write to complete. Nonblocking
I/O is possible by using the fcntl(2) F_SETFL operation to enable the
O_NONBLOCK open file status flag.
我有这样一个问题：
前提是管道缓冲区为空；
读取在管道上阻塞；
现在关闭写端，读端会自动解封吗？
是的，read 将被解锁并且 return EOF (0)。