in what way is java.net.Socket threadsafe?

java sockets thread-safety bufferedreader bufferedwriter
lacker picture lacker · Jul 13, 2011 · Viewed 13.2k times · Source

I have a Socket that I am both reading and writing to, via BufferedReaders and BufferedWriters. I'm not sure which operations are okay to do from separate threads. I would guess that writing to the socket from two different threads at the same time is a bad idea. Same with reading off the socket from two different threads at the same time. What about reading on one thread while writing on another?

I ask because I want to have one thread blocked for a long time on a read as it waits for more data, but during this wait I also have occasional data to send on the socket. I'm not clear if this is threadsafe, or if I should cancel the read before I write (which would be annoying).

Answer

Alex Gitelman picture Alex Gitelman · Jul 13, 2011

You actually read from InputStream and write to OutputStream. They are fairly independent and for as long as you serialize access to each of them you are ok.

You have to correlate, however, the data that you send with data that you receive. That's different from thread safety.

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