What is a process_reaper thread in Java?

问题

I'm getting hundreds of these process_reaper threads that build up over time in my application. Anyone have any idea what these may be? They seem to be in my use of Runtime.exec() however I'm destroying my process in a finally statement but they still show up

screen shot: http://www.dropmocks.com/mBxM5

Process proc = null;
        String line;
        try {
            logger.info("Trying to execute command " + Arrays.asList(command).toString().replace(",", ""));
            proc = Runtime.getRuntime().exec(command);

        } catch (IOException e) {
            logger.info("IOException while trying to execute " + command);
            return false;
        } finally {
            if(proc != null) {
                proc.destroy();
            }
    }

回答1:

I haven't seen this one myself so I searched a little; it seems a process reaper is related to the Linux kernel process management and is a daemon thread. It maintains the process state so that resources can be freed/released/collected on process termination and so on. This resource might help you. There is a mention on reapers in the final parts.

回答2:

you must call process.waitFor() after exec and before destory (asy action)

来源：https://stackoverflow.com/questions/3835830/what-is-a-process-reaper-thread-in-java