[SSHD-394] Use an ExecutorService to spawn SftpSubsystem command

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.14.0
• Fix Version/s: 0.14.0
• Assignee: Guillaume Nodet
• Reporter: Lyor Goldstein
• Created: 05/Jan/15 06:41
• Updated: 10/Feb/15 10:57
• Resolved: 10/Feb/15 10:57

Description

The current code simply uses

new Thread(this).start()

This precludes the user from configuring the thread's attributes - name, priority, stack size, thread-group and most important whether it is a daemon or not. By allowing to provide an ExecutorService we enable all these.

Note: the choice for using an ExecutorService rather than a simple(r) Executor is twofold:

1. The documentation for Executor#execute() clearly states:

   Executes the given command at some time in the future. The command may execute in a new thread, in a pooled thread, or in the calling thread, at the discretion of the Executor implementation.

   
   In our case we want to make sure that a new thread is spawned
2. The ExecutorService#submit() call returns a Future object which we can later use to stop the command when the destroy() method is called