[MESOS-9369] Avoid blocking `Future::get()` calls

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: libprocess
• Labels: libprocess
• Assignee: Unassigned
• Reporter: Chun-Hung Hsiao
• Shepherd: Benjamin Mahler
• Created: 02/Nov/18 22:51
• Updated: 21/Nov/18 19:47

Description

Future::get() does a wait if the future is still pending. If this is accidentally called in an actor, the actor will be blocked. We should avoid calling Future::get() in the code. The plan would be:

1. Introduce Future::value(): crash if not READY
2. Make Future::operator* and Future::operator-> akin to Future::value()