[MESOS-3426] process::collect and process::await do not perform discard propagation.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.25.0
• Component/s: libprocess
• Sprint: Twitter Mesos Q3 Sprint 5
• Story Points: 3
• Assignee: Benjamin Mahler
• Reporter: Benjamin Mahler
• Shepherd: Jie Yu
• Created: 14/Sep/15 20:11
• Updated: 15/Sep/15 19:04
• Resolved: 15/Sep/15 19:04

Description

When aggregating futures with collect, one may discard the outer future:

Promise<int> p1;
Promise<string> p2;

Future<int, string> collect = process::collect(p1.future(), p2.future());

collect.discard();

// collect will transition to DISCARDED

// However, p{1,2}.future().hasDiscard() remains false
// as there is no discard propagation!

Discard requests should propagate down into the inner futures being collected.