1768476 - Consistently pass around IPC::Message behind a UniquePtr

Status: RESOLVED FIXED

(Core :: IPC, task)

Description

[Nika Layzell [:nika] (ni? for response)]

IPC::Message currently is passed differently in many places, either being directly moved or stored behind a UniquePtr (or raw pointer). This inconsistency requires things such as IPC::Message having a manually-implemented move constructor and assignment operator (https://searchfox.org/mozilla-central/rev/c7183440fe8ad391e2ab2e990229dd85fac318d3/ipc/chromium/src/chrome/common/ipc_message.cc#56-71,87-99), and generally makes some code trickier to follow.

This bug tracks a patch to remove these move constructors, and instead always pass IPC::Message around behind a UniquePtr to simplify things and make adding e.g. members to IPC::Message less error prone.

Comment 1

[Nika Layzell [:nika] (ni? for response)]

Attachment: Bug 1768476 - Part 1: Consistently pass IPC::Message around by UniquePtr, r=#ipc-reviewers

This makes passing around the type more consistent, and hopefully will make
changes to IPC::Message easier to work with in the future.

In addition, this should save us a few copies as we move the message type into
and out of UniquePtr, however I expect this won't make much of a difference.

Comment 2

[Nika Layzell [:nika] (ni? for response)]

Attachment: Bug 1768476 - Part 2: Mark MessageTask::mMessage as guarded by the monitor, r=#ipc-reviewers

All accesses except those through the xpcom interfaces were already
guarded, and given it can be mutated, this seemed easier than adding
thread assertions or similar.

Depends on D145885

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6732ef394d0e
Part 1: Consistently pass IPC::Message around by UniquePtr, r=ipc-reviewers,mccr8
https://hg.mozilla.org/integration/autoland/rev/c9cb03579c09
Part 2: Mark MessageTask::mMessage as guarded by the monitor, r=ipc-reviewers,mccr8

Comment 4

[Noemi Erli[:noemi_erli]]

Backed out 2 changesets (Bug 1768476) for causing build bustages in ProtocolFuzzer.h

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&collapsedPushes=842382&selectedTaskRun=TwByL0ucTC6NwNuVcKKXZA.0&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=c9cb03579c0933688bd30359a5c755a9d9799bc7

Log: https://treeherder.mozilla.org/logviewer?job_id=377604506&repo=autoland&lineNumber=10096
https://treeherder.mozilla.org/logviewer?job_id=377603878&repo=autoland&lineNumber=101781

Backout: https://hg.mozilla.org/integration/autoland/rev/5b2d681db7a638f1c882a80b05d3710443def80d

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5933da5f8e3d
Part 1: Consistently pass IPC::Message around by UniquePtr, r=ipc-reviewers,mccr8
https://hg.mozilla.org/integration/autoland/rev/5a1aef360088
Part 2: Mark MessageTask::mMessage as guarded by the monitor, r=ipc-reviewers,mccr8

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/41c3bedf3d95
Correct merge conflict resolution. CLOSED TREE

Comment 7

[Nika Layzell [:nika] (ni? for response)]

Attachment: Bug 1768476 - Part 3: Fix nyx-fuzz only bustage on a CLOSED TREE

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/20902b19a0ef
Part 3: Fix nyx-fuzz only bustage on a CLOSED TREE

Comment 9

[bszekely]

https://hg.mozilla.org/mozilla-central/rev/5933da5f8e3d
https://hg.mozilla.org/mozilla-central/rev/5a1aef360088
https://hg.mozilla.org/mozilla-central/rev/41c3bedf3d95
https://hg.mozilla.org/mozilla-central/rev/20902b19a0ef