524220 - IPDL: Add a |nullable| type qualifier for actor params/returns

Status: RESOLVED FIXED

(Core :: IPC, enhancement)

Description

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Currently in IPDL, any message can pass in a NULL actor value, but I'm not sure this is desirable.  I think the instead we should make actor nullability part of IPDL's type system.  So one could say

  Msg(nullable FooActor foo) return (BarActor bar);

and C++ would be allowed to pass a NULL |foo|, but not a NULL |bar|.

There's also a regression caused by bug 506171 where invalid actor IDs silently result in NULL actors being passed to C++.  Invalid actor IDs should always cause a loud error.  I'll fix that as part of this bug.

Comment 1

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

I hear the places we're using NULL actors now are

 o PPluginScriptableObject:Variant
 o PPluginInstance::PBrowserStream `notifyData`

Comment 2

[Ben Turner (not reading bugmail, use the needinfo flag!)]

pretty much anywhere in npruntime where we use PPluginScriptableObject

Comment 3

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Attachment: v1

Comment 4

[Ben Turner (not reading bugmail, use the needinfo flag!)]

Comment on attachment 409201 [details] [diff] [review]
v1

Looks good, let's get this in, stat.

Comment 5

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

Pushed http://hg.mozilla.org/projects/electrolysis/rev/3716cd3234f3