437529 - Async.Generator errors: "missing a 'yield' call", "this.generator is null"

Status: RESOLVED FIXED

(Cloud Services :: General, defect)

Description

[Myk Melez [:myk] [@mykmelez]]

I'm seeing a bunch of Async.Generator errors after syncing the same profile a few times:

2008-06-05 16:23:02	Async.Generator	ERROR	Async method 'Engine__sync' is missing a 'yield' call (or called done() after being finalized)
2008-06-05 16:23:02	Async.Generator	ERROR	Async method 'WeaveSvc__syncEngine' is missing a 'yield' call (or called done() after being finalized)
2008-06-05 16:23:02	Async.Generator	ERROR	Async method 'WeaveNotifyWrapper' is missing a 'yield' call (or called done() after being finalized)
2008-06-05 16:23:02	Async.Generator	ERROR	Async method 'WeaveSync__sync' is missing a 'yield' call (or called done() after being finalized)
2008-06-05 16:23:02	Async.Generator	ERROR	Async method 'WeaveNotifyWrapper' is missing a 'yield' call (or called done() after being finalized)
2008-06-05 16:23:02	Async.Generator	ERROR	Exception: TypeError: this.generator is null
2008-06-05 16:23:02	Async.Generator	ERROR	Exception: this.generator is null
2008-06-05 16:23:02	Async.Generator	ERROR	Async method 'WeaveLockWrapper' is missing a 'yield' call (or called done() after being finalized)

Comment 1

[Myk Melez [:myk] [@mykmelez]]

Removing TabStore_ApplyCommands, which overrides Store_ApplyCommands, got rid of "Exception: TypeError: this.generator is null", but the others are still there.

Comment 2

[Myk Melez [:myk] [@mykmelez]]

Attachment: patch that fixes problem

This turns out to be a regression from changeset 397c72376858 (2008-05-28 20:11 -0700), "Dan Mills - Add and start using an object to represent a remote resource (file), and a server object to hold them. Resources will attempt to retry network operations if they fail."

In the previous revision of engines.js, Engine::_sync yields after it puts the status file to the server.  In the later revision, however, which changes the API for putting files, the function doesn't yield there, so it calls self.done() before the PUT request completes.

Then, when the PUT request completes, it attempts to call back the function, but the function has already been finalized, so the exception gets thrown.

Here's the fix that resolves the problem.  I'll check this in shortly.

Comment 3

[Myk Melez [:myk] [@mykmelez]]

changeset:   519:23744bd48479
date:        Wed Jun 11 17:44:08 2008 -0700
summary:     bug 437529: yield after starting to put the status file to the server so we don't finalize the sync until the PUT request completes

Comment 4

[Dan Mills [:thunder]]

Oops.  Sorry for the regression!