test updating instances in promiseSpace updates agoricNames

[Chris-Hibbert]

refs: #9970

Description

While preparing a coreEval for the vaults&Auctions release, I found it necessary to update both instance.produce.auctioneer and agoricNamesAdmin.lookupAdmin('instance').

This test shows that updating the former causes the latter to update.

Testing Considerations

[Chris-Hibbert]

For the purposes of conversation, this test shows that

 await space.instance.produce.auctioneer.reset();
  await space.instance.produce.auctioneer.resolve(auctionInstance2);

does indeed update agoricNames.

  const instanceLookup = await agoricNames.lookup('instance');
  t.is(await instanceLookup.lookup('auctioneer'), auctionInstance2);

[dckc]

This shows that the short version works in at least some cases.

It doesn't hurt to land this as-is, but should we look harder for problems first?

[dckc]

I suggest moving the error to where auctionInstance1 is declared:

Suggested change

	const auctionInstance1 = makeHandle('instance1');
	const instanceLookup = await agoricNames.lookup('instance');
	// @ts-expect-error storing fake instance
	space.instance.produce.auctioneer.resolve(auctionInstance1);
	// @ts-expect-error expecting instance
	t.is(await space.instance.consume.auctioneer, auctionInstance1);
	/** @type { Instance } */
	// @ts-expect-error mock
	const auctionInstance1 = makeHandle('instance1');
	const instanceLookup = await agoricNames.lookup('instance');
	space.instance.produce.auctioneer.resolve(auctionInstance1);
	t.is(await space.instance.consume.auctioneer, auctionInstance1);

[Chris-Hibbert]

It doesn't hurt to land this as-is, but should we look harder for problems first?

I'd like to look harder, but I don't know what to look for. My current (very tentative) hypothesis is that the promises are taking a while to resolve in the upgrade coreEval.

[dckc]

I'd like to look harder, but I don't know what to look for. My current (very tentative) hypothesis is that the promises are taking a while to resolve in the upgrade coreEval.

We can look there, I think, by controlling which promises resolve when in a test. We might have to introduce a few more moving parts. hm.

[Chris-Hibbert]

While preparing a coreEval for the vaults&Auctions release, I found it necessary to update both instance.produce.auctioneer and agoricNamesAdmin.lookupAdmin('instance').

I now suspect that the issue is a subtle form of TOCTOU.

When dealing with values in the promise space that are being updated during the same run, you can easily get a value from before the change, even if you think one proposal is supposed to happen after another. Particular with multiple core-evals, the process starts them in parallel, and satisfies consume directives eagerly.

Similarly, if you retrieve sub-tables from agoricNames (as agoricNamesAdmin.lookupAdmin('instance') does) you can easily end up with a copy of the sub-table that won't be updated even if you don't look up a specific name in it until later.

@dckc would you mind if I closed this? Is the test worth cleaning up and merging?

[dckc]

I don't mind. Go ahead