Make sure to call connection callbacks in synchronous failure #16509
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
If OperationalDeviceProxy::Connect fails synchronously it does not call pending failure callbacks except for the argument to the current call. This leads to unanswered connection requests as FindOrEstablishSession immediately calls ReleaseSession() after such a failure, which deletes the proxy.
pullapprove
bot
requested review from
andy31415,
anush-apple,
austinh0,
Byungjoo-Lee,
bzbarsky-apple,
carol-apple,
chrisdecenzo,
chshu,
chulspro,
Damian-Nordic,
dhrishi,
electrocucaracha,
erjiaqing,
franck-apple,
gjc13,
hawk248,
holbrookt,
harsha-rajendran,
isiu-apple,
jelderton,
jepenven-silabs,
jmartinez-silabs,
kpschoedel,
lazarkov,
LuDuda,
mlepage-google,
msandstedt and
robszewczyk
pullapprove
bot
requested review from
sagar-apple,
saurabhst,
selissia,
tcarmelveilleux,
tecimovic,
vijs,
vivien-apple,
wbschiller,
woody-apple,
xylophone21,
yufengwangca and
yunhanw-google
|
PR #16509: Size comparison from a72ab9b to 1d0d4e0 Increases (16 builds for cyw30739, efr32, esp32, k32w, linux, nrfconnect, p6, telink)
Full report (27 builds for cyw30739, efr32, esp32, k32w, linux, mbed, nrfconnect, p6, telink)
|
bzbarsky-apple
requested changes
Mar 22, 2022
| @@ -98,6 +98,10 @@ CHIP_ERROR OperationalDeviceProxy::Connect(Callback::Callback<OnDeviceConnected> | |||
| if (err != CHIP_NO_ERROR && onFailure != nullptr) | |||
There was a problem hiding this comment.
And if onFailure is null we won't call the other callbacks?
| @@ -98,6 +98,10 @@ CHIP_ERROR OperationalDeviceProxy::Connect(Callback::Callback<OnDeviceConnected> | |||
| if (err != CHIP_NO_ERROR && onFailure != nullptr) | |||
| { | |||
| onFailure->mCall(onFailure->mContext, mPeerId, err); | |||
|
|
|||
| DequeueConnectionSuccessCallbacks(/* executeCallback */ false); | |||
There was a problem hiding this comment.
So trying to understand the various cases here.
If we enter this function when state is State::Uninitialized will we have existing callbacks? I'd think not...
If we enter this function when state is State::NeedsAddress it actually looks like the existing logic (with or without this change) is buggy. We'll call LookupPeerAddress, enqueue the new callbacks, and then if the LookupPeerAddress call failed call the error callback but not dequeue it... which means we will later call it again.
If we enter this function when state is State::Initialized we will try to EstablishConnection... is this the part that was observed to sync-fail? But would we ever be in the Initialized state with pending callbacks? I guess we could get here if we had an earlier UpdateDeviceData call after DNS-SD resolve where EstablishConnection failed, OnSessionEstablishmentError was called but is a no-op (which it is), and we were left in the Initialized state with dangling callbacks? But then the right answer would seem to be to deque and call the callbacks at that point, so they're not left sitting there until someone else tries to connect and we sync-fail.
So overall, I think we should:
- Fix OperationalDeviceProxy::UpdateDeviceData to handle the sync-failure from
EstablishConnectionthere correctly. Either by calling callbacks, or by callingConnect(nullptr, nullptr)after moving to the new state. And nix the bogusOnSessionEstablishmentErrorcall (and probably the inheritance fromSessionEstablishmentDelegate. - Fix this code to be consistent in its error handling. Probably most simply by ensuring that all branches of the swich enqueue the callbacks and set
erras needed and after the switch iferris failure we invoke all of our queued callbacks. That would still cover up bugs like the one item 1 is fixing, but hopefully we won't have any at that point?
There was a problem hiding this comment.
Agree this needs more work, this was mostly intended as a fire extinguishing exercise as this particular case was reliably causing issues.
However other changes have mitigated that particular issue.
There was a problem hiding this comment.
The changes proposed above were made in #17266.
|
|
||
| DequeueConnectionSuccessCallbacks(/* executeCallback */ false); | ||
| DequeueConnectionFailureCallbacks(err, /* executeCallback */ true); | ||
| CloseCASESession(); |
There was a problem hiding this comment.
This should really live inside OperationalDeviceProxy::EstablishConnection in the case when EstablishSession returns error, because there it's clear we need to clean up mCASEClient.... Putting it here is a little odd.
There was a problem hiding this comment.
#17466 addresses this.
|
Closing this. Unfortunately, I don't have the cycles to own a proper cleanup pass of this code. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Problem
If OperationalDeviceProxy::Connect fails synchronously it does not call
pending failure callbacks except for the argument to the current call.
This leads to unanswered connection requests as FindOrEstablishSession
immediately calls ReleaseSession() after such a failure, which deletes
the proxy.
Change overview
Make sure to call pending callbacks on synchronous failure.
Testing
Connect to an non-routable address, which fails synchronously in sendmsg()
in the resolve callback. Application is still notified of failure.