"Request to Dart VM Service timed out: _flutter.listViews({})" during hot reload

@DanTup

Flutter version - 0.4.3-pre.16 & Dart Code - 2.12.2
@DanTup TimeoutException: Request to Dart VM Service timed out: _flutter.listViews({})

flutter_run.txt
observatory.txt

Does hot reload always work the first time, and then fail on subsequent attempts?

In these logs, the first one works (which said "Initializing hot reload") but the next one failed (and it instead said "Performing hot reload..."). I'm not sure if there's a difference in what's performed the first time versus others.

[5:34:17 PM]: ==> [{"id":"7","method":"app.restart","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","fullRestart":false,"pause":true}}]
[5:34:17 PM]: <== [{"event":"app.progress","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","id":"5","progressId":"hot.reload","message":"Initializing hot reload..."}}]
[5:34:18 PM]: <== [{"event":"app.progress","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","id":"5","progressId":"hot.reload","finished":true}}]
[5:34:18 PM]: <== Reloaded 3 of 395 libraries in 1,239ms.
[5:34:18 PM]: <== [{"id":"7","result":{"code":0,"message":"Reloaded 3 of 395 libraries"}}]
[5:34:24 PM]: ==> [{"id":"8","method":"app.restart","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","fullRestart":false,"pause":true}}]
[5:34:24 PM]: <== [{"event":"app.progress","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","id":"6","progressId":"hot.reload","message":"Performing hot reload..."}}]
[5:35:25 PM]: <== [{"event":"app.progress","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","id":"6","progressId":"hot.reload","finished":true}}]
[5:35:25 PM]: <== [{"id":"8","error":"TimeoutException: Request to Dart VM Service timed out: _flutter.listViews({})"}]

yes, it never gave exception at first attempt . It always give exception after subsequent attempts stating ' Performing hot reload'

…

On Thu, May 10, 2018, 1:21 PM Danny Tuppeny ***@***.***> wrote: Does hot reload always work the first time, and then fail on subsequent attempts? In these logs, the first one works (which said "Initializing hot reload") but the next one failed (and it instead said "Performing hot reload..."). I'm not sure if there's a difference in what's performed the first time versus others. [5:34:17 PM]: ==> [{"id":"7","method":"app.restart","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","fullRestart":false,"pause":true}}] [5:34:17 PM]: <== [{"event":"app.progress","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","id":"5","progressId":"hot.reload","message":"Initializing hot reload..."}}] [5:34:18 PM]: <== [{"event":"app.progress","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","id":"5","progressId":"hot.reload","finished":true}}] [5:34:18 PM]: <== Reloaded 3 of 395 libraries in 1,239ms. [5:34:18 PM]: <== [{"id":"7","result":{"code":0,"message":"Reloaded 3 of 395 libraries"}}] [5:34:24 PM]: ==> [{"id":"8","method":"app.restart","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","fullRestart":false,"pause":true}}] [5:34:24 PM]: <== [{"event":"app.progress","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","id":"6","progressId":"hot.reload","message":"Performing hot reload..."}}] [5:35:25 PM]: <== [{"event":"app.progress","params":{"appId":"cd36a340-0ea8-4cd4-80f8-158e72380363","id":"6","progressId":"hot.reload","finished":true}}] [5:35:25 PM]: <== [{"id":"8","error":"TimeoutException: Request to Dart VM Service timed out: _flutter.listViews({})"}] — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#17434 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AMCOnOBLMGOuwdbHgjKW26ehxrxyKLZwks5tw_F3gaJpZM4T4uQU> .

same issue here

Looking at the logs again; we never got a response to the resume request on the second hot reload.. The log ends here:

[5:34:25 PM]: ==> {"id":"414","method":"resume","params":{"isolateId":"isolates/61399362"}}

@aam

@aam @rmacnak-google, we've had issues in the past re: _flutter.listViews({}) and the VM being paused. There's some code in flutter_tools to avoid listing views if it thinks the VM is paused. That code is likely a bit racy however. We may want to consider moving to maintaining the list of views on the flutter_tools side, and adding and removing from the list based on flutter view added / flutter view removed events from the target device.

I had this consistently for some weeks but seems to be working now in dev channel.

Update
It happens less frequently, but still happens.

@zoechi

@zoechi Was that in IntelliJ? We were just discussing whether it might be a timing issue and Dart Code doing something differently to IntelliJ; but maybe it happens there too. Do you normally run with or without the debugger?

Yes IntelliJ. Always with debugger.

@devoncarew

@devoncarew I diff'd the good/bad restarts from the log above and the requests are all in the same order (obviously there may be timing variances), though the bad one never got a response to the resume.

I'm not sure how much we can do to change the timing (short of putting little delays in places).

Currently it looks like we wait for PausePostRequest, then we send requests to remove and re-add all breakpoints, then once they're all done, we send the resume.

Currently it looks like we wait for PausePostRequest, then we send requests to remove and re-add all breakpoints, then once they're all done, we send the resume.

OK, this matches what we're doing in IntelliJ; thanks for investigating.

same issue~~....

@DanTup

Any update on this issue @DanTup ?

I'm afraid this one is currently a little outside of my knowledge so is going to need some input from someone else. As a temporary workaround you could run from the terminal (though this means no debugger) or disable hot-reload-on-save and use Ctrl+F5 for full restarts (they're still pretty fast, but obviously lose state/position in app).

@DanTup

@DanTup, apologies, no, I don't believe so now. You do want to pause and resend breakpoints since the code might have moved as part of the hot reload. So yes, that is how you could end up in the same non-responsive engine state even if your code was not paused on the breakpoint when you did hot reload.
I'm working on a fix for this.

@aam

@aam Great; thanks!

Enable flutter service protocol rpcs to run on UI isolate.

after reading about breakpoints on this issue I started fiddling with them and got VERY different results.

This is how I fiddled:

The sequence I did was roughly the following:

disable 'break on exceptions'
Add characters one by one to new Text(''), with dart 2 enabled on AS.
hot reload
repeat sequence about 10 times
enable 'break on exceptions'
do steps 2 - 4. On 7th attempt it chocked and presented the usual problem
stop app, disable 'break on exceptions'
create a new new Text(''), launch app again
repeat steps 2 - 4
do step 5 (enable exceptions again)
repeat steps 2 - 4

Now I can't make this project hang at all. Next time it does I'll fiddle again with breakpoints.

Note: I usually disable all breakpoints and have none intentionally added, until this hot reload solves itself.

My logs and setup details were added in #17005 (comment). before this breakpoint fiddling. The only difference now is that I downloaded and launched an emulator based on nexus 5X with Android P, but I could reproduce the problems very easily there yesterday after taking such logs.

Something changed on my setup too in VSCode, I installed the Offical flutter extension in addition to the dart on that was already installed. I would see if it has break on uncaught exceptions enabled by default...

@aam

Something changed on my setup too in VSCode, I installed the Offical flutter extension in addition to the dart on that was already installed

This won't make any difference; at this point all of the debugging comes from the Dart extension (the Flutter extension has a dependency on the Dart one, so if you didn't already have it it would install it for you).

I would see if it has break on uncaught exceptions enabled by default...

It's not on by default (it's a tickbox at the bottom left of the debug sidebar). I wouldn't expect this setting to affect the ability for us to resume, but I'm not familiar with what's happening in the VM-side.

That said, from the comment above, I think may @aam may have figured out the issue now :-)

re install other version.. and then done~

Enable flutter service protocol rpcs to run on UI isolate. (#5263)

I think I can find an effective workaround the problem.

Today I opened pre-existing project
1st hot reload failed when editing string on text
stopped, started app, changed string, 1st hot reload failed again. That happened 3x
opened breakpoints menu, disabled all of them
hot reload works like magic
enable same breakpoints as before
hot reload still working as expected. I can't figure out how to make it fail again.

These are the details:

Different emulator since last time ( nexus 5x api 26, downloaded about 3 months ago )
Updated flutter intellij plugin from 24 to 24.0.1 since last report

> flutter --version
Flutter 0.4.5-pre.6 • channel master • https://github.com/flutter/flutter.git
Framework • revision a25bbc7bfc (2 days ago) • 2018-05-14 15:51:12 -0700
Engine • revision 06afdfe54e
Tools • Dart 2.0.0-dev.54.0.flutter-46ab040e58

The intended fix for this landed in 89cb5d2 . If folks could give it a try(get latest flutter from master channel/branch) and confirm, that would be awesome!

@aam

@aam, Works great! Even when on breakpoints while paused. Nice! Thank you!

Thank you for confirmation, @ThinkDigitalRepair !

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.

Navigation Menu

Repository navigation

"Request to Dart VM Service timed out: _flutter.listViews({})" during hot reload #17434

15 remaining items

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

"Request to Dart VM Service timed out: _flutter.listViews({})" during hot reload #17434

Description

Activity

DanTup commented on May 10, 2018

iampawan commented on May 10, 2018

darioielardi commented on May 10, 2018

DanTup commented on May 10, 2018

devoncarew commented on May 10, 2018

zoechi commented on May 10, 2018

DanTup commented on May 10, 2018

zoechi commented on May 10, 2018

DanTup commented on May 10, 2018

devoncarew commented on May 10, 2018

joon610 commented on May 11, 2018

iampawan commented on May 13, 2018

DanTup commented on May 14, 2018

15 remaining items

aam commented on May 15, 2018

DanTup commented on May 15, 2018

fmatosqg commented on May 15, 2018

rodydavis commented on May 16, 2018

DanTup commented on May 16, 2018

joon610 commented on May 16, 2018

fmatosqg commented on May 17, 2018

aam commented on May 18, 2018

ThinkDigitalSoftware commented on May 20, 2018

aam commented on May 21, 2018

github-actions commented on Sep 3, 2021

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions