Old instrumentation was designed to collect promise creation stack and
promise scheduled stack together. In DevTools for last 6 months we
show only creation stack for promises. We got strong support from users
for new model. Now we can drop support for scheduled stacks and
simplify implementation.
New promise instrumentation is straightforward:
- we send kDebugPromiseThen when promise is created by .then call,
- we send kDebugPromiseCatch when promise is created by .catch call,
- we send kDebugWillHandle before chained callback and kDebugDidHandle
after chained callback,
- and we send separate kDebugAsyncFunctionPromiseCreated for internal
promise inside async await function.
Advantages:
- we reduce amount of captured stacks (we do not capture stack for
promise that constructed not by .then or .catch),
- we can consider async task related to .then and .catch as one shot
since chained callback is executed once,
- on V8 side we can implement required instrumentation using only
promise hooks,
Disadvantage:
- see await-promise test, sometimes scheduled stack was useful since we
add catch handler in native code,
Implementation details:
- on kInit promise hook we need to figure out why promise was created.
We analyze builtin functions until first user defined function on
current stack. If there is kAsyncFunctionPromiseCreate function then
we send kDebugAsyncFunctionPromiseCreated event. If there is
kPromiseThen or kPromiseCatch then only if this function is bottom
builtin function we send corresponded event to inspector. We need it
because Promise.all internally calls .then and in this case we have
Promise.all and Promise.then on stack at the same time and we do not
need to report this internally created promise to inspector.
Bug: chromium:778796
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I53f47ce8c5c4a9897655c3396c249ea59529ae47
Reviewed-on: https://chromium-review.googlesource.com/765208
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49553}
Creation stack trace points to the place where callback was actually chained, scheduled points where parent promise was resolved.
For async tasks without creation stack (e.g. setTimeout) we continue to use scheduled as creation since usually they are the same.
BUG=v8:6189
R=dgozman@chromium.org
Review-Url: https://codereview.chromium.org/2868493002
Cr-Original-Commit-Position: refs/heads/master@{#45198}
Committed: e118462f18
Review-Url: https://codereview.chromium.org/2868493002
Cr-Commit-Position: refs/heads/master@{#45266}
Reason for revert:
CHECK is too strict.
Original issue's description:
> [inspector] use creation stack trace as parent for async call chains
>
> Creation stack trace points to the place where callback was actually chained, scheduled points where parent promise was resolved.
> For async tasks without creation stack (e.g. setTimeout) we continue to use scheduled as creation since usually they are the same.
>
> BUG=v8:6189
> R=dgozman@chromium.org
>
> Review-Url: https://codereview.chromium.org/2868493002
> Cr-Commit-Position: refs/heads/master@{#45198}
> Committed: e118462f18TBR=dgozman@chromium.org,alexclarke@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:6189
Review-Url: https://codereview.chromium.org/2868423004
Cr-Commit-Position: refs/heads/master@{#45242}
Creation stack trace points to the place where callback was actually chained, scheduled points where parent promise was resolved.
For async tasks without creation stack (e.g. setTimeout) we continue to use scheduled as creation since usually they are the same.
BUG=v8:6189
R=dgozman@chromium.org
Review-Url: https://codereview.chromium.org/2868493002
Cr-Commit-Position: refs/heads/master@{#45198}
- we should always set creation async stack if it's available regardless existing of current parent async stack,
- we should cleanup parent link iff there is no creation and schedule async stack for parent.
Let's consider example: Promise.resolve().then(x => x).then(x => x), there is three promises which will call following instrumentation:
1) created #1 (Promise.resolve()) - collected stack #1
2) scheduled #1 - collected stack #2
3) created #2 with #1 as parent (first .then) - collected stack #3
4) created #3 with #2 as parent (first .then) - collected stack #4
5) started #2 - use stack #2 as scheduled
6) scheduled #2 - collected stack #6
7) finished #2
8) started #3 - use stack #6 as scheduled
9) scheduled #3 - collected stack #7
10) finished #3
If we collect stacks between step 4 and 5, it's possible to collect scheduled stack #2 but still have creation stack for #2 - stack #3 - so we always need to add creation event if scheduled is collected.
If we collect stacks between created and scheduled we should not remove parent link even if parent was not scheduled yet.
BUG=v8:6189
R=dgozman@chromium.org
Review-Url: https://codereview.chromium.org/2844753002
Cr-Commit-Position: refs/heads/master@{#44990}
.. replace all of them with prepared global object template.
+ bonus: wrap inspector related methods with inspector namespace.
BUG=none
R=dgozman@chromium.org
Review-Url: https://codereview.chromium.org/2832723004
Cr-Commit-Position: refs/heads/master@{#44785}
- separated V8StackTraceImpl and AsyncStackTrace,
- V8Debugger owns all AsyncStackTrace and cleanup half of them when limit is reached (first created - first cleaned),
- V8StackTraceImpl, AsyncStackTrace and async-task-related tables in V8Debugger have weak reference to other async stack traces.
- async tasks are cleared with related async stacks.
BUG=v8:6189
R=dgozman@chromium.org
Review-Url: https://codereview.chromium.org/2816043006
Cr-Original-Commit-Position: refs/heads/master@{#44670}
Committed: 1bca73bc83
Review-Url: https://codereview.chromium.org/2816043006
Cr-Commit-Position: refs/heads/master@{#44694}
Reason for revert:
Speculative revert. Seems to block the roll:
https://codereview.chromium.org/2822983004/
Might require changing a browser test first?
Original issue's description:
> [inspector] avoid cloning of async call chains
>
> - separated V8StackTraceImpl and AsyncStackTrace,
> - V8Debugger owns all AsyncStackTrace and cleanup half of them when limit is reached (first created - first cleaned),
> - V8StackTraceImpl, AsyncStackTrace and async-task-related tables in V8Debugger have weak reference to other async stack traces.
> - async tasks are cleared with related async stacks.
>
> BUG=v8:6189
> R=dgozman@chromium.org
>
> Review-Url: https://codereview.chromium.org/2816043006
> Cr-Commit-Position: refs/heads/master@{#44670}
> Committed: 1bca73bc83TBR=dgozman@chromium.org,kozyatinskiy@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:6189
Review-Url: https://codereview.chromium.org/2825713002
Cr-Commit-Position: refs/heads/master@{#44678}
- separated V8StackTraceImpl and AsyncStackTrace,
- V8Debugger owns all AsyncStackTrace and cleanup half of them when limit is reached (first created - first cleaned),
- V8StackTraceImpl, AsyncStackTrace and async-task-related tables in V8Debugger have weak reference to other async stack traces.
- async tasks are cleared with related async stacks.
BUG=v8:6189
R=dgozman@chromium.org
Review-Url: https://codereview.chromium.org/2816043006
Cr-Commit-Position: refs/heads/master@{#44670}
