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Fix bug in selectQueueToTakeFromNext for trace profiles (jlfwong#450)
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I have been taking a lot of profiles using the Hermes profiler, but I noticed that they sometimes to not show up properly. After debugging what exactly was going on, I realized it was because the logic in `selectQueueToTakeFromNext` only checks for name, instead of the key for the event. I had a bunch of events with the name `anonymous` that were getting improperly exited before they should have been due to this logic. 

This fix makes the code more robust if there are added "args" which differentiate an event from another (as is the case in Hermes profiles), however it would still be an issue if they key just defaults to the name.

Example profile before:

<img width="1728" alt="Screenshot 2023-12-15 at 12 54 04 AM" src="https://github.com/jlfwong/speedscope/assets/9957046/345f556e-f944-40f1-b59c-748133acb950">

What it should look like (in Perfetto):
<img width="1051" alt="Screenshot 2023-12-15 at 8 51 38 AM" src="https://github.com/jlfwong/speedscope/assets/9957046/7473cdf8-95f1-49de-a0c7-ef4ac081ff85">

After the fix:

<img width="1728" alt="Screenshot 2023-12-15 at 12 54 29 AM" src="https://github.com/jlfwong/speedscope/assets/9957046/56b0870a-538b-4916-acc8-de2b7dfd78eb">
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zacharyfmarion authored Dec 16, 2023
1 parent ac4a015 commit dfd3a0d
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Showing 4 changed files with 82 additions and 2 deletions.
14 changes: 14 additions & 0 deletions sample/profiles/trace-event/simultaneous-anonymous-calls.json
Original file line number Diff line number Diff line change
@@ -0,0 +1,14 @@
[
{"pid": 0, "tid": 0, "ph": "B", "name": "anonymous", "ts": 0},
{"pid": 0, "tid": 0, "ph": "B", "name": "anonymous", "ts": 1, "args": { "parent": 1 }},
{"pid": 0, "tid": 0, "ph": "B", "name": "function1", "ts": 1, "args": { "parent": 2 }},
{"pid": 0, "tid": 0, "ph": "B", "name": "anonymous", "ts": 1, "args": { "parent": 3 }},
{"pid": 0, "tid": 0, "ph": "E", "name": "anonymous", "ts": 3, "args": { "parent": 3 }},
{"pid": 0, "tid": 0, "ph": "E", "name": "function1", "ts": 3, "args": { "parent": 2 }},
{"pid": 0, "tid": 0, "ph": "E", "name": "anonymous", "ts": 3, "args": { "parent": 1 }},
{"pid": 0, "tid": 0, "ph": "B", "name": "anonymous", "ts": 3, "args": { "parent": 1 }},
{"pid": 0, "tid": 0, "ph": "B", "name": "anonymous", "ts": 3, "args": { "parent": 8 }},
{"pid": 0, "tid": 0, "ph": "E", "name": "anonymous", "ts": 5, "args": { "parent": 8 }},
{"pid": 0, "tid": 0, "ph": "E", "name": "anonymous", "ts": 5, "args": { "parent": 1 }},
{"pid": 0, "tid": 0, "ph": "E", "name": "anonymous", "ts": 5}
]
62 changes: 62 additions & 0 deletions src/import/__snapshots__/trace-event.test.ts.snap
Original file line number Diff line number Diff line change
Expand Up @@ -172,6 +172,68 @@ exports[`importTraceEvents bad E events: indexToView 1`] = `0`;

exports[`importTraceEvents bad E events: profileGroup.name 1`] = `"too-many-end-events.json"`;

exports[`importTraceEvents different number of start and end calls to same function at same timestamp 1`] = `
Object {
"frames": Array [
Frame {
"col": undefined,
"file": undefined,
"key": "anonymous",
"line": undefined,
"name": "anonymous",
"selfWeight": 1,
"totalWeight": 5,
},
Frame {
"col": undefined,
"file": undefined,
"key": "anonymous {\\"parent\\":1}",
"line": undefined,
"name": "anonymous {\\"parent\\":1}",
"selfWeight": 0,
"totalWeight": 4,
},
Frame {
"col": undefined,
"file": undefined,
"key": "function1 {\\"parent\\":2}",
"line": undefined,
"name": "function1 {\\"parent\\":2}",
"selfWeight": 0,
"totalWeight": 2,
},
Frame {
"col": undefined,
"file": undefined,
"key": "anonymous {\\"parent\\":3}",
"line": undefined,
"name": "anonymous {\\"parent\\":3}",
"selfWeight": 2,
"totalWeight": 2,
},
Frame {
"col": undefined,
"file": undefined,
"key": "anonymous {\\"parent\\":8}",
"line": undefined,
"name": "anonymous {\\"parent\\":8}",
"selfWeight": 2,
"totalWeight": 2,
},
],
"name": "pid 0, tid 0",
"stacks": Array [
"anonymous 1.00µs",
"anonymous;anonymous {\\"parent\\":1};function1 {\\"parent\\":2};anonymous {\\"parent\\":3} 2.00µs",
"anonymous;anonymous {\\"parent\\":1};anonymous {\\"parent\\":8} 2.00µs",
],
}
`;

exports[`importTraceEvents different number of start and end calls to same function at same timestamp: indexToView 1`] = `0`;

exports[`importTraceEvents different number of start and end calls to same function at same timestamp: profileGroup.name 1`] = `"simultaneous-anonymous-calls.json"`;

exports[`importTraceEvents end event with empty stack 1`] = `
Object {
"frames": Array [
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4 changes: 4 additions & 0 deletions src/import/trace-event.test.ts
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,10 @@ test('importTraceEvents bad E events', async () => {
await checkProfileSnapshot('./sample/profiles/trace-event/too-many-end-events.json')
})

test('importTraceEvents different number of start and end calls to same function at same timestamp', async () => {
await checkProfileSnapshot('./sample/profiles/trace-event/simultaneous-anonymous-calls.json')
})

test('importTraceEvents event re-ordering', async () => {
await checkProfileSnapshot('./sample/profiles/trace-event/must-retain-original-order.json')
})
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4 changes: 2 additions & 2 deletions src/import/trace-event.ts
Original file line number Diff line number Diff line change
Expand Up @@ -103,12 +103,12 @@ function selectQueueToTakeFromNext(
// If we got here, the 'B' event queue and the 'E' event queue have events at
// the front with equal timestamps.

// If the front of the 'E' queue matches the front of the 'B' queue by name,
// If the front of the 'E' queue matches the front of the 'B' queue by key,
// then it means we have a zero duration event. Process the 'B' queue first
// to ensure it opens before we try to close it.
//
// Otherwise, process the 'E' queue first.
return bFront.name === eFront.name ? 'B' : 'E'
return frameInfoForEvent(bFront).key === frameInfoForEvent(eFront).key ? 'B' : 'E'
}

function convertToEventQueues(events: ImportableTraceEvent[]): [BTraceEvent[], ETraceEvent[]] {
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