Do not make the parent process visible by default when something is s…

…elected in the tab selector (#5198)

src/actions/receive-profile.js

@@ -315,9 +315,10 @@ export function finalizeFullProfileView(
     const hasUrlInfo = maybeSelectedThreadIndexes !== null;
 
     const tabToThreadIndexesMap = getTabToThreadIndexesMap(getState());
+    const tabFilter = hasUrlInfo ? getTabFilter(getState()) : null;
     const globalTracks = computeGlobalTracks(
       profile,
-      hasUrlInfo ? getTabFilter(getState()) : null,
+      tabFilter,
       tabToThreadIndexesMap
     );
     const localTracksByPid = computeLocalTracksByPid(
@@ -370,10 +371,13 @@ export function finalizeFullProfileView(
       // This is the case for the initial profile load.
       // We also get here if the URL info was ignored, for example if
       // respecting it would have caused all threads to become hidden.
+      const includeParentProcessThreads = tabFilter === null;
       hiddenTracks = computeDefaultHiddenTracks(
         tracksWithOrder,
         profile,
-        getThreadActivityScores(getState())
+        getThreadActivityScores(getState()),
+        // Only include the parent process if there is no tab filter applied.
+        includeParentProcessThreads
       );
     }
 
@@ -1877,10 +1881,13 @@ export function changeTabFilter(tabID: TabID | null): ThunkAction<void> {
       // This is the case for the initial profile load.
       // We also get here if the URL info was ignored, for example if
       // respecting it would have caused all threads to become hidden.
+      const includeParentProcessThreads = tabID === null;
       hiddenTracks = computeDefaultHiddenTracks(
         tracksWithOrder,
         profile,
-        getThreadActivityScores(getState())
+        getThreadActivityScores(getState()),
+        // Only include the parent process if there is no tab filter applied.
+        includeParentProcessThreads
       );
     }
 

src/profile-logic/tracks.js

@@ -818,14 +818,16 @@ export function tryInitializeHiddenTracksFromUrl(
 export function computeDefaultHiddenTracks(
   tracksWithOrder: TracksWithOrder,
   profile: Profile,
-  threadActivityScores: Array<ThreadActivityScore>
+  threadActivityScores: Array<ThreadActivityScore>,
+  includeParentProcessThreads: boolean
 ): HiddenTracks {
   return _computeHiddenTracksForVisibleThreads(
     profile,
     computeDefaultVisibleThreads(
       profile,
       tracksWithOrder,
-      threadActivityScores
+      threadActivityScores,
+      includeParentProcessThreads
     ),
     tracksWithOrder
   );
@@ -1054,7 +1056,8 @@ const IDLE_THRESHOLD_FRACTION = 0.05;
 export function computeDefaultVisibleThreads(
   profile: Profile,
   tracksWithOrder: TracksWithOrder,
-  threadActivityScores: Array<ThreadActivityScore>
+  threadActivityScores: Array<ThreadActivityScore>,
+  includeParentProcessThreads: boolean
 ): Set<ThreadIndex> {
   const threads = profile.threads;
   if (threads.length === 0) {
@@ -1099,11 +1102,33 @@ export function computeDefaultVisibleThreads(
   // to the thread with the most "sampleScore" activity.
   // We keep all threads whose sampleScore is at least 5% of the highest
   // sampleScore, and also any threads which are otherwise essential.
+  // We also remove the parent process if that was requested. That's why we
+  // have to ignore their scores while computing the highest score.
   const highestSampleScore = Math.max(
-    ...scores.map(({ score }) => score.sampleScore)
+    ...scores.map(({ score }) => {
+      if (score.isInParentProcess && !includeParentProcessThreads) {
+        // Do not account for the parent process threads if we do not want to
+        // include them for the visible threads by default.
+        return 0;
+      }
+      return score.sampleScore;
+    })
   );
   const thresholdSampleScore = highestSampleScore * IDLE_THRESHOLD_FRACTION;
-  const finalList = top15.filter(({ score }) => {
+  const tryToHideList = [];
+  let finalList = top15.filter((activityScore) => {
+    const { score } = activityScore;
+    if (score.isInParentProcess && !includeParentProcessThreads) {
+      // We try to hide this thread that belongs to the parent process.
+      // But when we hide all the threads we might encounter that all the
+      // threads are hidden now. For cases like this we would like to keep a
+      // tryToHideList, so we can add them back if the track is completely empty.
+      if (score.sampleScore >= thresholdSampleScore) {
+        tryToHideList.push(activityScore);
+      }
+      return false;
+    }
+
     if (score.isEssentialFirefoxThread) {
       return true; // keep.
     }
@@ -1113,13 +1138,22 @@ export function computeDefaultVisibleThreads(
     return score.sampleScore >= thresholdSampleScore;
   });
 
+  if (finalList.length === 0) {
+    // We tried to hide the main process threads, but this resulted us to have
+    // an empty list. Put them back.
+    finalList = tryToHideList;
+  }
+
   return new Set(finalList.map(({ threadIndex }) => threadIndex));
 }
 
 export type ThreadActivityScore = {|
   // Whether this thread is one of the essential threads that
   // should always be kept (unless there's too many of them).
   isEssentialFirefoxThread: boolean,
+  // Whether this thread belongs to the parent process. We do not want to show
+  // them by default if the tab selector is used.
+  isInParentProcess: boolean,
   // Whether this thread should be kept even if it looks very idle,
   // as long as there's a single sample with non-zero activity.
   isInterestingEvenWithMinimalActivity: boolean,
@@ -1146,6 +1180,7 @@ export function computeThreadActivityScore(
   maxCpuDeltaPerInterval: number | null
 ): ThreadActivityScore {
   const isEssentialFirefoxThread = _isEssentialFirefoxThread(thread);
+  const isInParentProcess = thread.processType === 'default';
   const isInterestingEvenWithMinimalActivity =
     _isFirefoxMediaThreadWhichIsUsuallyIdle(thread);
   const sampleScore = _computeThreadSampleScore(
@@ -1158,6 +1193,7 @@ export function computeThreadActivityScore(
     : sampleScore;
   return {
     isEssentialFirefoxThread,
+    isInParentProcess,
     isInterestingEvenWithMinimalActivity,
     sampleScore,
     boostedSampleScore,

src/test/components/TabSelectorMenu.test.js

@@ -134,7 +134,7 @@ describe('app/TabSelectorMenu', () => {
     // Note that the first thread will be visible too, because it's the parent
     // process which we always include.
     expect(getHumanReadableTracks(getState())).toEqual([
-      'show [thread GeckoMain default]',
+      'hide [thread GeckoMain default]',
       'show [thread GeckoMain tab] SELECTED',
       '  - show [thread DOM Worker]',
       '  - show [thread Style]',

src/test/components/TrackContextMenu.test.js

@@ -515,8 +515,8 @@ describe('timeline/TrackContextMenu', function () {
       expect(getHumanReadableTracks(getState())).toEqual([
         'show [thread GeckoMain default] SELECTED',
         'hide [thread GeckoMain tab]',
-        '  - show [thread DOM Worker]',
-        '  - show [thread Style]',
+        '  - hide [thread DOM Worker]',
+        '  - hide [thread Style]',
       ]);
     });
 

src/test/components/__snapshots__/GlobalTrack.test.js.snap

@@ -142,7 +142,7 @@ Process: \\"tab\\" (222)"
           class="react-contextmenu-wrapper timelineTrackLabel timelineTrackLocalLabel timelineTrackLocalGrippy"
           title="DOM Worker
 Thread: \\"DOM Worker\\" (33)
-Process: \\"default\\" (222)"
+Process: \\"tab\\" (222)"
         >
           <button
             class="timelineTrackNameButton"
@@ -233,7 +233,7 @@ Process: \\"default\\" (222)"
           class="react-contextmenu-wrapper timelineTrackLabel timelineTrackLocalLabel timelineTrackLocalGrippy"
           title="Style
 Thread: \\"Style\\" (44)
-Process: \\"default\\" (222)"
+Process: \\"tab\\" (222)"
         >
           <button
             class="timelineTrackNameButton"

src/test/components/__snapshots__/LocalTrack.test.js.snap

@@ -151,7 +151,7 @@ exports[`timeline/LocalTrack with a thread track matches the snapshot of a local
       class="react-contextmenu-wrapper timelineTrackLabel timelineTrackLocalLabel timelineTrackLocalGrippy"
       title="DOM Worker
 Thread: \\"DOM Worker\\" (33)
-Process: \\"default\\" (222)"
+Process: \\"tab\\" (222)"
     >
       <button
         class="timelineTrackNameButton"

src/test/fixtures/profiles/tracks.js

@@ -184,9 +184,11 @@ export function getProfileWithNiceTracks(): Profile {
 
   thread3.name = 'DOM Worker';
   thread3.pid = '222';
+  thread3.processType = 'tab';
   thread3.tid = 33;
 
   thread4.name = 'Style';
+  thread4.processType = 'tab';
   thread4.pid = '222';
   thread4.tid = 44;
   return profile;