1402541 - StrictMode violations while updating top site titles in Activity Stream

Status: RESOLVED INCOMPLETE

(Firefox for Android Graveyard :: Activity Stream, defect, P3)

Description

[:Grisha Kruglov]

Seems like use of the PRNG is triggering StrictMode violations. This seems to happen very often while we're syncing history in the background, for example.

D/StrictMode(11819): StrictMode policy violation; ~duration=275 ms: android.os.StrictMode$StrictModeDiskReadViolation: policy=543 violation=2
D/StrictMode(11819): 	at android.os.StrictMode$AndroidBlockGuardPolicy.onReadFromDisk(StrictMode.java:1107)
D/StrictMode(11819): 	at libcore.io.BlockGuardOs.read(BlockGuardOs.java:148)
D/StrictMode(11819): 	at libcore.io.IoBridge.read(IoBridge.java:432)
D/StrictMode(11819): 	at java.io.FileInputStream.read(FileInputStream.java:179)
D/StrictMode(11819): 	at libcore.io.Streams.readFully(Streams.java:81)
D/StrictMode(11819): 	at java.io.DataInputStream.readFully(DataInputStream.java:120)
D/StrictMode(11819): 	at java.io.DataInputStream.readFully(DataInputStream.java:116)
D/StrictMode(11819): 	at org.mozilla.gecko.util.PRNGFixes$LinuxPRNGSecureRandom.engineNextBytes(PRNGFixes.java:243)
D/StrictMode(11819): 	at java.security.SecureRandom.nextBytes(SecureRandom.java:273)
D/StrictMode(11819): 	at java.util.UUID.randomUUID(UUID.java:130)
D/StrictMode(11819): 	at org.mozilla.gecko.activitystream.homepanel.topsites.TopSitesCard$UpdateCardTitleAsyncTask.<init>(TopSitesCard.java:190)
D/StrictMode(11819): 	at org.mozilla.gecko.activitystream.homepanel.topsites.TopSitesCard.setTopSiteTitle(TopSitesCard.java:155)
D/StrictMode(11819): 	at org.mozilla.gecko.activitystream.homepanel.topsites.TopSitesCard.bind(TopSitesCard.java:118)
D/StrictMode(11819): 	at org.mozilla.gecko.activitystream.homepanel.topsites.TopSitesPageAdapter.onBindViewHolder(TopSitesPageAdapter.java:90)
D/StrictMode(11819): 	at org.mozilla.gecko.activitystream.homepanel.topsites.TopSitesPageAdapter.onBindViewHolder(TopSitesPageAdapter.java:29)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5471)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:5504)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4741)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4617)
D/StrictMode(11819): 	at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:1994)
D/StrictMode(11819): 	at android.support.v7.widget.GridLayoutManager.layoutChunk(GridLayoutManager.java:528)
D/StrictMode(11819): 	at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1353)
D/StrictMode(11819): 	at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:574)
D/StrictMode(11819): 	at android.support.v7.widget.GridLayoutManager.onLayoutChildren(GridLayoutManager.java:170)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3028)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2906)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3283)
D/StrictMode(11819): 	at android.view.View.layout(View.java:13754)
D/StrictMode(11819): 	at android.view.ViewGroup.layout(ViewGroup.java:4364)
D/StrictMode(11819): 	at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1695)
D/StrictMode(11819): 	at android.view.View.layout(View.java:13754)
D/StrictMode(11819): 	at android.view.ViewGroup.layout(ViewGroup.java:4364)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView$LayoutManager.layoutDecorated(RecyclerView.java:7650)
D/StrictMode(11819): 	at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1448)
D/StrictMode(11819): 	at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1353)
D/StrictMode(11819): 	at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:574)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3028)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2906)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView.consumePendingUpdateOperations(RecyclerView.java:1472)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView.access$400(RecyclerView.java:147)
D/StrictMode(11819): 	at android.support.v7.widget.RecyclerView$1.run(RecyclerView.java:294)
D/StrictMode(11819): 	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
D/StrictMode(11819): 	at android.view.Choreographer.doCallbacks(Choreographer.java:555)
D/StrictMode(11819): 	at android.view.Choreographer.doFrame(Choreographer.java:524)
D/StrictMode(11819): 	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
D/StrictMode(11819): 	at android.os.Handler.handleCallback(Handler.java:615)
D/StrictMode(11819): 	at android.os.Handler.dispatchMessage(Handler.java:92)
D/StrictMode(11819): 	at android.os.Looper.loop(Looper.java:137)
D/StrictMode(11819): 	at android.app.ActivityThread.main(ActivityThread.java:4745)
D/StrictMode(11819): 	at java.lang.reflect.Method.invokeNative(Native Method)
D/StrictMode(11819): 	at java.lang.reflect.Method.invoke

Comment 1

[Michael Comella (:mcomella) [NI reported issues only: ex-Mozilla]]

UUID hits the disk? Curious. I'll take a look tomorrow.

Comment 2

[Michael Comella (:mcomella) [NI reported issues only: ex-Mozilla]]

It looks like we are reading from /dev/urandom [1]. Since this is a special file and urandom is non-blocking, afaik we're not touching the disk or have a similar perf overhead so it should be fine to surround this read with a StrictMode override.

Since StrictMode is strictly (ha!) for developer builds, this won't need an uplift.

[1]: http://searchfox.org/mozilla-central/rev/f6dc0e40b51a37c34e1683865395e72e7fca592c/mobile/android/services/src/main/java/org/mozilla/gecko/util/PRNGFixes.java#267

Comment 3

[Michael Comella (:mcomella) [NI reported issues only: ex-Mozilla]]

That being said, I'm unable to reproduce this. Grisha, do you know how you can reproduce this warning? I wonder if, on occasion, /dev/urandom is actually pulling entropy from the disk. That being said, it's non-blocking so I'm not sure we'd see any performance hits.

Comment 4

[Michael Comella (:mcomella) [NI reported issues only: ex-Mozilla]]

I'm only working on P1 AS issues atm so unassigning.

Comment 5

[:Grisha Kruglov]

I most likely saw this in emulator (I imagine /dev/urandom might behave quite differently than on an actual device) logs while working on something unrelated. I recall it was showing up pretty consistently. Sorry, don't have more details than that.

Comment 6

[Michael Comella (:mcomella) [NI reported issues only: ex-Mozilla]]

fwiw, I think I was trying to repro on device.

Comment 7

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