How do I clear caches (app, individual apps, Dalvik, ART if possible) via ADB? Using apps, recovery, or doing it through Settings are not options for me. Also, my phone is not rooted.

I was looking into a couple of Android tombstones files of an old Samsung phone running Marshmallow. Found a crash in every single one with the same culprit, dex2oat. From my limited understanding it is a Compiler that takes arguments from Android Runtime and convert dex files to Android optimised ones in oat format. I ran into the same issue even if I factory reset or freezing a lot of apps. I have this device rooted and decided to take a risky step. I backed up first and deleted dex2oat from /system/bin. Then I rebooted system with risk of bricking it. So far it is working fine. Due my lack of understanding I don't know how crucial is this dex2oat to system stability and I want to know what is the impact on it.

I have compiled dex2oat on linux-x86_64 for linux-x86. I can run it just like a normal application. The background is, I have a tool which can generate dex codes and I want to perform some basic checks that dex2oat does. So it is not important for me to get an actual runnable file. I do get the following output: dex2oat I 4183 4183 art/dex2oat/dex2oat.cc:1239] out/host/linux-x86/bin/dex2oat --runtime-arg -Xms64m --runtime-arg -Xmx64m --image-classes=frameworks/base/preloaded-classes --dex-file=/home/marc/Apps/Example1.apk --dex-location=bla.apk --oat-file=bla.oat --image=out.art --base=0x60000000 --instruction-set=x86 --instruction-set-features=default --runtime-arg -Xrelocate --host --android-root=out/host/linux-x86 --include-patch-information dex2oat E 4183 4183 art/runtime/runtime.cc:1108] Failed to return pre-allocated NoClassDefFoundError dex2oat F 4183 4183 art/runtime/thread.h:330] Check failed: new_exception != NULL dex2oat F 4183 4183 art/runtime/runtime.cc:284] Runtime aborting... dex2oat F 4183 4183 art/runtime/runtime.cc:284] Aborting thread: dex2oat F 4183 4183 art/runtime/runtime.cc:284] "main" prio=5 tid=1 Runnable (still starting up) dex2oat F 4183 4183 art/runtime/runtime.cc:284] | group="" sCount=0 dsCount=0 obj=(nil) self=0xf89a8e78 dex2oat F 4183 4183 art/runtime/runtime.cc:284] | sysTid=4183 nice=0 cgrp=user/1000.user/c2.session sched=0/0 handle=0xf6b76700 dex2oat F 4183 4183 art/runtime/runtime.cc:284] | state=R schedstat=( 17496280 53788 15 ) utm=1 stm=0 core=7 HZ=100 dex2oat F 4183 4183 art/runtime/runtime.cc:284] | stack=0xff0f1000-0xff0f3000 stackSize=7MB dex2oat F 4183 4183 art/runtime/runtime.cc:284] | held mutexes= "abort lock" "mutator lock"(shared held) Does anyone know what causes this error or did I supply the wrong arguments? I have added a cout statement in the code and it turns out that the class being searched for is Ljava/lang/Object;

The Lollipop update for AT&T LG G2 has pretty much destroyed my phone. I'm hoping clearing out every sort of cache might help. But I can't clear the caches the usual ways because (1) the Settings app always crashes when I am in the section where you clear app caches, as does any other app that is made for clearing caches, and (2) restarting into recovery doesn't provide options for clearing any caches. Plus, I'm curious about how to clear ART caches since I haven't found much information about them online. By the way, my phone is not rooted. So, the question is: How do I clear (1) app caches, (2) individual apps' caches, (3) Dalvik cache (if applicable anymore), and (4) ART cache under these restraints? I'm thinking I'll have to do something via adb, but I can't find info anywhere on how to do it. Thanks for any help you can provide!

I want to get the answers for the following queries: If I remove the app's odex file from the data/app/packagename/oat/arm64/base.odex , then does it mean that the app will run in the same way as it would have run in the Dalvik Virtual Machine (DVM) environment? Is Android Runtime DVM compatible? The reasons for asking this is I removed the app's odex file as described above and still I am able to run the app? Thanks a lot for your response.

Every Android application runs in a virtual machine. We know that Dalvik virtual machine \was the one that is used by Android. Next, they changed to ART (Android Runtime machine). Just correct me if I am wrong. Android 11 uses which virtual machine, Dalvik or ART?

I am trying to measure the time it takes to launch an App (cold startup) on Android. As the official documentation states, that the startup time will be displayed in the logcat:

ActivityManager: Displayed com.android.myexample/.StartupTiming: +3s534ms

The problem I currently have is that startup times vary greatly. I tested on three different days à 10 times. These are the results: - Day 1: - ~1100ms - Day 2: - ~900ms - Day 3: - ~350ms **My Question:** Does Android perform any optimization in the background for the App startup? Is there a way to reliably measure the startup time? I haven't done any changes to the App in these three days. Before the testing, the phone was at 100% battery capacity and was cold to the touch (to eliminate the possibility of thermal throttling). On day 2 and 3, I deleted the App, restarted the phone, reinstalled the App and tested again with the same results (day 2 was again ~900ms and on day 3: ~350ms). Maybe it has something to do with the ART (Android RunTime) using JIT (just-in-time) and AOT (ahead-of-time) compiler?! The app does not perform any network actions. At startup it only ready about 100 pictures from the internal storage and displays them in a Recycler View . I used a Google Pixel 2 running on Android 9. The app is written in Java.

I am a begginer in android and I want to develop an application which show a list of jar files to user and user can choose one of them and run it. Is it possible to run a jar file in an android application? (not as a library) if yes, how does it run? I mean, a jar file needs to run in JVM but an apk file runs in ART.

I have some art apps that only let you choose images from built-in galleries that display images chronologically. I have hundreds/thousands of images on my tablet (organized in folders), especially older ones I want to edit. It'll take forever to find within these apps galleries. One thing I noticed is that downloaded images appear at the top of these galleries. So I thought a workaround would be to COPY & PASTE the older image (via file managers) - so that it appears as new. But for some reason, Android will only treat downloaded images as new - not copied pasted images. Is there any trick to make this work? Because I'm forced to edit on Android - but it's so annoying to do simple things as in Windows.

The Android OS was using interp years ago, then they added Just-In-Time (JIT). However, since Android 5.0, they replaced JIT with Ahead-Of-Time (AOT) compilation which increased app installation time quite a bit, so I wasn't following its development. Then in Android 7.0, it seemed JIT had come back, but I cannot understand how JIT and AOT would be able to work together. Does this mean they finally ditched AOT and switched back to JIT? (I have read some articles but since I have detached myself for a while from the follow ups to development, I am not sure if I still understand everything correctly.

The reason Andy Rubin chose Java for Android Dev is not publicly known, only speculations, but it seems to me that the combination of being able to run a Java app everywhere (because the earliest version of Android used JVM) and the huge popularity of Java made it a sexy choice. Android Run Time (ART) is the second Iteration of Java Virtual Machine after Dalvik Virtual Machine. Obviously, Write once, run everywhere, which Java promised is not True on Android due to the highly modified JVM == ART. My question is this: since apps written for Android are not portable (i.e the apps are platform dependent), why still hold on to it? Why convert to bytecode before running it on ART and not just compile to native code directly without the need for an interpreter (ART) like in the case of Apple's Swift? Why tolerate the performance loss just for ART? an iPhone App on 4gb ram will perform better than the same app on Android with 6gb of RAM due to the absence of the possibly unnecessary ART layer. In 2019 and beyond why is the ART necessary?

So I've been successfully using programs to change album arts for my cellphone for the past 3 years and something bothers me about the way that the actual app on the Samsung reverts this changes under the following circumstances: If I've put a music from a specific album, for example, *Abbey Road*, with a specific album art, onto the memory card of my cell phone, and then I decide that I want to change the art, and so I delete this album from the memory card and just put the same one or a different one, it doesn't matter with a different art but with the same album name, *Abbey Road*, the app will automatically show the album art that was the first time *Abbey Road* was in the cellphone. Are there any ways to fix it?

I know dalvik vm use dalvik bytecode. does ART use dalvik bytecode or something else ?

When switching custom ROMs (in ART), is it necessary to wipe the Dalvik Cache? Wiping the Cache is necessary, but should wiping Dalvik (which doesn't exist in Android Lollipop and afterward) be necessary? What impact will it cause if we wipe Dalvik (something not present)? In ART, what does the Dalvik cache contains? (is it an empty folder?)

I have recently bought a *MOTO E* and it's working cool. Then I have enabled *Developer options* and changed my runtime from *Dalvik* to *ART.* Afterwards I restarted my device. I got the message saying *Android is upgraging.* After completeing the process I got exceptions like unfortunately the process com.android.phone has stopped Please help me how to get out of this problem. I am getting that message for around 10 times and mobile restarting once again.

I activated the Android Runtime (ART) instead of Dalvik and after that my phone rebooted but it seems that it's stuck in a bootloop. Will the first bot after choosing ART take some extra time? How can I tell if it's stuck in a bootloop rather than just booting slowly? My device is an HTC Explorer running CM 11 beta 4 build.

May I first apologize for my english : non-native speaker, some erratic grammar might happen. *Si un francophone passe ici, ce sera bien plus facile pour moi ;)* I'm NOT skilled in android fix, so be patient and please forgive if i ask you more precision to understand what you say ! Some previous questions were on the same problem, but i did not succeed on performing the solution , or [doesn't dare other] for i did not understood it[2] I own a Motorola E, 1st Gen, since feb.2015. - Legal warranty void six weeks ago... - No root, no boot, no custom rom. - Kitkat 4.4 (or maybe 4.4.2, can't remember) In the last weeks, a trouble appeared : i could neither listen or speak to my interlocutor, but by pluging in a wire headset or putting the phone on speaker (the one you shan't but still use while driving). The normal "phone pressed against the ear" did not worked anymore. The first times, a simple reboot was all it needed to go back to normal. Since a few days, reboot have no effect. After an extend search on the internet, i found a solution for the Moto G (2nd gen) that appeared to work perfectly. **Going from Dalvik to ART, which i did friday (march 10th).** - 1st reboot, upgrading 150 apps => Several error messages stated that XXX app has stopped. Then "com.android.systemui" has stop, and i cannot validate the prompt : once I click "OK", it comes back before i could even read the next error message. I can't do anything with the phone. ==> Reboot by long hold on POWER - 2nd reboot, upgrading 39 apps => Several messages again, com.android.systemui again ==> Reboot by long hold on POWER - 3rd reboot, the same - 4th reboot, upgrading 29 apps - 5th reboot, the same - 6th reboot, the same - 7th reboot, upgrading 28 apps. - xxth reboot, the same ... Today, After a day's rest and no manipulation, count on upgrading application dropped to 27. By repetivly pressing "ok" and 'report" when avalaible, i somehow managed to get as far as parameters menu. Can't scoll in the microscopic time given between two prompt. However, -> The phone seems to receive calls (it ringed about an hour ago) but not to show the screen (caller ID, accepting the call, etc.) -> Afterward, the led flashed again. The android buttons (back, home, active application list) doesn't show up. And here i'm stuck ! What i tried : - A coffee. Did nothing to the phone, but improved my optimism - Shut it down, let it rest, power it - Fully charge it - Make it reboot by a long hold on power button while it was "upgrading 28 apps". - Pluging it to the computer, to see if it did anything (it didn't) - Making loud assumption on the engineer's mother honour and weight. - Go to recovery mode, and let it boot (if i understand well, it's just a normal boot for long inactivity) - Go to recovery mode, and wipe cache partition - Tried to do this : https://android.stackexchange.com/questions/81411/moto-e-is-not-switching-on-after-changing-runtime-to-art?noredirect=1&lq=1 => I made it up to the 5th step ; but 6th don't work "Not recognized as a command or program" I tried the shell on E:\Programmes\AndroidSDK and E:\AndroidSDK\platform-tools. Neither works. What should i do now ? Thanks a lot, Kaldui.

my lgl16c was behaving very poorly to the point of which I went to the developer options and swapped the runtime from dalvik to art on android 4.4.2...and now it got stuck "optimizing app 1 of 1" after countless reboots...it's been stuck on this for days without anything changing, and there is no answer on google...is this a special case or what?

I am using a Motorola Moto E with Android Kitkat and I am unable to move applications to my SD Card even for Apps that support moving to SD Card. I am using ART Runtime (Developer) instead of Dalvik.

I've asked this question before. After checking out logcat, it seems that the OS is looking for the odex files. I've checked the odex files of other system apps on my ROM, and it turns out they're ELF files. For the ones asking, these are bytecode files produced by ART (dex2oat, I'm not sure). I've observed that these files get generated on boot (Android is Starting: Optimizing App XXX of XXX). For some reason, my phone's ROM doesn't run the optimization part. Instead, the oat files are already pre-generated and stored on the system partition. As a result, the apps that I want to pre-install don't get the oat treatment and crashes when I launch them (ClassNotFoundException since the oat files don't exist.) **How do I manually run the app optimizer?** If it comes down to using the command line, how do I use dex2oat **without root access/on a Linux PC**?