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ma...@google.com
1. Have you saw crash in real device or only in simulators?
2. Do you use dynamic feature for language ID?
ma...@google.com
Tested on Android 12 Emulator with custom executor, but cannot repro this issue.
ma...@gmail.com
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Second crash in the description is from a real device. Experienced it myself on two different Xiaomi phones, plus lots of crashes from users in the Google Play console.
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Dynamic features are not used in the application.
As a wild guess, I have downgraded build tools from 31.0.0 to 30.0.3, compileSdk from 31 to 30, and moved all work with Language ID to the service in a separate process (just to be sure that crash can kill secondary process instead of main). This combination is in beta for 2 days by now and I don't see any SIGSEGV crashes.
an...@google.com
Hmm, I feel the crash might be something related to separate/secondary process.
I also changed compileSdk and targetSDK to 31 but still cannot repro this issue.
ma...@gmail.com
On the contrary, there was no separate process before, when crashes started.
In the new build (with the aforementioned changes) I can see SIGSEGV crash, but only one instead of dozens and it has a bit different backtrace:
signal 11 (SIGSEGV), code 1 (SEGV_MAPERR)
liblanguage_id_jni.so (offset 0x11e000)
backtrace:
#00 pc 000000000003c7c0 /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
#00 pc 000000000003b960 /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
#00 pc 000000000003bb48 /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
#00 pc 000000000003bafc /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
#00 pc 0000000000036c98 /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
#00 pc 0000000000032714 /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
#00 pc 0000000000031cac /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
#00 pc 0000000000057438 /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/oat/arm64/base.odex (offset 0x57000)
ap...@google.com
FYI, ML Kit launched a new language ID SDK in the latest release, which uses a new language ID model.
Could you try the new SDK version(17.0.0) to check if you can still repro this native crash? Thanks!
Description
Issue
Currently, each child of the
LazyColumnForcomposable is implicitlykeycontaining the index of the item. Because of this if the order of the items is changed, the children, that got reordered, are needlessly recomposed (this is because the value of the keys have changed). In the extreme case, when an item is inserted at the beginning of the list, the entire subtree ofLazyColumnForget recomposed.Motivation
Oftentimes the items that are rendered in these lazy composables, have unique ids. Thus, it would be useful if there was a way of specifying the id of the item as a key.
Possible solution
I have thought of several solutions:
Option 1 would function similarly to how it does in React. Not specifying a key could be a warning.
Personally, I like option 2 better. I am not sure how this parameter could be named, but its type could simply be:
(Int, T) -> AnyIntis the index of the itemTis the type of the itemThe default value for the parameter could be defined as
{ i, _ -> i }. This way, when the parameter is not specifiedLazyColumnFor(orLazyRowFor) would function exactly as it does now.Also maybe a better type signature could be
T.(Int) -> Any, this way if the user wants to use an id of the item as a key, the function would be as simple as{ id }instead of{ _, item -> item.id }.