[Mono.Android] avoid System.Reflection.Emit usage for common calls #6657

`dotnet new android` calls `JNINativeWrapper.CreateDelegate()` twice, while `dotnet new maui` ends up calling it 58 times during startup. This code path calls System.Reflection.Emit to generate a `System.Delegate` at runtime to be invoked. After some thought, it is possible to "hard code" common delegate types and avoid SRE: private static Delegate CreateBuiltInDelegate (Delegate dlg, Type delegateType) { switch (delegateType.Name) { case nameof (_JniMarshal_PP_V): { _JniMarshal_PP_V callback = (_JniMarshal_PP_V) Delegate.CreateDelegate (typeof (_JniMarshal_PP_V), dlg.Target, dlg.Method); _JniMarshal_PP_V result = (jnienv, klazz) => { JNIEnv.WaitForBridgeProcessing (); try { callback (jnienv, klazz); } catch (Exception e) { bool filter = Debugger.IsAttached || !JNIEnv.PropagateExceptions; if (filter && JNIEnv.mono_unhandled_exception != null) { JNIEnv.mono_unhandled_exception (e); } AndroidEnvironment.UnhandledException (e); if (filter) throw; } }; return result; } // etc. `dotnet new maui`'s startup can be covered if we hardcoded: _JniMarshal_PP_V _JniMarshal_PPI_V _JniMarshal_PPL_L _JniMarshal_PPL_V _JniMarshal_PPL_Z _JniMarshal_PPII_V _JniMarshal_PPLI_V _JniMarshal_PPLL_V _JniMarshal_PPLL_Z _JniMarshal_PPIIL_V _JniMarshal_PPILL_V _JniMarshal_PPLIL_Z _JniMarshal_PPLLL_L _JniMarshal_PPLLL_Z _JniMarshal_PPIIII_V _JniMarshal_PPLLLL_V _JniMarshal_PPLIIII_V _JniMarshal_PPZIIII_V _JniMarshal_PPLIIIIIIII_V Then System.Reflection.Emit isn't used at all. Other changes: * `TypeManager.GetActivateHandler()` needs to use `_JniMarshal_PPLLLL_V` instead of `Action<IntPtr, IntPtr, IntPtr, IntPtr, IntPtr, IntPtr>`, so the fast path can be used. * Added a log message for `debug.mono.log assembly`: Falling back to System.Reflection.Emit for delegate type '{delegateType}': {dlg.Method} * I was also able to remove `mono_unhandled_exception_method` from `JNINativeWrapper` as we already has this value in `JNIEnv`. ~~ Results ~~ Testing `dotnet new maui` with version: msbuild Xamarin.Android.sln -t:InstallMaui -bl -p:MauiVersion=6.0.200-preview.13.2536 A `Release` build on a Pixel 5 device, total startup time: Before: 01-21 11:58:39.030 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s83ms 01-21 11:58:41.297 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s127ms 01-21 11:58:43.429 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s68ms 01-21 11:58:45.702 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s113ms 01-21 11:58:47.906 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s125ms 01-21 11:58:50.082 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s92ms 01-21 11:58:52.297 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s133ms 01-21 11:58:54.465 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s102ms 01-21 11:58:56.673 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s126ms 01-21 11:58:58.848 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s94ms Average(ms): 1106.3 Std Err(ms): 6.91865433287267 Std Dev(ms): 21.8787060352704 After: 01-21 12:00:33.312 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s61ms 01-21 12:00:35.513 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s79ms 01-21 12:00:37.724 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s85ms 01-21 12:00:39.928 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s83ms 01-21 12:00:42.117 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s60ms 01-21 12:00:44.337 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s59ms 01-21 12:00:46.612 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s106ms 01-21 12:00:48.782 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s47ms 01-21 12:00:51.018 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s75ms 01-21 12:00:53.200 1867 2226 I ActivityTaskManager: Displayed com.companyname.bar/crc6474063b540de74d1e.MainActivity: +1s53ms Average(ms): 1070.8 Std Err(ms): 5.68584988272544 Std Dev(ms): 17.9802360632137 This might save ~35ms on average? If I time the message for one call, such as: 01-21 12:14:01.132 29819 29819 I monodroid-timing: Runtime.register: registering type `Microsoft.Maui.MauiApplication, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null` 01-21 12:14:01.150 29819 29819 I monodroid-timing: Runtime.register: end time; elapsed: 0s:17::794845 https://github.com/dotnet/maui/blob/bfba62ed796d3416c4fcaa7cfbea86dc8d5e04c2/src/Compatibility/ControlGallery/src/Android/MainApplication.cs The result is: Before: 01-21 13:21:22.261 9359 9359 I monodroid-timing: Runtime.register: end time; elapsed: 0s:23::868440 01-21 13:21:24.446 9424 9424 I monodroid-timing: Runtime.register: end time; elapsed: 0s:23::875159 01-21 13:21:26.639 9497 9497 I monodroid-timing: Runtime.register: end time; elapsed: 0s:23::829742 01-21 13:21:28.842 9570 9570 I monodroid-timing: Runtime.register: end time; elapsed: 0s:24::165211 01-21 13:21:31.021 9631 9631 I monodroid-timing: Runtime.register: end time; elapsed: 0s:23::976721 01-21 13:21:33.221 9697 9697 I monodroid-timing: Runtime.register: end time; elapsed: 0s:24::237034 01-21 13:21:35.418 9759 9759 I monodroid-timing: Runtime.register: end time; elapsed: 0s:23::857346 01-21 13:21:37.585 9821 9821 I monodroid-timing: Runtime.register: end time; elapsed: 0s:23::872138 01-21 13:21:39.805 9884 9884 I monodroid-timing: Runtime.register: end time; elapsed: 0s:23::840107 01-21 13:21:42.014 9952 9952 I monodroid-timing: Runtime.register: end time; elapsed: 0s:23::723805 Average(ms): 23.9245703 Std Err(ms): 0.0502830551065224 Std Dev(ms): 0.159008981848371 After: 01-21 13:22:28.004 10226 10226 I monodroid-timing: Runtime.register: end time; elapsed: 0s:18::12345 01-21 13:22:30.261 10298 10298 I monodroid-timing: Runtime.register: end time; elapsed: 0s:18::338022 01-21 13:22:32.443 10362 10362 I monodroid-timing: Runtime.register: end time; elapsed: 0s:18::56251 01-21 13:22:34.664 10427 10427 I monodroid-timing: Runtime.register: end time; elapsed: 0s:17::997397 01-21 13:22:36.902 10497 10497 I monodroid-timing: Runtime.register: end time; elapsed: 0s:17::787554 01-21 13:22:39.117 10563 10563 I monodroid-timing: Runtime.register: end time; elapsed: 0s:17::801772 01-21 13:22:41.306 10630 10630 I monodroid-timing: Runtime.register: end time; elapsed: 0s:18::28752 01-21 13:22:43.552 10695 10695 I monodroid-timing: Runtime.register: end time; elapsed: 0s:18::75522 01-21 13:22:45.761 10759 10759 I monodroid-timing: Runtime.register: end time; elapsed: 0s:17::958075 01-21 13:22:47.978 10823 10823 I monodroid-timing: Runtime.register: end time; elapsed: 0s:18::961773 Average(ms): 18.1017463 Std Err(ms): 0.107071213504746 Std Dev(ms): 0.338588906513177 Saving ~5.8ms for this one call. `.apk` size difference for `dotnet new android`: > apkdiff -f before.apk after.apk Size difference in bytes ([*1] apk1 only, [*2] apk2 only): + 3,390 assemblies/assemblies.blob + 54 assemblies/assemblies.x86_64.blob - 4 assemblies/assemblies.arm64_v8a.blob - 15 assemblies/assemblies.x86.blob - 65 assemblies/assemblies.armeabi_v7a.blob Summary: + 3,360 Other entries 0.03% (of 10,526,432) + 0 Dalvik executables 0.00% (of 7,816,392) + 0 Shared libraries 0.00% (of 18,414,404) + 4,096 Package size difference 0.02% (of 21,006,128)

Co-authored-by: Jonathan Pryor <[email protected]>

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[Mono.Android] avoid System.Reflection.Emit usage for common calls #6657

[Mono.Android] avoid System.Reflection.Emit usage for common calls #6657

Commits on Jan 28, 2022