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Xamarin Source Quest
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$ whoami
Atsushi Eno
Android dev. @ Xamarin (Microsoft)
(ex.) Mono dev.
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What is this session for ?
◉ You get better understanding on Xamarin/Mono sources
and become able to
○ track Xamarin issues, or
○ understand how Xamarin frameworks work
◉ Xamarin got OSS-ed, but hard to read them
◉ I don't want to keep my knowledge on Xamarin things
only to myself
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You'd like to read sources
when....
◉ You're facing stack traces while debugging
◉ You're wondering how the framework works
◉ You're exploring new features
You'd like to check the sources
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Are Xamarin sources difficult?
◉ It is. Because...
○ there are many modules and module dependencies
○ sources gap between product versions
○ for some parts, complete build is impossible (!?)
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Available on github
◉ mono/mono
◉ mono/monodevelop
◉ xamarin/xamarin-macios
◉ xamarin/xamarin-android
◉ xamarin/Xamarin.Forms
◉ many Xamarin Components
Which sources are available ?
N/A
◉ IDE addins (XS, VS)
◉ inspector, workbooks
◉ profiler
◉ UITest (test cloud)
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Xamarin Source Quest
Find exact sources
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Getting precise build versions
Sources are different if versions don't match...
though, XiOS/XA rev. != OSS repo rev.
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Getting precise build branch
Xamarin release "cycles" (cycle7, cycle8, cycle9 ...)
https://developer.xamarin.com/releases/current/
◉ xamarin-macios, xamarin-android: cycle
https://github.com/xamarin/xamarin-macios/branches/cycle8
◉ mono, monodevelop: historical versions
https://github.com/mono/mono/branches/mono-4-8-0-branch
◉ Components, Forms: independent versioning
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Getting precise stack trace
◉ Know your runtime. It only applies to mono
○ Apps on iOS, Android, Mac
○ Windows - most unlikely, depends on code.
◉ Useful mono runtime options
○ --debug to get line numbers.
○ -O=-all to get precise line numbers
■ disables optimizations
■ should not matter, but it often does...
● longstanding issue... JIT is difficult
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diagnose: mono --trace
◉ AssemblyName
◉ T:Full.Type.Name
◉ N:Namespace.Name
◉ M:Full.Type.Name:Method
(use colon)
◉ E:Full.Exception.Type.Name
(or "all")
$ mono --help-trace
$ mono --trace=System.Xml.Linq,N:System.Xml.XPath,E:all x.exe
Note that sometimes method call is JITted away...
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Specify runtime options
◉ Desktop executable (console, Xamarin.Mac)
○ mono [options] {foobar.exe}
◉ monodevelop, Xamarin Studio
○ MONO_OPTIONS=[options] monodevelop
◉ Xamarin.Android
○ adb shell setprop debug.mono.env [options]
○ adb shell setprop debug.mono.debug 1 (environment)
◉ Xamarin.iOS
○ 'Run' option on the IDE (MONO_TRACE=... etc.)
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Xamarin Source Quest
Mono
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building mono from source
◉ Prepare *nix environment (macosx, linux, WSL, cygwin)
○ Windows binaries: cross build or cygwin
◉ git clone --recursive ; ./autogen.sh; make; make install
○ --disable-nls on cygwin
◉ incremental builds - be careful, it's been broken (a while)
○ BK: run "make;make;make" to make sure to build(!?)
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mono source diretories
mono
mono [C runtime]
mcs [C#]
mcs [compiler] (being deprecated)
class [libraries]
tools
class
lib
{assembly, sometimes group}
{namespace}
{class}.cs
Test
referencesource
Facades
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framework profiles
different profiles / set of assemblies in mcs/class/lib:
◉ basic - minimum build to build "build" profile
◉ monolite - downloadable binaries of "basic" equivalents
◉ build - the profile which is used to build everything
◉ net4_x - desktop profile
◉ xbuild_12, xbuild_14 - profile to run xbuild
◉ monotouch, monodroid - if you are building mobile
basic: built by system (preinstalled) mono / build: built by basic
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dll.sources: the list of sources
> because it's not in the list? They are per profile.
corlib.dll.sources -> default
net_4_x_corlib.dll.sources -> net_4_x
often #include-d in those files
> checked #if MONOTOUCH, #if MONODROID, #if MOBILE ?
"I'm making changes but it does not get compiled!"
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making changes in mono
◉ classlibs (./mcs/class)
○ `make [PROFILE=xxx]` => mcs/class/lib/xxx
○ `make run-test` in the assembly dir for minimum tests.
◉ compiler (./mcs/mcs)
○ see mcs/tests and mcs/errors (check expected errors)
◉ runtime (./mono)
○ `make` in mono
◉ full tests: `make check` at top-level dir.
○ (yet, jenkins build should run for each mono PRs)
make changes, run tests, create a PR!
cf. Inside Xamarin #3
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useful mono hacking tips
◉ MONO_PATH={topdir}/mcs/class/lib/net_4_x
{topdir}/mono/runtime/mono-wrapper [YourApp.exe]
... to try your local changes without installing.
◉ mobile builds: ./configure
--with-monotouch, --with-monodroid, --with-xammac etc.
◉ Mono framework assemblies for mobiles can be copied to:
○ $(installed_dir)/lib/xbuild-frameworks/{product}/v1.0
■ `Facades` subdir too.
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Xamarin Source Quest
MSBuild quick tour
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MSBuild: .NET build engine
◉ Why MSBuild now?
○ Xamarin Platform "SDK" = console dev. tools and Fx.
○ xamarin-android, xamarin-macios and Xamarin.Forms
depend on MSBuild system.
■ like Android does on Gradle, Apple does no xcodebuild
◉ xbuild on Mono so far (`msbuild` in the future)
◉ XA, XiOS, XM and XF extend each set of MSBuild tasks.
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MSBuild project files
users have *.csproj:
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MSBuild tasks and targets
Fx. devs maintain *.targets:
custom s: xbuild /t:SignAndroidPackage
property overrides: $(BuildDependsOn), ...
custom properties: xbuild /p:XamMacArch=x86_64
List of Xamarin targets & props ("Build Process")
Tasks DLLs: should contain Task implementation classses.
*.targets and *.dlls: placed in a subdir under $(MSBuildExtensionsPath)
Task Writing: https://msdn.microsoft.com/en-us/library/t9883dzc.aspx
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Xamarin Source Quest
Apple Platforms
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Xamarin.iOS / Xamarin.Mac
What are they?
◉ Framework assemblies (objc interop with iOS, macOS etc.)
◉ native runtime "libmonotouch"
◉ MSBuild extensions
◉ App build toolchains: mtouch etc.
◉ Binding build toolchains: btouch etc. Objective-sharpie
◉ Visual Studio/MonoDevelop addins to support
◉ Inspector, Profiler etc.
Inside Xamarin (5) (Xamarin.iOSのソフトウェア構成要素) 10/4
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xamarin-macios: frameworks
configure && make && make install (or install-system)
=> built outputs: _ios-build and _mac-build
Xamarin.iOS.sln, Xamarin.Mac.sln : framework
src: iOS/watchOS/tvOS/macOS assemblies, and btouch etc.
tools: packaging tools (mtouch, mmp) etc.
runtime: libmonotouch, using external/(watch-)mono
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xamarin-macios: build tools
◉ might be helpful when investigating build failures...
○ Build logging: diagnostic (or, xbuild /v:diag)
◉ mtouch (Xamarin.iOS.sln), mmp (Xamarin.Mac.sln)
○ the app build tool - linking, AOT, packaging, signing
○ IDEs also do those jobs too (e.g. mac codesign)
◉ MSBuild Tasks (msbuild/Xamarin.MacDev.Tasks.sln)
○ msbuild/Xamarin.{iOS|Mac}.Tasks - apps
○ Xamarin.MacDev (external/Xamarin.MacDev)
■ .NET API to manipulate SDKs
○ msbuild/Xamarin.ObjCBinding.Tasks - bindings
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Xamarin Source Quest
Xamarin.Android
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Xamarin.Android
What are they?
◉ Framework assemblies: Mono.Android.dll etc.
◉ native runtime "libmonodroid"
◉ MSBuild extensions
◉ Binding build toolchains: generator etc.
◉ Debugging support (shared runtime, Xamarin.Android.Debugging.Tasks.dll)
◉ Visual Studio/MonoDevelop addins to support
◉ Inspector, Profiler etc.
grimoire of Android
オープンソース化された Xamarin.Androidの概要
Inside Xamarin #7
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Xamarin.Android platform
make prepare & make
all in Xamarin.Android.sln (but not really editable...)
◉ src/Mono.Android (Mono.Android.dll)
○ (kind of) standard binding project
○ partly hand-written, API XML prebuilt and "api-merge"d
○ lots of metadata fixup in .csv files
◉ external/Java.Interop/src/Java.Interop (Java.Interop.dll)
○ JNIEnv and co.
○ *may* work with desktop Java
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Java Android Platform
◉ investigate underlying Android Fx behavior
○ platform/frameworks/base
■ android.googlesource.com (original)
■ github/Android (mirrors)
■ tools.oesf.biz (OESF Android code search)
○ android-sdk-[windows|macosx|linux]/sources
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Android MSBuild Tasks
MSBuild Tasks (src/Xamarin.Android.Build.Tasks)
◉ Xamarin.Android.Common.targets for App projects
◉ tasks: GenerateResourceDesigner, LinkAssemblies, CompileToDalvik etc.
◉ remember: no debugging support (no Fast Deployment)
◉ Xamarin.Android.Bindings.targets for Java binding projects
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Android binding generator
in java.interop:
◉ converts *.jar/*.aar -> *.xml -> *.cs -> *.dll
◉ API parsing:
○ ~cycle8: "jar2xml" (not in OSS repo)
○ cycle9~: "class-parse"
■ src/Xamarin.Android.Tools.Bytecode
■ src/Xamarin.Android.Tools.ApiXmlAdjuster
◉ API XML fixup and C# generation: tools/generator
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Xamarin Source Quest
Xamarin Libraries
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XamarinComponents
Start from github/xamarin/XamarinComponents...
◉ AndroidSupportComponents
○ branches per m2repository rev.
◉ GooglePlayServicesComponents
○ (ditto)
◉ ...
mostly normal iOS/Android libs.
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Xamarin.Forms
https://github.com/xamarin/Xamarin.Forms/
Basically a set of mobile libraries
and MSBuild tasks (nupkg-ed) to run xamlg, xamlc
Xamarin.Forms.Core
Xamarin.Forms.Platform.*
Xamarin.Forms.Xaml - its own parser impl.
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Xamarin Source Quest
Case Study #1
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Fixing Xamarin.Forms async
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tracking sources
If the current thread is the UI thread, then
the action is executed immediately. If the
current thread is not the UI thread, the
action is posted to the event queue of the
UI thread.
Xamarin.Forms.Core/Device.cs
Xamarin.Forms.Platform.Android/Forms.cs
android-sdk-*/sources/android-24/android/app/Activity.java
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creating a PR
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Xamarin Source Quest
Case Study #2
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Where is ur HttpClient from?
Is Xamarin affected?
mono/mcs/class/System.Net.Http
System.Net.HttpClient.dll.sources
says
System.Net.Http/HttpClient.cs
(NOT referencesource)
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Is mono HttpClient alright?
HttpClient.Dispose() -> HttpMessageInvoker.Dispose() ->
{HttpMessageHandler implementation}.Dispose()
HttpClient() ... #if !XAMARIN_MODERN in HttpClient.cs
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Is Android HttpClient alright?
HttpClient.Android.cs ...GetDefaultHandler()
...Wat?
Type type = Type.GetType("Android.Runtime.AndroidEnvironment,
Mono.Android");
...
MethodInfo method = type.GetMethod ("GetHttpMessageHandler",
BindingFlags.Static | BindingFlags.NonPublic);
...
object ret = method.Invoke (null, null);
if (ret == null)
return GetFallback ("Xamarin.Android returned no custom HttpClientHandler");
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Is Android HttpClient alright?
github/xamarin/xamarin-android...
AndroidEnvironment.GetHttpMessageHandler()
... returns null (by default)
default HttpClientHandler's Dispose():
if (disposing && !disposed) {
Volatile.Write (ref disposed, true);
ServicePointManager.CloseConnectionGroup (connectionGroupName);
}
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How about Mac/iOS?
(homework!)
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Xamarin Source Quest
How to contribute
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Many ways to contribute
It's not just code
◉ code (github)
○ bugfixes
○ implement a new feature
◉ bugzilla.xamarin.com
○ github issues - second citizens
◉ components/bindings, Xam plugins, IDE addins
◉ other general stuff (blogs, writing apps, libs, meetups...)
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How to contribute to repos
◉ github flow: send pull requests
○ git branch [bname]
○ git checkout [bname]
○
○ git commit
○ fork on github
○ git remote add [youralias] [forkURL]
○ git push [youralias] [bname]
○ open repo web and create PR (you'll be navigated)
◉ MS CLA (contributors license agreement) is required
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coding conventions
◉ depends on project
○ Mostly mono coding guidelines rule
○ Xamarin.Forms follows VS style
○ Xamarin Studio has code formats for both
◉ Adding tests for better contribution
○ We use NUnit almost everywhere
○ NUnit is similar to MSTest / xunit
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questions?
not now, but I'll be around
Thanks