1. Microsoft Consumer Channels and Central Marketing Group
7/13/2019
Porting to Metro
Sridhar Madhugiri
Software Design Engineer
Microsoft Corporation
© 2012 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

2. Agenda Metro SDK API Prepare for porting Win32 technologies Libraries
7/13/2019
Agenda
Metro SDK API
Prepare for porting
Win32 technologies
Mentions these are not in order of importance. Hint of Windows on ARM, but don’t add it as a bullet.
Libraries
Porting
© 2012 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

3. Metro SDK API

4. Metro SDK API WinRT API Win32 API COM Components New APIs
Operation that can block implemented as asynchronous operation
Win32 API
Subset of Win32 API available in Metro
Similar Win32 API may be part of Metro SDK
InitializeCriticalSectionAndSpinCount -> InitializeCriticalSectionEx
COM Components
Some OS components available under Metro

5. Identifying Non Metro SDK API usage
Documentation
Preprocessor define
WINAPI_FAMILY=WINAPI_PARTITION_APP
Add the define to C++ preprocessor settings in Projects settings
Compiler stops after 100 errors so may not get full list API not available in Metro SDK
Windows App Certification Kit tool
Create an Appx package with app binaries
Run resulting package through tool
<Program Files>\Windows Kits\8.0\App Certification Kit\appcert.exe

6. Prepare for Porting

7. Get the desktop app ready for Porting
Build with VS 11
Compile, test on Windows 8 desktop
Desktop API usage
Use alternate Win32 APIs available in Metro SDK
Wrap API usage in abstractions

8. Asynchronous operations
WinRT APIs are asynchronous
Refactor existing code to consume asynchronous operations
DO refactor code to deal with partial data
DO keep UI responsive while asynchronous operations are in progress
Convert long running operations to asynchronous
Schedule long running work on thread pool
DO return partial results as and when available
Options
Rewrite existing code
Write a wrapper that invokes existing code on a thread pool thread

9. Isolate core logic Separate platform specific code into abstractions
Refactor direct call to APIs to call an abstraction over the API
Use existing abstraction in libraries if available
Use Standard C++ libraries for core logic
Refactor core logic to operate on buffers, containers, etc

10. Win32 technologies

11. UI User and GDI based UI DirectX UI Options for UI in Metro Rewrite
Available in Metro
Use DirectX template as starting point
Template sets up the start up code required for Metro
Options for UI in Metro
XAML
DirectX

12. MFC MFC not available under Metro Options in Metro Rewrite UI XAML
DirectX
Form based App
Consider XAML databinding
Utility classes
Consider STL, CRT

13. Libraries

14. CRT Subset available in Metro
APIs for concepts not available in Metro not available in CRT
APIs available in Metro but not recommended
File api
ANSI char functions

15. CRT APIs not in Metro Multi-byte functions: mb* and _ismb*
Process control: exec* and spawn functions
Threading: beginthread* and endthread*
Heap and stack functions: heapwalk, heapmin, resetstkoflw(), …
Environment variable functions and globals putenv, getenv, _enviorn, …
Console function, cprintf, cscanf, …
Port functions, outp, inp, …
Pipe functions: pipe, popen, pclose, …

16. ATL Subset available in Metro APIs available in metro DLL server
COM objects (without IDispatch)
CStringW
ATL container classes
CCriticalSection, CEvent, CMutex, CSemaphore, CMutexLock
CComVariant
CComSafeArray
CComBSTR

17. Porting

18. Static Libs Consumption of WinRT in static libs
C++/CX – supported
WRL – supported
Authoring WinRT component in static libs
C++/CX – not supported
WRL – partially supported
Have to take explicit steps to make sure that component is part of the final binary
WrlCreatorMapIncludePragma used to make sure that specific class is pulled in from static lib

19. Using existing code in Metro
(or do I need to convert all my code to WinRT components)
C++ Metro Apps can use existing static libs, DLLs and COM components
DO make sure that the existing code is ported to use Metro SDK APIs
Link to static libs or import library as usual
Include binary components in APPX package, DLLs are app local
Using COM components
Use Reg-Free COM for activation
Activation through new API - CoCreateInstanceFromAppx

20. Convert types to WinRT types
DO change variable to WinRT type if
It frequently crosses boundary AND
Costly to convert between the two types
String and Array as input parameters to WinRT API can be efficiently converted without copying
StringRef, ArrayRef add a WinRT veneer using “borrow” semantics
Container and Collections
Requires copy to go from std::* to Platform::*
std::* efficient compared to Platform::*
Use std::* or Platform::* based on how often collection contents change vs how often they cross WinRT boundary

21. Strategies to create WinRT component
Choose technology
C++/CX, WRL, Your own implementation
Wrapper
Define interface and in the implementation delegate to existing C++ code after any type conversions
Creates a WINRT veneer over your existing code
Covert existing code
Rewrite code to use WinRT types and concepts
Have good reasons to go this route

22. Converting COM components to WinRT
Choose the technology
C++/CX, WRL, Your own implementation
Component already written using ATL, may be easier to move to WRL
Steps
Create WinRT interfaces corresponding to the previous interfaces
Port to one of the above technologies
Generate WinMD (if using IDL, modify MDIL flags)
Ship DLL and WinMD for others to consume the component

23. Technologies to use during porting
Language and Libraries
CRT and STL for utility functions and classes
C++/CX and/or WRL to interact with WinRT
See other talks for details about C++/CX and WRL UI
XAML
DirectX

24. Conclusion

25. Conclusion Metro SDK UI C++ Build, test, validate often
7/13/2019
Conclusion
Metro SDK
Work involved to move but not all throw away
Lot of the business logic, core application logic is portable UI
DirectX – easy
Win32 – rewrite in C++ using Modern UI framework
C++
Two way to interact with WinRT C++/CX, WRL
Use familiar C++ concepts and types for parts that don’t directly interact with platfrom
Build, test, validate often
Use Release configuration
© 2012 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

26. Microsoft Consumer Channels and Central Marketing Group
7/13/2019
© 2012 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
© 2012 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.