#lockdown Nick.Penwarden
#rb none
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MAJOR FEATURES + CHANGES
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Change 3209340 on 2016/11/23 by Ben.Marsh
Convert UE4 codebase to an "include what you use" model - where every header just includes the dependencies it needs, rather than every source file including large monolithic headers like Engine.h and UnrealEd.h.
Measured full rebuild times around 2x faster using XGE on Windows, and improvements of 25% or more for incremental builds and full rebuilds on most other platforms.
* Every header now includes everything it needs to compile.
* There's a CoreMinimal.h header that gets you a set of ubiquitous types from Core (eg. FString, FName, TArray, FVector, etc...). Most headers now include this first.
* There's a CoreTypes.h header that sets up primitive UE4 types and build macros (int32, PLATFORM_WIN64, etc...). All headers in Core include this first, as does CoreMinimal.h.
* Every .cpp file includes its matching .h file first.
* This helps validate that each header is including everything it needs to compile.
* No engine code includes a monolithic header such as Engine.h or UnrealEd.h any more.
* You will get a warning if you try to include one of these from the engine. They still exist for compatibility with game projects and do not produce warnings when included there.
* There have only been minor changes to our internal games down to accommodate these changes. The intent is for this to be as seamless as possible.
* No engine code explicitly includes a precompiled header any more.
* We still use PCHs, but they're force-included on the compiler command line by UnrealBuildTool instead. This lets us tune what they contain without breaking any existing include dependencies.
* PCHs are generated by a tool to get a statistical amount of coverage for the source files using it, and I've seeded the new shared PCHs to contain any header included by > 15% of source files.
Tool used to generate this transform is at Engine\Source\Programs\IncludeTool.
[CL 3209342 by Ben Marsh in Main branch]
- Linkers are no longer UObjects. Renamed ULinker, ULinkerLoad and ULinkerSave to FLinker, FLinkerLoad, FLinkerSave respectively
- Linkers are now associated with their UPackages
- Linker version is now stored in UPackages
- Async loading is now performed on a separate thread (if platform supports it and only in cooked builds), with the exception of PostLoad which is still done on the game thread
- Added UObject::IsPostLoadThreadSafe() function to determine if PostLoad is thread safe and can be executed on the async loading thread (defaults to false)
- UObject creation is now thread safe and can be performed on any thread
- Move many of the linker/UObject globals into FUObjectThreadContext (TLS)
- GetAsyncLoadPercentage() now takes PostLoad into account
- More async loading stats
- Added AtomicallySetFlags/ClearFlags to UObject
- Made FModuleManager thread safe.
- Added FGCScopeGuard as means of preventing GC from executing from non-game thread
- It's possible to disable async loading thread through ini settings.
- Cancelling async loading will now also trigger GC
- Implemented a basic version of async streaming priorities.
Change 2410813 by Mikolaj Sieluzycki:
Change Sleep in while loop to ConditionalSleep in FMultiReaderSingleWriterGT
Change 2410734 by Mikolaj Sieluzycki:
Make FModuleManager thread safe.
Change 2399879 by Mikolaj Sieluzycki:
Basic version of async streaming priorities.
Change 2410707 by Mikolaj Sieluzycki:
Implement conditional and no stat versions of sleep.
Change 2371939 by Robert Manuszewski:
Async Loading Improvements: adding more stats (accumulators)
Change 2372403 by Robert Manuszewski:
Fixing compile errors when STATs are not enabled
Change 2371526 by Robert Manuszewski:
AsyncLoading Improvements (WIP)
Change 2407198 by Robert Manuszewski:
Re-implementing delegate fixes for Async Loading
Change 2407425 by Robert Manuszewski:
Re-implementing cancelling async loading in the async loading branch.
Change 2484362 by Robert Manuszewski:
Making it possible to disable async loading thread through ini settings.
Change 2484744 by Robert Manuszewski:
Minimizing locks in GC and other threads when handling UObjects
Change 2480190 by Robert Manuszewski:
Fixing infinite stall after canceling async loading in non-cooked builds
Change 2484268 by Robert Manuszewski:
Fixing crash when allocating permanent object pool.
Change 2489761 by Robert Manuszewski:
Fixing BulkData using linker archive on the main thread even if the linker was created on the async loading thread.
Change 2493624 by Robert Manuszewski:
Cancelling async loading will now also trigger GC
Change 2487881 by Robert Manuszewski:
Making ShaderIdMap operations thread safe.
Change 2488067 by Robert Manuszewski:
Fixing GetAsyncLoadPercentage. It will now also respect PostLoad.
Change 2458640 by Robert Manuszewski:
Fixing crash in PIE
Change 2458825 by Robert Manuszewski:
Fixing a few crashes when streaming and the package is missing.
Change 2476935 by Robert Manuszewski:
Fixing crash while async loading ANavigationData
Change 2477361 by Robert Manuszewski:
Fixing crashes in cooked game
Change 2480095 by Robert Manuszewski:
Making FUObjectArray more thread safe
Change 2475443 by Robert Manuszewski:
Re-enabling single-threaded async loading path for the editor and platforms that don't support multithreading.
Change 2475458 by Robert Manuszewski:
Making sure bulk data is only loaded on a separate thread if it's not being loaded on the async loading thread.
Change 2476661 by Robert Manuszewski:
Fixing FlushAsyncLoading not flushing everything
Change 2401089 by Jaroslaw Surowiec:
Core - Added AtomicallySetFlags/ClearFlags to UObject, added a comment to ThisThreadAtomicallyClearedRFUnreachable
[CL 2498249 by Robert Manuszewski in Main branch]
Some dialogs, e.g. from save menu actions, don't need the two options.
#jira UE-10400 - Clicking on Save All brings up same window as when closing the editor
[CL 2463740 by Richard TalbotWatkin in Main branch]
* Moved Slate.h into SlateBasics.h and began shifting less commonly used headers into SlateExtras.h.
* Slate.h now simply includes SlateBasics.h and SlateExtras.h.
* Slate.h includes a deprecated warning now to indicate that SlateBasics.h + specific includes should be used instead.
* Moved dozens of inlined functions using Slate widgets into .cpp files to avoid header dependencies.
* All code samples now include SlateBasics.h and SlateExtras.h so future shifts will not break most those projects, but not trigger the deprecation warning of including Slate.h.
#BUN
[CL 2329610 by Wes Hunt in Main branch]
Breaking changes include:
* Rename of GEditorModeTools -> GLevelEditorModeTools to signify that it applies only to the level editor modes
* Addition of FEditorModeRegistry, responsible for managing and creating new editor modes. Modes are no longer registered with an instance of the mode, instead with a mode factory that is able to create a new mode of that type.
* Editor modes now operate on FEditorViewportClients rather than FLevelEditorViewportClients
* Added ability to specify an FEditorModeTools when creating an FEditorViewport
Moved component vizualiser manager handling outside of individual editor modes, and into FLevelEditorViewportClient. This should make it easier to transplant in future.
This work addresses TTP#334640 - EDITOR: Investigate making editor modes a per-'editor' concept
Reviewed by Michael Noland, Matt Kuhlenschmidt
[CL 2109245 by Andrew Rodham in Main branch]
Please note that file comments had no purpose in nearly all cases and just added visual clutter. The two files that had meaningful file comments had their comments moved into the corresponding classes. There are still hundreds of file comments left in other files that will be removed over time.
Also cleaned up some random stuff along the way:
- relative paths to public headers within the same module are no longer necessary (automatically discovered by UBT now)
- header guards are deprecated, use #pragma once instead (all compilers support it now)
- space between multiple template brackets is no longer required (all compilers support >> now)
- NULL to nullptr, OVERRIDE to override
- spelling errors, whitespace, line breaks
[CL 2104067 by Max Preussner in Main branch]
I also added code to retain backwards compatibility. Existing settings from EditorUserSettings.ini will be migrated to EditorLayout.ini
#CodeReview: nick.atamas, matt.kuhlenschmidt
[CL 2074798 by Max Preussner in Main branch]
