IJobConfig - Add require exclusive write for EPD and CDFE + Cleanup

[mbaker3]

• Add require methods for
  • Exclusive EntityPersistentData write
  • Exclusive CDFE write
  • Shared DBFE write
• Cleanup IJobConfig and implementations

What is the current behaviour?

Within an TaskDriver there is no way to:

• Get exclusive write access to EntityPersistentData
• Get exclusive write access to a CDFE
• Get shared write access to a DBFE

As the use of Task Drivers has expanded well beyond the simple use cases originally imaged the the method naming for write access requirements has become ambiguous. Depending on the type, "Write" in a method name (Ex: RequireEntityPersistentDataForWrite could mean that the access handle is shared between all other concurrent write requests globally, all concurrent write requests associated with a Task Driver type's TaskDriverSystem, or something else. It's easy to forget or assume what type of access a you're getting as a developer. Shared vs Exclusive needs to be spell explicitly and new terminology needs to be devised to describe the unique write access provided to Unity ECS backed types (CDFE, DBFE, etc..)

What is the new behaviour?

IJobConfig: Rename require methods to better describe provided access

• Introduce the key term "SystemShared" for Unity ECS backed type requests (Ex: CDFE, DBFE, etc...)
  • "SystemShared" denotes that the shared write fence is on the TaskDriver system vs a normal SharedWrite that shares write access across all access scopes. This is due to the way Unity handles component dependencies.
• Rename RequireCDFEForWrite to RequireCDFEForSystemSharedWrite.
• Rename RequireEntityPersistentDataForWrite to RequireEntityPersistentDataForSharedWrite

IJobConfig: Additional require types

• Add RequireEntityPersistentDataForExclusiveWrite
• Add RequireCDFEForExclusiveWrite
• Add RequireDBFEForSystemSharedWrite

IJobConfig + Implementations: Cleanup

• Add comment headers to all sections
• Reorder methods to consistently declare require methods in the order read, shared write, exclusive write
• Refactor implementations to match the method order defined in IJobConfig

Notes: The following methods were left as is for the reasons given below. I'm not against changing their names if you think it would be beneficial and have some naming ideas.

• RequireThreadPersistentDataForWrite has been left as is since there is no concept of shared vs exclusive access.
• RequireDataStreamForWrite has been left as is since exclusive writing isn't a user space operation that should ever be performed.

What issues does this resolve?

• None

What PRs does this depend on?

• None

Does this introduce a breaking change?

• [x] Yes - See the method renames above.
• [ ] No

[mbaker3]

Ready for re-review.

I think it's fine to leave the ThreadPersistentData as just "Write". Technically, it's a shared write if we want to be specific.

Same thing for the data stream, I'm fine with it being just "Write" but again if we wanted to be specific, it's a Shared Write.

Agreed, Shared write felt a bit weird since it's not something you need to be concerned about the way you are with other types. ...at least not if used correctly.