Class InplaceUpdateRequirement

If inplaceUpdate is true, then an implementation supporting this feature may permit tools to directly update files with writable: true in InitialWorkDirRequirement. That is, as an optimization, files may be destructively modified in place as opposed to copied and updated.

An implementation must ensure that only one workflow step may access a writable file at a time. It is an error if a file which is writable by one workflow step file is accessed (for reading or writing) by any other workflow step running independently. However, a file which has been updated in a previous completed step may be used as input to multiple steps, provided it is read-only in every step.

Workflow steps which modify a file must produce the modified file as output. Downstream steps which futher process the file must use the output of previous steps, and not refer to a common input (this is necessary for both ordering and correctness).

Workflow authors should provide this in the hints section. The intent of this feature is that workflows produce the same results whether or not InplaceUpdateRequirement is supported by the implementation, and this feature is primarily available as an optimization for particular environments.

Users and implementers should be aware that workflows that destructively modify inputs may not be repeatable or reproducible. In particular, enabling this feature implies that WorkReuse should not be enabled.