The runtime prepares simultaneous Changes against one state snapshot. It then groups writes by object and property.
Compatible writes
Multiple numeric change operations to the same object property combine. The runtime applies the sum to the prior numeric value.
WorkSpec.task("receive_a").onComplete(() => change("stock", "quantity", 2));
WorkSpec.task("receive_b").onComplete(() => change("stock", "quantity", 3));If both tasks complete together, the quantity increases by 5.
Conflicting writes
Other simultaneous writes to the same property conflict. A property write also conflicts with a simultaneous create or remove for that object.
The runtime rejects each conflicting write group. It emits interaction.write.conflict and marks the contributing tasks as failed.
This rule prevents source order from deciding an ambiguous world state.
Generator precedence
Generator writes have explicit precedence over Changes at the same logical time.
- A Generator write replaces a conflicting completion Change.
- A conflicting start Change is suppressed.
- The runtime emits
generator.changes.conflictwith the target, property, and time.
The warning is non-blocking. Non-conflicting Changes at that time still apply.
Temporary-write conflicts
The runtime rejects overlapping temporary writes to the same property. It reports interaction.temporary.overlap.
Transaction boundary
Conflict handling groups writes by target property or lifecycle identity. It does not make every handler a whole-project transaction.
If one task produces any failed write, the runtime rejects that task's prepared writes for the phase. Other non-conflicting tasks can still succeed.