39 lines
1.1 KiB
GDScript
39 lines
1.1 KiB
GDScript
class_name Task extends RefCounted
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## Promise-like abstraction for (hopefully) safer concurrency.
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signal _sig_finished
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## Value returned by task. Null if, but not only if, task has not finished.
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var result: Variant = null
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var _finished := false
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## Awaits the given Callable concurrently and reports back when it finishes.
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func _init(thunk: Callable) -> void:
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var coro := func() -> void:
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result = await thunk.call()
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_finished = true
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_sig_finished.emit()
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coro.call()
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## Returns true iff the task has finished.
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func is_finished() -> bool:
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return _finished
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## Waits for the task to finish (if necessary) and returns its result.
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func sync() -> Variant:
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if not _finished:
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await _sig_finished
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return result
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## Creates a Task which can only finish when all subtasks have finished.
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##
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## Syncing the task will return an array of the tasks' results
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## in the same respective order.
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static func group(subtasks: Array[Task]) -> Task:
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var thunk := func() -> Array:
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var results := []
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for task in subtasks:
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results.push_back(await task.sync())
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return results
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return Task.new(thunk)
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