dagga 🌿

A crate for scheduling directed acyclic graphs.

Features

• node creates resources semantics
• node reads resource semantics, ie borrow
• writes resource semantics, ie mutable/exclusive borrow
• consumes resource semantics, ie move
• node dependencies
  • node X must run before node Y
  • node X must run after node Y
  • barriers - nodes added before a barrier will always be scheduled before the barrier and nodes added after a barrier will always be scheduled after the barrier

Example uses

• scheduling parallel operations with dependencies, shared and exclusive resources
• scheduling steps in a render graph
• scheduling system batches in ECS
• scheduling audio nodes in an audio graph

Example

use dagga::*;// Create names/values for our resources.//// These represent the types of the resources that get created, passed through// and consumed by each node.let[a, b, c, d]:[usize;4] = [0,1,2,3];// Add the nodes with their dependencies and build the schedule.// The order they are added should not matter (it may cause differences in// scheduling, but always result in a valid schedule).let dag = Dag::<(),usize>::default().with_node({// This node results in the creation of an `a`.Node::new(()).with_name("create-a").with_result(a)}).with_node({// This node creates a `b`.Node::new(()).with_name("create-b").with_result(b)}).with_node({// This node reads `a` and `b` and results in `c`Node::new(()).with_name("create-c").with_read(a).with_read(b).with_result(c)}).with_node({// This node modifies `a`, but for reasons outside of the scope of the types// expressed here (just as an example), it must be run before// "create-c". There is no result of this node beside the side-effect of// modifying `a`.Node::new(()).with_name("modify-a").with_write(a).with_read(b).run_before("create-c")}).with_node({// This node consumes `a`, `b`, `c` and results in `d`.Node::new(()).with_name("reduce-abc-to-d").with_move(a).with_move(b).with_move(c).with_result(d)});
dagga::assert_batches(&["create-a, create-b",/* each batch can be run in parallel w/o violating * exclusive borrows */"modify-a","create-c","reduce-abc-to-d",],
dag.clone(),);

You can also have dagga create a dot graph file to visualize the schedule (using graphiz or similar):