DHTMLX Planning Engine Documentation

Execution#

How Project.EvaluateWith scores candidates: one after another, or on worker threads. Get a value from Execution.Sequential or Execution.Parallel(...). Both modes return the same results.

Declaration#

namespace Plen;

public readonly record struct Execution

Execution has no public constructor. default(Execution) is Execution.Sequential.

Properties#

Property Type Description
IsParallel bool true for a value made by Parallel, false for Sequential.
Threads int? The thread count passed to Parallel. null means the processor count, and it's always null for Sequential.

Static members#

Sequential#

public static Execution Sequential { get; }

Scores one candidate after another. It's the default, and it's what Project.Evaluate uses.

Parallel#

public static Execution Parallel(int? threads = null)

Scores candidates on thread-pool workers, threads of them at most. Results and their order are the same as with Sequential. For memory use and error order, see Project.EvaluateWith.

Parameters

Name Type Description
threads int? Optional, default null. The maximum number of worker threads. null uses Environment.ProcessorCount.

Returns - a parallel Execution with IsParallel == true.

Errors - throws ArgumentOutOfRangeException when threads is 0 or negative.

Equality#

Execution has value equality. Execution.Parallel() equals Execution.Parallel(null), and Execution.Parallel(4) equals another Execution.Parallel(4).

Example#

Score two candidates on up to four threads.

using Plen;

var monday = Moment.FromYmdHm(2026, 8, 10, 8, 0) ?? throw new InvalidOperationException("invalid date");
var data = new ProjectData
{
    Tasks = [new TaskData("A") { StartDate = monday, Duration = 2.0 }],
    Resources = [new ResourceData { Id = "dev1" }, new ResourceData { Id = "dev2" }],
    Assignments = [new AssignmentData { Id = "aA", Task = "A", Resource = "dev1", Value = 1.0 }],
};
var project = new Project();
project.Solve(data, new SolveOptions());

var toDev2 = new SchedulingChanges();
toDev2.Assignments.Update.Add(new AssignmentUpdate("aA") { Resource = Patch<Id>.Of("dev2") });

Candidate[] candidates =
[
    new() { Id = "stay", Changes = new SchedulingChanges() },
    new() { Id = "dev2", Changes = toDev2 },
];

var execution = Execution.Parallel(4);
var result = project.EvaluateWith(candidates, new EvaluateOptions(), execution);

foreach (var candidate in result.Candidates)
    Console.WriteLine($"{candidate.Id}: cost {candidate.Cost}");