HPThreadPool

HPThreadPool is a High Performance Thread Pool design for Lazarus Free pascal

Design

The goal is to provide a nice and simple way to work with threads without the excessive overhead of runtime thread creation, the major topics of a thread pool is covered, including:

• Statics
  • Minimum
  • Maximum
  • Threads running
  • Work enqueued
• Resize of thread pool
• Zero sleep time when a job is available
• WaitForAll and WaitForAny
• Worker thread class customization (if needed)
• OnTerminateWorker callback sync (Synchronized) and async (Thread context)

Quick Example

unit Demo;

interface

uses
 HPThreadPool;
 
type
 TMyJobs = class(TObject)
 private
 public
   class procedure MyFiboWork(AParameters: Pointer);
 end;
 
implementation

procedure TMyJobs.MyFiboWork(AParameters: Pointer);
var
 I: Integer;
 Value: Integer; 
 Sum: Integer = 0;
 NumA: Integer = 1;
 NumB: Integer = 0;
begin
 Value := PInteger(AParameters)^;
 
 for I := 1 to Value do
 begin
   Sum := NumA + NumB;
   NumB := NumA;
   NumA := Sum;
 end;
 
 PInteger(AParameters)^ := Sum;
end;

// Example working with 100 jobs and a random value of fibonnaci
const
 MAXJOBS = 100;
var
 I: Integer;
 Fibo: array of Integer;  
 Tasks: TTaskList;
begin
 Randomize;
 Tasks := TTaskList.Create;
 SetLength(Fibo, MAXJOBS);
 
 for I := 0 to MAXJOBS - 1 do
 begin
   Fibo[I] := Random(10000);
   Tasks.Add(THPTask.Run(@TMyJobs.MyFiboWork, @Fibo[I]));
 end;
 
 THPTask.WaitForAll(Tasks.ToArray);
 
 for I := 0 to High(Fibo) do
   WriteLn(I, ' - ', Fibo[I]);
 
 Tasks.Free;
end;