BorlandTalk.com

mamcx · Guest

I'm investigating how far can Delphi mimic the Erlang aproach to
multi-threads...n However, my experience in this is, like the mayority
of the average developers, not much ;(

I have this (is the concept of how can be):

unit ParallelCode;

interface

uses
{VCL}Classes ,
{JCL}JclContainerIntf,JclQueues,JclAlgorithms,JclHashMaps;

type
TBufferType = (tbInt,tbString,tbData);

IParallelCode = interface
function GetSession(key: String): TObject;
procedure SetSession(key: String; const Value: TObject);

procedure Post(PID:Integer;Value:String);

procedure BroadCast(PidList: array of Integer;Value:String);overload;
procedure BroadCast(Value:String);overload;
procedure Execute;
procedure Get(FromPID:Integer;Value:String);

property Session[key:String]:TObject read GetSession write SetSession;

function GetIsDone: Boolean;
function GetPid: Integer;
end;

TParallelCode = class(TInterfacedObject,IParallelCode)
private
FPId : Integer;
FSession: IJclStrIntfMap;
FIsDone: Boolean;
function GetIsDone: Boolean;
function GetPid: Integer;
function GetSession(key: String): TObject;
procedure SetSession(key: String; const Value: TObject);
protected
FApply:TApplyFunction;
FValue:TObject;

procedure
DoPost(PID:Integer;Value:TStream;DataType:TBufferType);virtual;
public
procedure Execute;

procedure Post(PID:Integer;Value:String);

procedure BroadCast(PidList: array of Integer;Value:String);overload;
procedure BroadCast(Value:String);overload;

procedure Get(FromPID:Integer;Value:String);

property Session[key:String]:TObject read GetSession write SetSession;

property IsDone:Boolean read GetIsDone;

property PID:Integer read GetPid;

constructor
Create(Apply:TApplyFunction;Data:TObject;AutoStart:Boolean=True);
destructor Destroy; override;

end;

implementation

{ TParallelCode }

procedure TParallelCode.BroadCast(PidList: array of Integer; Value: String);
var
Pid:Integer;
begin
for Pid in PidList do
begin
Post(Pid,Value);
end;//for
end;

procedure TParallelCode.BroadCast(Value: String);
begin

end;

constructor TParallelCode.Create(Apply: TApplyFunction; Data:
TObject;AutoStart:Boolean=True);
begin
FSession := TJclStrIntfHashMap.Create();

FApply := Apply;
FValue := Data;

if AutoStart then
begin
Execute;
end;
end;

destructor TParallelCode.Destroy;
begin
Post(-1,'Terminado');

FSession.Clear;
FApply := nil;
FValue := nil;
inherited;
end;

procedure TParallelCode.DoPost(PID: Integer; Value: TStream;
DataType: TBufferType);
begin

end;

procedure TParallelCode.Execute;
var
value:Integer;
begin
Value := Integer(FApply(FValue));
end;

procedure TParallelCode.Get(FromPID: Integer; Value: String);
begin

end;

function TParallelCode.GetIsDone: Boolean;
begin

end;

function TParallelCode.GetPid: Integer;
begin

end;

function TParallelCode.GetSession(key: String): TObject;
begin
Result := nil;
end;

procedure TParallelCode.SetSession(key: String; const Value: TObject);
begin

end;

procedure TParallelCode.Post(PID: Integer; Value: String);
var
Bufer: TStringStream;
begin
Bufer := TStringStream.Create(Value);

DoPost(PID,Bufer,tbString);
end;

end.

So, the idea (borrowed from Erlang and clasisc web development):

Do a funcion:

function Add2(AObject: TObject): TObject;
begin
Result := TObject(Integer(AObject) + 2);
end;

Call It:

Fork( Add2, TObject(1) );

Communicate using only:

Post(ToPID=1,'Data)

and recieve messages:

procedure Get(FromPid,Data):
begin

end;

I try using Coroutine
(http://www.festra.com/wwwboard/messages/12775.html) and try with Indy
Fibers but I'm blocked because:

a) Don't know the best aproach to send and recieve message (is using
windows messages)

b) Don't know what dangers or mainly, limitations cause the use of
Coroutine/Fibers

c) Maybe I must start using normal threads then evolve the thing?

Bart van der Werf · Guest

"mamcx" <this (AT) notexist (DOT) com> wrote in message
news:44f5aaeb (AT) newsgroups (DOT) borland.com...

theo · Guest

Bart van der Werf · Guest

"theo" <nospam (AT) for (DOT) me> wrote in message
news:44f6e107$1 (AT) newsgroups (DOT) borland.com...

theo · Guest

Bart van der Werf schrieb:

mamcx · Guest

Excellent!

But where I get ComtecCollection and that classes?

You are interested in put this forward? I like the idea of have a easy-to-use parallering library to incorporate in MUTIS (mutis.sourceforge.net)