initial unlock use for in 線程 self. private aps 自帶

unit sfContnrs;

interface

{$DEFINE MULTI_THREAD_QUEUE} //線程安全版本，如果不需要線程安全，請註釋掉此行代碼

{$IFDEF MULTI_THREAD_QUEUE}
uses
Windows;
{$ENDIF}

type
TsfQueue=class
private
FCapacity:Integer;
FTmpBuff:Pointer;
FBuff:Pointer;
FPosition:Integer;
{$IFDEF MULTI_THREAD_QUEUE}
FCS:TRTLCriticalSection;

{$ENDIF}
//\\
FPushIndex:Integer;
FPopIndex:Integer;

procedure Lock();
procedure UnLock();
procedure Inernal_SetCapacity(const Value:Integer);
//\\
procedure setCapacity(const Value: Integer);
function getCapacity: Integer;
public
constructor Create(InitCapacity: Integer=1024);

destructor Destroy();override;
//\\
function Push(AItem: Pointer): Pointer;
function Pop(): Pointer;
public
property Capacity:Integer read getCapacity write setCapacity;
end;

implementation

{ TsfQueue }

constructor TsfQueue.Create(InitCapacity:Integer);
begin
{$IFDEF MULTI_THREAD_QUEUE}

InitializeCriticalSection(FCS);
{$ENDIF}

if InitCapacity < 1024 then InitCapacity := 1024;

Inernal_SetCapacity(InitCapacity);

end;

destructor TsfQueue.Destroy;
begin
FreeMem(FBuff);
if FTmpBuff <> nil then
FreeMem(FTmpBuff);
//\\
{$IFDEF MULTI_THREAD_QUEUE}
DeleteCriticalSection(FCS);
{$ENDIF}

inherited;
end;

procedure TsfQueue.Lock;
begin
{$IFDEF MULTI_THREAD_QUEUE}
EnterCriticalSection(FCS);
{$ENDIF}
end;

procedure TsfQueue.UnLock;
begin
{$IFDEF MULTI_THREAD_QUEUE}
LeaveCriticalSection(FCS);
{$ENDIF}
end;

procedure TsfQueue.Inernal_SetCapacity(const Value: Integer);
var
PageCount,ASize:Integer;
begin
if Value > FCapacity then
begin
if FTmpBuff <> nil then
FreeMem(FTmpBuff);

//擴容
ASize := Value * 4;//計算出所需要的字節數量
Pagecount := ASize div 4096;
if (ASize mod 4096) > 0 then Inc(PageCount);

//轉移數據
GetMem(FTmpBuff,PageCount * 4096);
FillChar(FTmpBuff^,PageCount * 4096,#0);

if FBuff <> nil then
begin
Move(FBuff^,FTmpBuff^,FCapacity * 4);
FreeMem(FBuff);
end;

FBuff := FTmpBuff;

//計算新的容量
FCapacity := (PageCount * 4096) div 4;

if FCapacity >= 2048 then
begin
//FTmpBuff 分配用於Pop時候，移動內存用
GetMem(FTmpBuff,PageCount * 4096);
end
else
FTmpBuff := nil;
end;
end;

function TsfQueue.Pop: Pointer;
procedure AdjuestMem();
var
pSrc:PInteger;
pTmp:Pointer;
begin
FillChar(FTmpBuff^,FCapacity * 4,#0);
pSrc := PInteger(FBuff);
Inc(pSrc,FPopIndex);
Move(pSrc^,FTmpBuff^,(FCapacity - FPopIndex) * 4);
//\\
//交換指針
pTmp := FBuff;
FBuff := FTmpBuff;
FTmpBuff := pTmp;
//\\
end;

const
_MoveRange_ = 2048;

var
P:PInteger;
begin
Lock();
try
Result := nil;
if (FPopIndex = FPushIndex) then
Exit;
P := PInteger(FBuff);
Inc(P,FPopIndex);
Result := Pointer(P^);
Inc(FPopIndex);
//隊列底部空余內存達到 8192 整體搬遷
if FPopIndex = _MoveRange_ then
begin
AdjuestMem();
FPopIndex := 0;
Dec(FPushIndex,_MoveRange_);
end;
finally
UnLock();
end;
end;

function TsfQueue.Push(AItem: Pointer): Pointer;
var
P:PInteger;
begin
Lock();
try
P := PInteger(FBuff);
Inc(P,FPushIndex);
P^ := Integer(AItem);
Inc(FPushIndex);
if FPushIndex >= FCapacity then
begin
//擴容加 1024 個位置
Inernal_SetCapacity(FCapacity + 1024);
end;
finally
UnLock();
end;
end;

procedure TsfQueue.setCapacity(const Value: Integer);
begin
Lock();
try
Inernal_SetCapacity(Value);
finally
UnLock();
end;
end;

function TsfQueue.getCapacity: Integer;
begin
Lock();
try
Result := Self.FCapacity;
finally
UnLock();
end;
end;

end.

//測試函數

procedure TfrmMain.btnQueueClick(Sender: TObject);
var
A:TsfQueue; //優化後的高速隊類實現（線程安全）
B:TQueue;
Index:Integer;
begin
A := TsfQueue.Create();
B := TQueue.Create();
SW.Start();
for Index := 1 to 10000 * 2 do
begin
b.Push(0);
end;
for Index := 1 to 10000 * 2 do
begin
b.Pop();
end;

SW.Stop();

showMessage(IntToStr(SW.ElapsedMiliseconds));

end;

轉自：http://www.cnblogs.com/lwm8246/archive/2011/10/06/2200009.html

一個隊列類的實現(比delphi自帶的速度快70倍)(線程安全版本)