简略单纯高效的Delphi原子队列

unit utAtomFIFO;

interface

Uses
  SysUtils，
  SyncObjs;

Type
  TAtomFIFO = Class
  Protected
    FWritePtr: Integer;
    FReadPtr: Integer;
    FCount:Integer;
    FHighBound:Integer;
    FisEmpty:Integer;
    FData: array of Pointer;
    function GetSize:Integer;
  Public
    procedure Push（Item: Pointer）;
    function Pop: Pointer;
    Constructor Create（Size: Integer）; Virtual;
    Destructor Destroy; Override;
    Procedure Empty;
    property Size: Integer read GetSize;
    property UsedCount:Integer read FCount;
  End;

Implementation

{￥I InterlockedAPIs.inc}
//创建队列，大小必须是2的幂，须要开辟足够大的队列，防止队列溢出

Constructor TAtomFIFO.Create（Size: Integer）;
var
  i:NativeInt;
  OK:Boolean;
Begin
  Inherited Create;
  OK:=（Size and （Size-1）=0）;

  if not OK then raise Exception.Create（""FIFO长度必须大于便是256并为2的幂""）;

  try
    SetLength（FData， Size）;
    FHighBound:=Size-1;
  except
    Raise Exception.Create（""FIFO申请内存失败""）;
  end;
End;

Destructor TAtomFIFO.Destroy;
Begin
  SetLength（FData， 0）;
  Inherited;
End;

procedure TAtomFIFO.Empty;
begin
  while （InterlockedExchange（FReadPtr， 0）<>0） and （InterlockedExchange（FWritePtr， 0）<>0） and （InterlockedExchange（FCount， 0）<>0） do;
end;

function TAtomFIFO.GetSize: Integer;
begin
  Result:=FHighBound+1;
end;

procedure TAtomFIFO.Push（Item:Pointer）;
var
  N:Integer;
begin
  if Item=nil then Exit;

  N:=InterlockedIncrement（FWritePtr） and FHighBound;
  FData[N]:=Item;
  InterlockedIncrement（FCount）;
end;

Function TAtomFIFO.Pop:Pointer;
var
  N:Integer;
begin
  if InterlockedDecrement（FCount）<0 then
  begin
    InterlockedIncrement（FCount）;
    Result:=nil;
  end
  else
  begin
    N:=InterlockedIncrement（FReadPtr） and FHighBound;
    while FData[N]=nil do Sleep（1）;
    Result:=FData[N];

    FData[N]:=nil;
  end;
end;

End.

{*******************************************************}
{                                                       }
{           CodeGear Delphi Runtime Library             }
{                                                       }
{ Copyright（c） 1995-2014 Embarcadero Technologies， Inc. }
{                                                       }
{*******************************************************}

{￥IFDEF CPUX86}

function InterlockedAdd（var Addend: Integer; Increment: Integer）: Integer;
asm
      MOV   ECX，EAX
      MOV   EAX，EDX
 LOCK XADD  [ECX]，EAX
      ADD   EAX，EDX
end;

function InterlockedCompareExchange（var Target: Integer; Exchange: Integer; Comparand: Integer）: Integer;
asm
      XCHG    EAX，ECX
 LOCK CMPXCHG [ECX]，EDX
end;

function InterlockedCompareExchangePointer（var Target: Pointer; Exchange: Pointer; Comparand: Pointer）: Pointer;
asm
      JMP InterlockedCompareExchange
end;

function InterlockedDecrement（var Addend: Integer）: Integer;
asm
      MOV   EDX，-1
      JMP   InterlockedAdd
end;

function InterlockedExchange（var Target: Integer; Value: Integer）: Integer;
asm
      MOV     ECX，EAX
      MOV     EAX，[ECX]
＠＠loop:
 LOCK CMPXCHG [ECX]，EDX
      JNZ     ＠＠loop
end;

function InterlockedExchangePointer（var Target: Pointer; Value: Pointer）: Pointer;
asm
      JMP InterlockedExchange
end;

function InterlockedIncrement（var Addend: Integer）: Integer;
asm
      MOV   EDX，1
      JMP   InterlockedAdd
end;

{￥ENDIF CPUX86}

{￥IFDEF CPUX64}

function InterlockedExchangeAdd（var Addend: Integer; Value: Integer）: Integer;
asm
      .NOFRAME
      MOV   EAX，EDX
 LOCK XADD  [RCX].Integer，EAX
end;

function InterlockedDecrement（var Addend: LongInt）: LongInt;
asm
      .NOFRAME
      MOV   EAX，-1
 LOCK XADD  [RCX].Integer，EAX
      DEC   EAX
end;

function InterlockedIncrement（var Addend: LongInt）: LongInt;
asm
      MOV   EAX，1
 LOCK XADD  [RCX].Integer，EAX
      INC   EAX
end;

function InterlockedCompareExchange（var Destination: Integer; Exchange: Integer; Comparand: Integer）: Integer;
asm
      .NOFRAME
      MOV     EAX，R8d
 LOCK CMPXCHG [RCX].Integer，EDX
end;

function InterlockedCompareExchange64（var Destination: Int64; Exchange: Int64; Comparand: Int64）: Int64; overload;
asm
      .NOFRAME
      MOV     RAX，R8
 LOCK CMPXCHG [RCX]，RDX
end;

function InterlockedCompareExchangePointer（var Destination: Pointer; Exchange: Pointer; Comparand: Pointer）: Pointer;
asm
      .NOFRAME
      MOV     RAX，R8
 LOCK CMPXCHG [RCX]，RDX
end;

function InterlockedExchangePointer（var Target: Pointer; Value: Pointer）: Pointer;
asm
       .NOFRAME
  LOCK XCHG [RCX]，RDX
       MOV RAX，RDX
end;

function InterlockedExchange（var Target: Integer; Value: Integer）: Integer;// inline;
asm
       .NOFRAME
  LOCK XCHG [RCX]，EDX
       MOV EAX，EDX
end;

{￥ENDIF CPUX64}

{￥IFDEF CPUARM}

function InterlockedAdd（var Addend: Integer; Increment: Integer）: Integer;
begin
  Result := AtomicIncrement（Addend， Increment）;
end;

function InterlockedCompareExchange（var Target: Integer; Exchange: Integer; Comparand: Integer）: Integer;
begin
  Result := AtomicCmpExchange（Target， Exchange， Comparand）;
end;

function InterlockedCompareExchangePointer（var Target: Pointer; Exchange: Pointer; Comparand: Pointer）: Pointer;
begin
  Result := AtomicCmpExchange（Target， Exchange， Comparand）;
end;

function InterlockedDecrement（var Addend: Integer）: Integer;
begin
  Result := AtomicDecrement（Addend）;
end;

function InterlockedExchange（var Target: Integer; Value: Integer）: Integer;
begin
  Result := AtomicExchange（Target， Value）;
end;

function InterlockedExchangePointer（var Target: Pointer; Value: Pointer）: Pointer;
begin
  Result := AtomicExchange（Target， Value）;
end;

function InterlockedIncrement（var Addend: Integer）: Integer;
begin
  Result := AtomicIncrement（Addend）;
end;

{￥ENDIF CPUARM}