我创建了这个“threadsafe”通用属性,我可以在主线程和后台线程之间使用.我做到这一点,因为我厌倦了为所有的属性和变量创建Lock对象.
TLockedProp<MyType> = class
private
FMyProp:MyType;
PropLock:TObject;
procedure SetMyProp(const Value: MyType);
function GetMyProp: MyType;
published
property Value:MyType read GetMyProp write SetMyProp;
public
Constructor Create;
Destructor Destroy;override;
end;
{ TLockedProp<MyType> }
constructor TLockedProp<MyType>.Create;
begin
inherited;
PropLock:=TObject.create
end;
destructor TLockedProp<MyType>.Destroy;
begin
PropLock.Free;
inherited;
end;
function TLockedProp<MyType>.GetMyProp: MyType;
begin
TMonitor.Enter(PropLock);
result := FMyProp;
TMonitor.Exit(PropLock);
end;
procedure TLockedProp<MyType>.SetMyProp(const Value: MyType);
begin
TMonitor.Enter(PropLock);
FMyProp := Value;
TMonitor.Exit(PropLock);
end;
有什么问题我俯瞰吗？
这是使用这个属性类的一些代码.告诉我你的想法.
TBgThread=class(TThread)
private
FPaused: TLockedProp<boolean>;
FCount:TLockedProp<integer>;
procedure ChangeCount(pPlusMin:integer);
function GetPaused:boolean;
function GetCount:integer;
public
constructor Create;
destructor Destroy;override;
{Toggle Pause}
procedure PausePlay;
protected
procedure Execute;override;
published
Property Paused:boolean read GetPaused;
Property Count:integer read GetCount;
end;
constructor TBgThread.Create();
begin
inherited Create(true);;
FPaused:=TLockedProp<boolean>.create;
FPaused.Value:=false;
FCount:=TLockedProp<integer>.create;
FCount.Value:=0;
end;
destructor TBgThread.Destroy;
begin
FPaused.Free;
FCount.free;
inherited;
end;
procedure TBgThread.Execute;
begin
inherited;
Repeat
if not Paused then begin
Try
//do something
finally
ChangeCount(+1);
end;
end else
Sleep(90);
Until Terminated;
end;
function TBgThread.GetCount: integer;
begin
Result:=FCount.Value;
end;
procedure TBgThread.ChangeCount(pPlusMin: integer);
begin
FCount.Value:=FCount.Value+pPlusMin;
end;
function TBgThread.GetPaused: boolean;
begin
result := FPaused.Value;
end;
procedure TBgThread.PausePlay;
begin
FPaused.Value:=not FPaused.Value;
end;
解决方法
你的代码很好,并且将序列化对该属性的读/写访问.我唯一的注释是,您不需要创建一个单独的锁定对象.您可以删除PropLock并锁定Self.
我的代码库中有几乎相同的类.唯一的区别是：
>我使用关键部分而不是TMonitor,因为我仍然不信任TMonitor.早期的版本有一些错误,并且暗示了我的信心.不过,我怀疑现在TMonitor代码很可能是正确的.所以我看不到你改变的理由.
>我使用try / finally与锁定和解锁的代码.这可能对我来说有点悲观,因为很难看到你如何从getter和setter方法中的异常中有效地恢复.假设我的习惯.
FWIW,我的班级看起来像这样：
type
TThreadsafe<T> = class
private
FLock: TCriticalSection;
FValue: T;
function GetValue: T;
procedure SetValue(const NewValue: T);
public
constructor Create;
destructor Destroy; override;
property Value: T read GetValue write SetValue;
end;
{ TThreadsafe<T> }
constructor TThreadsafe<T>.Create;
begin
inherited;
FLock := TCriticalSection.Create;
end;
destructor TThreadsafe<T>.Destroy;
begin
FLock.Free;
inherited;
end;
function TThreadsafe<T>.GetValue: T;
begin
FLock.Acquire;
Try
Result := FValue;
Finally
FLock.Release;
End;
end;
procedure TThreadsafe<T>.SetValue(const NewValue: T);
begin
FLock.Acquire;
Try
FValue := NewValue;
Finally
FLock.Release;
End;
end;
我想真的只有一种方法来写这个课程！