在WINDOWS里面使用临界来保护多线程需要访问的共享对象，现在，DELPHI有了新的跨平台临界保护者--System.TMonitor

代码演示如下：

FConnections := TObjectDictionary<TIdTCPConnection,TDSTCPChannel>.Create;

。。。

procedure TCMServerForm.CMServerTransportDisconnectEvent(Event: TDSTCPDisconnectEventObject);
var
Index: Integer;
begin
if (FConnections = nil) or (Event.Connection = nil) then
Exit;

//进入临界保护
System.TMonitor.Enter(FConnections);
try
FConnections.Remove(TIdTCPConnection(Event.Connection));

TThread.Synchronize(nil, procedure
begin
//update the connection list box, removing the connection that was just closed
Index := ConnectionsList.Items.IndexOfObject(Event.Connection);
if Index > -1 then
begin
ConnectionsList.Items.Delete(Index);

if ConnectionsList.SelCount = 0 then
SessionIdList.ClearSelection;
end;
end);
finally

// 终止临界保护
System.TMonitor.Exit(FConnections);
end;
end;