BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Automatic objects for delphi Goto page 1, 2  Next          BorlandTalk.com Forum Index -> Delphi OO design View previous topic :: View next topic   Author Message Vivek Guest Posted: Sat Oct 22, 2005 6:50 pm    Post subject: Automatic objects for delphi Please see http://cc.borland.com/Item.aspx?ID=23718 for a cool automatic objects hack for delphi 6 and above Back to top Bob Dawson Guest Posted: Sat Oct 22, 2005 7:46 pm    Post subject: Re: Automatic objects for delphi "Vivek" wrote Quote: Please see http://cc.borland.com/Item.aspx?ID=23718 Sorry, don't see the point. ISTM that Free works fine, runs faster, and is easier to read: bobD Back to top Marc Rohloff [TeamB] Guest Posted: Sat Oct 22, 2005 9:27 pm    Post subject: Re: Automatic objects for delphi On Sat, 22 Oct 2005 14:46:44 -0500, Bob Dawson wrote: Quote: "Vivek" wrote Please see http://cc.borland.com/Item.aspx?ID=23718 Sorry, don't see the point. ISTM that Free works fine, runs faster, and is easier to read: Just to play devil's advocate here, at least it doesn't require exception handling. -- Marc Rohloff [TeamB] marc rohloff -at- myrealbox -dot- com Back to top Bob Dawson Guest Posted: Sat Oct 22, 2005 11:45 pm    Post subject: Re: Automatic objects for delphi "Marc Rohloff [TeamB]" wrote Quote: Just to play devil's advocate here, at least it doesn't require exception handling. Admit I didn't try it, but would be willing to bet that the try finally block is faster than the interfaced wrapper. bobD Back to top Marc Rohloff [TeamB] Guest Posted: Sun Oct 23, 2005 12:30 am    Post subject: Re: Automatic objects for delphi On Sat, 22 Oct 2005 18:45:29 -0500, Bob Dawson wrote: Quote: Just to play devil's advocate here, at least it doesn't require exception handling. Admit I didn't try it, but would be willing to bet that the try finally block is faster than the interfaced wrapper. I don't know exception handling is *really* expensive and you could even possibly create your interface wrapper without reference counting since its should never get more than one AddRef. Although to be honest here I should mention that the moment you add an interface ref to a procedure it will get a hidden try..finally block to handle it (although this block is probably already created since it also needs to exist for strings and dynamic arrays) -- Marc Rohloff [TeamB] marc rohloff -at- myrealbox -dot- com Back to top Bob Dawson Guest Posted: Sun Oct 23, 2005 12:55 am    Post subject: Re: Automatic objects for delphi "Marc Rohloff [TeamB]" wrote Quote: I don't know exception handling is *really* expensive Alright--I'll try to run a test or two tonight or tomorrow and report back. bobD Back to top Rob Kennedy Guest Posted: Sun Oct 23, 2005 4:32 am    Post subject: Re: Automatic objects for delphi Bob Dawson wrote: Quote: "Marc Rohloff [TeamB]" wrote Just to play devil's advocate here, at least it doesn't require exception handling. Admit I didn't try it, but would be willing to bet that the try finally block is faster than the interfaced wrapper. When you use interfaces in a function, the compiler automatically wraps the body of the function in a try-finally handler so it can call _Release on the interface. It's the same try-finally the compiler inserts to ensure that AnsiStrings, WideStrings, dynamic arrays, and Variants get freed. So, although you don't actually type the words "try" and "finally," there's still a try-finally block there, and it still gets triggered on exceptions. -- Rob Back to top Vivek Guest Posted: Sun Oct 23, 2005 6:22 am    Post subject: Re: Automatic objects for delphi Hi Sure it might be a little inefficient because of all the wrapping, but just consider that you can jump out of the method using Exit, without bothering that youve left something unfreed ,this reduces in many cases the level of nesting of if blocks. For me, coming from a C++ background, the convenience of this is worth the slight inefficiency. Maybe the functions can be inlined if performance is an issue. Regards Back to top Thomas Mueller Guest Posted: Sun Oct 23, 2005 10:42 am    Post subject: Re: Automatic objects for delphi Hi, Vivek wrote: Quote: Sure it might be a little inefficient because of all the wrapping, but just consider that you can jump out of the method using Exit, without bothering that youve left something unfreed ,this reduces in many cases the level of nesting of if blocks. You could instead just use one try..finally begin MyObj := TMyClass.Create; try [more code here] exit; // -> this will also execute the finally block [more code here] finally MyObj.Free; end; end; But I have to admit, that I have started using more and more interfaces. twm Back to top Abdullah Kauchali Guest Posted: Sun Oct 23, 2005 10:55 am    Post subject: Re: Automatic objects for delphi Vivek wrote: Quote: Please see http://cc.borland.com/Item.aspx?ID=23718 for a cool automatic objects hack for delphi 6 and above Thanks for that! Just one question: why D6 and above? What's missing in D5? Back to top Vivek Guest Posted: Sun Oct 23, 2005 12:52 pm    Post subject: Re: Automatic objects for delphi Abdullah Kauchali <non (AT) non (DOT) com> wrote: Quote: Thanks for that! Just one question: why D6 and above? What's missing in D5? I believe TInterfacedObject was provided only in D6. There might be some other similar class which can be substituted for it in D5. Cheerio Back to top Vivek Guest Posted: Sun Oct 23, 2005 1:57 pm    Post subject: Re: Automatic objects for delphi Thomas Mueller <spam (AT) dummzeuch (DOT) de> wrote: Quote: You could instead just use one try..finally .... Snip ... But I have to admit, that I have started using more and more interfaces. Well, the fact that it goes to the finally block on Exit was new to me! What my hack allows is that you dont have to bother making any interfaces, You can make it work with any TObject descendent. Why type all that extra try..finally code just for freeing objects when the compiler adds it for you? BTW preformance testing on d6 and d2005 trial show : D2005 (TStringList) Auto objects - 1.18 Million objects per second Normal objects - 2 Million objects per second D6 Auto objects - 1.26 Million objects per second Normal objects - 2.05 Million objects per second using register and/or inline didn't make any difference. So there is a 5:3 performance penalty... However for TBitmap, All return identical results of about 1.14 million objects per second. Regards Back to top Bob Dawson Guest Posted: Sun Oct 23, 2005 3:58 pm    Post subject: Re: Automatic objects for delphi "Vivek" wrote Quote: [...] just consider that you can jump out of the method using Exit, without bothering So one advantage to the technique is that it makes it easier to write poorly structured code? <g> bobD Back to top Krisztian Pinter Guest Posted: Sun Oct 23, 2005 4:19 pm    Post subject: Re: Automatic objects for delphi On 22 Oct 2005 11:50:56 -0700, Vivek <rep.movsd (AT) gmail (DOT) com> wrote: Quote: Please see http://cc.borland.com/Item.aspx?ID=23718 for a cool automatic objects hack for delphi 6 and above can anyone please tell me where in the documentation is precisely described the automatic cleanup policy? afaik, it is not fixed, so compiler can optimize your code, and might release the interface and thus the object: 1. on TestIt routine exit. that's ok. 2. immediately after calling MakeAutoObject, as you don't use it anymore 3. inside MakeAutoObject, after the Make call, as you don't use it anymore it can be the case, that the current implementation of the compiler does not recognise these possibilities, but A. how can you be sure, if not told? reverse engineer compiler? B. how can you tell it will not change in future? Back to top Bob Dawson Guest Posted: Sun Oct 23, 2005 4:36 pm    Post subject: Re: Automatic objects for delphi "Krisztian Pinter" wrote Quote: afaik, it is not fixed, so compiler can optimize your code, and might release the interface and thus the object: Keen observation--I'm pretty sure it's not guaranteed to be the last thing before the final 'end;'. Would be interesting to play around with the routine to see if your could affect that--perhaps by adding wait states, making other allocation calls, or some other technique that might trigger the compiler (or runtime, if reference management is handled opportunistically) to handle cleanup earlier. bobD Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> Delphi OO design All times are GMT Goto page 1, 2  Next Page 1 of 2   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.