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digitalmars.D.learn - Any application shutdown hooks?

reply Matthew Ong <ongbp yahoo.com> writes:
Hi,

If I am writing a database library such as DSL, Data Service Layer, 
there is a need for me to do a good clean up for the connections/results 
sets/transactions that this library is currently handling.

How ever, if another library/package somewhere else calls for a


java.lang.Runtime#public void addShutdownHook(Thread hook)


How do code or what library to use?

can someone please provide a simple working D example for try out.

Of cause, in Even in Java there is event if some cleaning lady were to 
accidentally unplug the main socket of your server. :)


-- 
Matthew Ong
email: ongbp yahoo.com
May 25 2011
parent reply "Steven Schveighoffer" <schveiguy yahoo.com> writes:
http://www.digitalmars.com/d/2.0/class.html#StaticDestructor

-Steve
May 25 2011
parent reply Matthew Ong <ongbp yahoo.com> writes:
On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:

 http://www.digitalmars.com/d/2.0/class.html#StaticDestructor

 -Steve


Static Destructor maybe executed when the class is being unloaded GC?
Because this is a class level. It is more like the application level 
exit and such.

That is not really the same as:
http://download.oracle.com/javase/1.4.2/docs/api/java/lang/Runtime.html#addShutdownHook%28java.lang.Thread%29


This is triggered when:

when the exit (equivalently, System.exit) method is invoked, or


such as typing ^C, or a system-wide event, such as user logoff or system 
shutdown.



-- 
Matthew Ong
email: ongbp yahoo.com
May 25 2011
next sibling parent reply =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:
On 05/25/2011 08:35 AM, Matthew Ong wrote:

 On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:

 http://www.digitalmars.com/d/2.0/class.html#StaticDestructor

 -Steve


 Static Destructor maybe executed when the class is being unloaded GC?
 Because this is a class level. It is more like the application level
 exit and such.


There is a problem at Digital Mars's site. Steve must have meant the 
module static destructor. Search for "Static Construction and 
Destruction" on the module page:

   http://www.digitalmars.com/d/2.0/module.html

(Do not click StaticDestructor at the top of the page. That is linked to 
the class page.)

Ali
May 25 2011
parent "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Wed, 25 May 2011 11:50:16 -0400, Ali Çehreli <acehreli yahoo.com> wrote:


 On 05/25/2011 08:35 AM, Matthew Ong wrote:

 On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:

 http://www.digitalmars.com/d/2.0/class.html#StaticDestructor

 -Steve


 Static Destructor maybe executed when the class is being unloaded GC?
 Because this is a class level. It is more like the application level
 exit and such.


 There is a problem at Digital Mars's site. Steve must have meant the  
 module static destructor. Search for "Static Construction and  
 Destruction" on the module page:

    http://www.digitalmars.com/d/2.0/module.html

 (Do not click StaticDestructor at the top of the page. That is linked to  
 the class page.)


Oh, yeah, that's exactly what I did!  hm...

Need to file a bug. (filed as  
http://d.puremagic.com/issues/show_bug.cgi?id=6055 )

Note that class static dtors are exactly the same as module static dtors,  
they just are inside the class namespace.

-Steve
May 25 2011
prev sibling parent reply "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Wed, 25 May 2011 11:35:51 -0400, Matthew Ong <ongbp yahoo.com> wrote:


 On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:

 http://www.digitalmars.com/d/2.0/class.html#StaticDestructor

 -Steve


 Static Destructor maybe executed when the class is being unloaded GC?
 Because this is a class level. It is more like the application level  
 exit and such.


This is *exactly* what static destructors do.

"A static destructor gets called on program termination"

Actually, that description is inaccurate for non-shared static dtors,  
someone should fix that.


 That is not really the same as:
 http://download.oracle.com/javase/1.4.2/docs/api/java/lang/Runtime.html#addShutdownHook%28java.lang.Thread%29


If you want a static dtor that runs on every thread shutdown, use a normal  
static dtor.  If you want one that runs on the entire application  
shutdown, use a shared static dtor.

-Steve
May 25 2011
next sibling parent Matthew Ong <ongbp yahoo.com> writes:
On 5/25/2011 11:52 PM, Steven Schveighoffer wrote:

 If you want a static dtor that runs on every thread shutdown, use a
 normal static dtor. If you want one that runs on the entire application
 shutdown, use a shared static dtor.

 -Steve


Module Destructor: Cool feature that I can consider to use for other 
purpose.


If you want one that runs on the entire application shutdown, use a 
shared static dtor.


It is more like an entire application shutdown event. So I will be 
placing that at the same module dtor and file as the main(string[] args)
using template mixin.

That might work. I will test that out.

-- 
Matthew Ong
email: ongbp yahoo.com
May 25 2011
prev sibling next sibling parent "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Wed, 25 May 2011 11:52:14 -0400, Steven Schveighoffer  
<schveiguy yahoo.com> wrote:


 On Wed, 25 May 2011 11:35:51 -0400, Matthew Ong <ongbp yahoo.com> wrote:


 On 5/25/2011 11:13 PM, Steven Schveighoffer wrote:

 http://www.digitalmars.com/d/2.0/class.html#StaticDestructor

 -Steve


 Static Destructor maybe executed when the class is being unloaded GC?
 Because this is a class level. It is more like the application level  
 exit and such.


 This is *exactly* what static destructors do.

 "A static destructor gets called on program termination"

 Actually, that description is inaccurate for non-shared static dtors,  
 someone should fix that.


 That is not really the same as:
 http://download.oracle.com/javase/1.4.2/docs/api/java/lang/Runtime.html#addShutdownHook%28java.lang.Thread%29


 If you want a static dtor that runs on every thread shutdown, use a  
 normal static dtor.  If you want one that runs on the entire application  
 shutdown, use a shared static dtor.


I should clarify that when I wrote this, I thought the description was  
 from the module.html file, not the class.html file.  Ali pointed out the  
bug in the web site.  So I didn't get why you were talking about classes,  
sorry :)

Class and module static ctor/dtors should be exactly what you are looking  
for.

-Steve
May 25 2011
prev sibling parent reply Andrej Mitrovic <andrej.mitrovich gmail.com> writes:
On 5/25/11, Steven Schveighoffer <schveiguy yahoo.com> wrote:

 If you want a static dtor that runs on every thread shutdown, use a normal
 static dtor.  If you want one that runs on the entire application
 shutdown, use a shared static dtor.


I saw some commits change a static dtor to a shared static dtor and
wondered what was that all about..
May 25 2011
parent reply Matthew Ong <ongbp yahoo.com> writes:
On 5/26/2011 12:23 AM, Andrej Mitrovic wrote:

 On 5/25/11, Steven Schveighoffer<schveiguy yahoo.com>  wrote:

 If you want a static dtor that runs on every thread shutdown, use a normal
 static dtor.  If you want one that runs on the entire application
 shutdown, use a shared static dtor.


 I saw some commits change a static dtor to a shared static dtor and
 wondered what was that all about..


Thanks a lot for the all the comments and instructions shown here.

-- 
Matthew Ong
email: ongbp yahoo.com
May 25 2011
parent Matthew Ong <ongbp yahoo.com> writes:
 On 5/25/11, Steven Schveighoffer<schveiguy yahoo.com> wrote:




If you want a static dtor that runs on every thread shutdown, use a

 normal
 static dtor. If you want one that runs on the entire application
 shutdown, use a shared static dtor.


 I saw some commits change a static dtor to a shared static dtor and
 wondered what was that all about..


 Thanks a lot for the all the comments and instructions shown here.


Perhaps writing a mixin at module where the main method is located will 
do that exactly.

others may be dll and could be unloaded and cause __dtor to be called.

Will try such direction. Thanks people.

-- 
Matthew Ong
email: ongbp yahoo.com
May 26 2011