Threading and Session Objects

[Roberto López]

Hi,
I´m doing an asp.net application that uploads and downloads files and
folders between the client and the server on my intranet. To do this I have
create threads and it runs Ok but I need to show to the user the progress of
the operation and here is the problem. I try to access to the Session
Variables from inside the thread to show it on a page that automatically
refresh, BUT, I have discovered that there is no access to the httpcontext
from inside the new thread. Is there any other way to do this??

Thanks a lot.

--
Roberto López
Dpto. Soporte Software
Eurosistemas Informáticos y Comunicaciones, S.L.

[S. Justin Gengo]

Here's an article:

[url]http://www.ftponline.com/vsm/2002_11/magazine/features/chester/[/url]

--
S. Justin Gengo, MCP
Web Developer

Free code library at:
[url]www.aboutfortunate.com[/url]

"Out of chaos comes order."
Nietzche
"Roberto López" <rlopez@eurosistemas.net> wrote in message
news:%23Ww7zVpWDHA.2032@TK2MSFTNGP11.phx.gbl...

> Hi,
> I´m doing an asp.net application that uploads and downloads files and
> folders between the client and the server on my intranet. To do this I

have

> create threads and it runs Ok but I need to show to the user the progress

of

> the operation and here is the problem. I try to access to the Session
> Variables from inside the thread to show it on a page that automatically
> refresh, BUT, I have discovered that there is no access to the httpcontext
> from inside the new thread. Is there any other way to do this??
>
> Thanks a lot.
>
> --
> Roberto López
> Dpto. Soporte Software
> Eurosistemas Informáticos y Comunicaciones, S.L.
>
>

[Roberto López]

I just readed this article but, what i need is to access to the session
object from within a class. And doing it I alwais receive an error.


"S. Justin Gengo" <sjgengo@aboutfortunate.com> escribió en el mensaje
news:#m8a6gpWDHA.2040@TK2MSFTNGP11.phx.gbl...

> Here's an article:
>
> [url]http://www.ftponline.com/vsm/2002_11/magazine/features/chester/[/url]
>
> --
> S. Justin Gengo, MCP
> Web Developer
>
> Free code library at:
> [url]www.aboutfortunate.com[/url]
>
> "Out of chaos comes order."
> Nietzche
> "Roberto López" <rlopez@eurosistemas.net> wrote in message
> news:%23Ww7zVpWDHA.2032@TK2MSFTNGP11.phx.gbl...

> > Hi,
> > I´m doing an asp.net application that uploads and downloads files and
> > folders between the client and the server on my intranet. To do this I

> have

> > create threads and it runs Ok but I need to show to the user the

progress

> of

> > the operation and here is the problem. I try to access to the Session
> > Variables from inside the thread to show it on a page that automatically
> > refresh, BUT, I have discovered that there is no access to the

httpcontext

> > from inside the new thread. Is there any other way to do this??
> >
> > Thanks a lot.
> >
> > --
> > Roberto López
> > Dpto. Soporte Software
> > Eurosistemas Informáticos y Comunicaciones, S.L.
> >
> >

>
>

[Roberto López]

The same error appears. For some reason, when the new thread is started from
a class, the httpcontext is set to null to the thread. If it is done from a
aspx page there is no error. Why? I don´t know.


"S. Justin Gengo" <sjgengo@aboutfortunate.com> escribió en el mensaje
news:#vEL9GqWDHA.536@TK2MSFTNGP10.phx.gbl...

> How about passing the session object into the class through a public
> property?
>
> --
> S. Justin Gengo, MCP
> Web Developer
>
> Free code library at:
> [url]www.aboutfortunate.com[/url]
>
> "Out of chaos comes order."
> Nietzche
> "Roberto López" <rlopez@eurosistemas.net> wrote in message
> news:OwpoO%23pWDHA.1640@TK2MSFTNGP10.phx.gbl...

> > I just readed this article but, what i need is to access to the session
> > object from within a class. And doing it I alwais receive an error.
> >
> >
> > "S. Justin Gengo" <sjgengo@aboutfortunate.com> escribió en el mensaje
> > news:#m8a6gpWDHA.2040@TK2MSFTNGP11.phx.gbl...

> > > Here's an article:
> > >
> > > [url]http://www.ftponline.com/vsm/2002_11/magazine/features/chester/[/url]
> > >
> > > --
> > > S. Justin Gengo, MCP
> > > Web Developer
> > >
> > > Free code library at:
> > > [url]www.aboutfortunate.com[/url]
> > >
> > > "Out of chaos comes order."
> > > Nietzche
> > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > news:%23Ww7zVpWDHA.2032@TK2MSFTNGP11.phx.gbl...
> > > > Hi,
> > > > I´m doing an asp.net application that uploads and downloads files

and

> > > > folders between the client and the server on my intranet. To do this

I

> > > have
> > > > create threads and it runs Ok but I need to show to the user the

> > progress

> > > of
> > > > the operation and here is the problem. I try to access to the

Session

> > > > Variables from inside the thread to show it on a page that

> automatically

> > > > refresh, BUT, I have discovered that there is no access to the

> > httpcontext

> > > > from inside the new thread. Is there any other way to do this??
> > > >
> > > > Thanks a lot.
> > > >
> > > > --
> > > > Roberto López
> > > > Dpto. Soporte Software
> > > > Eurosistemas Informáticos y Comunicaciones, S.L.
> > > >
> > > >
> > >
> > >

> >
> >

>
>

[Roberto López]

I have tryed it too. :-(


"John Saunders" <john.saunders@surfcontrol.com> escribió en el mensaje
news:uneo$gqWDHA.2064@TK2MSFTNGP11.phx.gbl...

> Try HttpContext.Current.Session.
> --
> John Saunders
> Internet Engineer
> [email]john.saunders@surfcontrol.com[/email]
>
> "Roberto López" <rlopez@eurosistemas.net> wrote in message
> news:OwpoO%23pWDHA.1640@TK2MSFTNGP10.phx.gbl...

> > I just readed this article but, what i need is to access to the session
> > object from within a class. And doing it I alwais receive an error.
> >
> >
> > "S. Justin Gengo" <sjgengo@aboutfortunate.com> escribió en el mensaje
> > news:#m8a6gpWDHA.2040@TK2MSFTNGP11.phx.gbl...

> > > Here's an article:
> > >
> > > [url]http://www.ftponline.com/vsm/2002_11/magazine/features/chester/[/url]
> > >
> > > --
> > > S. Justin Gengo, MCP
> > > Web Developer
> > >
> > > Free code library at:
> > > [url]www.aboutfortunate.com[/url]
> > >
> > > "Out of chaos comes order."
> > > Nietzche
> > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > news:%23Ww7zVpWDHA.2032@TK2MSFTNGP11.phx.gbl...
> > > > Hi,
> > > > I´m doing an asp.net application that uploads and downloads files

and

> > > > folders between the client and the server on my intranet. To do this

I

> > > have
> > > > create threads and it runs Ok but I need to show to the user the

> > progress

> > > of
> > > > the operation and here is the problem. I try to access to the

Session

> > > > Variables from inside the thread to show it on a page that

> automatically

> > > > refresh, BUT, I have discovered that there is no access to the

> > httpcontext

> > > > from inside the new thread. Is there any other way to do this??
> > > >
> > > > Thanks a lot.
> > > >
> > > > --
> > > > Roberto López
> > > > Dpto. Soporte Software
> > > > Eurosistemas Informáticos y Comunicaciones, S.L.
> > > >
> > > >
> > >
> > >

> >
> >

>
>

[John Saunders]

Perhaps you could supply a reproducer? I don't immediately see why there
would be a problem passing Page.Context to the new thread before it starts.
In particular, I can't imagine how, if you passed a non-null HttpContext
into the thread, it would become null. I can understand how it could become
invalid, but not how it could become null.
--
John Saunders
Internet Engineer
[email]john.saunders@surfcontrol.com[/email]

"Roberto López" <rlopez@eurosistemas.net> wrote in message
news:eHD7uoqWDHA.2100@TK2MSFTNGP11.phx.gbl...

> I have tryed it too. :-(
>
>
> "John Saunders" <john.saunders@surfcontrol.com> escribió en el mensaje
> news:uneo$gqWDHA.2064@TK2MSFTNGP11.phx.gbl...

> > Try HttpContext.Current.Session.
> > --
> > John Saunders
> > Internet Engineer
> > [email]john.saunders@surfcontrol.com[/email]
> >
> > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > news:OwpoO%23pWDHA.1640@TK2MSFTNGP10.phx.gbl...

> > > I just readed this article but, what i need is to access to the

session

> > > object from within a class. And doing it I alwais receive an error.
> > >
> > >
> > > "S. Justin Gengo" <sjgengo@aboutfortunate.com> escribió en el mensaje
> > > news:#m8a6gpWDHA.2040@TK2MSFTNGP11.phx.gbl...
> > > > Here's an article:
> > > >
> > > > [url]http://www.ftponline.com/vsm/2002_11/magazine/features/chester/[/url]
> > > >
> > > > --
> > > > S. Justin Gengo, MCP
> > > > Web Developer
> > > >
> > > > Free code library at:
> > > > [url]www.aboutfortunate.com[/url]
> > > >
> > > > "Out of chaos comes order."
> > > > Nietzche
> > > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > > news:%23Ww7zVpWDHA.2032@TK2MSFTNGP11.phx.gbl...
> > > > > Hi,
> > > > > I´m doing an asp.net application that uploads and downloads files

> and

> > > > > folders between the client and the server on my intranet. To do

this

> I

> > > > have
> > > > > create threads and it runs Ok but I need to show to the user the
> > > progress
> > > > of
> > > > > the operation and here is the problem. I try to access to the

> Session

> > > > > Variables from inside the thread to show it on a page that

> > automatically

> > > > > refresh, BUT, I have discovered that there is no access to the
> > > httpcontext
> > > > > from inside the new thread. Is there any other way to do this??
> > > > >
> > > > > Thanks a lot.
> > > > >
> > > > > --
> > > > > Roberto López
> > > > > Dpto. Soporte Software
> > > > > Eurosistemas Informáticos y Comunicaciones, S.L.
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >

> >
> >

>
>

[Roberto López]

The problem is that I not only need to read values from session variables,
i need to update session variables while the new thread is running, and here
is the problem. When i try to set a new value to a session variable I
receive
the error of HttpContext is a Null Reference.
I need to store a value into the session variable to read it periodically
from other
page to know about the status of the process. I hope you understand me.

My code is like this:

public class AccessIO

public sub New()

end sub

public sub CopyFiles()
...routine to copy files...
...... ..... ... ..


...here is the error...
httpcontext.current.session("PercentComplete") = anyvalue

end sub

end class


"John Saunders" <john.saunders@surfcontrol.com> escribió en el mensaje
news:Ogl801qWDHA.1644@TK2MSFTNGP10.phx.gbl...

> Perhaps you could supply a reproducer? I don't immediately see why there
> would be a problem passing Page.Context to the new thread before it

starts.

> In particular, I can't imagine how, if you passed a non-null HttpContext
> into the thread, it would become null. I can understand how it could

become

> invalid, but not how it could become null.
> --
> John Saunders
> Internet Engineer
> [email]john.saunders@surfcontrol.com[/email]
>
> "Roberto López" <rlopez@eurosistemas.net> wrote in message
> news:eHD7uoqWDHA.2100@TK2MSFTNGP11.phx.gbl...

> > I have tryed it too. :-(
> >
> >
> > "John Saunders" <john.saunders@surfcontrol.com> escribió en el mensaje
> > news:uneo$gqWDHA.2064@TK2MSFTNGP11.phx.gbl...

> > > Try HttpContext.Current.Session.
> > > --
> > > John Saunders
> > > Internet Engineer
> > > [email]john.saunders@surfcontrol.com[/email]
> > >
> > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > news:OwpoO%23pWDHA.1640@TK2MSFTNGP10.phx.gbl...
> > > > I just readed this article but, what i need is to access to the

> session

> > > > object from within a class. And doing it I alwais receive an error.
> > > >
> > > >
> > > > "S. Justin Gengo" <sjgengo@aboutfortunate.com> escribió en el

mensaje

> > > > news:#m8a6gpWDHA.2040@TK2MSFTNGP11.phx.gbl...
> > > > > Here's an article:
> > > > >
> > > > > [url]http://www.ftponline.com/vsm/2002_11/magazine/features/chester/[/url]
> > > > >
> > > > > --
> > > > > S. Justin Gengo, MCP
> > > > > Web Developer
> > > > >
> > > > > Free code library at:
> > > > > [url]www.aboutfortunate.com[/url]
> > > > >
> > > > > "Out of chaos comes order."
> > > > > Nietzche
> > > > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > > > news:%23Ww7zVpWDHA.2032@TK2MSFTNGP11.phx.gbl...
> > > > > > Hi,
> > > > > > I´m doing an asp.net application that uploads and downloads

files

> > and

> > > > > > folders between the client and the server on my intranet. To do

> this

> > I

> > > > > have
> > > > > > create threads and it runs Ok but I need to show to the user the
> > > > progress
> > > > > of
> > > > > > the operation and here is the problem. I try to access to the

> > Session

> > > > > > Variables from inside the thread to show it on a page that
> > > automatically
> > > > > > refresh, BUT, I have discovered that there is no access to the
> > > > httpcontext
> > > > > > from inside the new thread. Is there any other way to do this??
> > > > > >
> > > > > > Thanks a lot.
> > > > > >
> > > > > > --
> > > > > > Roberto López
> > > > > > Dpto. Soporte Software
> > > > > > Eurosistemas Informáticos y Comunicaciones, S.L.
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >

> >
> >

>
>

[John Saunders]

Roberto, don't do that.

Instead, house your thread in a separate class. Give that class a private
member variable of type HttpContext, say, m_Context. Write a public property
of type HttpContext say, TheContext.

To use the thread, create an instance of the thread class. Then use that
instance to set the property:

myThread.TheContext = Page.Context

Then start the thread. The thread can then access m_Context instead of
HttpContext.Current.

--
John Saunders
Internet Engineer
[email]john.saunders@surfcontrol.com[/email]

"Roberto López" <rlopez@eurosistemas.net> wrote in message
news:O3LPLErWDHA.2268@TK2MSFTNGP11.phx.gbl...

> The problem is that I not only need to read values from session variables,
> i need to update session variables while the new thread is running, and

here

> is the problem. When i try to set a new value to a session variable I
> receive
> the error of HttpContext is a Null Reference.
> I need to store a value into the session variable to read it periodically
> from other
> page to know about the status of the process. I hope you understand me.
>
> My code is like this:
>
> public class AccessIO
>
> public sub New()
>
> end sub
>
> public sub CopyFiles()
> ...routine to copy files...
> ...... ..... ... ..
>
>
> ...here is the error...
> httpcontext.current.session("PercentComplete") = anyvalue
>
> end sub
>
> end class
>
>
> "John Saunders" <john.saunders@surfcontrol.com> escribió en el mensaje
> news:Ogl801qWDHA.1644@TK2MSFTNGP10.phx.gbl...

> > Perhaps you could supply a reproducer? I don't immediately see why there
> > would be a problem passing Page.Context to the new thread before it

> starts.

> > In particular, I can't imagine how, if you passed a non-null HttpContext
> > into the thread, it would become null. I can understand how it could

> become

> > invalid, but not how it could become null.
> > --
> > John Saunders
> > Internet Engineer
> > [email]john.saunders@surfcontrol.com[/email]
> >
> > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > news:eHD7uoqWDHA.2100@TK2MSFTNGP11.phx.gbl...

> > > I have tryed it too. :-(
> > >
> > >
> > > "John Saunders" <john.saunders@surfcontrol.com> escribió en el mensaje
> > > news:uneo$gqWDHA.2064@TK2MSFTNGP11.phx.gbl...
> > > > Try HttpContext.Current.Session.
> > > > --
> > > > John Saunders
> > > > Internet Engineer
> > > > [email]john.saunders@surfcontrol.com[/email]
> > > >
> > > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > > news:OwpoO%23pWDHA.1640@TK2MSFTNGP10.phx.gbl...
> > > > > I just readed this article but, what i need is to access to the

> > session

> > > > > object from within a class. And doing it I alwais receive an

error.

> > > > >
> > > > >
> > > > > "S. Justin Gengo" <sjgengo@aboutfortunate.com> escribió en el

> mensaje

> > > > > news:#m8a6gpWDHA.2040@TK2MSFTNGP11.phx.gbl...
> > > > > > Here's an article:
> > > > > >
> > > > > > [url]http://www.ftponline.com/vsm/2002_11/magazine/features/chester/[/url]
> > > > > >
> > > > > > --
> > > > > > S. Justin Gengo, MCP
> > > > > > Web Developer
> > > > > >
> > > > > > Free code library at:
> > > > > > [url]www.aboutfortunate.com[/url]
> > > > > >
> > > > > > "Out of chaos comes order."
> > > > > > Nietzche
> > > > > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > > > > news:%23Ww7zVpWDHA.2032@TK2MSFTNGP11.phx.gbl...
> > > > > > > Hi,
> > > > > > > I´m doing an asp.net application that uploads and downloads

> files

> > > and
> > > > > > > folders between the client and the server on my intranet. To

do

> > this

> > > I
> > > > > > have
> > > > > > > create threads and it runs Ok but I need to show to the user

the

> > > > > progress
> > > > > > of
> > > > > > > the operation and here is the problem. I try to access to the
> > > Session
> > > > > > > Variables from inside the thread to show it on a page that
> > > > automatically
> > > > > > > refresh, BUT, I have discovered that there is no access to the
> > > > > httpcontext
> > > > > > > from inside the new thread. Is there any other way to do

this??

> > > > > > >
> > > > > > > Thanks a lot.
> > > > > > >
> > > > > > > --
> > > > > > > Roberto López
> > > > > > > Dpto. Soporte Software
> > > > > > > Eurosistemas Informáticos y Comunicaciones, S.L.
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >

> >
> >

>
>

[Homa]

Although I don't know what will the performance impact be, but I think
this should work:

In your main thread, the thread have valid permission to access/modify
Session, you can process the events raised by the threads and do
Invokes inside the handlers, then you can do what ever you want.

Therefore, create some events for the theads (I assume you use a class
to wrap the thread function).

Hope it helps,
Homa Wong

"Roberto López" <rlopez@eurosistemas.net> wrote in message news:<O3LPLErWDHA.2268@TK2MSFTNGP11.phx.gbl>...

> The problem is that I not only need to read values from session variables,
> i need to update session variables while the new thread is running, and here
> is the problem. When i try to set a new value to a session variable I
> receive
> the error of HttpContext is a Null Reference.
> I need to store a value into the session variable to read it periodically
> from other
> page to know about the status of the process. I hope you understand me.
>
> My code is like this:
>
> public class AccessIO
>
> public sub New()
>
> end sub
>
> public sub CopyFiles()
> ...routine to copy files...
> ...... ..... ... ..
>
>
> ...here is the error...
> httpcontext.current.session("PercentComplete") = anyvalue
>
> end sub
>
> end class
>
>
> "John Saunders" <john.saunders@surfcontrol.com> escribió en el mensaje
> news:Ogl801qWDHA.1644@TK2MSFTNGP10.phx.gbl...

> > Perhaps you could supply a reproducer? I don't immediately see why there
> > would be a problem passing Page.Context to the new thread before it

> starts.

> > In particular, I can't imagine how, if you passed a non-null HttpContext
> > into the thread, it would become null. I can understand how it could

> become

> > invalid, but not how it could become null.
> > --
> > John Saunders
> > Internet Engineer
> > [email]john.saunders@surfcontrol.com[/email]
> >
> > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > news:eHD7uoqWDHA.2100@TK2MSFTNGP11.phx.gbl...

> > > I have tryed it too. :-(
> > >
> > >
> > > "John Saunders" <john.saunders@surfcontrol.com> escribió en el mensaje
> > > news:uneo$gqWDHA.2064@TK2MSFTNGP11.phx.gbl...
> > > > Try HttpContext.Current.Session.
> > > > --
> > > > John Saunders
> > > > Internet Engineer
> > > > [email]john.saunders@surfcontrol.com[/email]
> > > >
> > > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > > news:OwpoO%23pWDHA.1640@TK2MSFTNGP10.phx.gbl...
> > > > > I just readed this article but, what i need is to access to the

> session

> > > > > object from within a class. And doing it I alwais receive an error.
> > > > >
> > > > >
> > > > > "S. Justin Gengo" <sjgengo@aboutfortunate.com> escribió en el

> mensaje

> > > > > news:#m8a6gpWDHA.2040@TK2MSFTNGP11.phx.gbl...
> > > > > > Here's an article:
> > > > > >
> > > > > > [url]http://www.ftponline.com/vsm/2002_11/magazine/features/chester/[/url]
> > > > > >
> > > > > > --
> > > > > > S. Justin Gengo, MCP
> > > > > > Web Developer
> > > > > >
> > > > > > Free code library at:
> > > > > > [url]www.aboutfortunate.com[/url]
> > > > > >
> > > > > > "Out of chaos comes order."
> > > > > > Nietzche
> > > > > > "Roberto López" <rlopez@eurosistemas.net> wrote in message
> > > > > > news:%23Ww7zVpWDHA.2032@TK2MSFTNGP11.phx.gbl...
> > > > > > > Hi,
> > > > > > > I´m doing an asp.net application that uploads and downloads

> files
> and

> > > > > > > folders between the client and the server on my intranet. To do

> this
> I
> have

> > > > > > > create threads and it runs Ok but I need to show to the user the

> progress
> of

> > > > > > > the operation and here is the problem. I try to access to the

> Session

> > > > > > > Variables from inside the thread to show it on a page that

> automatically

> > > > > > > refresh, BUT, I have discovered that there is no access to the

> httpcontext

> > > > > > > from inside the new thread. Is there any other way to do this??
> > > > > > >
> > > > > > > Thanks a lot.
> > > > > > >
> > > > > > > --
> > > > > > > Roberto López
> > > > > > > Dpto. Soporte Software
> > > > > > > Eurosistemas Informáticos y Comunicaciones, S.L.
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >

> >
> >

[Natty Gur]

Hi,

Pass the session as a parameter to the thread (works like charm). This
link contain example :

[url]http://www.developersdex.com/gurus/code/662.asp[/url]

Natty Gur, CTO
Dao2Com Ltd.
34th Elkalay st. Raanana
Israel , 43000
Phone Numbers:
Office: +972-(0)9-7740261
Fax: +972-(0)9-7740261
Mobile: +972-(0)58-888377


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[Roberto López]

I don´t understand clearly the code you write, but, with this, can I write
new values in session variables and these are readable from other page while
the thread is running?


"Natty Gur" <natty@dao2com.com> escribió en el mensaje
news:OZbn9RxWDHA.3924@tk2msftngp13.phx.gbl...

> Hi,
>
> Pass the session as a parameter to the thread (works like charm). This
> link contain example :
>
> [url]http://www.developersdex.com/gurus/code/662.asp[/url]
>
> Natty Gur, CTO
> Dao2Com Ltd.
> 34th Elkalay st. Raanana
> Israel , 43000
> Phone Numbers:
> Office: +972-(0)9-7740261
> Fax: +972-(0)9-7740261
> Mobile: +972-(0)58-888377
>
>
> *** Sent via Developersdex [url]http://www.developersdex.com[/url] ***
> Don't just participate in USENET...get rewarded for it!