Class used by multiple threads to write to Table

[cj]

I want to make a class that will write data to a in memory table. This
class will be called by multiple threads. I'm hoping the table can stay
in memory between calls and all the call by the thread will have to do
is pass some data to be added to the table. Kinda like this class I
have to write to a log file.

Public Class MyStringLogger
Private Shared m_loglock As New Object

Public Shared Sub Write(ByVal fileName As String, ByVal strToWrite
As String)
SyncLock (m_loglock)
Try
Dim sw As New System.io.Strea mWriter(fileNam e, True)
sw.WriteLine(st rToWrite)
sw.Close()
Catch
End Try
End SyncLock
End Sub
End Class

Any idea how I'd do this?

[Cor Ligthert [MVP]]

Re: Class used by multiple threads to write to Table

cj,

Are you sure that you don't need the queue class which is very standard for
this?

http://msdn2.microsoft.com/en-us/library/ms287330.aspx

I hope this helps,

Cor

"cj" <cj@nospam.nosp amschreef in bericht
news:OenEEPunGH A.4892@TK2MSFTN GP03.phx.gbl...

>I want to make a class that will write data to a in memory table. This
>class will be called by multiple threads. I'm hoping the table can stay in
>memory between calls and all the call by the thread will have to do is pass
>some data to be added to the table. Kinda like this class I have to write
>to a log file.
>
Public Class MyStringLogger
Private Shared m_loglock As New Object
>
Public Shared Sub Write(ByVal fileName As String, ByVal strToWrite As
String)
SyncLock (m_loglock)
Try
Dim sw As New System.io.Strea mWriter(fileNam e, True)
sw.WriteLine(st rToWrite)
sw.Close()
Catch
End Try
End SyncLock
End Sub
End Class
>
Any idea how I'd do this?

[Jeffrey Tan[MSFT]]

RE: Class used by multiple threads to write to Table

Hi Cj,

It seems Cor Ligthert [MVP] provided an incorrect URL for queue class, I
think he is referring the URL below:
"Queue Class"

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/

frlrfsystemcoll ectionsqueuecla sstopic.asp

There are several container classes in .Net may fit your need, such as
ArrayList, Hashtable, Queue etc..., they all exist under System.Collecti ons
namespace. They all have different usages, you may refer to MSDN for their
difference and choose the suitable for using as memory container table.

Hope this helps!

Best regards,
Jeffrey Tan
Microsoft Online Community Support
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[Cor Ligthert [MVP]]

Re: Class used by multiple threads to write to Table

Jeffrey,

Thank you, I did not copy it this was from a previous answer, mine was

http://msdn2.microsoft.com/en-us/library/system.collections.queue.aspx

A little bit shorter than your URL.

By the way, the queue class (FIFO) is extremely sufficient with multi
threading.

Cor

""Jeffrey Tan[MSFT]"" <jetan@online.m icrosoft.comsch reef in bericht
news:IIsQlK1nGH A.4612@TK2MSFTN GXA01.phx.gbl.. .

Hi Cj,
>
It seems Cor Ligthert [MVP] provided an incorrect URL for queue class, I
think he is referring the URL below:
"Queue Class"

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/

frlrfsystemcoll ectionsqueuecla sstopic.asp
>
There are several container classes in .Net may fit your need, such as
ArrayList, Hashtable, Queue etc..., they all exist under
System.Collecti ons
namespace. They all have different usages, you may refer to MSDN for their
difference and choose the suitable for using as memory container table.
>
Hope this helps!
>
Best regards,
Jeffrey Tan
Microsoft Online Community Support
=============== =============== =============== =====
When responding to posts, please "Reply to Group" via your newsreader so
that others may learn and benefit from your issue.
=============== =============== =============== =====
This posting is provided "AS IS" with no warranties, and confers no
rights.
>

[cj]

Re: Class used by multiple threads to write to Table

I'm don't think that's what I'm looking for. My program creates threads
to handle IP connections made to it. I've seen up to 66 concurrent
threads running to date. But usually it's around 3 or 4. For
accountability purposes each thread uses the MyStringLogger class I
posted in my first message to write it's results to a log file.
SyncLock is used to ensure only one thread is writing data at a time.

Now I'm trying to write into this program another type of log. Each
thread will be required to write two fields to an in memory db table.
Why--Each thread receives a request from a IP client then calculates and
sends a response to it. Part of the calculations involve other machines
and if the network is down the threads can't calculate the response so
they return an error code. In the future if the network is down I want
the program to search the new in memory db table for the last time that
question was asked by an ip client and return the same answer as it will
most likely still be correct.

Perhaps hourly a maintenance routine will be run to remove entries from
this in memory db table older than X hours or minutes or whatever is
determined to be appropriate.

Any suggestions?


Cor Ligthert [MVP] wrote:

Jeffrey,
>
Thank you, I did not copy it this was from a previous answer, mine was
>

http://msdn2.microsoft.com/en-us/library/system.collections.queue.aspx

>
A little bit shorter than your URL.
>
By the way, the queue class (FIFO) is extremely sufficient with multi
threading.
>
Cor
>
""Jeffrey Tan[MSFT]"" <jetan@online.m icrosoft.comsch reef in bericht
news:IIsQlK1nGH A.4612@TK2MSFTN GXA01.phx.gbl.. .

>Hi Cj,
>>
>It seems Cor Ligthert [MVP] provided an incorrect URL for queue class, I
>think he is referring the URL below:
>"Queue Class"
>http://msdn.microsoft.com/library/de...us/cpref/html/
>frlrfsystemcol lectionsqueuecl asstopic.asp
>>
>There are several container classes in .Net may fit your need, such as
>ArrayList, Hashtable, Queue etc..., they all exist under
>System.Collect ions
>namespace. They all have different usages, you may refer to MSDN for their
>difference and choose the suitable for using as memory container table.
>>
>Hope this helps!
>>
>Best regards,
>Jeffrey Tan
>Microsoft Online Community Support
>============== =============== =============== ======
>When responding to posts, please "Reply to Group" via your newsreader so
>that others may learn and benefit from your issue.
>============== =============== =============== ======
>This posting is provided "AS IS" with no warranties, and confers no
>rights.
>>

>
>

[Cor Ligthert [MVP]]

Re: Class used by multiple threads to write to Table

cj,

Reading it, and trying to understand it, would I go to the sorted list (with
a good created key) or the hashtable with the same as already stated by
Jeffrey,

Cor

"cj" <cj@nospam.nosp amschreef in bericht
news:uQJyWnDoGH A.776@TK2MSFTNG P04.phx.gbl...

I'm don't think that's what I'm looking for. My program creates threads
to handle IP connections made to it. I've seen up to 66 concurrent
threads running to date. But usually it's around 3 or 4. For
accountability purposes each thread uses the MyStringLogger class I posted
in my first message to write it's results to a log file. SyncLock is used
to ensure only one thread is writing data at a time.
>
Now I'm trying to write into this program another type of log. Each
thread will be required to write two fields to an in memory db table.
Why--Each thread receives a request from a IP client then calculates and
sends a response to it. Part of the calculations involve other machines
and if the network is down the threads can't calculate the response so
they return an error code. In the future if the network is down I want
the program to search the new in memory db table for the last time that
question was asked by an ip client and return the same answer as it will
most likely still be correct.
>
Perhaps hourly a maintenance routine will be run to remove entries from
this in memory db table older than X hours or minutes or whatever is
determined to be appropriate.
>
Any suggestions?
>
>
Cor Ligthert [MVP] wrote:

>Jeffrey,
>>
>Thank you, I did not copy it this was from a previous answer, mine was
>>
>http://msdn2.microsoft.com/en-us/lib...ons.queue.aspx
>>
>A little bit shorter than your URL.
>>
>By the way, the queue class (FIFO) is extremely sufficient with multi
>threading.
>>
>Cor
>>
>""Jeffrey Tan[MSFT]"" <jetan@online.m icrosoft.comsch reef in bericht
>news:IIsQlK1nG HA.4612@TK2MSFT NGXA01.phx.gbl. ..

>>Hi Cj,
>>>
>>It seems Cor Ligthert [MVP] provided an incorrect URL for queue class, I
>>think he is referring the URL below:
>>"Queue Class"
>>http://msdn.microsoft.com/library/de...us/cpref/html/
>>frlrfsystemco llectionsqueuec lasstopic.asp
>>>
>>There are several container classes in .Net may fit your need, such as
>>ArrayList, Hashtable, Queue etc..., they all exist under
>>System.Collec tions
>>namespace. They all have different usages, you may refer to MSDN for
>>their
>>difference and choose the suitable for using as memory container table.
>>>
>>Hope this helps!
>>>
>>Best regards,
>>Jeffrey Tan
>>Microsoft Online Community Support
>>============= =============== =============== =======
>>When responding to posts, please "Reply to Group" via your newsreader so
>>that others may learn and benefit from your issue.
>>============= =============== =============== =======
>>This posting is provided "AS IS" with no warranties, and confers no
>>rights.
>>>

>>

[Jeffrey Tan[MSFT]]

Re: Class used by multiple threads to write to Table

Hi Cj,

Thanks for your feedback!

Based on my reading, your main concern is writing 2 fields to the memory
table instead of 1 field.

I think you have 2 choice to resolve this:
1. If one of your field is unique, you can use it as a key for lookup. Just
as Cor suggested, you may use SortedList or Hashtable for storage, since
they both use a key for lookup. So your first field is used as a key, and
the other field is stored in the SortedList/Hashtable associated with the
key(first field). This implementation is easy.
2. If your 2 fields are not unique, you can implement a customized class
which contains 2 properties to store these 2 fields, and you may store this
class instance in the System.Collecti ons.* class. Choose what class in this
namespace you want.

Thanks.

Best regards,
Jeffrey Tan
Microsoft Online Community Support
=============== =============== =============== =====
When responding to posts, please "Reply to Group" via your newsreader so
that others may learn and benefit from your issue.
=============== =============== =============== =====
This posting is provided "AS IS" with no warranties, and confers no rights.