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edwwsw (VIP)
$ Thread Safety
$ This type is safe for multithreaded read operations. You must synchronize
any write operations.

I am trying to figure out exactly what this statement means.

So if I have multiple threads accessing an ADO.Net dataset and only one of
those threads ever writes to the database but multiple threads are reading
from it. Do I have to write code to synchronize access to the ADO.Net
dataset or is that built into the Ado.Net dataset? Basically are updates
atomic and are the events guarentteed to fire in the UI thread?

If synchronization code needs to be written, how does this effect data
binding to grid controls where access to the data is outside of programmer
control, hence can not have synchronization code injected (note the grid
control is in read only mode)?
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Miha Markic [MVP C#]
"edwwsw" <Click here to reveal e-mail address> wrote in message
news:Click here to reveal e-mail address...
[Original message clipped]

Nothing is guaranteed. Only that you'll get in trouble doing these kind oh
hacks :-)

[Original message clipped]

If the dataset is bound to a data consumer such as grid, every change has to
happen inside the UI thread (the thread the control was created in).

--
Miha Markic [MVP C#] - RightHand .NET consulting & development
miha at rthand com
www.rthand.com
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David Browne
"edwwsw" <Click here to reveal e-mail address> wrote in message
news:Click here to reveal e-mail address...
[Original message clipped]

Updates are not atomic, and you must have exclusive access to the DataSet to
update it.

But winforms events are guaranteed to fire in the UI thread. When a user
clicks a button or hits a key this queues a message in the window's message
queue. The UI thread dequeues these messages one at a time and dispatches
to the event handler. So UI events are guaranteed to run on the UI thread,
and are therefore serialized.

David
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edwwsw (VIP)
I think Miha confirmed one of my suspicions. When the dataset is bound to a
UI control – all updates to the database must be made in same thread the UI
component is in.

The eventing I was referring to in my post was not the UI eventing but the
eventing issued from the dataset. When the dataset is changed in any way, it
issues events about the changes. Any UI control that is bound to a dataset
listens for these changes and updates itself based on them.

If the update to a dataset occurs in a different thread from the UI thread
then the delegate for updating the UI will be launched in the non UI thread.
The delegate for data bound control is most likely directly updating the UI
control and hence this creates a situation where multiple threads are
updating the same UI component – not good.

"David Browne" wrote:

[Original message clipped]
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System.Data.DataSet




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