ZODB problem to change an attribute from 2 diferent threads
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Ariel Argañaraz
Apr 23, 2014, 6:11:57 PM4/23/14
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Hi, I have a problem with threads.
The documentation says:
A process with multiple threads will often have multiple connections to the same database, with different threads having different connections.
But I don't Know if I create different connections in the right way.
I have 2 threads.
In the main.py, the connection works well with this:
#main.py
db = ZODB.config.databaseFromURL('configs/database.conf')
connection = db.open()
root = connection.root()
I have a function that change something in the object I want to persist. When I use this function locally all works perfect, The element is updated and saved.
def changePos(self, x):
"""a function to change the x position of an element"""
self.element._x = x
self._p_changed = True
transaction.commit()
print "change success"
The second thread is launched from the main.py. It is a xml-rpc server. That serves the mentioned method "changePos()"
i create the connection in that thread like this.
db2 = ZODB.config.databaseFromURL('configs/database.conf')
connection2 = db2.open()
root2 = connection2.root()
But the problem is that, when I call "changePos(3)" with a xml-rpc client. It seems to do the job because it changes the X value and print the "change success" message but when I stop the main.py and inspect the X value from the data.fs with the Eye program or with another python script to show the X value I can see that the X value is not "3" as I would expect. So the change was not commited!
Can someone give some help with this? maybe i am doing something wrong, or if anyone has an example of how to deal with threads, i 'd be very gratefull.
BTW: I try to use the ZEO and I made and example with 2 diferent process and it works but I can't do it with 2 threads!
The documentation says:
A process with multiple threads will often have multiple connections to the same database, with different threads having different connections.
But I don't Know if I create different connections in the right way.
I have 2 threads.
In the main.py, the connection works well with this:
#main.py
db = ZODB.config.databaseFromURL('configs/database.conf')
connection = db.open()
root = connection.root()
I have a function that change something in the object I want to persist. When I use this function locally all works perfect, The element is updated and saved.
def changePos(self, x):
"""a function to change the x position of an element"""
self.element._x = x
self._p_changed = True
transaction.commit()
print "change success"
The second thread is launched from the main.py. It is a xml-rpc server. That serves the mentioned method "changePos()"
i create the connection in that thread like this.
db2 = ZODB.config.databaseFromURL('configs/database.conf')
connection2 = db2.open()
root2 = connection2.root()
But the problem is that, when I call "changePos(3)" with a xml-rpc client. It seems to do the job because it changes the X value and print the "change success" message but when I stop the main.py and inspect the X value from the data.fs with the Eye program or with another python script to show the X value I can see that the X value is not "3" as I would expect. So the change was not commited!
Can someone give some help with this? maybe i am doing something wrong, or if anyone has an example of how to deal with threads, i 'd be very gratefull.
BTW: I try to use the ZEO and I made and example with 2 diferent process and it works but I can't do it with 2 threads!
Chris McDonough
Apr 23, 2014, 6:17:12 PM4/23/14
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On 04/23/2014 06:11 PM, Ariel Argañaraz wrote:
> Hi, I have a problem with threads.
You'll want to ask this question at
> Hi, I have a problem with threads.
<https://groups.google.com/forum/#!forum/zodb>. The Pylons Project does
not maintain ZODB.
>
> The documentation says:
> A processwith multiple threads will often have multiple connections to
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Ariel Argañaraz
Apr 23, 2014, 6:25:44 PM4/23/14
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Ok, Sorry.
I asked in the zodb as well, I found some people asking about zodb here so I did it. Sorry again
I asked in the zodb as well, I found some people asking about zodb here so I did it. Sorry again
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