Hi,
Hi,
i'm using activemq in my c++ application. I have one connection and
one
session for this connection. I see that the session
(SessionExecutor) starts
a new thread. I set my class that starts the connection and the
session to
be the exceptionListener. Does that mean that the onException will
be called
from the session Thread?
Yes, the C++ client mirrors this concept of JMS - all the other
clients (Java, .NET, etc.) are the same in this regard.
If so, then i get here a thread unsafe application.
During a connect I update my members ( session, producer and
consumer for
example), if an exception will occur, i will access my members from
two
different threads. Am I correct?
Correct - standard multithreading stuff.
what is the possible solution? can i disable session thread?
No, you can't disable the fact that onException is called in a
different thread. However, you can be guaranteed that all calls to
onException from the same session will be executed in the same thread
context. i.e. session = 1 thread.
Do i need to
lock my members?
A safe answer to this question is yes. Any time you try to access the
same data from multiple threads, it's a critical section. ActiveMQ-
CPP provides some mechanisms that simplify this process. The
activemq::concurrent::Mutex class should do the trick.
I saw some explanation about optimizedDispatch=true option that looked
suitable for disabling session thread, but couldn't find a cms
support for
this.
There is no support for this feature in ActiveMQ-CPP at this time.
Any help will be appreciated.
One other thing you should be aware of is that there are two ways of
receiving messages: asynchronous (onException) and synchronous
(receive). If you'd rather poll from your application thread for new
messages, you can call one of the MessageConsumer's receive methods,
which will optionally block until it gets a new message and return
it. No threading involved on the part of the application.
Regards,
Nate
