What happens if two COM classes each without a threading model are implemented in one in-proc COM se

Posted by sharptooth on Stack Overflow See other posts from Stack Overflow or by sharptooth
Published on 2010-03-29T09:45:49Z Indexed on 2010/03/29 13:13 UTC
Read the original article Hit count: 473

Filed under:

com

|

multithreading

|

synchronization

|

language-agnostic

|

Windows

Consider a situation. I have an in-proc COM server that contains two COM classes. Both classes are marked as "no threading model" in the registry - the "ThreadingModel" value is just absent. Both classes read/write the same set of global variable without any synchronization.

As far as I know "no threading model" will enforce COM to disallow concurrent access to the same or different instances of the same class by different threads.

Will COM prevent concurrent access to instances of the two abovementioned different classes? Do I need synchronization when accessing the global variables from two different COM classes in this situation?

© Stack Overflow or respective owner

Related posts about com

Cannot update, apt-get cannot fetch index files

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I have a fresh install of Ubuntu 11.10 from the iso 'ubuntu-11.10-desktop-amd64.iso'. I installed this in VMWare Fusion 4.1.1 running on OSX 10.7.3. When setting up the VM, I allowed easy install to take care of creating my user and installing VMWare tools. No problems during installation, everything… >>> More
'sudo apt-get update' error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've been having an issue with 'sudo apt-get update' for several days now. I've tried every proposed solution I could find but to no avail. Here is the output to 'apt-get update'. Ign http://us.archive.ubuntu.com precise InRelease Ign http://us.archive.ubuntu.com precise-updates… >>> More
I have finally traded my Blackberry in for a Droid!

as seen on Geeks with Blogs - Search for 'Geeks with Blogs'
Over the years I have used a number of different types of phones. Windows Mobile, Blackberry, Nokia, and now Android. Until the Blackberry, which was my last phone (and I still have one issued from my office) I had never found a phone that “just worked” especially with email and messaging. The Blackberry… >>> More
"Something wicked happened" error in apt-get

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
Everytime I try to install through terminal I get this" I am not able to install or update and I can't find working answer for this here. Here is my apt-get update result: Hit http://ppa.launchpad.net raring Release.gpg Hit http://deb.opera.com stable Release.gpg… >>> More
Split a long JSON string into lines in Ruby

as seen on Stack Overflow - Search for 'Stack Overflow'
First, the background: I'm writing a Ruby app that uses SendGrid to send mass emails. SendGrid uses a custom email header (in JSON format) to set recipients, values to substitute, etc. SendGrid's documentation recommends splitting up the header so that the lines are shorter than 1,000 bytes. My… >>> More

Related posts about multithreading

C++ Multithreading on Unix

as seen on Programmers - Search for 'Programmers'
I have two related questions: 1) Are there any good books for multithreading in C++, especially now that C++11 contains multithreading in the standard library? 2) I have the Wrox Programming on Unix book (1000 pages fat red one) and within it, it uses the Unix Thread class. How does this code relate… >>> More
what are the difficulties of operating system multithreading?

as seen on Stack Overflow - Search for 'Stack Overflow'
I am reading a book that compares two ways of implementing threads, Middleware Threads and OS Threads. I have a question about these sentences: "A difficulty of operating system multithreading, however, is performance overhead. Since it is the operating system that is involved in switching threads… >>> More
TCP multicast and multithreading

as seen on Stack Overflow - Search for 'Stack Overflow'
I need to come up with clients that can multicast to other clients reliably. That implies I'll be using TCP to connect reliably between clients within a multicast group. Doesn't that come up to n^2 number of connections? That seems a little silly to me. Wouldn't/shouldn't there be a way to more easily… >>> More
Multithreading recommendation based on program description

as seen on Stack Overflow - Search for 'Stack Overflow'
I would like to describe some specifics of my program and get feedback on what the best multithreading model to use would be most applicable. I've spent a lot of time now reading on ThreadPool, Threads, Producer/Consumer, etc. and have yet to come to solid conclusions. I have a list of files (all… >>> More
How to achieve multithreading using JavaScript with IE6?

as seen on Stack Overflow - Search for 'Stack Overflow'
How to achieve multithreading using JavaScript with IE6? Is there a third party library to do this? >>> More