Does my Dictionary must use locking mechanism?

Posted by theateist on Stack Overflow See other posts from Stack Overflow or by theateist
Published on 2012-06-17T15:09:57Z Indexed on 2012/06/17 15:16 UTC
Read the original article Hit count: 225

Filed under:

c#

|

multithreading

|

dictionary

|

locking

Many threads have access to summary. Each thread will have an unique key for accessing the dictionary;

Dictionary<string, List<Result>> summary;

Do I need locking for following operations?

summary[key] = new List<Result>()
summary[key].Add(new Result());

It seems that I don't need locking because each thread will access dictionary with different key, but won't the (1) be problematic because of adding concurrently new record to dictionary with other treads?

© Stack Overflow or respective owner

Related posts about c#

.NET WebRequest.PreAuthenticate not quite what it sounds like

as seen on West-Wind - Search for 'West-Wind'
I’ve run into the problem a few times now: How to pre-authenticate .NET WebRequest calls doing an HTTP call to the server – essentially send authentication credentials on the very first request instead of waiting for a server challenge first? At first glance this sound like it should be easy:… >>> More
HttpWebRequest and Ignoring SSL Certificate Errors

as seen on West-Wind - Search for 'West-Wind'
Man I can't believe this. I'm still mucking around with OFX servers and it drives me absolutely crazy how some these servers are just so unbelievably misconfigured. I've recently hit three different 3 major brokerages which fail HTTP validation with bad or corrupt certificates at least according to… >>> More
Dynamic Type to do away with Reflection

as seen on West-Wind - Search for 'West-Wind'
The dynamic type in C# 4.0 is a welcome addition to the language. One thing I’ve been doing a lot with it is to remove explicit Reflection code that’s often necessary when you ‘dynamically’ need to walk and object hierarchy. In the past I’ve had a number of ReflectionUtils that used string based expressions… >>> More
The dynamic Type in C# Simplifies COM Member Access from Visual FoxPro

as seen on West-Wind - Search for 'West-Wind'
I’ve written quite a bit about Visual FoxPro interoperating with .NET in the past both for ASP.NET interacting with Visual FoxPro COM objects as well as Visual FoxPro calling into .NET code via COM Interop. COM Interop with Visual FoxPro has a number of problems but one of them at least got a lot… >>> More
Finding a Relative Path in .NET

as seen on West-Wind - Search for 'West-Wind'
Here’s a nice and simple path utility that I’ve needed in a number of applications: I need to find a relative path based on a base path. So if I’m working in a folder called c:\temp\templates\ and I want to find a relative path for c:\temp\templates\subdir\test.txt I want to receive back subdir\test… >>> 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
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
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