Does SetThreadPriority cause thread reschedulling?

Posted by Suma on Stack Overflow See other posts from Stack Overflow or by Suma
Published on 2010-04-14T13:49:54Z Indexed on 2010/04/14 13:53 UTC
Read the original article Hit count: 128

Filed under:

winapi

|

threads

|

multithreading

|

priority

Consider following situation, assuming single CPU system:

thread A is running with a priority THREAD_PRIORITY_NORMAL, signals event E
thread B with a priority THREAD_PRIORITY_LOWEST is waiting for an event E (Note: at this point the thread is not scheduled because it is runnable, but A is higher priority and runnable as well)
thread A calls SetThreadPriority(B, THREAD_PRIORITY_ABOVE_NORMAL)

Is thread B re-scheduled immediately to run, or is thread A allowed to continue until current time-slice is over, and B is scheduled only once a new time-slice has begun?

I would be interested to know the answer for WinXP, Vista and Win7, if possible.

Note: the scenario above is simplified from my real world code, where multiple threads are running on multiple cores, but the main object of the question stays: does SetThreadPriority cause thread scheduling to happen?

© Stack Overflow or respective owner

Related posts about winapi

C: WinAPI CreateDIBitmap() from byte[] problem

as seen on Stack Overflow - Search for 'Stack Overflow'
I have been working on this problem for a while now. I am trying to add JPEG support to a program with libjpeg. For the most part, it is working fairly well, But for some JPEGs, they show up like the picture on the left. It may not be obvious, but the background shows up with alternating red green… >>> More
mouse_event WinAPI call not working when cursor is over Flash

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am writing a small program which can simulate mouse clicks at specified positions. Using the Win32 API call mouse_event like so: [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)] public static extern void mouse_event(uint dwFlags, uint dx, uint… >>> More
Custom form designer, move/resize controls using WinAPI

as seen on Stack Overflow - Search for 'Stack Overflow'
I have to fix some problems and enchance form designer written long ago for a database project. In Design Panel class code I encountered these lines private void DesignPanel_MouseDown(object sender, MouseEventArgs e) { if (e.Button == MouseButtons.Left) { (sender as Control).Capture… >>> More
winapi c - read/write mbr of system drive

as seen on Stack Overflow - Search for 'Stack Overflow'
Does anyone have any example code that shows how to identify the system boot harddisk, and read/write the mbr from the harddisk in windows xp and vista? I know createfile can be used. But I do not know how to properly identify which device is the boot device. Like how do you find out which ones… >>> More
How to use WINAPI from newer SDK but still using the old SDK in WindowsMobile.

as seen on Stack Overflow - Search for 'Stack Overflow'
Specifically, I want to use Point-to-point Message Queue but because I am still using legacy codes in eVC++ 4 and it only support until PocketPC 2003SE SDK, I cannot find CreateMsgQueue and friends in the headers (the port to newer VisualStudio is still in progess) I am using the Message Queue to… >>> More

Related posts about threads

Application threads vs Service threads

as seen on Stack Overflow - Search for 'Stack Overflow'
What are the advantages/disadvantages in placing a lengthy network access code in a thread in an activity or a thread in a service? How would it affect the application? I am writing a streaming audio player and from what I've read so far putting the code in a service will still end up blocking the… >>> More
[newbie]Webservice - Threads - close if no active threads, if any activen, then wait till its compl

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi I have an ASP.Net webservice running. When the system date changes, i want to close all the threads and restart them again, if the thread/s aren't doing any work. If any of the thread/s is in the process of doing some work(active threads), then i need to wait till the current thread/s complete… >>> More
Multiple threads or process with threads

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, this is for an assignment so I'm not looking for code. I have to simulate a game where each player has turns and needs to 'pay attention' to what's going on. So far, i know I'll need two threads for each player, one that will sleep until the player's turn and the other paying attention. My… >>> More
Tomcat threads vs Java threads

as seen on Stack Overflow - Search for 'Stack Overflow'
When using java threads, one has to take care of the basic problems that come with concurrency through synchronization etc. AFAIK Tomcat also works with threads to handle its workload. Why is it, that I don't have to think about making my code threadsafe when it is running in Tomcat? >>> More
C# threads - Posting messages between threads

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi All, I am working on a project which involves reusing as well as migrating some of the existing MFC code to C#. The current code in MFC, creates some threads and uses ::PostthreadeMessage() and ON_THREAD_MESSAGE(msg,func) for inter thread asynchronous communication through messages. ::PostthreadeMessage()… >>> More