Solved

How often can I call CFile::Flush(), or how often should I?

Posted on 2014-02-07
5
720 Views
Last Modified: 2014-02-08
I have a program that saves data using a CFile object. I call Write() followed by Flush() every time data is available to be saved. My question is, how often should I be calling Flush()? My program can call the Write() function up to 100 times a second. Is it ok to call Flush() 100 times a second? Will this cause any problems? My program is hanging and I'm looking for likely places where the performance could be problematic.
0
Comment
Question by:goondoo27
  • 3
  • 2
5 Comments
 
LVL 86

Expert Comment

by:jkr
ID: 39844127
You can of course call it as often as you want, the performance penalty should be minimal - if there is no data to be written, the function will just return without doing anything. Depending on what kind of data you are writing. You however might want to consider opening the file as 'unbuffered' , so you don't even have to explicitly 'flush' any file buffers.
0
 

Author Comment

by:goondoo27
ID: 39844621
Thanks jkr. There will be data to flush every time I call Flush() because I only call it after a Write(). I'll look at opening the file as unbuffered. So you don't see any performance issue with calling Flush() right after Write() at say 100 to 300 times a second?
0
 
LVL 86

Expert Comment

by:jkr
ID: 39844647
Again, that will depend on the amount of data you are writing. Also, why do you need everyhing to be written immediately? I'd say that flushing all buffers is a good thing to do when a coherent point is reached, e.g. if you were writing audio data, you'd call 'Flush()' when a full song/track is ready (yes, not really a perfect example)...
0
 

Author Comment

by:goondoo27
ID: 39844657
I'm writing a text file. Each Write() will put a single line of statistical data into the file. I'd estimate that up to 200 characters are written each time I call Write(). I originally put the Flush() call in the code so that the stats were immediately saved to the file and could be viewed by programs tailing the text file. Is there a better way to do this?
0
 
LVL 86

Accepted Solution

by:
jkr earned 500 total points
ID: 39844666
No, that sounds reasonable. And given the amount of data, that shouldn't cause any trouble.
0

Featured Post

Gigs: Get Your Project Delivered by an Expert

Select from freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely and get projects done right.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Container Orchestration platforms empower organizations to scale their apps at an exceptional rate. This is the reason numerous innovation-driven companies are moving apps to an appropriated datacenter wide platform that empowers them to scale at a …
Basic understanding on "OO- Object Orientation" is needed for designing a logical solution to solve a problem. Basic OOAD is a prerequisite for a coder to ensure that they follow the basic design of OO. This would help developers to understand the b…
The viewer will learn how to successfully create a multiboot device using the SARDU utility on Windows 7. Start the SARDU utility: Change the image directory to wherever you store your ISOs, this will prevent you from having 2 copies of an ISO wit…
This is used to tweak the memory usage for your computer, it is used for servers more so than workstations but just be careful editing registry settings as it may cause irreversible results. I hold no responsibility for anything you do to the regist…

776 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question