Difference between monolithic and microkernel
what is the difference between monolithic and microkernel. ...
operating-system
OS bootstraping process
I try to understand os bootstraping process. Some questions are not clear to me. One of them is : How does bootstrap code in Volume boot record know about absolute LBA address of 0 sector of patition where Volume boot record resides? ...
Why are file handles such an expensive resource?
In holy wars about whether garbage collection is a good thing, people often point out that it doesn't handle things like freeing file handles. Putting this logic in a finalizer is considered a bad thing because the resource then gets freed non-deterministically. However, it seems like an easy solution would be for the OS to just make s...
iPhone - why only one application at a time
I tried to find an explanation for this question, but couldn't. I am new to iPhone development and I was wondering why the iPhone cannot allow/run more than one app at a time? I am pretty sure this is a design feature rather than a lack of functionality. Could someone please explain to me in technical/non-technical words why you can't...
What is the overhead involved in a mode switch
Hi Many a times i read/hear the argument that making a lot of system calls etc would be inefficient since the application make a mode switch i.e goes from user mode to kernel mode and after executing the system call starts executing in the user mode by making a mode switch again. My question is what is the overhead of a mode switch ? D...
Track process-ids of sub-/child-processes?
Hi, I need to execute and terminate/abort different shell scripts from inside Java (>= 1.5; ProcessBuilder). With the standard java mechanisms I am only able to kill the main process used for the shell script execution. When this shell script starts other processes (for instance ./foo.sh &; ./bar.sh &) then there processes are still run...
multithreading and multiprocessing
I am trying to understand basic OS concepts Want to know if my understanding is right multi-processing Example: I invoke A.exe on my machine. I invoke another instance of it again. So there would be two A.exe on the RAM which are called processes and the OS would do multi-processing between them by means of context switching and blah b...
Are there applications that can crunch numbers directly?
Applications that would boot straight from boot media like a bios. WOuld this lead to better performance, leaving the OS behind? Or would there be no difference, basically replacing system calls with function calls? edit: I am after lists of applications similar to memtest86 but for number crunching as examples ...
Where can I find statistics on OS usage?
I am trying to decide whether it is worth it or not to put in the time to make an app work on Windows 2000 and/or Windows 98, so I'm curious to find out how many people are still using these operating systems. Thanks, as always. ...
Blackberry - Get list of Profiles and active Profile info
Hi, I'm developing a Blackberry application, where I need to get the list of profiles from phone (for sound settings). Is there any way for getting the profile info? ...
Putting a compiled boot sector onto an USB Stick
Hey I'm actually interested in how an OS works, from the POST over the Boot process to the Kernel, GUI, etc. Well I have to start at the beginning: The bootsector Most tutorials only specify how to get your .bin bootstrapper onto an USB stick for Linux users. But as I'm using XP I would like to ask how do I get my 512 byte .bin onto ...
Do any common OS file systems use hashes to avoid storing the same content data more than once?
Many file storage systems use hashes to avoid duplication of the same file content data (among other reasons), e.g., Git and Dropbox both use SHA256. The file names and dates can be different, but as long as the content gets the same hash generated, it never gets stored more than once. It seems this would be a sensible thing to do in a ...
BlackBerry - Programmatically create new exception in profile?
Hi everyone! Actually i trying how to read the profile status but i am not getting that. .... If anyone have an idea how to create new exception in profile programmatically, will really helpful for me. Thanks ...
Blackberry - read profileIndex status using NotificationManager and Consequence API
Below link is not enough to get profile status.... http://stackoverflow.com/questions/1892579/blackberry-get-list-of-profiles-and-active-profile-info Is there any indirect way to get Profile status, programmatically? I am trying to find the profileIndex but failed. If anyone know anything about this problem solution pls pls share . Th...
best way to get user browser,os,flash etc. info from users using a javascript?
hi, i need a way to get user information for individual users on my website. I know i can use google analytics to get the information i require but i don't know how to extract this and send it to a php script when a user submits a form. i would prefer to use google analytics to extract the data, since it would save me a lot of work, ...
Does the JVM or the underlying OS handle thread state changes
When I create a multi-threaded program and I use methods such as Wait or Signal to control threads among other things, does JVM control all the thread state changes or does the underlying OS have anything to do with it. ...
Which mobile os is easy to program with?
I want to learn some mobile stuff, and programming interesting things myself on mobile phones, what is popular and easy-to-use mobile operating system? ...
Worst case operating system clock precision?
I am not sure if this question belongs on StackOverflow but here it is. I need to generate a timestamp using C# for some data which is to be transferred from one party to another party and I need to know what is the worst case precision of the system clock in all operating system (Windows, Linux and Unix)? What I need is to figure out t...
How to permanently delete file so that it becomes unrecoverable?
If I want my application (written in .NET) to delete a file such that it can not be recovered by disk recovery tool. What are my options? One that I can think of is that I open it up in write mode, overwrite all of it with some random data and it would make the file unrecoverable. Is there any other way? ...
strange performance behavior when running app from scripting language
Hi, I wrote tcl script as an glue between different apps which are computationally intensive. When I run top command I see that 2 cpu's are 100% utilized. The one is for the tcl and the second is for the application I am running. The question is: why the tcl is utilizing fully one of the processors when the binary application is heavil...