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Categories >> Software >> Operating Systems >> RTOS >> RTOS AllOther


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 RTOS AllOther interview questions  RTOS AllOther Interview Questions (20)
What is the difference between Hard and Soft real-time systems ?
 Question Submitted By :: RTOS-AllOther
I also faced this Question!!     Answer Posted By  
# 1
In Real time system correctness of an operation depends not
only on the logical correctness but it should be
deterministic. Real time system are of two types, hard and
real. In hard real time system any output after the
deadline should be treated as useless,so it lead to
complete failure. But in soft realtime some late answer
also consider as a right answer, it tolerate such lateness
Is This Answer Correct ?    141 Yes 21 No
# 2
A hard real-time system guarantees that critical tasks
complete on time. This goal requires that all delays in the
system be bounded from the retrieval of the stored data to
the time that it takes the operating system to finish any
request made of it. A soft real time system where a critical
real-time task gets priority over other tasks and retains
that priority until it completes. As in hard real time
systems kernel delays need to be bounded
Is This Answer Correct ?    55 Yes 11 No
# 3
Often a hard real-time system operates on a preemptive,
context switching operating system where tasks will be
switched in and out execution state upon its defined and
scheduled time slots to maintain its real-time
characteristics. A soft real-time system, often denotes a
system that attempts to meet all time constaints imposed by
its tasks or operations or applications by enjoying the
powerful system resources such as high clock rate, faster
processors, speedy cache, and lightening buses. Yet, it is
still a 'soft' real-time system because some critical tasks
might be delayed due to some system-oriented processes that
are bulky and time-consuming and not preemptive.
Is This Answer Correct ?    63 Yes 37 No
# 4
A hard real time system is the one in which all the tasks
have to be completed within a specified deadline. Where as
there is no any such deadlines present in soft real time
Is This Answer Correct ?    29 Yes 7 No
# 5
In hard real time system the late output is harmful and can
not be tolarate,while in soft real time sytem the late
output is annoying and but can be tolarate.
most general purpose OS are made in soft real time system.
Is This Answer Correct ?    13 Yes 3 No
Prabhash Awasthi
# 6
*Hard real-time system
1. Secondary storage limited or absent, data stored in short- term memory, or read-only memory (ROM)
2. Conflicts with time-sharing systems, not supported by general-purpose operating systems.

*Soft real-time system
1. Limited utility in industrial control or robotics
2. Useful in applications (multimedia, virtual reality) requiring advanced operating system features.
Is This Answer Correct ?    12 Yes 4 No
Omari Jk
# 7
Hard real-time systems must have at least some actions with hard deadlines. But the converse is not true - soft real-time systems may have actions with hard deadlines. Those systems are soft real-time because they do not employ the hard real-time sequencing timeliness criterion, they employ soft real-time ones such as "minimize the expected number of missed deadlines," regardless of whether the deadlines are hard or soft. 
Is This Answer Correct ?    5 Yes 2 No
# 8
hard real-time" and "soft real-time" apply only to a "system," because their definitions are based on sequencing. In this sense, a system is any resource management facility that includes sequencing (of threads, only by our convention in this document), anywhere from the hardware up through the OS and middleware to the application(s) 
Is This Answer Correct ?    4 Yes 4 No
Surendra Singh
# 9
soft real time system:it is used in critical application
like robotics,industrial control etc.
real time sys:the few application which it use in plantary
rover'smultimedia, undersea exploration.
Is This Answer Correct ?    13 Yes 22 No
# 10
hard is very hard but soft is very soft that is the main diff dude........... 
Is This Answer Correct ?    9 Yes 76 No

Other RTOS AllOther Interview Questions
  Question Asked @ Answers
What is the state of the processor, when a process is waiting for some event to occur? MTS 14
what is the need of creating 4GB of pages in linux? TCS 1
What is the difference b/n any GPOS and RTOS?Give suitable examples or characteristic of RTOS to support your answer. What changes can be done in a GPOS to make it work like a RTOS? What basic features will you support, if you have to design a RTOS? Emulogic 7
What is a Real-Time System ?   5
If two processes which shares same system memory and system clock in a distributed system, What is it called?   6
What is the difference between Hard and Soft real-time systems ? Satyam 10
what is major concerns about any RTOS selection ? Bosch 4
What is priority inversion ? and What is the solution ? Qualcomm 6
What is the important aspect of a real-time system ?   6
what are the rules u follow when u r writing critical section of code? TCS 6
I have been working on one thread which manage and control a couple of circular buffers. It has api for other thread to access. As the thread grows bigger and bigger, I split it as 3 to 4 threads which need to share common buffers, and also their api could be used by other threads, (not these three threads). Inside api, I also allow other threads to access these three threads' common buffers(more than one buffer). SO I have to use mutex to avoid race condition . But I found mutex will be everwhere in all the threads when they update the common buffer. I am wondering whether I could reduce mutex usage(more mutex will hure my system performance). any ideas for how to reduce mutex usage meanwhile to avoid race condition. Thanks   2
When would you choose bottom up methodology? Knowx-Innovations 5
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