Error Handling in Operating System

An operating system is defined as an interface between the computer system and its users. Once the operating system is loaded into the computer system through the boot program it is responsible for managing all the applications on the device. The operating system is a significant component of the system software in a computer system.

As the operating system is a collection of various software there may be some errors that can cause the system to have some severe fault or severe stoppage of any service which can lead to false results or some defective results to handle this error handling should be properly applied. The below article covers in detail the error, its types, the concept of error handling, and their needs.

What is an Error?

In simple terms, an error is an abnormal condition or scenario that basically occurs in the operating system or in the execution of any program or system that basically restricts the system from performing the desired or expected action. Now this action can be of any certain activity, or any certain action given to that system, like copying any file or deleting any certain data. So any restriction for this action, for performing these three side actions, is called an error The sources of these errors can be runtime errors, logical errors, system crashes, and many more. These errors basically lead to some false results, or they lead to some system vulnerabilities or system instability.

Types of Error

Below are the two types of errors that are seen in the context of the Operating System:

1. Transient Failure

Transient failures are basically defined as temporary or short-term errors that occur in the system, or in a certain process, in the operating system. Basically, these are caused due to some temporal conditions which are not very severe. Transient Failure does not persist in problems with the hardware or any software activity. Transient failures are normal failures and are not more severe, these can be recoverable failures and the system can continue its normal operations by overcoming this temporal issue after performing the solution for recovering the errors from these transient failures.

Example: Deadlock Condition, where processes cause temporary conflicts in accessing shared resources.

2. Permanent Failure

Permanent failure is the most severe problem, or severe error in the operating system, which cannot be recovered or resolved through some error handling activities or some normal activities or operations. Permanent failure deals with the problems that are occurred in hardware or software components. And this cannot be easily recovered as sometimes the system completely crashes and stops the execution of all the processes or hardware. This is the most severe problem which requires some more complex solutions to recover the system from this failure.

Example: Defective CPU that constantly generates incorrect results or false outputs.

What is Error Handling in OS?

Error handling in an operating system basically refers to the systematic process or systematic approach for Detecting, Managing, and properly responding to the errors that actually occurred by some failures, like Transient failures or permanent failures. Error handling in an operating system consists of some mechanisms or some solutions to handle these types of failures or exceptions or some unexpected scenarios. By ensuring that system can continue its operation or continue its desired action, although if any error is been occurred, the main aim of this error handling in the operating system is to basically handle the errors which have occurred in runtime or in compile time in an efficient and stable manner. Error handling consists of some of the strategies, like exception handling, error codes, and messages, retry mechanisms, Logging and debugging, etc. Using all these mechanisms, we can easily detect and manage the failures which are been occurred in the operating system.

What is the Need of Error Handling in OS?

Below are the reasons, why Error Handling is important in Operating Systems:

1. Robustness and Reliability

Using error handling improves the robustness and reliability of our operating system. It basically allows us to properly and efficiently handle failures And exceptional conditions without crashing or making the processes or software halt. By managing and handling the errors in the operating system, it allows us to recover from failures and continue the functioning of our processes, which have been desired to perform any action This also, overall, maintains the stability of our system.

2. Improves User Experience

Error handling in the operating system plays a significant role in offering a positive user experience. When a Failure or area occurs in our operating system, or in some process, there should be some clear and relevant error messages that should be understandable to the users, so that the user can troubleshoot the error, or to should understand the causeway of the error or failure. This reduces the frustration by guiding them toward the appropriate action and solutions for finding the root of the error and resolving them.

3. Maintains Security

Efficient error handling process also helps the system security by providing relevant and useful error messages without compromising any sensitive information, error handling basically prevents potential attackers from exploiting the bug or vulnerabilities are gaining unauthorized permission access to system resources. Error handling strategies maintains the integrity, confidentiality and availability of data.

4. Problem Troubleshooting and Debugging

Error handling is basically very useful in problem diagnosis or problem troubleshooting and debugging. When errors are properly logged and reported, a system administrator who takes care of the entire system, developer, or support personnel can analyse these error details to identify the cause of the errors or failures.

Example:

Scenario: Operating System Error Handling in File I/O

In the below example, we will consider a scenario where a system user wants to read the file from the local disc drive using the operating system’s file input-output of functions. And in this example, we will cover both the transistor and permanent failure during the processes. Also, we will consider this response Operating system, and how the error handling is been done by the operating system.

Transient Failure

• User Action: The user initiates the process where a file read operation is being performed to open and read the content of a file named report.pdf. Using this operating systems file I/O API.

• Transient Failure: Once the user initiates this process for reading the content from the file, a transient failure occurs, where the file read operation is stopped due to momentary power fluctuation, which causes the disc drive to be briefly disconnected.

• Operating System Response (Error Handling): The movement operating system detects the transient failure while communicating with the disc drive. Its error handling mechanisms get activated like buffered IO and retries. The operating system reattempts or performs retries to build the communication with the disc drive and continues the file read operation from where it was stopped, or from where it was getting disconnected. The user might not be aware that this was a temporary glitch, as the operating system compensates for the transient failure automatically.

Permanent Failure

• User Action: Here, the user initiates to open a file name data.csv, which is located on an external USB device, using the operating systems file I/O functions.

• Permanent Failure: As we have seen permanent failure, is basically caused by hardware and software components. So in permanent failure, the external USB drive encounters a severe physical failure in the read and write head, which makes it impossible or problematic for the operating system to access any data on that particular drive.

• Operating System Response (Error Handling): Once the operating system detects the permanent failure while trying to communicate with the USB device, in this case, the operating system directly cannot recover from the hardware defect. It actually returns an error code that specifies to the user the actual problem which has been caused. So the error message may indicate that the external drive has been filled due to some reason, or due to this, it cannot be actually accessed. The user is also advised to check its drives connexion or take some professional assistance help so that they can perform the data recovery action, or can also replace the faulty drive with a new working drive.

FAQs on Error Handling

Q.1: How segmentation fault is handled by operating system?

Answer:

Segmentation fault is defined as a type of fault where program tries to access or use the memory for which it is not allowed. For handling segmentation fault the operating system logs the error by terminating the program.

Q.2: Does user level program handles their errors independently as that of operating system?

Answer:

User level programs can handle their errors through mechanisms such as exception handling and error checking functions.

Q.3: Does operating system improves security through error handling?

Answer:

Yes, operating system improves security through error handling by handling the exceptions and errors, protect against unauthorized access and denial of service attacks.

Q.4: Which types of errors can even cause to computer system crash?

Answer:

Permanent failures can lead to crash of the system as majorly problem occurs with hardware or software components and they cannot be recovered easily.