Difference between Interrupt and Exception

Although interrupt and exception are two distinct ideas, they are related in the sense that they both force the central processing unit (CPU) to halt the normal flow of execution of instructions and instead begin executing another programme in the kernel space in order to deal with the issue at hand. This is true even though interrupt and exception are distinct ideas. The primary distinction lies in the manner in which they deal with unforeseen occurrences that may take place anywhere in the system, the processor, or even within the programme itself.

What is an Interrupt?

An interruption is a signal that is provided to the central processing unit (CPU) of the computer from either an external device that is connected to the computer or a program that is running on the system itself that requires the OS to intervene in the current process.

As their name suggests, interruptions are sudden occurrences that bring to a halt the consistent flow of instructions being carried out by a system. It instructs the operating system to take immediate action on the following steps to take. These unforeseen occurrences are typically associated with an I/O device, which is primarily concerned with communicating with the outside world. For instance, the moment you hit a key on the keyboard or move the mouse, hardware interrupts are generated.

These interrupts cause the central processing unit (CPU) to read the keystroke or mouse movement. When an interrupt occurs, the central processing unit (CPU) executes a function known as the "interrupt handling routine" or the "interrupt handler" to deal with the situation that triggered the interrupt in the first place.

The moment an interrupt is detected, control is handed over to the operating system, which prompts the OS to begin taking rapid action. Interruptions are prioritized, which means that those with a high priority require quick attention and must be handled before those with lower priorities.

There are 4 different categories of Exceptions − interrupt, fault, abort, and trap. Despite the fact that interrupt is a type of exception, there are a number of key differences between the two.

Trap − Typically, it is a form of synchronous interrupt that is triggered whenever an extraordinary condition occurs (e.g., breakpoint, division by zero, invalid memory access).
Fault − A client application will make use of a fault exception in order to catch faults in SOAP that have been contractually specified. You are unable to determine the reason for the error based on the standard exception message; hence, a Fault Exception is quite helpful.
Abort − An instance of this kind of exception is thrown whenever the execution of an instruction fetches results in an error.

What is an Exception?

The phrase "exception" is an abbreviation for "exceptional event," which describes unanticipated occurrences that might take place anywhere in the system, the processor, or within a program and call for the attention of the central processing unit (CPU). Exceptions, similar to interruptions, divert the regular flow of instructions during the execution of a program.

However, unlike interrupts, exceptions occur during program execution and are so extraordinary that they cannot be handled by the program itself. If you give the processor the command to divide a number by zero, for instance, it will give a divide-by-zero exception, which will cause the computer to either stop the operation or display an error notice.

When an error occurs, the central processing unit (CPU) halts the process that is now being carried out and instantly reacts to the error by invoking a particular exception handler function, which differs according to the type of execution being carried out.

In a general sense, exceptions can be split up into two categories: those that are noticed by the processor and those that are created by the programming. The first type of exception is raised whenever the central processing unit (CPU) discovers any kind of irregularity while carrying out an instruction, whereas the second type of exception is raised whenever the programmer specifically requests it.

Difference between Interrupt and Exception

The term "interrupt" refers to one of the classes that fall under the umbrella term "exception." Other exception classes include "fault," "trap," and "abort." Both interruptions and exceptional circumstances abruptly bring the ongoing execution of instructions to a halt. Exceptions and interruptions have the same effect.

Interruptions are prioritized, which means that those with the highest priority, which require immediate attention, are dealt with first. The CPU would execute an interrupt handler or an exception handler whenever it comes across an interrupt or an exception, and it would do so while pausing the process that was now running. As soon as the execution of the handler is complete, the processor will immediately restore control of the process that was paused.

The following table highlights the major differences between Interrupt and Exception −

Basis of Comparison	Interrupt	Exception
Synonym	These are known as Hardware Interrupts.	These are known as Software Interrupts.
Operation	In most cases, the occurrence of one hardware interrupt will render the operation of all other hardware interrupts inoperable.	In terms of Exception, this is not a valid case.
Service	These are asynchronous external service requests (like keyboard or printer needs service).	These are synchronous internal service requests triggered by abnormal events (think of illegal instructions, illegal address, overflow, etc.).
Program	Interrupts can occur at any point in the program because it is asynchronous.	Because exceptions are synchronous, they occur when an abnormal event occurs in your program, such as a divide by zero or an illegal memory location.
Events	These are normal events that should not disrupt the normal operation of a computer.	These are unusual events that frequently result in the termination of a program.
Source	When a key is struck on a keyboard or the mouse is moved, it causes hardware interrupts. These interrupts tell the CPU to read the keystroke or mouse movement that was detected. Errors that occur during the execution of a program can result in software interruptions, which are commonly referred to as exceptions.	Exceptions can occur anywhere in the system, the processor, or within a program, and each one requires the attention of the central processing unit (CPU). If you give the processor the command to divide a number by zero, for instance, it will give a divide-by-zero exception, which will cause the computer to either stop the operation or display an error notice.

Conclusion

Both interrupts and exceptions are unanticipated events that can take place anywhere in the system, the processor, or within a program and need the immediate attention of the central processing unit (CPU). Both of these bring about an immediate halt to the ongoing flow of instructions that are being carried out.

The CPU would execute an interrupt handler or an exception handler whenever it came across an interrupt or an exception, and it would do so while pausing the process that was now running. As soon as the execution of the handler is complete, the processor will immediately restore control of the process that was paused.

If there are many interruptions, the one with the highest importance should be dealt with first if there are multiple interruptions. The fact that exceptions are generated from within the processor, as opposed to interruptions, which are caused by external events, is one of the most significant differences between the two circumstances.