There is a big difference between polling and interrupts. Interrupts are used to notify the CPU that an event has occurred that requires immediate attention, while polling is a technique used to determine when an event has occurred. In this post, we’ll take a closer look at these two approaches, and discuss the pros and cons of each.
What is Polling?
Polling is a technique used by CPUs to check whether new data has been received from an external device. The CPU will periodically check the status of the device, and if the device is ready, the CPU will read the data. Polling is simple to implement, but it can be inefficient because the CPU spends a lot of time checking for new data even when none is available. As a result, newer devices often use interrupts instead of polling. Interrupts allow the device to send a signal to the CPU whenever new data is available, eliminating the need for regular checking. This can improve response times and save CPU resources.
What is Interrupt?
- Interrupts are a type of computer architecture that allows for the temporary suspension of a process in order to handle another process. Interrupts can be internal or external, and they can be generated by hardware or software. Interrupts are used to handling errors, managing I/O devices, and servicing interrupts.
- Interrupt handling is typically performed by an Interrupt Service Routine (ISR), which is a piece of code that is executed when an interrupt is generated. ISRs typically save the state of the current process, handle the interrupt, and then restore the state of the previous process.
- Interrupts can be nested, which means that an ISR can be interrupted by another interrupt. Interrupts can also be disabled, which prevents them from being handled. Interrupts are an important part of many computer systems, and they are essential for error handling and I/O management.
Difference between Polling and Interrupt
- Polling and Interrupt are two mechanisms that are used to manage the flow of data between devices. Polling is a process whereby a device checks for the presence of data at regular intervals.
- Interrupt, on the other hand, is a mechanism whereby a device is notified immediately when data is available. Polling is typically used for devices with a low data rate, such as keyboard or mouse.
- Interrupt is usually used for devices with a high data rate, such as network or storage. Polling can be implemented in hardware or software, while Interrupt is typically implemented in hardware. Polling is more simple and efficient than Interrupt, but it can lead to latency issues if the data rate is high. Interrupt is less simple and efficient than Polling, but it can avoid latency issues.
Polling and interrupts are two different techniques used to manage the flow of data between devices. They both have their own advantages and disadvantages, which we’ve outlined in this post. So, what’s the best technique for your next project? It depends on a few factors such as how much bandwidth is available and how critical real-time communication is. Try out both polling and interrupts and see which one works better for your specific needs.