# Reduced I/O Latency with Futures

## TL;DR

This paper introduces a method using futures to hide I/O latency in interactive applications, providing theoretical guarantees and an efficient implementation that outperforms prior approaches.

## Contribution

It proposes a novel futures-based algorithm for hiding I/O latency, with theoretical analysis and a practical, efficient implementation on the Cilk-F runtime.

## Key findings

- The algorithm offers better execution time guarantees than previous methods.
- The prototype implementation demonstrates significant efficiency improvements.
- Experimental results validate the effectiveness of the approach.

## Abstract

Task parallelism research has traditionally focused on optimizing computation-intensive applications. Due to the proliferation of commodity parallel processors, there has been recent interest in supporting interactive applications. Such interactive applications frequently rely on I/O operations that may incur significant latency. In order to increase performance, when a particular thread of control is blocked on an I/O operation, ideally we would like to hide this latency by using the processing resources to do other ready work instead of blocking or spin waiting on this I/O. There has been limited prior work on hiding this latency and only one result that provides a theoretical bound for interactive applications that use I/Os. In this work, we propose a method for hiding the latency of I/O operations by using the futures abstraction. We provide a theoretical analysis of our algorithm that shows our algorithm provides better execution time guarantees than prior work. We also implemented the algorithm in a practically efficient prototype library that runs on top of the Cilk-F runtime, a runtime system that supports futures within the context of the Cilk Plus language, and performed experiments that demonstrate the efficiency of our implementation.