Evaluating JavaScript Execution Behavior and Improving the Performance of Web Applications with Thread-Level Speculation

Sammanfattning: This thesis addresses two issues: (i) The execution behavior of JavaScript in established benchmarks and in real-world Web Applications and (ii) whether Thread-Level Speculation is a suitable technique for taking advantage of multicore systems in Web Applications written in JavaScript. The first key result is that JavaScript execution behavior by the benchmarks and the JavaScript execution behavior by the Web Applications differ in several important aspects. For instance Web Applications often use function types such as anonymous and eval functions. Our results also show that just-in-time compilation often increases the execution time of Web Applications, despite that just-in-time compilation decreases the execution time for most of the benchmarks. The second key result is that our implementation of Thread-Level Speculation shows that it can be used to take advantage of multicore systems for Web Applications. We have measured the effect on the execution time for a set of Web Applications, and found that we are able to reduce JavaScript execution time more than 8 times compared to the sequential version on a dual quad core computer. For our use-cases we found that we used between 1.1 and 31.0 MB to store information associated with speculation.