InteractiveProfilingTool

This is a graphical Profiling-Tool for use in the Squeak-Smalltalk Environment.

Features

Profile the whole world via a start/stop-button
See the calls made during the profiling as a graphical tree structure
Filter the tree by method and class name
Visual highlighting of expensive method calls
Browse called methods directly from the profiler
Edit code directly inside the profiler
View GC stats for the profiled period

Setup

Setup the project using Metacello. You may specify a branch other than master.

Metacello new
    baseline: 'InteractiveProfilingTool';
    repository: 'github://hpi-swa-teaching/InteractiveProfilingTool:master/packages';
    load.

Usage

Profiling World

Open the Profiler via the World Menu under Apps -> Interactive Profiler
Toggle profiling
A report window as shown above opens
Profit :money_with_wings:

Remarks

A relevance threshold is employed to hide method calls with an insignificant runtime. The value is hardcoded in such a way that method calls with less than 1% relative runtime are excluded from the result tree. If you want to change the threshhold, you can do so by changing the return value of IPTMessageTallyWrapper >> callRelevancePercentage.
Moreover, the spy-on functionality that allows profiling of individual methods is not yet fully implemented. If you know what you are doing, you can make a hacky solution like:
```
tally := MessageTally new.
tally spyEvery: (MessageTally defaultPollPeriod) on: ["put your code here"].
IPTReport openReportFor: tally
```
Using the GC Stats you can view garbage collection stats for the profiled period:

Since there is no comprehensive, central documentation for the Squeak Garbage Collector, this may be a useful primer for you:

The Squeak garbage collector follows the Mark-Sweep-Compact GC pattern. Memory is divided into two regions, the young and the old space. The young space contains short-lived objects, the old space contains long-lived objects (tenures). There are two different garbage collection methods: Full GC and Incremental GC. An incremental GC collects garbage from the young space only, while a full GC runs in both regions.

If you are looking for more information on garbage collection in Squeak, this wiki entry on garbage collection in Squeak may be a good starting point.

Further Work & Questions

If you want to work on this (or have to in a future SWT lesson :wink:) and have any questions, feel free to open Issues and/or @ us here on GitHub.

hpi-swa-teaching / InteractiveProfilingTool