ECG

ECG is an Erlang function Call graph Generator, which draws function calls and process spawns automatically. ECG utilizes Erlang's powerful trace mechanism and the visualization tool graphviz, make sure you have graphviz installed, and since Python binding is used here, you also need Digraph package installed. The graph generation flow is as follows:

Start tracer -> Start program -> Stop trace -> Analyze trace binary -> Draw graph

Usage

For a simple usage, compile tracer.erl and add tracer.beam to Erlang's code load path together with your program. And specify the modules you want to trace and trace mode: global or local which means global or local function calls to trace, then start you program, and stop trace at where you want to end analysis, then parse trace binary and finally draw the graph.

Demo

Suppose we want to draw the graph for modules in demo directory, we can do following steps:

Compile

# Go to demo directory
mkdir ebin
erlc -o ebin *.erl ../tracer.erl
erl -pa ebin

Trace

%% Trace modules foo and bar in local mode
tracer:trace("trace.bin", [foo, bar], local).
foo:start().
%% Stop trace when you want to
tracer:stop().
tracer:analyze("trace.bin", "trace.txt").

Draw

python ../draw.py trace.txt

Finally, we get the graph:

In the graph, we can see that every function call and process spawn is tagged by a sequence number which means the execution order. Each process is sperated by a blue rectangle in which inner function calls are grouped. The red arrows connecting the rectangles mean the process spawn.

License

MIT