UProbes.jl

Lightweight instrumentation for dtrace/bpftrace for Julia programs

UProbes.jl allows you to insert lightweight instrumentation points into your Julia program and lets you enable that instrumentation during runtime with bpftrace on Linux and dtrace elsewhere.

Entrypoints

• @query(provider, name, types...), query whether a probe is active.
• @probe(provider, name, args...), place a probepoint and pass along args.

Example

using UProbes

function f(arg)
    if @query(:julia, :test, typeof(arg))
        @probe(:julia, :test, arg)
    end
end

while true
    i = rand(Int64)
    f(i)
end

sudo bpftrace -p $PID -e "usdt:julia:test { @[comm] = count(); }"
Attaching 1 probe...
^C

@[8906]: 4071763

Status

• Semaphore support works!
• Argument passing does not :/

Also see

• https://github.com/cuviper/rust-libprobe