The goal is to trace functions with minimal overhead and no modifications to the source code.
The package is a prototype for demonstration purposes, use at your own risk (e.g., attempting to trace Base.:+ will likely crash Julia).
using TraceIt
@trace Base.sum; @trace Base.log
reduce(log, map(sum, [[1, 2, 3], [4, 5], [6]]))
# mostly compile time on the first run:
printtrace()
Func. ╲ Stat. │ called mem, b gctime, s time, s time, %
──────────────┼──────────────────────────────────────────────
sum │ 3 12272 0.0 0.0102889 54.94 %
log │ 2 138281 0.0 0.0084373 45.06 %
──────────────┼──────────────────────────────────────────────
Σ │ 5 150553 0.0 0.0187262 100.0 %The tracing is implemented with the use of Base.invoke_in_world, in the following way.
Say, there is function foo to be traced in Foo:
module Foo
foo(x) = x
endTracing is done by (somewhere inside @trace Foo.foo):
primary_world = Base.get_world_counter()
@eval Foo function foo(x)
#= record some statistics globally =#
@info "foo is now traced!"
return Base.invoke_in_world($primary_world, foo, x)
endUn-tracing (somewhere inside @untrace Foo.foo):
@eval Foo function foo(x)
return Base.invoke_in_world($primary_world, foo, x)
end