Struct Profiler 

pub struct Profiler { /* private fields */ }

Counts what a run executes, by the instruction that executed.

Implementations

impl Profiler

pub fn new() -> Profiler

A profiler with nothing recorded yet.

pub fn counted(&self) -> u64

How many instructions were counted.

pub fn total(&self) -> Cost

What the whole run cost, by the four figures a row carries.

pub fn hottest(&self) -> Vec<((FunctionId, u32), Cost)>

Every instruction that ran, and how often, hottest first.

Ties are broken by the instruction’s own identity, so two runs of one program report the same order: a profile that reordered its own ties would make an unchanged program look changed.

pub fn by_function(&self) -> Vec<(FunctionId, Cost)>

Every function that ran, and what the instructions of it cost, hottest first.

pub fn rows(&self) -> Vec<((FunctionId, u32), Cost)>

Every instruction that ran and what it cost, in no particular order.

For a reader that wants to group by something only the program knows — the opcode an instruction is, the callee a call names — which this crate deliberately does not: a profiler that read the program would have to be given one, and the two things that want these groupings already hold it.

Trait Implementations

impl Debug for Profiler

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Debugger for Profiler

fn at(&self, stop: &Stop<'_>) -> Resume

Closes the instruction that just ran and opens the one about to.

The count belongs to the instruction this stop is before; the time and the heap belong to the one the previous stop was before, because those are what moved in between.

The clock is read twice, first thing and last thing, and the bookkeeping sits between the two reads. So the interval a number is measured over holds the instruction, the dispatch that reached it and two clock reads — and not this hook’s mutex and map, which is the expensive part and which would otherwise swamp what it is trying to measure. An add.int is a nanosecond or two and the map is a hundred.

impl Default for Profiler

fn default() -> Profiler

Returns the “default value” for a type.