sap_profiling

Instrumentation profiler for C++20. Records scoped timings per thread and writes them as Chrome Tracing JSON, viewable in Perfetto or chrome://tracing.

Part of the Sapfire library ecosystem.

How it works

Instrumentor is a thread-safe singleton that manages a profiling session. InstrumentationTimer is a RAII guard: it records a std::chrono::steady_clock timestamp on construction and writes a ProfileResult (name, start, duration, thread ID) to the output stream on destruction.

Results are written in the Chrome Tracing {"traceEvents": [...]} format. Each event carries a thread ID, enabling per-thread timeline views in Perfetto.

Usage

#include <sap_profiling/profiling.h>

// Start a session — opens results.json (or a path of your choice)
sap::prof::Instrumentor::get().begin_session("MyApp");

{
    SAP_PROFILE_SCOPE("expensive_work");
    do_expensive_work();
} // timer fires here, writes the event

sap::prof::Instrumentor::get().end_session();

Open results.json in Perfetto UI or chrome://tracing to view the flame graph.

Build

Requires CMake 3.20+, C++20, and sap_core.

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build