Simple C++ RDTSC intrusive profiler

Allows for quickly getting relative performance metrics for a section of code.

Low overhead and as simple as possible.

This is a standard implementation of the idea, done many times before. This repository exists mostly so that I have a minimal implementation where I have a full understanding and can easily control how stuff is done.

Usage

1. Include profiler_inline.cpp in the file you want to profile.

   #include "profiler_inline.cpp"
   

2. Place BeginProfiling() and FinishProfiling() statements to delineate the code you want to profile.

   BeginProfiling()
   
   // Profiled code goes here.
   
   FinishProfiling()

3. Within the delineated code section, place PROFILE_BLOCK statements to mark sections you're interested in.

   void MyFunction() {
     PROFILE_BLOCK("my function");
   
     // ...
   
     for(int i = 0; i < 10; ++i) {
       PROFILE_BLOCK("inside the loop");
   
       // ...
   
     }
   }

4. After FinishProfiling, call PrintProfilingResults to print the results to standard output. You'll get something like this:

    ==== Profile results ====
    9.08% total | 9.08% exclusive - my function [hits: 1]
    90.92% total | 90.92% exclusive - inside the loop [hits: 10]
    ==== End of profile results ====
   

Capabilities

• Works with recursive functions.

Limitations

• POSIX only (tested only on Linux, relies on POSIX headers).
• x86/amd64 only (relies on RDTSC instruction being available through x86intrin.h).
• Doesn't allow for profiling across compilation units (due to use of __COUNTER__ preprocessor macro).