PAPI_hl_read(3)

Hey bestie! Welcome to the PAPI_hl_read(3) page from the PAPI manual 💖 This one is lowkey the “grab the delta since the region started” moment, and yes, it’s iconic.

🌸 NAME 🌸

PAPI_hl_read — read performance events inside of a region and store the difference to the corresponding beginning of the region. That’s the whole assignment, periodt. 💅

✨ SYNOPSIS ✨

💖 Detailed Description 💖

Okay so here’s the C interface, bestie — keep it cute and keep it exact:

💻 C Interface: 💻

#include <papi.h>
int PAPI_hl_read( const char* region );

🎀 Parameters 🎀

• region — a unique region name corresponding to PAPI_hl_region_begin. Yes, it has to match, bestie. 🌈

🚦 Return values 🚦

• PAPI_OK — the good one, slay ✨
• PAPI_ENOTRUN — the EventSet is currently not running or couldn’t be determined. 😭
• PAPI_ESYS — a system or C library call failed inside PAPI; see the errno variable. 🔥
• PAPI_EMISC — PAPI has been deactivated due to previous errors. 💀
• PAPI_ENOMEM — insufficient memory. 😵‍💫

PAPI_hl_read reads performance events inside of a region and stores the difference to the corresponding beginning of the region. It’s giving “calculate the region difference” energy, no cap. 💫

Heads up: it assumes that PAPI_hl_region_begin was called before. Do not skip the begin, bestie. 🫶

🧪 Example 🧪

Here’s the example, exactly as it is — copy it with your whole chest:

int retval;

retval = PAPI_hl_region_begin("computation");
if ( retval != PAPI_OK )
    handle_error(1);

 //Do some computation here

retval = PAPI_hl_read("computation");
if ( retval != PAPI_OK )
    handle_error(1);

 //Do some computation here

retval = PAPI_hl_region_end("computation");
if ( retval != PAPI_OK )
    handle_error(1);

👀 See also 👀

• PAPI_hl_region_begin
• PAPI_hl_region_end
• PAPI_hl_stop

💖 Author 💖

The author line is literally: Generated automatically by Doxygen for PAPI from the source code. Iconic, honestly. 🎀

---

This page is from PAPI version 7.2.0.0 and is dated Wed Jun 25 2025 19:30:48. Bye bestie, go read those performance events! 💅💖