---
name: "QMC"
section: "3"
platform: "linux"
package: "pcp"
version: "7.2.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/QMC"
---

# QMC(3)

library for managing groups of Performance Co-Pilot metrics

## NAME

**QMC** - library for managing groups of Performance Co-Pilot metrics

## C++ SYNOPSIS

**#include \<qmc.h\>**

**c++ ... -lpcp\_qmc -lpcp**

## DESCRIPTION

The Qt-based Performance Metrics Class (**QMC**) class library is a collection of C++ classes for managing a large set of performance metrics from a variety of sources.  This library is built over [**PMAPI**(3)](/PMAPI/3.md).

## DIAGNOSTICS

Error messages are generated using [**pmprintf**(3)](/pmprintf/3.md) but are not flushed. It is the responsibility of the user to call [**pmflush**(3)](/pmflush/3.md) to output any messages.

Additional diagnostics may be activated by adding the option **pmc** to the global debugging specification, as described in [**pmSetDebug**(3)](/pmSetDebug/3.md).

## SEE ALSO

[**PMAPI**(3)](/PMAPI/3.md), [**QmcContext**(3)](/QmcContext/3.md), [**QmcDesc**(3)](/QmcDesc/3.md), [**QmcGroup**(3)](/QmcGroup/3.md), [**QmcIndom**(3)](/QmcIndom/3.md), [**QmcMetric**(3)](/QmcMetric/3.md), [**QmcSource**(3)](/QmcSource/3.md), [**pmflush**(3)](/pmflush/3.md) and [**pmprintf**(3)](/pmprintf/3.md).