---
name: "zmq_atomic_counter_inc"
section: "3"
platform: "linux"
package: "zeromq"
version: "4.3.5-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/zmq_atomic_counter_inc"
---

# zmq\_atomic\_counter\_inc(3)

increment an atomic counter

## NAME

zmq\_atomic\_counter\_inc - increment an atomic counter

## SYNOPSIS

**int zmq\_atomic\_counter\_inc (void \*counter);**

## DESCRIPTION

The *zmq\_atomic\_counter\_inc* function increments an atomic counter in a threadsafe fashion. This function uses platform specific atomic operations.

## RETURN VALUE

The *zmq\_atomic\_counter\_inc()* function returns the old value of the counter, before incrementing.

## EXAMPLE

**Test code for atomic counters**.

```
void *counter = zmq_atomic_counter_new ();
assert (zmq_atomic_counter_value (counter) == 0);
assert (zmq_atomic_counter_inc (counter) == 0);
assert (zmq_atomic_counter_inc (counter) == 1);
assert (zmq_atomic_counter_inc (counter) == 2);
assert (zmq_atomic_counter_value (counter) == 3);
assert (zmq_atomic_counter_dec (counter) == 1);
assert (zmq_atomic_counter_dec (counter) == 1);
assert (zmq_atomic_counter_dec (counter) == 0);
zmq_atomic_counter_set (counter, 2);
assert (zmq_atomic_counter_dec (counter) == 1);
assert (zmq_atomic_counter_dec (counter) == 0);
zmq_atomic_counter_destroy (&counter);
return 0;
```

## SEE ALSO

[**zmq\_atomic\_counter\_new**(3)](/zmq_atomic_counter_new/3.md) [**zmq\_atomic\_counter\_set**(3)](/zmq_atomic_counter_set/3.md) [**zmq\_atomic\_counter\_dec**(3)](/zmq_atomic_counter_dec/3.md) [**zmq\_atomic\_counter\_value**(3)](/zmq_atomic_counter_value/3.md) [**zmq\_atomic\_counter\_destroy**(3)](/zmq_atomic_counter_destroy/3.md)

## AUTHORS

This page was written by the 0MQ community. To make a change please read the 0MQ Contribution Policy at **http://www.zeromq.org/docs:contributing**.