---
name: "pthread_cond_wait"
section: "3"
platform: "macos"
package: "libpthread"
version: "539.100.4"
release: "macOS 26.5"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/pthread_cond_wait"
---

# pthread\_cond\_wait(3)

wait on a condition variable

## NAME

**pthread\_cond\_wait** – wait on a condition variable

## SYNOPSIS

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

*int*\

**pthread\_cond\_wait**(*pthread\_cond\_t \*cond*, *pthread\_mutex\_t \*mutex*);

## DESCRIPTION

The **pthread\_cond\_wait**() function atomically blocks the current thread waiting on the condition variable specified by *cond*, and releases the mutex specified by *mutex*. The waiting thread unblocks only after another thread calls [pthread\_cond\_signal(3)](/pthread_cond_signal/3.md), or [pthread\_cond\_broadcast(3)](/pthread_cond_broadcast/3.md) with the same condition variable, and the current thread reacquires the lock on *mutex*.

## RETURN VALUES

If successful, the **pthread\_cond\_wait**() function will return zero. Otherwise an error number will be returned to indicate the error.

## ERRORS

The **pthread\_cond\_wait**() function will fail if:

- \[EINVAL\]

  The value specified by *cond* or the value specified by *mutex* is invalid.

## SEE ALSO

[pthread\_cond\_broadcast(3)](/pthread_cond_broadcast/3.md), [pthread\_cond\_destroy(3)](/pthread_cond_destroy/3.md), [pthread\_cond\_init(3)](/pthread_cond_init/3.md), [pthread\_cond\_signal(3)](/pthread_cond_signal/3.md), [pthread\_cond\_timedwait(3)](/pthread_cond_timedwait/3.md)

## STANDARDS

The **pthread\_cond\_wait**() function conforms to ISO/IEC 9945-1:1996 (“POSIX.1”).