# PR_CNotify

Notify a thread waiting on a change in the state of monitored data.

## Syntax

```{code}
#include <prcmon.h>

PRStatus PR_CNotify(void *address);
```

### Parameter

The function has the following parameter:

`address`

: The address of the monitored object. The calling thread must be in
  the monitor defined by the value of the address.

### Returns

> - `PR_SUCCESS` indicates that the calling thread is the holder of the
>   mutex for the monitor referred to by the address parameter.
> - `PR_FAILURE` indicates that the monitor has not been entered by the
>   calling thread.

## Description

Using the value specified in the `address` parameter to find a monitor
in the monitor cache, {ref}`PR_CNotify` notifies single a thread waiting
for the monitor's state to change. If a thread is waiting on the monitor
(having called {ref}`PR_CWait`), then that thread is made ready. As soon as
the thread is scheduled, it attempts to reenter the monitor.