# PR_Initialize

Provides an alternate form of explicit initialization. In addition to
establishing the sequence of operations, {ref}`PR_Initialize` implicitly
calls {ref}`PR_Cleanup` on exiting the primordial function.

## Syntax

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

PRIntn PR_Initialize(
  PRPrimordialFn prmain,
  PRIntn argc,
  char **argv,
  PRUintn maxPTDs);
```

### Parameters

{ref}`PR_Initialize` has the following parameters:

`prmain`

: The function that becomes the primordial thread's root function.
  Returning from prmain leads to termination of the process.

`argc`

: The length of the argument vector, whether passed in from the host's
  program-launching facility or fabricated by the actual main program.
  This approach conforms to standard C programming practice.

`argv`

: The base address of an array of strings that compromise the program's
  argument vector. This approach conforms to standard C programming
  practice.

`maxPTDs`

: This parameter is ignored.

### Returns

The value returned from the root function, `prmain`.

## Description

{ref}`PR_Initialize` initializes the NSPR runtime and places NSPR between
the caller and the runtime library. This allows `main` to be treated
like any other function, signaling its completion by returning and
allowing the runtime to coordinate the completion of the other threads
of the runtime.

{ref}`PR_Initialize` does not return to its caller until all user threads
have terminated.

The priority of the main (or primordial) thread is
`PR_PRIORITY_NORMAL`. The thread may adjust its own priority by using
{ref}`PR_SetThreadPriority`.