PR_CreateThread

Creates a new thread.

Syntax

#include <prthread.h>

PRThread* PR_CreateThread(
   PRThreadType type,
   void (*start)(void *arg),
   void *arg,
   PRThreadPriority priority,
   PRThreadScope scope,
   PRThreadState state,
   PRUint32 stackSize);

Parameters

PR_CreateThread has the following parameters:

type

Specifies that the thread is either a user thread (PR_USER_THREAD) or a system thread (PR_SYSTEM_THREAD).

start

A pointer to the thread's root function, which is called as the root of the new thread. Returning from this function is the only way to terminate a thread.

arg

A pointer to the root function's only parameter. NSPR does not assess the type or the validity of the value passed in this parameter.

priority

The initial priority of the newly created thread.

scope

Specifies your preference for making the thread local (PR_LOCAL_THREAD), global (PR_GLOBAL_THREAD) or global bound (PR_GLOBAL_BOUND_THREAD). However, NSPR may override this preference if necessary.

state

Specifies whether the thread is joinable (PR_JOINABLE_THREAD) or unjoinable (PR_UNJOINABLE_THREAD).

stackSize

Specifies your preference for the size of the stack, in bytes, associated with the newly created thread. If you pass zero in this parameter, PR_CreateThread chooses the most favorable machine-specific stack size.

Returns

The function returns one of the following values:

• If successful, a pointer to the new thread. This pointer remains valid until the thread returns from its root function.
• If unsuccessful, (for example, if system resources are unavailable), NULL.

Description

If you want the thread to start up waiting for the creator to do something, enter a lock before creating the thread and then have the thread's root function enter and exit the same lock. When you are ready for the thread to run, exit the lock. For more information on locks and thread synchronization, see Introduction to NSPR.

If you want to detect the completion of the created thread, make it joinable. You can then use PR_JoinThread to synchronize the termination of another thread.