## thread_get_special_port

Function - Return a send right to the caller-specified special port.

### SYNOPSIS

    kern_return_t   thread_get_special_port
                    (thread_act_t                            thread,
                     int                                 which_port,
                     thread                            special_port);

#### Macro form:

    kern_return_t   thread_get_kernel_port
                    (thread_act_t                            thread,
                     thread                            special_port);

### PARAMETERS

thread
  [in thread send right] The thread for which to return the port's send right.

which_port
  [in scalar] The special port for which the send right is requested. Valid values are:

  THREAD_KERNEL_PORT
    [thread-self send right] The port used to name the thread. Used to invoke operations that affect the thread. This is the port returned by mach_thread_self.

special_port
  [out thread-special send right] The returned value for the port.

### DESCRIPTION

The thread_get_special_port function returns a send right for a special port belonging to thread.

The thread kernel port is a port for which the kernel holds the receive right. The kernel uses this port to identify the thread.

If one thread has a send right for the kernel port of another thread, it can use the port to perform kernel operations for the other thread. Send rights for a kernel port normally are held only by the thread to which the port belongs, or by the task that contains the thread. Using the mach_msg function, however, any thread can pass a send right for its kernel port to another thread.

### RETURN VALUES

Only generic errors apply.

### RELATED INFORMATION

Functions: mach_thread_self, task_get_special_port, task_set_special_port, thread_create, thread_set_special_port.