current_task(9r) [osf1 man page]

current_task(9r)														  current_task(9r)

NAME

       current_task - General: Returns a pointer to the task structure associated with the currently running kernel thread

SYNOPSIS

       struct task * current_task(
	       void );

ARGUMENTS

       None

DESCRIPTION

       The current_task routine returns a pointer to the task structure associated with the currently running kernel thread.  A device driver typ-
       ically calls this routine in preparation for doing a DMA operation to a user's buffer. The device driver uses the pointer returned by  cur-
       rent_task in the call to the vm_map_pageable routine.

CAUTIONS

       You must not call the current_task routine from a driver's interrupt handler.

RETURN VALUES

       The current_task routine returns a pointer to the task structure for the currently running kernel thread.

SEE ALSO

       Routines: round_page(9r), trunc_page(9r), vm_map_pageable(9r)

       Data Structures: thread(9s)

																  current_task(9r)

round_page(9r)															    round_page(9r)

NAME

       round_page - General: Rounds the specified address

SYNOPSIS

       #include <mach/vm_param.h>

       vm_offset_t round_page(
	       vm_offset_t address );

ARGUMENTS

       Specifies the address (or byte count) that is being rounded.

DESCRIPTION

       The  round_page	routine rounds the specified address (or byte count) to a multiple of the page size. For example, round_page would round a
       1-byte count to be equal to the size of one page.  This routine shields the driver writer from having to know the page size of the  system,
       which  could  vary in different CPU architectures and on different CPU types within the same architecture. Typically, a device driver calls
       round_page in preparation for doing a DMA operation to a user's buffer. The value returned by this routine is  used  in	the  call  to  the
       vm_map_pageable routine. To use this routine, the driver writer must include the <mach/vm_param.h> header file in the driver.

RETURN VALUES

       The round_page routine returns the rounded address or byte count.

SEE ALSO

       Routines: current_task(9r), trunc_page(9r), vm_map_pageable(9r)

																    round_page(9r)