NAME    [Toc]    [Back]

       kernel_isrthread - General: Starts a fixed priority kernel
       thread dedicated to interrupt service

SYNOPSIS    [Toc]    [Back]

       thread_t kernel_isrthread(
               task_t task,
               void (*start) (void),
               int pri );

ARGUMENTS    [Toc]    [Back]

       Specifies a pointer to a  task  structure.   This  pointer
       identifies  the task in which the kernel_isrthread routine
       starts the newly created kernel thread dedicated to interrupt
  service handling.  Specifies a pointer to an routine
       that is the entry  point  for  the  newly  created  kernel
       thread.   Specifies  the scheduling priority level for the
       newly created kernel thread. See the  DESCRIPTION  section
       for  the  priority usage table that describes the possible
       scheduling priorities.

DESCRIPTION    [Toc]    [Back]

       The kernel_isrthread routine creates and starts  a  kernel
       thread  at  the  specified entry point. This kernel thread
       handles only interrupt service requests in  the  specified
       task  and at the specified priority level. A kernel module
       should always  attach  a  kernel  thread  to  the  ``first
       task.''

       The  following priority usage table describes the possible
       scheduling priorities. The first column shows a  range  of
       priorities. The second column shows an associated scheduling
 priority constant defined in <src/kernel/kern/sched.h>
       (if  applicable).  The third column describes the usage of
       the priority ranges. To specify a scheduling  priority  of
       38,  you  pass  the  constant BASEPRI_SYSTEM. To specify a
       scheduling priority of 33, you  can  pass  the  following:
       BASEPRI_HIGHEST + 1.

       -------------------------------------------------------------
       Priority   Constant                  Usage
       -------------------------------------------------------------
       0--31      N/A                       Realtime kernel threads
       32--38     BASEPRI_HIGHEST      --   Operating system kernel
                  BASEPRI_SYSTEM            threads
       44--64     BASEPRI_USER         --   User kernel threads
                  BASEPRI_LOWEST
       -------------------------------------------------------------

RETURN VALUES    [Toc]    [Back]

       Upon successful  completion,  kernel_isrthread  returns  a
       pointer to the thread structure associated with the kernel
       thread started at the specified entry point.  Kernel  modules
 can use this pointer as a handle to a specific kernel
       thread in calls to other kernel threads-related  routines.

SEE ALSO    [Toc]    [Back]

       Routines: kernel_thread_w_arg(9r)

       Data Structures: task(9s), thread(9s)



                                             kernel_isrthread(9r)