rom/exec/findtask.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Search a task by name.
   6     Lang: english
   7 */
   8 #include <exec/execbase.h>
   9 #include <aros/libcall.h>
  10 #include <proto/exec.h>
  11 #include "exec_intern.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16
  17         AROS_LH1(struct Task *, FindTask,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(CONST_STRPTR, name, A1),
  21
  22 /*  LOCATION */
  23         struct ExecBase *, SysBase, 49, Exec)
  24
  25 /*  FUNCTION
  26         Find a task with a given name or get the address of the current task.
  27         Finding the address of the current task is a very quick function
  28         call, but finding a special task is a very CPU intensive instruction.
  29         Note that generally a task may already be gone when this function
  30         returns.
  31
  32     INPUTS
  33         name - Pointer to name or NULL for current task.
  34
  35     RESULT
  36         Address of task structure found.
  37
  38     NOTES
  39
  40     EXAMPLE
  41
  42     BUGS
  43
  44     SEE ALSO
  45
  46     INTERNALS
  47
  48 ******************************************************************************/
  49 {
  50     AROS_LIBFUNC_INIT
  51
  52     struct Task *ret;
  53
  54     /* Quick return for a quick argument */
  55     if(name==NULL)
  56         return GET_THIS_TASK;
  57
  58     /* Always protect task lists with a Disable(). */
  59     Disable();
  60
  61     /* First look into the ready list. */
  62     ret=(struct Task *)FindName(&SysBase->TaskReady,name);
  63     if(ret==NULL)
  64     {
  65         /* Then into the waiting list. */
  66         ret=(struct Task *)FindName(&SysBase->TaskWait,name);
  67         if(ret==NULL)
  68         {
  69             /*
  70                 Finally test the current task. Note that generally
  71                 you know the name of your own task - so it is close
  72                 to nonsense to look for it this way.
  73             */
  74             char *s1=GET_THIS_TASK->tc_Node.ln_Name;
  75             const char *s2=name;
  76
  77             /* Check as long as the names are identical. */
  78             while(*s1++==*s2)
  79                 /* Terminator found? */
  80                 if(!*s2++)
  81                 {
  82                     /* Got it. */
  83                     ret=GET_THIS_TASK;
  84                     break;
  85                 }
  86         }
  87     }
  88
  89     /* Return whatever I found. */
  90     Enable();
  91     return ret;
  92     AROS_LIBFUNC_EXIT
  93 } /* FindTask */
  94