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