arch/i386-pc/exec/remtask.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Remove a task
   6     Lang: english
   7 */
   8 #include <exec/execbase.h>
   9 #include <exec/tasks.h>
  10 #include <aros/libcall.h>
  11 #include <proto/exec.h>
  12
  13 #include "exec_debug.h"
  14 #ifndef DEBUG_RemTask
  15 #   define DEBUG_RemTask 0
  16 #endif
  17 #undef DEBUG
  18 #if DEBUG_RemTask
  19 #   define DEBUG 1
  20 #endif
  21 #include <aros/debug.h>
  22
  23 extern void Exec_Dispatch();
  24
  25 /*****************************************************************************
  26
  27     NAME */
  28
  29         AROS_LH1(void, RemTask,
  30
  31 /*  SYNOPSIS */
  32         AROS_LHA(struct Task *,     task, A1),
  33
  34 /*  LOCATION */
  35         struct ExecBase *, SysBase, 48, Exec)
  36
  37 /*  FUNCTION
  38         Remove a task from the task lists. All memory in the tc_MemEntry list
  39         is freed and a rescedule is done. It's safe to call RemTask() out
  40         of Forbid() or Disable().
  41         This function is one way to get rid of the current task. The other way
  42         is to fall through the end of the entry point.
  43
  44     INPUTS
  45         task - Task to be removed. NULL means current task.
  46
  47     RESULT
  48
  49     NOTES
  50
  51     EXAMPLE
  52
  53     BUGS
  54
  55     SEE ALSO
  56         AddTask()
  57
  58     INTERNALS
  59
  60     HISTORY
  61
  62 ******************************************************************************/
  63 {
  64     AROS_LIBFUNC_INIT
  65     struct MemList *mb;
  66
  67     /* A value of NULL means current task */
  68     if (task==NULL)
  69         task=SysBase->ThisTask;
  70
  71     D(bug("Call RemTask (%08lx (\"%s\"))\n", task, task->tc_Node.ln_Name));
  72
  73     /*
  74         Since it's possible that the following will free a task
  75         structure that is used for some time afterwards it's
  76         necessary to protect the free memory list so that nobody
  77         can allocate that memory.
  78     */
  79     Forbid();
  80
  81     /* Remove() here, before freeing the MemEntry list. Because
  82        the MemEntry list might contain the task struct itself! */
  83
  84     if(task != SysBase->ThisTask)
  85     {
  86         Remove(&task->tc_Node);
  87     }
  88
  89     /* Free all memory in the tc_MemEntry list. */
  90     while((mb=(struct MemList *)RemHead(&task->tc_MemEntry))!=NULL)
  91         /* Free one MemList node */
  92         FreeEntry(mb);
  93
  94     /* Changing the task lists always needs a Disable(). */
  95     Disable();
  96
  97     /* Freeing myself? */
  98     if(task==SysBase->ThisTask)
  99     {
 100         /* Can't do that - let the dispatcher do it. */
 101         task->tc_State=TS_REMOVED;
 102
 103         /*
 104             Since I don't know how many levels of Forbid()
 105             are already pending I set a default value.
 106         */
 107         SysBase->TDNestCnt=-1;
 108
 109 //        task->tc_Node.ln_Pred->ln_Succ = task->tc_Node.ln_Succ;
 110 //      task->tc_Node.ln_Succ->ln_Pred = task->tc_Node.ln_Pred;
 111
 112         /* And force a task switch. Note: Dispatch, not Switch,
 113            because the state of thistask must not be saved ->
 114            after all the mem for the task + intetask + context
 115            could already have been freed by the FreeEntry() call
 116            above!!! */
 117
 118
 119         Supervisor(__AROS_GETVECADDR(SysBase, 10));
 120         /* Does not return. */
 121     }
 122
 123     /* All done. */
 124     Enable();
 125     Permit();
 126
 127     ReturnVoid ("RemTask");
 128     AROS_LIBFUNC_EXIT
 129 }
 130
 131