arch/ppc-sam440/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 #include <proto/kernel.h>
  13
  14 #include "../kernel/kernel_intern.h"
  15
  16 #include "exec_util.h"
  17 #include "exec_debug.h"
  18 #ifndef DEBUG_RemTask
  19 #   define DEBUG_RemTask 0
  20 #endif
  21 #undef DEBUG
  22 #if DEBUG_RemTask
  23 #   define DEBUG 1
  24 #endif
  25 #include <aros/debug.h>
  26
  27 /*****************************************************************************
  28
  29     NAME */
  30
  31         AROS_LH1(void, RemTask,
  32
  33 /*  SYNOPSIS */
  34         AROS_LHA(struct Task *,     task, A1),
  35
  36 /*  LOCATION */
  37         struct ExecBase *, SysBase, 48, Exec)
  38
  39 /*  FUNCTION
  40         Remove a task from the task lists. All memory in the tc_MemEntry list
  41         is freed and a rescedule is done. It's safe to call RemTask() out
  42         of Forbid() or Disable().
  43         This function is one way to get rid of the current task. The other way
  44         is to fall through the end of the entry point.
  45
  46     INPUTS
  47         task - Task to be removed. NULL means current task.
  48
  49     RESULT
  50
  51     NOTES
  52
  53     EXAMPLE
  54
  55     BUGS
  56
  57     SEE ALSO
  58         AddTask()
  59
  60     INTERNALS
  61
  62     HISTORY
  63
  64 ******************************************************************************/
  65 {
  66     AROS_LIBFUNC_INIT
  67     struct MemList *mb;
  68     struct ETask *et;
  69
  70     /* A value of NULL means current task */
  71     if (task==NULL)
  72         task=SysBase->ThisTask;
  73
  74     D(bug("[exec] Call RemTask (%012lx (\"%s\"))\n", task, task->tc_Node.ln_Name));
  75
  76     /*
  77         Since it's possible that the following will free a task
  78         structure that is used for some time afterwards it's
  79         necessary to protect the free memory list so that nobody
  80         can allocate that memory.
  81     */
  82     Forbid();
  83
  84     /* Remove() here, before freeing the MemEntry list. Because
  85        the MemEntry list might contain the task struct itself! */
  86
  87     if(task != SysBase->ThisTask)
  88     {
  89         Remove(&task->tc_Node);
  90     }
  91
  92     /* Free all memory in the tc_MemEntry list. */
  93     while((mb=(struct MemList *)RemHead(&task->tc_MemEntry))!=NULL)
  94         /* Free one MemList node */
  95         FreeEntry(mb);
  96
  97     /* Uninitialize ETask structure */
  98     et = GetETask(task);
  99     if(et != NULL)
 100     {
 101         CleanupETask(task, et);
 102     }
 103
 104     /* Changing the task lists always needs a Disable(). */
 105     Disable();
 106
 107     /* Freeing myself? */
 108     if(task==SysBase->ThisTask)
 109     {
 110         void *KernelBase = getKernelBase();
 111
 112         /* Can't do that - let the dispatcher do it. */
 113         task->tc_State=TS_REMOVED;
 114
 115         /*
 116             Since I don't know how many levels of Forbid()
 117             are already pending I set a default value.
 118         */
 119         SysBase->TDNestCnt=-1;
 120
 121 //        task->tc_Node.ln_Pred->ln_Succ = task->tc_Node.ln_Succ;
 122 //      task->tc_Node.ln_Succ->ln_Pred = task->tc_Node.ln_Pred;
 123
 124         /* And force a task switch. Note: Dispatch, not Switch,
 125            because the state of thistask must not be saved ->
 126            after all the mem for the task + intetask + context
 127            could already have been freed by the FreeEntry() call
 128            above!!! */
 129
 130         KrnDispatch();
 131         /* Does not return. */
 132     }
 133
 134     /* All done. */
 135     Enable();
 136     Permit();
 137
 138     ReturnVoid ("RemTask");
 139     AROS_LIBFUNC_EXIT
 140 }
 141
 142