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_util.h"
  14 #include "exec_debug.h"
  15 #ifndef DEBUG_RemTask
  16 #   define DEBUG_RemTask 0
  17 #endif
  18 #undef DEBUG
  19 #if DEBUG_RemTask
  20 #   define DEBUG 1
  21 #endif
  22 #include <aros/debug.h>
  23
  24 extern void Exec_Dispatch();
  25
  26 /*****************************************************************************
  27
  28     NAME */
  29
  30         AROS_LH1(void, RemTask,
  31
  32 /*  SYNOPSIS */
  33         AROS_LHA(struct Task *,     task, A1),
  34
  35 /*  LOCATION */
  36         struct ExecBase *, SysBase, 48, Exec)
  37
  38 /*  FUNCTION
  39         Remove a task from the task lists. All memory in the tc_MemEntry list
  40         is freed and a rescedule is done. It's safe to call RemTask() out
  41         of Forbid() or Disable().
  42         This function is one way to get rid of the current task. The other way
  43         is to fall through the end of the entry point.
  44
  45     INPUTS
  46         task - Task to be removed. NULL means current task.
  47
  48     RESULT
  49
  50     NOTES
  51
  52     EXAMPLE
  53
  54     BUGS
  55
  56     SEE ALSO
  57         AddTask()
  58
  59     INTERNALS
  60
  61     HISTORY
  62
  63 ******************************************************************************/
  64 {
  65     AROS_LIBFUNC_INIT
  66     struct MemList *mb;
  67     struct ETask *et;
  68
  69     /* A value of NULL means current task */
  70     if (task==NULL)
  71         task=SysBase->ThisTask;
  72
  73     D(bug("Call RemTask (%08lx (\"%s\"))\n", task, task->tc_Node.ln_Name));
  74
  75     /*
  76         Since it's possible that the following will free a task
  77         structure that is used for some time afterwards it's
  78         necessary to protect the free memory list so that nobody
  79         can allocate that memory.
  80     */
  81     Forbid();
  82
  83     /* Remove() here, before freeing the MemEntry list. Because
  84        the MemEntry list might contain the task struct itself! */
  85
  86     if(task != SysBase->ThisTask)
  87     {
  88         Remove(&task->tc_Node);
  89     }
  90
  91     /* The task has been removed */
  92     task->tc_State = TS_REMOVED;
  93
  94     /* Free all memory in the tc_MemEntry list. */
  95     while((mb=(struct MemList *)RemHead(&task->tc_MemEntry))!=NULL)
  96         /* Free one MemList node */
  97         FreeEntry(mb);
  98
  99     /* Uninitialize ETask structure */
 100     et = GetETask(task);
 101     if(et != NULL)
 102     {
 103         CleanupETask(task, et);
 104     }
 105
 106     /* Changing the task lists always needs a Disable(). */
 107     Disable();
 108
 109     /* Freeing myself? */
 110     if(task==SysBase->ThisTask)
 111     {
 112         /*
 113             Since I don't know how many levels of Forbid()
 114             are already pending I set a default value.
 115         */
 116         SysBase->TDNestCnt=-1;
 117
 118 //        task->tc_Node.ln_Pred->ln_Succ = task->tc_Node.ln_Succ;
 119 //      task->tc_Node.ln_Succ->ln_Pred = task->tc_Node.ln_Pred;
 120
 121         /* And force a task switch. Note: Dispatch, not Switch,
 122            because the state of thistask must not be saved ->
 123            after all the mem for the task + intetask + context
 124            could already have been freed by the FreeEntry() call
 125            above!!! */
 126
 127
 128         Supervisor(__AROS_GETVECADDR(SysBase, 10));
 129         /* Does not return. */
 130     }
 131
 132     /* All done. */
 133     Enable();
 134     Permit();
 135
 136     ReturnVoid ("RemTask");
 137     AROS_LIBFUNC_EXIT
 138 }
 139
 140