rom/exec/signal.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Send some signal to a given task
   6     Lang: english
   7 */
   8
   9 #include <exec/execbase.h>
  10 #include <aros/libcall.h>
  11 #include <proto/exec.h>
  12 #include <aros/debug.h>
  13
  14 /*****************************************************************************
  15
  16     NAME */
  17
  18         AROS_LH2(void, Signal,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(struct Task *,     task,      A1),
  22         AROS_LHA(ULONG,             signalSet, D0),
  23
  24 /*  LOCATION */
  25         struct ExecBase *, SysBase, 54, Exec)
  26
  27 /*  FUNCTION
  28         Send some signals to a given task. If the task is currently waiting
  29         on these signals, has a higher priority as the current one and if
  30         taskswitches are allowed the new task begins to run immediately.
  31
  32     INPUTS
  33         task      - Pointer to task structure.
  34         signalSet - The set of signals to send to the task.
  35
  36     RESULT
  37
  38     NOTES
  39         This function may be used from interrupts.
  40
  41     EXAMPLE
  42
  43     BUGS
  44
  45     SEE ALSO
  46         AllocSignal(), FreeSignal(), Wait(), SetSignal(), SetExcept()
  47
  48     INTERNALS
  49
  50     HISTORY
  51
  52 ******************************************************************************/
  53 {
  54     AROS_LIBFUNC_INIT
  55
  56     /* Protect the task lists against other tasks that may use Signal(). */
  57     Disable();
  58
  59     /* Set the signals in the task structure. */
  60     task->tc_SigRecvd|=signalSet;
  61
  62     /* Do those bits raise exceptions? */
  63     if(task->tc_SigExcept&task->tc_SigRecvd)
  64     {
  65         /* Yes. Set the exception flag. */
  66         task->tc_Flags|=TF_EXCEPT;
  67
  68         /* task is running (Signal() called from within interrupt)? Raise the exception or defer it for later. */
  69         if (task->tc_State==TS_RUN)
  70         {
  71             /* Order a reschedule */
  72             Reschedule();
  73
  74             /* All done. */
  75             Enable();
  76             return;
  77         }
  78     }
  79
  80     /*
  81         Is the task receiving the signals waiting on them
  82         (or on a exception) ?
  83     */
  84     if((task->tc_State==TS_WAIT)&&
  85        (task->tc_SigRecvd&(task->tc_SigWait|task->tc_SigExcept)))
  86     {
  87         /* Yes. Move him to the ready list. */
  88         task->tc_State=TS_READY;
  89         Remove(&task->tc_Node);
  90         Enqueue(&SysBase->TaskReady,&task->tc_Node);
  91
  92         /* Has it a higher priority as the current one? */
  93         if (task->tc_Node.ln_Pri > SysBase->ThisTask->tc_Node.ln_Pri)
  94         {
  95             /*
  96                 Yes. A taskswitch is necessary. Prepare one if possible.
  97                 (If the current task is not running it is already moved)
  98             */
  99             if (SysBase->ThisTask->tc_State == TS_RUN)
 100                 Reschedule();
 101         }
 102     }
 103
 104     Enable();
 105
 106     AROS_LIBFUNC_EXIT
 107 }
 108