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 #include "exec_intern.h"
  15
  16 /*****************************************************************************
  17
  18     NAME */
  19
  20         AROS_LH2(void, Signal,
  21
  22 /*  SYNOPSIS */
  23         AROS_LHA(struct Task *,     task,      A1),
  24         AROS_LHA(ULONG,             signalSet, D0),
  25
  26 /*  LOCATION */
  27         struct ExecBase *, SysBase, 54, Exec)
  28
  29 /*  FUNCTION
  30         Send some signals to a given task. If the task is currently waiting
  31         on these signals, has a higher priority as the current one and if
  32         taskswitches are allowed the new task begins to run immediately.
  33
  34     INPUTS
  35         task      - Pointer to task structure.
  36         signalSet - The set of signals to send to the task.
  37
  38     RESULT
  39
  40     NOTES
  41         This function may be used from interrupts.
  42
  43     EXAMPLE
  44
  45     BUGS
  46
  47     SEE ALSO
  48         AllocSignal(), FreeSignal(), Wait(), SetSignal(), SetExcept()
  49
  50     INTERNALS
  51
  52     HISTORY
  53
  54 ******************************************************************************/
  55 {
  56     AROS_LIBFUNC_INIT
  57
  58     /* Protect the task lists against other tasks that may use Signal(). */
  59     Disable();
  60
  61     /* Set the signals in the task structure. */
  62     task->tc_SigRecvd|=signalSet;
  63
  64     /* Do those bits raise exceptions? */
  65     if(task->tc_SigExcept&task->tc_SigRecvd)
  66     {
  67         /* Yes. Set the exception flag. */
  68         task->tc_Flags|=TF_EXCEPT;
  69
  70         /* task is running (Signal() called from within interrupt)? Raise the exception or defer it for later. */
  71         if (task->tc_State==TS_RUN)
  72         {
  73             /* Order a reschedule */
  74             Reschedule();
  75
  76             /* All done. */
  77             Enable();
  78             return;
  79         }
  80     }
  81
  82     /*
  83         Is the task receiving the signals waiting on them
  84         (or on a exception) ?
  85     */
  86     if((task->tc_State==TS_WAIT)&&
  87        (task->tc_SigRecvd&(task->tc_SigWait|task->tc_SigExcept)))
  88     {
  89         /* Yes. Move him to the ready list. */
  90         task->tc_State=TS_READY;
  91         Remove(&task->tc_Node);
  92         Enqueue(&SysBase->TaskReady,&task->tc_Node);
  93
  94         /* Has it a higher priority as the current one? */
  95         if (task->tc_Node.ln_Pri > GET_THIS_TASK->tc_Node.ln_Pri)
  96         {
  97             /*
  98                 Yes. A taskswitch is necessary. Prepare one if possible.
  99                 (If the current task is not running it is already moved)
 100             */
 101             if (GET_THIS_TASK->tc_State == TS_RUN)
 102                 Reschedule();
 103         }
 104     }
 105
 106     Enable();
 107
 108     AROS_LIBFUNC_EXIT
 109 }
 110