rom/exec/signal.c

   1 /*
   2     Copyright © 1995-2001, 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? Raise the exception or defer it for later. */
  69         if(task->tc_State==TS_RUN)
  70         {
  71             /* Are taskswitches allowed? (Don't count own Disable() here) */
  72             if(SysBase->TDNestCnt>=0||SysBase->IDNestCnt>0)
  73                 /* No. Store it for later. */
  74                 SysBase->AttnResched|=0x80;
  75             else
  76             {
  77                 /* Switches are allowed. Move the current task away. */
  78 //              SysBase->ThisTask->tc_State=TS_READY;
  79 //              Enqueue(&SysBase->TaskReady,&SysBase->ThisTask->tc_Node);
  80
  81                 /* And force a rescedule. */
  82                 Reschedule(task);
  83             }
  84
  85             /* All done. */
  86             Enable();
  87             return;
  88         }
  89     }
  90
  91     /*
  92         Is the task receiving the signals waiting on them
  93         (or on a exception) ?
  94     */
  95     if((task->tc_State==TS_WAIT)&&
  96        (task->tc_SigRecvd&(task->tc_SigWait|task->tc_SigExcept)))
  97     {
  98         /* Yes. Move him to the ready list. */
  99         task->tc_State=TS_READY;
 100         Remove(&task->tc_Node);
 101         Enqueue(&SysBase->TaskReady,&task->tc_Node);
 102
 103         /* Has it a higher priority as the current one? */
 104         if(task->tc_Node.ln_Pri>SysBase->ThisTask->tc_Node.ln_Pri)
 105         {
 106             /*
 107                 Yes. A taskswitch is necessary. Prepare one if possible.
 108                 (If the current task is not running it is already moved)
 109             */
 110             if(SysBase->ThisTask->tc_State==TS_RUN)
 111             {
 112                 /* Are taskswitches allowed? */
 113                 if(SysBase->TDNestCnt>=0||SysBase->IDNestCnt>0)
 114                     /* No. Store it for later. */
 115                     SysBase->AttnResched|=0x80;
 116                 else
 117                     /* Switches are allowed. Move the current task away.
 118                        And force a rescedule. */
 119                     Reschedule(task);
 120             }
 121         }
 122     }
 123
 124     Enable();
 125     AROS_LIBFUNC_EXIT
 126 }
 127