rom/exec/signal.c

   1 /*
   2     Copyright © 1995-2015, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Send some signal to a given task
   6     Lang: english
   7 */
   8 #define DEBUG 0
   9
  10 #include <aros/debug.h>
  11 #include <exec/execbase.h>
  12 #include <aros/libcall.h>
  13 #include <proto/exec.h>
  14
  15 #include "exec_intern.h"
  16 #if defined(__AROSEXEC_SMP__)
  17 #include <proto/kernel.h>
  18 #include "etask.h"
  19 #endif
  20
  21 /*****************************************************************************
  22
  23     NAME */
  24
  25         AROS_LH2(void, Signal,
  26
  27 /*  SYNOPSIS */
  28         AROS_LHA(struct Task *,     task,      A1),
  29         AROS_LHA(ULONG,             signalSet, D0),
  30
  31 /*  LOCATION */
  32         struct ExecBase *, SysBase, 54, Exec)
  33
  34 /*  FUNCTION
  35         Send some signals to a given task. If the task is currently waiting
  36         on these signals, has a higher priority as the current one and if
  37         taskswitches are allowed the new task begins to run immediately.
  38
  39     INPUTS
  40         task      - Pointer to task structure.
  41         signalSet - The set of signals to send to the task.
  42
  43     RESULT
  44
  45     NOTES
  46         This function may be used from interrupts.
  47
  48     EXAMPLE
  49
  50     BUGS
  51
  52     SEE ALSO
  53         AllocSignal(), FreeSignal(), Wait(), SetSignal(), SetExcept()
  54
  55     INTERNALS
  56
  57     HISTORY
  58
  59 ******************************************************************************/
  60 {
  61     AROS_LIBFUNC_INIT
  62
  63     struct Task *ThisTask = GET_THIS_TASK;
  64 #if defined(__AROSEXEC_SMP__)
  65     spinlock_t *task_listlock = NULL;
  66     int cpunum = KrnGetCPUNumber();
  67 #endif
  68
  69     D(
  70         bug("[Exec] Signal(0x%p, %08lX)\n", task, signalSet);
  71         bug("[Exec] Signal: signaling '%s' (state %08x)\n", task->tc_Node.ln_Name, task->tc_State);
  72         bug("[Exec] Signal: from '%s'\n", ThisTask->tc_Node.ln_Name);
  73     )
  74
  75 #if defined(__AROSEXEC_SMP__)
  76     EXEC_SPINLOCK_LOCK(&IntETask(task->tc_UnionETask.tc_ETask)->iet_TaskLock, SPINLOCK_MODE_WRITE);
  77 #endif
  78     Disable();
  79     /* Set the signals in the task structure. */
  80     task->tc_SigRecvd |= signalSet;
  81 #if defined(__AROSEXEC_SMP__)
  82     EXEC_SPINLOCK_UNLOCK(&IntETask(task->tc_UnionETask.tc_ETask)->iet_TaskLock);
  83     Enable();
  84 #endif
  85
  86     /* Do those bits raise exceptions? */
  87     if (task->tc_SigRecvd & task->tc_SigExcept)
  88     {
  89         /* Yes. Set the exception flag. */
  90         task->tc_Flags |= TF_EXCEPT;
  91
  92         D(bug("[Exec] Signal: TF_EXCEPT set\n"));
  93
  94         /*
  95                 if the target task is running (called from within interrupt handler),
  96                 raise the exception or defer it for later.
  97             */
  98         if (task->tc_State == TS_RUN)
  99         {
 100             D(bug("[Exec] Signal: signaling running task\n"));
 101 #if defined(__AROSEXEC_SMP__)
 102             if (IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuNumber == cpunum)
 103             {
 104 #endif
 105             /* Order a reschedule */
 106             Reschedule();
 107 #if defined(__AROSEXEC_SMP__)
 108             }
 109             else
 110             {
 111                 D(bug("[Exec] Signal:\n"));
 112             }
 113 #else
 114             Enable();
 115 #endif
 116
 117             /* All done. */
 118             return;
 119         }
 120     }
 121
 122     /*
 123         Is the task receiving the signals waiting on them
 124         (or on a exception) ?
 125     */
 126     if ((task->tc_State == TS_WAIT) &&
 127        (task->tc_SigRecvd & (task->tc_SigWait | task->tc_SigExcept)))
 128     {
 129         D(bug("[Exec] Signal: signaling waiting task\n"));
 130
 131         /* Yes. Move it to the ready list. */
 132 #if defined(__AROSEXEC_SMP__)
 133         task_listlock = &PrivExecBase(SysBase)->TaskWaitSpinLock;
 134         EXEC_SPINLOCK_LOCK(task_listlock, SPINLOCK_MODE_WRITE);
 135         Forbid();
 136 #endif
 137         Remove(&task->tc_Node);
 138         task->tc_State = TS_READY;
 139 #if defined(__AROSEXEC_SMP__)
 140         EXEC_SPINLOCK_UNLOCK(task_listlock);
 141         Permit();
 142         task_listlock = EXEC_SPINLOCK_LOCK(&PrivExecBase(SysBase)->TaskReadySpinLock, SPINLOCK_MODE_WRITE);
 143         Forbid();
 144 #endif
 145         Enqueue(&SysBase->TaskReady, &task->tc_Node);
 146 #if defined(__AROSEXEC_SMP__)
 147         EXEC_SPINLOCK_UNLOCK(task_listlock);
 148         Permit();
 149         task_listlock = NULL;
 150 #endif
 151         /* Has it a higher priority as the current one? */
 152         if (
 153 #if defined(__AROSEXEC_SMP__)
 154             (IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuAffinity & KrnGetCPUMask(cpunum)) &&
 155 #endif
 156             (task->tc_Node.ln_Pri > ThisTask->tc_Node.ln_Pri))
 157         {
 158             /*
 159                 Yes. A taskswitch is necessary. Prepare one if possible.
 160                 (If the current task is not running it is already moved)
 161             */
 162             if (ThisTask->tc_State == TS_RUN)
 163             {
 164                 Reschedule();
 165             }
 166         }
 167     }
 168
 169 #if !defined(__AROSEXEC_SMP__)
 170     Enable();
 171 #endif
 172
 173     D(bug("[Exec] Signal: 0x%p finished signal processing\n", task));
 174
 175     AROS_LIBFUNC_EXIT
 176 }
 177