rom/exec/signal.c

   1 /*
   2     Copyright © 1995-2017, 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 #define DEBUG 0
  10 #include <aros/debug.h>
  11
  12 #include <exec/execbase.h>
  13 #include <aros/libcall.h>
  14 #include <proto/exec.h>
  15
  16 #define __AROS_KERNEL__
  17 #include "exec_intern.h"
  18
  19 #if defined(__AROSEXEC_SMP__)
  20 #include <utility/hooks.h>
  21
  22 #include "kernel_ipi.h"
  23
  24 AROS_UFH3(IPTR, signal_hook,
  25     AROS_UFHA(struct IPIHook *, hook, A0),
  26     AROS_UFHA(APTR, object, A2),
  27     AROS_UFHA(APTR, message, A1)
  28 )
  29 {
  30     AROS_USERFUNC_INIT
  31
  32     struct ExecBase *SysBase = (struct ExecBase *)hook->ih_Args[0];
  33     struct Task *target = (struct Task *)hook->ih_Args[1];
  34     ULONG sigset = (ULONG)hook->ih_Args[2];
  35
  36     D(
  37         struct KernelBase *KernelBase = __kernelBase;
  38         int cpunum = KrnGetCPUNumber();
  39         bug("[Exec] CPU%03d: Using IPI to do Signal(%p, %08x), SysBase=%p\n", cpunum, msg->target, msg->sigset, SysBase);
  40     );
  41
  42     Signal(target, sigset);
  43
  44     return 0;
  45
  46     AROS_USERFUNC_EXIT
  47 }
  48 #endif
  49
  50 /*****************************************************************************
  51
  52     NAME */
  53
  54         AROS_LH2(void, Signal,
  55
  56 /*  SYNOPSIS */
  57         AROS_LHA(struct Task *,     task,      A1),
  58         AROS_LHA(ULONG,             signalSet, D0),
  59
  60 /*  LOCATION */
  61         struct ExecBase *, SysBase, 54, Exec)
  62
  63 /*  FUNCTION
  64         Send some signals to a given task. If the task is currently waiting
  65         on these signals, has a higher priority as the current one and if
  66         taskswitches are allowed the new task begins to run immediately.
  67
  68     INPUTS
  69         task      - Pointer to task structure.
  70         signalSet - The set of signals to send to the task.
  71
  72     RESULT
  73
  74     NOTES
  75         This function may be used from interrupts.
  76
  77     EXAMPLE
  78
  79     BUGS
  80
  81     SEE ALSO
  82         AllocSignal(), FreeSignal(), Wait(), SetSignal(), SetExcept()
  83
  84     INTERNALS
  85
  86     HISTORY
  87
  88 ******************************************************************************/
  89 {
  90     AROS_LIBFUNC_INIT
  91
  92     struct Task *thisTask = GET_THIS_TASK;
  93
  94 #if defined(__AROSEXEC_SMP__)
  95     struct KernelBase *KernelBase = __kernelBase;
  96     int cpunum = KrnGetCPUNumber();
  97
  98     /*
  99         * # If current CPU number is not the task's CPU and the task is running now, send signal to that task
 100         *   from CPU which the task is running on.
 101         * # If task is not running and the current CPU is not in the Affinitymask, send signal to CPU form Affinity mask
 102         * # If task is not running and the current CPU is in the Affinity mask, just proceed with regular signal
 103     */
 104     if ((PrivExecBase(SysBase)->IntFlags & EXECF_CPUAffinity) &&
 105         ((IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuNumber != cpunum && task->tc_State == TS_RUN) ||
 106         !KrnCPUInMask(cpunum, IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuAffinity)))
 107     {
 108         struct Hook h;
 109         IPTR args[3];
 110         // We cannot use KrnAllocCPUMask() since this function uses AllocMem
 111         // And we cannot use AllocMem from interrupts (where Signal() is allowed)...
 112         ULONG mask[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; // CPU mask large enough for 256 CPUs...
 113         void *cpu_mask = &mask;
 114
 115         args[0] = (IPTR)SysBase;
 116         args[1] = (IPTR)task;
 117         args[2] = (IPTR)signalSet;
 118
 119         /* Task is running *now* on another CPU, send signal there */
 120         if (task->tc_State == TS_RUN)
 121         {
 122             KrnGetCPUMask(IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuNumber, cpu_mask);
 123         }
 124         else
 125         {
 126             int i;
 127             int cpumax = KrnGetCPUCount();
 128
 129             /* Task is not running now, find first cpu suitable to run this task. Use CPU balancing some day... */
 130             for (i=0; i < cpumax; i++)
 131             {
 132                 if (KrnCPUInMask(i, IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuAffinity))
 133                 {
 134                     KrnGetCPUMask(i, cpu_mask);
 135                     break;
 136                 }
 137             }
 138         }
 139
 140         D(bug("[Exec] Signal: Signaling from CPU%03d -> CPU%03d using IPI...\n", cpunum, IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuNumber));
 141
 142         h.h_Entry = signal_hook;
 143
 144         D(bug("[Exec] Sending IPI...\n"));
 145         core_DoCallIPI(&h, cpu_mask, 1, 3, args, (void *)KernelBase);
 146         D(bug("[Exec] IPI Sent\n"));
 147     }
 148     else
 149     {
 150
 151         if (cpunum != 0)
 152         {
 153             D(bug("[Exec] Signal(0x%p, %08lX) on CPU%03d\n", task, signalSet, cpunum));
 154         }
 155 #else
 156         D(bug("[Exec] Signal(0x%p, %08lX)\n", task, signalSet);)
 157 #endif
 158
 159         D(
 160             bug("[Exec] Signal: Signaling '%s', state = %08x\n", task->tc_Node.ln_Name, task->tc_State);
 161             if (((struct KernelBase *)KernelBase)->kb_ICFlags & KERNBASEF_IRQPROCESSING)
 162                 bug("[Exec] Signal: (Called from Interrupt)\n");
 163             else
 164                 bug("[Exec] Signal: (Called from '%s')\n", thisTask->tc_Node.ln_Name);
 165         )
 166
 167         Disable();
 168         D(bug("[Exec] Signal: Target signal flags : %08x ->", task->tc_SigRecvd);)
 169         /* Set the signals in the task structure. */
 170 #if defined(__AROSEXEC_SMP__)
 171         __AROS_ATOMIC_OR_L(task->tc_SigRecvd, signalSet);
 172 #else
 173         task->tc_SigRecvd |= signalSet;
 174 #endif
 175         D(bug(" %08x\n", task->tc_SigRecvd);)
 176
 177         /* Do those bits raise exceptions? */
 178         if (task->tc_SigRecvd & task->tc_SigExcept)
 179         {
 180             /* Yes. Set the exception flag. */
 181 #if defined(__AROSEXEC_SMP__)
 182             __AROS_ATOMIC_OR_B(task->tc_Flags, TF_EXCEPT);
 183 #else
 184             task->tc_Flags |= TF_EXCEPT;
 185 #endif
 186             D(bug("[Exec] Signal: TF_EXCEPT set\n");)
 187
 188             /*
 189                     if the target task is running (called from within interrupt handler, or from another processor),
 190                     raise the exception or defer it for later.
 191                 */
 192             if (task->tc_State == TS_RUN)
 193             {
 194 #if defined(__AROSEXEC_SMP__)
 195                 if (!(PrivExecBase(SysBase)->IntFlags & EXECF_CPUAffinity) ||
 196                     (IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuNumber == cpunum))
 197                 {
 198 #endif
 199                 D(bug("[Exec] Signal: Raising Exception for 'running' Task\n");)
 200                 /* Order a reschedule */
 201                 Reschedule();
 202 #if defined(__AROSEXEC_SMP__)
 203                 }
 204                 else
 205                 {
 206                     (bug("[Exec] Signal: Raising Exception for 'running' Task on CPU %03u\n", IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuNumber));
 207                     KrnScheduleCPU(IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuAffinity);
 208                 }
 209 #endif
 210                 Enable();
 211
 212                 /* All done. */
 213                 return;
 214             }
 215         }
 216         /*
 217             Is the task receiving the signals waiting on them
 218             (or on a exception) ?
 219         */
 220         if ((task->tc_State == TS_WAIT) &&
 221         (task->tc_SigRecvd & (task->tc_SigWait | task->tc_SigExcept)))
 222         {
 223             D(bug("[Exec] Signal: Signaling 'waiting' Task\n");)
 224
 225             /* Yes. Move it to the ready list. */
 226 #if defined(__AROSEXEC_SMP__)
 227             krnSysCallReschedTask(task, TS_READY);
 228 #else
 229             Remove(&task->tc_Node);
 230             task->tc_State = TS_READY;
 231             Enqueue(&SysBase->TaskReady, &task->tc_Node);
 232 #endif
 233             /* Has it a higher priority as the current one? */
 234             if (
 235 #if defined(__AROSEXEC_SMP__)
 236                 (!(PrivExecBase(SysBase)->IntFlags & EXECF_CPUAffinity) ||
 237                 (KrnCPUInMask(cpunum, IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuAffinity))) &&
 238 #endif
 239                 (task->tc_Node.ln_Pri >= thisTask->tc_Node.ln_Pri))
 240             {
 241                 /*
 242                     Yes. A taskswitch is necessary. Prepare one if possible.
 243                     (If the current task is not running it is already moved)
 244                 */
 245                 if (thisTask->tc_State == TS_RUN)
 246                 {
 247                     D(bug("[Exec] Signal: Rescheduling 'running' Task to let it process the signal...\n"));
 248                     Reschedule();
 249                 }
 250             }
 251 #if defined(__AROSEXEC_SMP__)
 252             else if ((PrivExecBase(SysBase)->IntFlags & EXECF_CPUAffinity) &&
 253                 !(KrnCPUInMask(cpunum, IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuAffinity)))
 254             {
 255                 D(bug("[Exec] Signal: Signaling task on another CPU\n"));
 256                 krnSysCallReschedTask(task, TS_READY);
 257                 KrnScheduleCPU(IntETask(task->tc_UnionETask.tc_ETask)->iet_CpuAffinity);
 258             }
 259 #endif
 260             else
 261             {
 262                 D(bug("[Exec] Signal: Letting Task process signal when next scheduled to run...\n"););
 263             }
 264         }
 265
 266         Enable();
 267
 268         D(bug("[Exec] Signal: 0x%p finished signal processing\n", task);)
 269 #if defined(__AROSEXEC_SMP__)
 270     }
 271 #endif
 272
 273     AROS_LIBFUNC_EXIT
 274 }