877 lines
27 KiB
C++
877 lines
27 KiB
C++
/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
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/*
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* Copyright (c) 2008 University of Washington
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation;
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "simulator.h"
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#include "realtime-simulator-impl.h"
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#include "wall-clock-synchronizer.h"
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#include "scheduler.h"
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#include "event-impl.h"
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#include "synchronizer.h"
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#include "ns3/ptr.h"
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#include "ns3/pointer.h"
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#include "ns3/assert.h"
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#include "ns3/fatal-error.h"
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#include "ns3/log.h"
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#include "ns3/system-mutex.h"
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#include "ns3/boolean.h"
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#include "ns3/enum.h"
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#include <math.h>
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NS_LOG_COMPONENT_DEFINE ("RealtimeSimulatorImpl");
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namespace ns3 {
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NS_OBJECT_ENSURE_REGISTERED (RealtimeSimulatorImpl);
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TypeId
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RealtimeSimulatorImpl::GetTypeId (void)
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{
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static TypeId tid = TypeId ("ns3::RealtimeSimulatorImpl")
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.SetParent<Object> ()
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.AddConstructor<RealtimeSimulatorImpl> ()
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.AddAttribute ("SynchronizationMode",
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"What to do if the simulation cannot keep up with real time.",
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EnumValue (SYNC_BEST_EFFORT),
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MakeEnumAccessor (&RealtimeSimulatorImpl::SetSynchronizationMode),
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MakeEnumChecker (SYNC_BEST_EFFORT, "BestEffort",
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SYNC_HARD_LIMIT, "HardLimit"))
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.AddAttribute ("HardLimit",
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"Maximum acceptable real-time jitter (used in conjunction with SynchronizationMode=HardLimit)",
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TimeValue (Seconds (0.1)),
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MakeTimeAccessor (&RealtimeSimulatorImpl::m_hardLimit),
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MakeTimeChecker ())
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;
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return tid;
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}
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void
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RealtimeEventLock::Lock (void)
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{
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m_eventMutex.Lock ();
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}
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void
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RealtimeEventLock::Unlock (void)
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{
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m_eventMutex.Unlock ();
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}
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RealtimeSimulatorImpl::RealtimeSimulatorImpl ()
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{
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NS_LOG_FUNCTION_NOARGS ();
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EventImpl::SetEventLock (&m_eventLock);
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m_stop = false;
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m_stopAt = 0;
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m_running = false;
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// uids are allocated from 4.
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// uid 0 is "invalid" events
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// uid 1 is "now" events
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// uid 2 is "destroy" events
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m_uid = 4;
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// before ::Run is entered, the m_currentUid will be zero
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m_currentUid = 0;
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m_currentTs = 0;
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m_unscheduledEvents = 0;
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// Be very careful not to do anything that would cause a change or assignment
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// of the underlying reference counts of m_synchronizer or you will be sorry.
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m_synchronizer = CreateObject<WallClockSynchronizer> ();
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}
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RealtimeSimulatorImpl::~RealtimeSimulatorImpl ()
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{
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NS_LOG_FUNCTION_NOARGS ();
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while (m_events->IsEmpty () == false)
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{
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EventId next = m_events->RemoveNext ();
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}
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m_events = 0;
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m_synchronizer = 0;
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EventImpl::SetNoEventLock ();
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}
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void
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RealtimeSimulatorImpl::Destroy ()
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{
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NS_LOG_FUNCTION_NOARGS ();
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//
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// This function is only called with the private version "disconnected" from
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// the main simulator functions. We rely on the user not calling
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// Simulator::Destroy while there is a chance that a worker thread could be
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// accessing the current instance of the private object. In practice this
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// means shutting down the workers and doing a Join() before calling the
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// Simulator::Destroy().
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//
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while (m_destroyEvents.empty () == false)
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{
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Ptr<EventImpl> ev = m_destroyEvents.front ().PeekEventImpl ();
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m_destroyEvents.pop_front ();
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NS_LOG_LOGIC ("handle destroy " << ev);
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if (ev->IsCancelled () == false)
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{
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ev->Invoke ();
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}
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}
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}
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void
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RealtimeSimulatorImpl::SetScheduler (Ptr<Scheduler> scheduler)
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{
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NS_LOG_FUNCTION_NOARGS ();
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{
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CriticalSection cs (m_mutex);
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if (m_events != 0)
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{
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while (m_events->IsEmpty () == false)
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{
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EventId next = m_events->RemoveNext ();
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scheduler->Insert (next);
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}
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}
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m_events = scheduler;
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}
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}
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Ptr<Scheduler>
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RealtimeSimulatorImpl::GetScheduler (void) const
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{
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NS_LOG_FUNCTION_NOARGS ();
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return m_events;
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}
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void
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RealtimeSimulatorImpl::ProcessOneEvent (void)
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{
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NS_LOG_FUNCTION_NOARGS ();
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//
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// The idea here is to wait until the next event comes due. In the case of
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// a realtime simulation, we want real time to be consumed between events.
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// It is the realtime synchronizer that causes real time to be consumed by
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// doing some kind of a wait.
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//
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// We need to be able to have external events (such as a packet reception event)
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// cause us to re-evaluate our state. The way this works is that the synchronizer
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// gets interrupted and returs. So, there is a possibility that things may change
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// out from under us dynamically. In this case, we need to re-evaluate how long to
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// wait in a for-loop until we have waited sucessfully (until a timeout) for the
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// event at the head of the event list.
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//
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// m_synchronizer->Synchronize will return true if the wait was completed without
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// interruption, otherwise it will return false indicating that something has changed
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// out from under us. If we sit in the for-loop trying to synchronize until
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// Synchronize() returns true, we will have successfully synchronized the execution
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// time of the next event with the wall clock time of the synchronizer.
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//
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for (;;)
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{
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uint64_t tsDelay = 0;
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uint64_t tsNext = 0;
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//
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// It is important to understand that m_currentTs is interpreted only as the
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// timestamp of the last event we executed. Current time can a bit of a
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// slippery concept in realtime mode. What we have here is a discrete event
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// simulator, so the last event is, by defintion, executed entirely at a single
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// discrete time. This is the definition of m_currentTs. It really has
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// nothing to do with the current real time, except that we are trying to arrange
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// that at the instant of the beginning of event execution, the current real time
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// and m_currentTs coincide.
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//
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// We use tsNow as the indication of the current real time.
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//
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uint64_t tsNow;
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{
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CriticalSection cs (m_mutex);
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//
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// Since we are in realtime mode, the time to delay has got to be the
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// difference between the current realtime and the timestamp of the next
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// event. Since m_currentTs is actually the timestamp of the last event we
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// executed, it's not particularly meaningful for us here since real time has
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// certainly elapsed since it was last updated.
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//
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// It is possible that the current realtime has drifted past the next event
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// time so we need to be careful about that and not delay in that case.
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//
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NS_ASSERT_MSG (m_synchronizer->Realtime (),
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"RealtimeSimulatorImpl::ProcessOneEvent (): Synchronizer reports not Realtime ()");
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//
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// tsNow is set to the normalized current real time. When the simulation was
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// started, the current real time was effectively set to zero; so tsNow is
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// the current "real" simulation time.
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//
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// tsNext is the simulation time of the next event we want to execute.
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//
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tsNow = m_synchronizer->GetCurrentRealtime ();
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tsNext = NextTs ();
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//
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// tsDelay is therefore the real time we need to delay in order to bring the
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// real time in sync with the simulation time. If we wait for this amount of
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// real time, we will accomplish moving the simulation time at the same rate
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// as the real time. This is typically called "pacing" the simulation time.
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//
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// We do have to be careful if we are falling behind. If so, tsDelay must be
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// zero. If we're late, don't dawdle.
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//
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if (tsNext <= tsNow)
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{
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tsDelay = 0;
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}
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else
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{
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tsDelay = tsNext - tsNow;
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}
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//
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// We've figured out how long we need to delay in order to pace the
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// simulation time with the real time. We're going to sleep, but need
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// to work with the synchronizer to make sure we're awakened if something
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// external happens (like a packet is received). This next line resets
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// the synchronizer so that any future event will cause it to interrupt.
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//
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m_synchronizer->SetCondition (false);
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}
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//
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// We have a time to delay. This time may actually not be valid anymore
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// since we released the critical section immediately above, and a real-time
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// ScheduleReal or ScheduleRealNow may have snuck in, well, between the
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// closing brace above and this comment so to speak. If this is the case,
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// that schedule operation will have done a synchronizer Signal() that
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// will set the condition variable to true and cause the Synchronize call
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// below to return immediately.
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//
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// It's easiest to understand if you just consider a short tsDelay that only
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// requires a SpinWait down in the synchronizer. What will happen is that
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// whan Synchronize calls SpinWait, SpinWait will look directly at its
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// condition variable. Note that we set this condition variable to false
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// inside the critical section above.
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//
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// SpinWait will go into a forever loop until either the time has expired or
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// until the condition variable becomes true. A true condition indicates that
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// the wait should stop. The condition is set to true by one of the Schedule
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// methods of the simulator; so if we are in a wait down in Synchronize, and
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// a Simulator::ScheduleReal is done, the wait down in Synchronize will exit and
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// Synchronize will return false. This means we have not actually synchronized
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// to the event expiration time. If no real-time schedule operation is done
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// while down in Synchronize, the wait will time out and Synchronize will return
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// true. This indicates that we have synchronized to the event time.
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//
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// So we need to stay in this for loop, looking for the next event timestamp and
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// attempting to sleep until its due. If we've slept until the timestamp is due,
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// Synchronize returns true and we break out of the sync loop. If an external
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// event happens that requires a re-schedule, Synchronize returns false and
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// we re-evaluate our timing by continuing in the loop.
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//
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// It is expected that tsDelay become shorter as external events interrupt our
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// waits.
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//
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if (m_synchronizer->Synchronize (tsNow, tsDelay))
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{
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NS_LOG_LOGIC ("Interrupted ...");
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break;
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}
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//
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// If we get to this point, we have been interrupted during a wait by a real-time
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// schedule operation. This means all bets are off regarding tsDelay and we need
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// to re-evaluate what it is we want to do. We'll loop back around in the
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// for-loop and start again from scratch.
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//
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}
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//
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// If we break out of the for-loop above, we have waited until the time specified
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// by the event that was at the head of the event list when we started the process.
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// Since there is a bunch of code that was executed outside a critical section (the
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// Synchronize call) we cannot be sure that the event at the head of the event list
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// is the one we think it is. What we can be sure of is that it is time to execute
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// whatever event is at the head of this list if the list is in time order.
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//
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EventId next;
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{
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CriticalSection cs (m_mutex);
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//
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// We do know we're waiting for an event, so there had better be an event on the
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// event queue. Let's pull it off. When we release the critical section, the
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// event we're working on won't be on the list and so subsequent operations won't
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// mess with us.
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//
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NS_ASSERT_MSG (m_events->IsEmpty () == false,
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"RealtimeSimulatorImpl::ProcessOneEvent(): event queue is empty");
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next = m_events->RemoveNext ();
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--m_unscheduledEvents;
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//
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// We cannot make any assumption that "next" is the same event we originally waited
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// for. We can only assume that only that it must be due and cannot cause time
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// to move backward.
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//
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NS_ASSERT_MSG (next.GetTs () >= m_currentTs,
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"RealtimeSimulatorImpl::ProcessOneEvent(): "
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"next.GetTs() earlier than m_currentTs (list order error)");
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NS_LOG_LOGIC ("handle " << next.GetTs ());
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//
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// Update the current simulation time to be the timestamp of the event we're
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// executing. From the rest of the simulation's point of view, simulation time
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// is frozen until the next event is executed.
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//
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m_currentTs = next.GetTs ();
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m_currentUid = next.GetUid ();
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//
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// We're about to run the event and we've done our best to synchronize this
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// event execution time to real time. Now, if we're in SYNC_HARD_LIMIT mode
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// we have to decide if we've done a good enough job and if we haven't, we've
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// been asked to commit ritual suicide.
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//
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// We check the simulation time against the current real time to make this
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// judgement.
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//
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if (m_synchronizationMode == SYNC_HARD_LIMIT)
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{
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uint64_t tsFinal = m_synchronizer->GetCurrentRealtime ();
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uint64_t tsJitter;
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if (tsFinal >= m_currentTs)
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{
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tsJitter = tsFinal - m_currentTs;
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}
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else
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{
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tsJitter = m_currentTs - tsFinal;
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}
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if (tsJitter > static_cast<uint64_t>(m_hardLimit.GetTimeStep ()))
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{
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NS_FATAL_ERROR ("RealtimeSimulatorImpl::ProcessOneEvent (): "
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"Hard real-time limit exceeded (jitter = " << tsJitter << ")");
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}
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}
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}
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//
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// We have got the event we're about to execute completely disentangled from the
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// event list so we can execute it outside a critical section without fear of someone
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// changing things out from under us.
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EventImpl *event = next.PeekEventImpl ();
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m_synchronizer->EventStart ();
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event->Invoke ();
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m_synchronizer->EventEnd ();
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}
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bool
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RealtimeSimulatorImpl::IsFinished (void) const
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{
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NS_LOG_FUNCTION_NOARGS ();
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bool rc;
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{
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CriticalSection cs (m_mutex);
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rc = m_events->IsEmpty ();
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}
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return rc;
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}
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//
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// Peeks into event list. Should be called with critical section locked.
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//
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uint64_t
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RealtimeSimulatorImpl::NextTs (void) const
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{
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NS_LOG_FUNCTION_NOARGS ();
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NS_ASSERT_MSG (m_events->IsEmpty () == false,
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"RealtimeSimulatorImpl::NextTs(): event queue is empty");
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EventId id = m_events->PeekNext ();
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return id.GetTs ();
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}
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//
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// Calls NextTs(). Should be called with critical section locked.
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//
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Time
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RealtimeSimulatorImpl::Next (void) const
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{
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NS_LOG_FUNCTION_NOARGS ();
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return TimeStep (NextTs ());
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}
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void
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RealtimeSimulatorImpl::Run (void)
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{
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NS_LOG_FUNCTION_NOARGS ();
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NS_ASSERT_MSG (m_running == false,
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"RealtimeSimulatorImpl::Run(): Simulator already running");
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m_running = true;
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m_synchronizer->SetOrigin (m_currentTs);
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for (;;)
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{
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bool done = false;
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{
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CriticalSection cs (m_mutex);
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//
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// In all cases we stop when the event list is empty. If you are doing a
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// realtime simulation and you want it to extend out for some time, you must
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// call StopAt. In the realtime case, this will stick a placeholder event out
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// at the end of time.
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//
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if (m_stop || m_events->IsEmpty ())
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{
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done = true;
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}
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//
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// We also want to stop the simulator at some time even if there are events
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// that have been scheduled out in the future. If we're in realtime mode, we
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// actually have time passing, so we must look at the realtime clock to see if
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// we're past the end time.
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//
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if (m_stopAt && m_stopAt <= m_synchronizer->GetCurrentRealtime ())
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{
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done = true;
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}
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}
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if (done)
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{
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break;
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}
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ProcessOneEvent ();
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}
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//
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// If the simulator stopped naturally by lack of events, make a
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// consistency test to check that we didn't lose any events along the way.
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//
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{
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CriticalSection cs (m_mutex);
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NS_ASSERT_MSG (m_events->IsEmpty () == false || m_unscheduledEvents == 0,
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"RealtimeSimulatorImpl::Run(): Empty queue and unprocessed events");
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}
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m_running = false;
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}
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bool
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RealtimeSimulatorImpl::Running (void) const
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{
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NS_LOG_FUNCTION_NOARGS ();
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return m_running;
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}
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bool
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RealtimeSimulatorImpl::Realtime (void) const
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{
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NS_LOG_FUNCTION_NOARGS ();
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return m_synchronizer->Realtime ();
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}
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//
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// This will run the first event on the queue without considering any realtime
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// synchronization. It's mainly implemented to allow simulations requiring
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// the multithreaded ScheduleRealtimeNow() functions the possibility of driving
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// the simulation from their own event loop.
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//
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// It is expected that if there are any realtime requirements, the responsibility
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// for synchronizing with real time in an external event loop will be picked up
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// by that loop. For example, they may call Simulator::Next() to find the
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// execution time of the next event and wait for that time somehow -- then call
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// RunOneEvent to fire the event.
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//
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void
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RealtimeSimulatorImpl::RunOneEvent (void)
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{
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NS_LOG_FUNCTION_NOARGS ();
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NS_ASSERT_MSG (m_running == false,
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"RealtimeSimulatorImpl::RunOneEvent(): An internal simulator event loop is running");
|
|
|
|
EventId next;
|
|
EventImpl *event = 0;
|
|
|
|
//
|
|
// Run this in a critical section in case there's another thread around that
|
|
// may be inserting things onto the event list.
|
|
//
|
|
{
|
|
CriticalSection cs (m_mutex);
|
|
|
|
next = m_events->RemoveNext ();
|
|
|
|
NS_ASSERT (next.GetTs () >= m_currentTs);
|
|
--m_unscheduledEvents;
|
|
|
|
NS_LOG_LOGIC ("handle " << next.GetTs ());
|
|
m_currentTs = next.GetTs ();
|
|
m_currentUid = next.GetUid ();
|
|
event = next.PeekEventImpl ();
|
|
}
|
|
|
|
event->Invoke ();
|
|
}
|
|
|
|
void
|
|
RealtimeSimulatorImpl::Stop (void)
|
|
{
|
|
NS_LOG_FUNCTION_NOARGS ();
|
|
m_stop = true;
|
|
}
|
|
|
|
static void Placeholder (void) {}
|
|
|
|
//
|
|
// Schedule a stop for a _relative_ time in the future. If the simulation
|
|
// hasn't started yet, this will effectively be an absolute time.
|
|
//
|
|
void
|
|
RealtimeSimulatorImpl::Stop (Time const &time)
|
|
{
|
|
NS_LOG_FUNCTION (time);
|
|
|
|
Time tAbsolute = Simulator::Now () + time;
|
|
NS_ASSERT (tAbsolute.IsPositive ());
|
|
NS_ASSERT (tAbsolute >= TimeStep (m_currentTs));
|
|
m_stopAt = tAbsolute.GetTimeStep ();
|
|
|
|
//
|
|
// For the realtime case, we need a real event sitting out at the end of time
|
|
// to keep the simulator running (sleeping) while there are no other events
|
|
// present. If an "external" device in another thread decides to schedule an
|
|
// event, the sleeping synchronizer will be awakened and the new event will
|
|
// be run.
|
|
//
|
|
// The easiest thing to do is to call back up into the simulator to take
|
|
// advantage of all of the nice event wrappers. This will call back down into
|
|
// RealtimeSimulatorImpl::Schedule to do the work. This path interprets the
|
|
// time as relative, so pass the relative time.
|
|
//
|
|
Simulator::Schedule (time, &Placeholder);
|
|
}
|
|
|
|
//
|
|
// Schedule an event for a _relative_ time in the future.
|
|
//
|
|
// A little side-note on events and multthreading:
|
|
//
|
|
// This is a little tricky. We get a Ptr<EventImpl> passed down to us in some
|
|
// thread context. This Ptr<EventImpl> is not yet shared in any way. It is
|
|
// possible however that the calling context is not the context of the main
|
|
// scheduler thread (e.g. it is in the context of a separate device thread).
|
|
// It would be bad (TM) if we naively wrapped the EventImpl up in an EventId
|
|
// that would be accessible from multiple threads without considering thread
|
|
// safety.
|
|
//
|
|
// It's clear that we cannot have a situation where the EventImpl is "owned" by
|
|
// multiple threads. The calling thread is free to hold the EventId as long as
|
|
// it wants and manage the reference counts to the underlying EventImpl all it
|
|
// wants. The scheduler is free to do the same; and will eventually release
|
|
// the reference in the context of thread running ProcessOneEvent(). It is
|
|
// "a bad thing" (TM) if these two threads decide to release the underlying
|
|
// EventImpl "at the same time" since the result is sure to be multiple frees,
|
|
// memory leaks or bus errors.
|
|
//
|
|
// The answer is to make the reference counting of the EventImpl thread safe;
|
|
// which we do. We don't want to force the event implementation to carry around
|
|
// a mutex, so we "lend" it one using a RealtimeEventLock object (m_eventLock)
|
|
// in the constructor of the event and take it back in the destructor. See the
|
|
// event code for details.
|
|
//
|
|
EventId
|
|
RealtimeSimulatorImpl::Schedule (Time const &time, const Ptr<EventImpl> &event)
|
|
{
|
|
NS_LOG_FUNCTION (time << event);
|
|
|
|
EventId id;
|
|
{
|
|
CriticalSection cs (m_mutex);
|
|
//
|
|
// This is the reason we had to bring the absolute time calcualtion in from the
|
|
// simulator.h into the implementation. Since the implementations may be
|
|
// multi-threaded, we need this calculation to be atomic. You can see it is
|
|
// here since we are running in a CriticalSection.
|
|
//
|
|
Time tAbsolute = Simulator::Now () + time;
|
|
NS_ASSERT_MSG (tAbsolute.IsPositive (), "RealtimeSimulatorImpl::Schedule(): Negative time");
|
|
NS_ASSERT_MSG (tAbsolute >= TimeStep (m_currentTs), "RealtimeSimulatorImpl::Schedule(): time < m_currentTs");
|
|
uint64_t ts = (uint64_t) tAbsolute.GetTimeStep ();
|
|
id = EventId (event, ts, m_uid);
|
|
m_uid++;
|
|
++m_unscheduledEvents;
|
|
m_events->Insert (id);
|
|
m_synchronizer->Signal ();
|
|
}
|
|
|
|
return id;
|
|
}
|
|
|
|
EventId
|
|
RealtimeSimulatorImpl::ScheduleNow (const Ptr<EventImpl> &event)
|
|
{
|
|
NS_LOG_FUNCTION_NOARGS ();
|
|
EventId id;
|
|
{
|
|
CriticalSection cs (m_mutex);
|
|
|
|
id = EventId (event, m_currentTs, m_uid);
|
|
m_uid++;
|
|
++m_unscheduledEvents;
|
|
m_events->Insert (id);
|
|
m_synchronizer->Signal ();
|
|
}
|
|
|
|
return id;
|
|
}
|
|
|
|
Time
|
|
RealtimeSimulatorImpl::Now (void) const
|
|
{
|
|
return TimeStep (m_currentTs);
|
|
}
|
|
|
|
//
|
|
// Schedule an event for a _relative_ time in the future.
|
|
//
|
|
EventId
|
|
RealtimeSimulatorImpl::ScheduleRealtime (Time const &time, const Ptr<EventImpl> &event)
|
|
{
|
|
NS_LOG_FUNCTION (time << event);
|
|
|
|
EventId id;
|
|
{
|
|
CriticalSection cs (m_mutex);
|
|
|
|
uint64_t ts = m_synchronizer->GetCurrentRealtime () + time.GetTimeStep ();
|
|
NS_ASSERT_MSG (ts >= m_currentTs, "RealtimeSimulatorImpl::ScheduleRealtime(): schedule for time < m_currentTs");
|
|
id = EventId (event, ts, m_uid);
|
|
m_uid++;
|
|
++m_unscheduledEvents;
|
|
m_events->Insert (id);
|
|
m_synchronizer->Signal ();
|
|
}
|
|
|
|
return id;
|
|
}
|
|
|
|
EventId
|
|
RealtimeSimulatorImpl::ScheduleRealtimeNow (const Ptr<EventImpl> &event)
|
|
{
|
|
NS_LOG_FUNCTION_NOARGS ();
|
|
EventId id;
|
|
{
|
|
CriticalSection cs (m_mutex);
|
|
|
|
//
|
|
// If the simulator is running, we're pacing and have a meaningful
|
|
// realtime clock. If we're not, then m_currentTs is were we stopped.
|
|
//
|
|
uint64_t ts = m_running ? m_synchronizer->GetCurrentRealtime () : m_currentTs;
|
|
NS_ASSERT_MSG (ts >= m_currentTs, "RealtimeSimulatorImpl::ScheduleRealrimeNow(): schedule for time < m_currentTs");
|
|
id = EventId (event, ts, m_uid);
|
|
m_uid++;
|
|
++m_unscheduledEvents;
|
|
m_events->Insert (id);
|
|
m_synchronizer->Signal ();
|
|
}
|
|
|
|
return id;
|
|
}
|
|
|
|
Time
|
|
RealtimeSimulatorImpl::RealtimeNow (void) const
|
|
{
|
|
return TimeStep (m_synchronizer->GetCurrentRealtime ());
|
|
}
|
|
|
|
EventId
|
|
RealtimeSimulatorImpl::ScheduleDestroy (const Ptr<EventImpl> &event)
|
|
{
|
|
NS_LOG_FUNCTION_NOARGS ();
|
|
EventId id;
|
|
|
|
{
|
|
CriticalSection cs (m_mutex);
|
|
|
|
//
|
|
// Time doesn't really matter here (especially in realtime mode). It is
|
|
// overridden by the uid of 2 which identifies this as an event to be
|
|
// executed at Simulator::Destroy time.
|
|
//
|
|
id = EventId (event, m_currentTs, 2);
|
|
m_destroyEvents.push_back (id);
|
|
m_uid++;
|
|
}
|
|
|
|
return id;
|
|
}
|
|
|
|
Time
|
|
RealtimeSimulatorImpl::GetDelayLeft (const EventId &id) const
|
|
{
|
|
//
|
|
// If the event has expired, there is no delay until it runs. It is not the
|
|
// case that there is a negative time until it runs.
|
|
//
|
|
if (IsExpired (id))
|
|
{
|
|
return TimeStep (0);
|
|
}
|
|
|
|
return TimeStep (id.GetTs () - m_currentTs);
|
|
}
|
|
|
|
void
|
|
RealtimeSimulatorImpl::Remove (const EventId &ev)
|
|
{
|
|
if (ev.GetUid () == 2)
|
|
{
|
|
// destroy events.
|
|
for (DestroyEvents::iterator i = m_destroyEvents.begin ();
|
|
i != m_destroyEvents.end ();
|
|
i++)
|
|
{
|
|
if (*i == ev)
|
|
{
|
|
m_destroyEvents.erase (i);
|
|
break;
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
if (IsExpired (ev))
|
|
{
|
|
return;
|
|
}
|
|
|
|
{
|
|
CriticalSection cs (m_mutex);
|
|
|
|
m_events->Remove (ev);
|
|
--m_unscheduledEvents;
|
|
|
|
Cancel (ev);
|
|
|
|
}
|
|
}
|
|
|
|
void
|
|
RealtimeSimulatorImpl::Cancel (const EventId &id)
|
|
{
|
|
if (IsExpired (id) == false)
|
|
{
|
|
id.PeekEventImpl ()->Cancel ();
|
|
}
|
|
}
|
|
|
|
bool
|
|
RealtimeSimulatorImpl::IsExpired (const EventId &ev) const
|
|
{
|
|
if (ev.GetUid () == 2)
|
|
{
|
|
// destroy events.
|
|
for (DestroyEvents::const_iterator i = m_destroyEvents.begin ();
|
|
i != m_destroyEvents.end (); i++)
|
|
{
|
|
if (*i == ev)
|
|
{
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
//
|
|
// If the time of the event is less than the current timestamp of the
|
|
// simulator, the simulator has gone past the invocation time of the
|
|
// event, so the statement ev.GetTs () < m_currentTs does mean that
|
|
// the event has been fired even in realtime mode.
|
|
//
|
|
// The same is true for the next line involving the m_currentUid.
|
|
//
|
|
if (ev.PeekEventImpl () == 0 ||
|
|
ev.GetTs () < m_currentTs ||
|
|
(ev.GetTs () == m_currentTs && ev.GetUid () <= m_currentUid) ||
|
|
ev.PeekEventImpl ()->IsCancelled ())
|
|
{
|
|
return true;
|
|
}
|
|
else
|
|
{
|
|
return false;
|
|
}
|
|
}
|
|
|
|
Time
|
|
RealtimeSimulatorImpl::GetMaximumSimulationTime (void) const
|
|
{
|
|
// XXX: I am fairly certain other compilers use other non-standard
|
|
// post-fixes to indicate 64 bit constants.
|
|
return TimeStep (0x7fffffffffffffffLL);
|
|
}
|
|
|
|
void
|
|
RealtimeSimulatorImpl::SetSynchronizationMode (enum SynchronizationMode mode)
|
|
{
|
|
NS_LOG_FUNCTION (mode);
|
|
m_synchronizationMode = mode;
|
|
}
|
|
|
|
RealtimeSimulatorImpl::SynchronizationMode
|
|
RealtimeSimulatorImpl::GetSynchronizationMode (void) const
|
|
{
|
|
NS_LOG_FUNCTION_NOARGS ();
|
|
return m_synchronizationMode;
|
|
}
|
|
|
|
void
|
|
RealtimeSimulatorImpl::SetHardLimit (Time limit)
|
|
{
|
|
NS_LOG_FUNCTION (limit);
|
|
m_hardLimit = limit;
|
|
}
|
|
|
|
Time
|
|
RealtimeSimulatorImpl::GetHardLimit (void) const
|
|
{
|
|
NS_LOG_FUNCTION_NOARGS ();
|
|
return m_hardLimit;
|
|
}
|
|
|
|
}; // namespace ns3
|