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unison/src/stats/examples/time-probe-example.cc
2022-10-14 14:13:12 +00:00

256 lines
8.7 KiB
C++

/*
* Copyright (c) 2014 University of Washington
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
//
// This example is designed to show the main features of an ns3::TimeProbe.
// A test object is used to emit values through a trace source. The
// example shows three ways to use a ns3::TimeProbe to hook the output
// of this trace source (in addition to hooking the raw trace source).
//
// It produces two types of output. By default, it will generate a
// gnuplot of interarrival times. If the '--verbose=1' argument is passed,
// it will also generate debugging output of the form (for example):
//
// Emitting at 96.5378 seconds
// context: raw trace source old 0.293343 new 0.00760254
// context: probe1 old 0.293343 new 0.00760254
// context: probe2 old 0.293343 new 0.00760254
// context: probe3 old 0.293343 new 0.00760254
//
// The stopTime defaults to 100 seconds but can be changed by an argument.
//
#include "ns3/core-module.h"
#include "ns3/gnuplot-helper.h"
#include "ns3/time-probe.h"
#include <string>
using namespace ns3;
NS_LOG_COMPONENT_DEFINE("TimeProbeExample");
/**
* This is our test object, an object that emits values according to
* a Poisson arrival process. It emits a traced Time value as a
* trace source; this takes the value of interarrival time
*/
class Emitter : public Object
{
public:
/**
* Register this type.
* \return The TypeId.
*/
static TypeId GetTypeId();
Emitter();
private:
void DoInitialize() override;
/// Generate data.
void Emit();
TracedValue<Time> m_interval; //!< Interarrival time between events.
Time m_last; //!< Current interarrival time.
Ptr<ExponentialRandomVariable> m_var; //!< Random number generator.
};
NS_OBJECT_ENSURE_REGISTERED(Emitter);
TypeId
Emitter::GetTypeId()
{
static TypeId tid = TypeId("ns3::Emitter")
.SetParent<Object>()
.SetGroupName("Stats")
.AddConstructor<Emitter>()
.AddTraceSource("Interval",
"Trace source",
MakeTraceSourceAccessor(&Emitter::m_interval),
"ns3::TracedValueCallback::Time");
return tid;
}
Emitter::Emitter()
: m_interval(Seconds(0)),
m_last(Seconds(0))
{
m_var = CreateObject<ExponentialRandomVariable>();
}
void
Emitter::DoInitialize()
{
Simulator::Schedule(Seconds(m_var->GetValue()), &Emitter::Emit, this);
}
void
Emitter::Emit()
{
NS_LOG_DEBUG("Emitting at " << Simulator::Now().As(Time::S));
m_interval = Simulator::Now() - m_last;
m_last = Simulator::Now();
TimeProbe::SetValueByPath("/Names/probe3", m_interval);
Simulator::Schedule(Seconds(m_var->GetValue()), &Emitter::Emit, this);
}
// This is a function to test hooking a raw function to the trace source
void
NotifyViaTraceSource(std::string context, Time oldVal, Time newVal)
{
BooleanValue verbose;
GlobalValue::GetValueByName("verbose", verbose);
if (verbose.Get())
{
std::cout << "context: " << context << " old " << oldVal.As(Time::S) << " new "
<< newVal.As(Time::S) << std::endl;
}
}
// This is a function to test hooking it to the probe output
void
NotifyViaProbe(std::string context, double oldVal, double newVal)
{
BooleanValue verbose;
GlobalValue::GetValueByName("verbose", verbose);
if (verbose.Get())
{
std::cout << "context: " << context << " old " << oldVal << " new " << newVal << std::endl;
}
}
static ns3::GlobalValue g_verbose("verbose",
"Whether to enable verbose output",
ns3::BooleanValue(false),
ns3::MakeBooleanChecker());
int
main(int argc, char* argv[])
{
double stopTime = 100.0;
bool verbose = false;
CommandLine cmd(__FILE__);
cmd.AddValue("stopTime", "Time (seconds) to terminate simulation", stopTime);
cmd.AddValue("verbose", "Whether to enable verbose output", verbose);
cmd.Parse(argc, argv);
bool connected;
// Set a global value, so that the callbacks can access it
if (verbose)
{
GlobalValue::Bind("verbose", BooleanValue(true));
LogComponentEnable("TimeProbeExample", LOG_LEVEL_ALL);
}
Ptr<Emitter> emitter = CreateObject<Emitter>();
Names::Add("/Names/Emitter", emitter);
//
// The below shows typical functionality without a probe
// (connect a sink function to a trace source)
//
connected =
emitter->TraceConnect("Interval", "raw trace source", MakeCallback(&NotifyViaTraceSource));
NS_ASSERT_MSG(connected, "Trace source not connected");
//
// Next, we'll show several use cases of using a Probe to access and
// filter the values of the underlying trace source
//
//
// Probe1 will be hooked directly to the Emitter trace source object
//
// probe1 will be hooked to the Emitter trace source
Ptr<TimeProbe> probe1 = CreateObject<TimeProbe>();
// the probe's name can serve as its context in the tracing
probe1->SetName("probe1");
// Connect the probe to the emitter's Interval
connected = probe1->ConnectByObject("Interval", emitter);
NS_ASSERT_MSG(connected, "Trace source not connected to probe1");
// The probe itself should generate output. The context that we provide
// to this probe (in this case, the probe name) will help to disambiguate
// the source of the trace
connected = probe1->TraceConnect("Output", probe1->GetName(), MakeCallback(&NotifyViaProbe));
NS_ASSERT_MSG(connected, "Trace source not connected to probe1 Output");
//
// Probe2 will be hooked to the Emitter trace source object by
// accessing it by path name in the Config database
//
// Create another similar probe; this will hook up via a Config path
Ptr<TimeProbe> probe2 = CreateObject<TimeProbe>();
probe2->SetName("probe2");
// Note, no return value is checked here
probe2->ConnectByPath("/Names/Emitter/Interval");
// The probe itself should generate output. The context that we provide
// to this probe (in this case, the probe name) will help to disambiguate
// the source of the trace
connected = probe2->TraceConnect("Output", "probe2", MakeCallback(&NotifyViaProbe));
NS_ASSERT_MSG(connected, "Trace source not connected to probe2 Output");
//
// Probe3 will be called by the emitter directly through the
// static method SetValueByPath().
//
Ptr<TimeProbe> probe3 = CreateObject<TimeProbe>();
probe3->SetName("probe3");
// By adding to the config database, we can access it later
Names::Add("/Names/probe3", probe3);
// The probe itself should generate output. The context that we provide
// to this probe (in this case, the probe name) will help to disambiguate
// the source of the trace
connected = probe3->TraceConnect("Output", "probe3", MakeCallback(&NotifyViaProbe));
NS_ASSERT_MSG(connected, "Trace source not connected to probe3 Output");
// Plot the interval values
GnuplotHelper plotHelper;
plotHelper.ConfigurePlot("time-probe-example",
"Emitter interarrivals vs. Time",
"Simulation time (Seconds)",
"Interarrival time (Seconds)",
"png");
// Helper creates a TimeProbe and hooks it to the /Names/Emitter/Interval
// source. Helper also takes the Output of the TimeProbe and plots it
// as a dataset labeled 'Emitter Interarrival Time'
plotHelper.PlotProbe("ns3::TimeProbe",
"/Names/Emitter/Interval",
"Output",
"Emitter Interarrival Time",
GnuplotAggregator::KEY_INSIDE);
// The Emitter object is not associated with an ns-3 node, so
// it won't get started automatically, so we need to do this ourselves
Simulator::Schedule(Seconds(0.0), &Emitter::Initialize, emitter);
Simulator::Stop(Seconds(stopTime));
Simulator::Run();
Simulator::Destroy();
return 0;
}