Control the virtual time and the execution of simulation events. More...

Collaboration diagram for Simulator:

Topics
	Realtime Simulator
	Realtime simulator implementation.

Files
file	default-simulator-impl.cc
	ns3::DefaultSimulatorImpl implementation.
file	default-simulator-impl.h
	ns3::DefaultSimulatorImpl declaration.
file	des-metrics.cc
	ns3::DesMetrics implementation.
file	des-metrics.h
	ns3::DesMetrics declaration.
file	node-printer.cc
	ns3::DefaultNodePrinter implementation.
file	sample-simulator.cc
	Example program demonstrating use of various Schedule functions.
file	sample-simulator.py
	Python example program demonstrating use of various Schedule functions.
file	simulator-impl.cc
	ns3::SimulatorImpl implementation.
file	simulator-impl.h
	ns3::SimulatorImpl declaration.
file	simulator.cc
	ns3::Simulator implementation, as well as implementation pointer, global scheduler implementation.
file	simulator.h
	ns3::Simulator declaration.

Classes
class	ns3::DefaultSimulatorImpl
	The default single process simulator implementation. More...
class	ns3::DistributedSimulatorImpl
	Distributed simulator implementation using lookahead. More...
class	ns3::Simulator
	Control the scheduling of simulation events. More...
class	ns3::SimulatorImpl
	The SimulatorImpl base class. More...
class	ns3::VisualSimulatorImpl
	A replacement simulator that starts the visualizer. More...

Functions
static SimulatorImpl *	ns3::GetImpl ()
	Get the SimulatorImpl singleton.
void	ns3::Initialize (std::vector< std::string > args, std::string outDir="")
	Event trace data collector for the DES Metrics project.
Time	ns3::Now ()
	create an ns3::Time instance which contains the current simulation time.
static SimulatorImpl **	ns3::PeekImpl ()
	Get the static SimulatorImpl instance.

Variables
static GlobalValue	ns3::g_simTypeImpl
	The specific simulator implementation to use.

Detailed Description

Control the virtual time and the execution of simulation events.

Function Documentation

◆ GetImpl()

SimulatorImpl * ns3::GetImpl ( )

static

Get the SimulatorImpl singleton.

Returns: The singleton pointer.

See also: Simulator::GetImplementation()

Definition at line 93 of file simulator.cc.

References ns3::ObjectFactory::Create(), DefaultNodePrinter(), DefaultTimePrinter(), g_schedTypeImpl, g_simTypeImpl, ns3::StringValue::Get(), GetPointer(), LogSetNodePrinter(), LogSetTimePrinter(), PeekImpl(), and ns3::ObjectFactory::SetTypeId().

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◆ Initialize()

void ns3::Initialize	(	std::vector< std::string >	args,
		std::string	outDir = "" )

Event trace data collector for the DES Metrics project.

This feature generates a JSON file with event trace data, including the source and destination context for each event, and the (virtual) times when the event was scheduled and when it will execute.

See the DES Metrics Project page: https://github.com/wilseypa/desMetrics for more information and analysis tools.

If enabled (see below), ns-3 scripts should use CommandLine to parse arguments, which will open the JSON file with the same name as the script, and write the JSON header. Failure to use CommandLine when DES Metrics is enabled will put the trace data in the file desTraceFile.json instead. All examples accessible from test.py use CommandLine, and so generate JSON files.

Output from scripts ends up in the current working directory (normally the top level directory). When test.py is used to run tests or examples the trace files are generated in a time-stamped subdirectory of testpy-output/, which test.py normally deletes. To keep the output of examples, use the --retain argument to test.py.

The output file has the following form:

{
 "simulator_name" : "ns-3",
 "model_name" : "ipv4-raw",
 "capture_date" : "Fri May 27 00:34:27 2016",
 "command_line_arguments" : "ipv4-raw [ns3-dev-test-runner-debug] --test-name=ipv4-raw
--stop-on-failure --fullness=QUICK --xml --tempdir=testpy-output/2016-05-27-04-33-35-CUT
--out=testpy-output/2016-05-27-04-33-35-CUT/ipv4-raw.xml", "events" : [
  ["0",0,"0",0],
  ["1",0,"0",0],
  ["0",0,"0",0],
  ...
  ["0",0,"0",0]
 ]
}

The first few fields are self-explanatory. The event record consists of the source context, the event send time, the destination context, and the event execution time. Times are given in the current Time resolution.

Enabling DES Metrics

Enable DES Metrics at configure time with

   $ ns3 configure ... --enable-des-metrics

Working with DES Metrics

Some useful shell pipelines:

Run everything, retaining the results directory:

./test.py --nobuild --retain

test
-ns3 Test suite for the ns3 wrapper script
Example traces end up in testpy-output/, so move there:

cd testpy-output/$(date +"%F")*_/

(Remove the `_', which is to work around a Doxygen limitation.)
Remove the traces with less than 10 events:

wc -l *.json | sort -nr | grep "^ *[789] " | cut -d ' ' -f 9 | xargs rm -f
Show the largest file, and total number of trace files:

wc -l *.json | sort -n | tail -2

*/ class DesMetrics : public Singleton<DesMetrics> { public: /** Open the DesMetrics trace file and print the header.

The trace file will have the same base name as the main program, '.json' as the extension.

Parameters

args	[in] Command line arguments.
outDir	[in] Directory where the trace file should be written.

References Initialize().

Referenced by Initialize(), and TraceWithContext().

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◆ Now()

Time ns3::Now ( )

create an ns3::Time instance which contains the current simulation time.

This is really a shortcut for the ns3::Simulator::Now method. It is typically used as shown below to schedule an event which expires at the absolute time "2 seconds":

Simulator::Schedule (Seconds (2.0) - Now (), &my_function);

ns3::Simulator::Schedule

static EventId Schedule(const Time &delay, FUNC f, Ts &&... args)

Schedule an event to expire after delay.

Definition simulator.h:561

ns3::Now

Time Now()

create an ns3::Time instance which contains the current simulation time.

Definition simulator.cc:294

ns3::Seconds

Time Seconds(double value)

Construct a Time in the indicated unit.

Definition nstime.h:1369

Returns: The current simulation time.

Definition at line 294 of file simulator.cc.

References ns3::Simulator::Now().

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◆ PeekImpl()

SimulatorImpl ** ns3::PeekImpl ( )

static

Get the static SimulatorImpl instance.

Returns: The SimulatorImpl instance pointer.

Definition at line 80 of file simulator.cc.

Referenced by ns3::Simulator::Cancel(), ns3::Simulator::Destroy(), GetImpl(), ns3::Simulator::GetSystemId(), ns3::Simulator::IsExpired(), ns3::Simulator::Remove(), and ns3::Simulator::SetImplementation().

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Variable Documentation

◆ g_simTypeImpl

GlobalValue ns3::g_simTypeImpl

static

Initial value:

=
    GlobalValue("SimulatorImplementationType",
                "The object class to use as the simulator implementation",
                StringValue("ns3::DefaultSimulatorImpl"),
                MakeStringChecker())

The specific simulator implementation to use.

Must be derived from SimulatorImpl.

Definition at line 55 of file simulator.cc.

Referenced by GetImpl().

Topics

Files

Classes

Functions

Variables

Detailed Description

Function Documentation

◆ GetImpl()

◆ Initialize()

◆ Now()

◆ PeekImpl()

Variable Documentation

◆ g_simTypeImpl