ns3::RngSeedManager Class Reference

Manage the seed number and run number of the underlying random number generator, and automatic assignment of stream numbers. More...

#include "rng-seed-manager.h"

Static Public Member Functions
static uint64_t	GetNextStreamIndex (void)
	Get the next automatically assigned stream index. More...
static uint64_t	GetRun (void)
	Get the current run number. More...
static uint32_t	GetSeed (void)
	Get the current seed value which will be used by all subsequently instantiated RandomVariableStream objects. More...
static void	SetRun (uint64_t run)
	Set the run number of simulation. More...
static void	SetSeed (uint32_t seed)
	Set the seed. More...

Related Functions
(Note that these are not member functions.)
static uint64_t	g_nextStreamIndex = 0
static ns3::GlobalValue	g_rngRun ("RngRun", "The substream index used for all streams", ns3::UintegerValue(1), ns3::MakeUintegerChecker< uint64_t >())
static ns3::GlobalValue	g_rngSeed ("RngSeed", "The global seed of all rng streams", ns3::UintegerValue(1), ns3::MakeUintegerChecker< uint32_t >())

Detailed Description

Manage the seed number and run number of the underlying random number generator, and automatic assignment of stream numbers.

Definition at line 39 of file rng-seed-manager.h.

Member Function Documentation

GetNextStreamIndex()

uint64_t ns3::RngSeedManager::GetNextStreamIndex ( void  )

static

Get the next automatically assigned stream index.

Returns

The next stream index.

Definition at line 100 of file rng-seed-manager.cc.

References g_nextStreamIndex, and NS_LOG_FUNCTION_NOARGS.

Referenced by ns3::RandomVariableStream::SetStream().

GetRun()

uint64_t ns3::RngSeedManager::GetRun ( void  )

static

Get the current run number.

Returns

The current run number

See also

SetRun

Definition at line 91 of file rng-seed-manager.cc.

References g_rngRun, ns3::UintegerValue::Get(), ns3::GlobalValue::GetValue(), and NS_LOG_FUNCTION_NOARGS.

Referenced by ns3::RandomVariableStream::SetStream(), and anonymous_namespace{random-variable-stream-test-suite.cc}::SetTestSuiteSeed().

GetSeed()

uint32_t ns3::RngSeedManager::GetSeed ( void  )

static

Get the current seed value which will be used by all subsequently instantiated RandomVariableStream objects.

Returns

The seed value.

This returns the current seed value.

Definition at line 71 of file rng-seed-manager.cc.

References g_rngSeed, ns3::UintegerValue::Get(), ns3::GlobalValue::GetValue(), and NS_LOG_FUNCTION_NOARGS.

Referenced by ns3::RandomVariableStream::SetStream(), and anonymous_namespace{random-variable-stream-test-suite.cc}::SetTestSuiteSeed().

SetRun()

void ns3::RngSeedManager::SetRun ( uint64_t  run )

static

Set the run number of simulation.

RngSeedManager::SetSeed(12);
int N = atol(argv[1]);      // Read in run number from command line.
RngSeedManager::SetRun(N);
UniformVariable x(0,10);
ExponentialVariable y(2902);

In this example, N could successively be equal to 1,2,3, etc. and the user would continue to get independent runs out of the single simulation. For this simple example, the following might work:

./simulation 0
...Results for run 0:...

./simulation 1
...Results for run 1:...

Parameters

[in]

run

The run number.

Definition at line 85 of file rng-seed-manager.cc.

References NS_LOG_FUNCTION, and ns3::Config::SetGlobal().

Referenced by ns3::olsr::Bug780Test::DoRun(), ns3::olsr::HelloRegressionTest::DoRun(), and ns3::olsr::TcRegressionTest::DoRun().

SetSeed()

void ns3::RngSeedManager::SetSeed ( uint32_t  seed )

static

Set the seed.

This sets the global initial seed which will be used all subsequently instantiated RandomVariableStream objects.

RngSeedManger::SetSeed(15);
UniformVariable x(2,3);     // These will give the same output every time
ExponentialVariable y(120); // as long as the seed stays the same.

Parameters

[in]

seed

The seed value to use.

Note

While the underlying RNG takes six integer values as a seed; it is sufficient to set these all to the same integer, so we provide a simpler interface here that just takes one integer.

Definition at line 79 of file rng-seed-manager.cc.

References NS_LOG_FUNCTION, and ns3::Config::SetGlobal().

Referenced by ns3::olsr::Bug780Test::DoRun(), SteadyStateRandomWaypointTest::DoRun(), ns3::olsr::HelloRegressionTest::DoRun(), ns3::olsr::TcRegressionTest::DoRun(), and anonymous_namespace{random-variable-stream-test-suite.cc}::SetTestSuiteSeed().

Friends And Related Function Documentation

g_nextStreamIndex

uint64_t g_nextStreamIndex = 0

related

The next random number generator stream number to use for automatic assignment.

Definition at line 42 of file rng-seed-manager.cc.

Referenced by GetNextStreamIndex().

g_rngRun

ns3::GlobalValue g_rngRun("RngRun", "The substream index used for all streams", ns3::UintegerValue(1), ns3::MakeUintegerChecker< uint64_t >())

related

The random number generator substream index. This is used to generate new PRNG sequences for all streams (random variables) in such a manner that the streams remain uncorrelated. Incrementing this variable can be used for independent replications.

This is accessible as "--RngRun" from CommandLine.

Referenced by GetRun().

g_rngSeed

ns3::GlobalValue g_rngSeed("RngSeed", "The global seed of all rng streams", ns3::UintegerValue(1), ns3::MakeUintegerChecker< uint32_t >())

related

The random number generator seed number global value. This is used to generate an new master PRNG sequence. It is typically not modified by user programs; the variable RngRun is preferred for independent replications.

This is accessible as "--RngSeed" from CommandLine.

Referenced by GetSeed().

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The documentation for this class was generated from the following files:

• src/core/model/rng-seed-manager.h
• src/core/model/rng-seed-manager.cc