ns-3
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Base class used for synchronizing the simulation events to some real time "wall clock.". More...
#include <synchronizer.h>
Public Member Functions | |
bool | Realtime (void) |
Return true if this synchronizer is actually synchronizing to a realtime clock. The simulator sometimes needs to know this. | |
uint64_t | GetCurrentRealtime (void) |
Retrieve the value of the origin of the underlying normalized wall clock time in simulator timestep units. | |
void | SetOrigin (uint64_t ts) |
Establish a correspondence between a simulation time and the synchronizer real time. | |
uint64_t | GetOrigin (void) |
Retrieve the value of the origin of the simulation time in simulator timestep units. | |
int64_t | GetDrift (uint64_t ts) |
Retrieve the difference between the real time clock used to synchronize the simulation and the simulation time (in simulator timestep units). | |
bool | Synchronize (uint64_t tsCurrent, uint64_t tsDelay) |
Wait until the real time is in sync with the specified simulation time or until the synchronizer is Sigalled. | |
void | Signal (void) |
Tell a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time. This will cause the thread to wake and return to the simulator proper where it can get its bearings. | |
void | SetCondition (bool) |
Set the condition variable that tells a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time. | |
void | EventStart (void) |
Ask the synchronizer to remember what time it is. Typically used with EventEnd to determine the real execution time of a simulation event. | |
uint64_t | EventEnd (void) |
Ask the synchronizer to return the time step between the instant remembered during EventStart and now. Used in conjunction with EventStart to determine the real execution time of a simulation event. | |
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virtual TypeId | GetInstanceTypeId (void) const |
template<typename T > | |
Ptr< T > | GetObject (void) const |
template<typename T > | |
Ptr< T > | GetObject (TypeId tid) const |
void | Dispose (void) |
void | AggregateObject (Ptr< Object > other) |
AggregateIterator | GetAggregateIterator (void) const |
void | Start (void) |
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SimpleRefCount (const SimpleRefCount &o) | |
SimpleRefCount & | operator= (const SimpleRefCount &o) |
void | Ref (void) const |
void | Unref (void) const |
uint32_t | GetReferenceCount (void) const |
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void | SetAttribute (std::string name, const AttributeValue &value) |
bool | SetAttributeFailSafe (std::string name, const AttributeValue &value) |
void | GetAttribute (std::string name, AttributeValue &value) const |
bool | GetAttributeFailSafe (std::string name, AttributeValue &attribute) const |
bool | TraceConnect (std::string name, std::string context, const CallbackBase &cb) |
bool | TraceConnectWithoutContext (std::string name, const CallbackBase &cb) |
bool | TraceDisconnect (std::string name, std::string context, const CallbackBase &cb) |
bool | TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb) |
Static Public Member Functions | |
static TypeId | GetTypeId (void) |
This method returns the TypeId associated to ns3::Synchronizer. |
Protected Member Functions | |
virtual void | DoSetOrigin (uint64_t ns)=0 |
Establish a correspondence between a simulation time and a wall-clock (real) time. | |
virtual bool | DoRealtime (void)=0 |
Return true if this synchronizer is actually synchronizing to a realtime clock. The simulator sometimes needs to know this. | |
virtual uint64_t | DoGetCurrentRealtime (void)=0 |
Retrieve the value of the origin of the underlying normalized wall clock time in simulator timestep units. | |
virtual bool | DoSynchronize (uint64_t nsCurrent, uint64_t nsDelay)=0 |
Wait until the real time is in sync with the specified simulation time. | |
virtual void | DoSignal (void)=0 |
Declaration of the method used to tell a possible simulator thread waiting in the DoSynchronize method that an event has happened which demands a reevaluation of the wait time. | |
virtual void | DoSetCondition (bool)=0 |
Declaration of the method used to set the condition variable that tells a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time. | |
virtual int64_t | DoGetDrift (uint64_t ns)=0 |
Declaration of method used to retrieve drift between the real time clock used to synchronize the simulation and the current simulation time. | |
virtual void | DoEventStart (void)=0 |
virtual uint64_t | DoEventEnd (void)=0 |
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virtual void | NotifyNewAggregate (void) |
virtual void | DoStart (void) |
virtual void | DoDispose (void) |
Object (const Object &o) |
Protected Attributes | |
uint64_t | m_realtimeOriginNano |
uint64_t | m_simOriginNano |
Base class used for synchronizing the simulation events to some real time "wall clock.".
The simulation clock is maintained as a 64-bit integer in a unit specified by the user through the TimeStepPrecision::Set function. This means that it is not possible to specify event expiration times with anything better than this user-specified accuracy. We use this clock for the simulation time.
The real-time clock is maintained as a 64-bit integer count of nanoseconds.
The synchronization between the simulation clock and the real-time clock is maintained using a combination of sleep-waiting, busy-waiting and a feedback loop.
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protectedpure virtual |
Declaration of the method used to set the condition variable that tells a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time.
Implemented in ns3::WallClockSynchronizer.
Referenced by SetCondition().
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protectedpure virtual |
Declaration of the method used to tell a possible simulator thread waiting in the DoSynchronize method that an event has happened which demands a reevaluation of the wait time.
Implemented in ns3::WallClockSynchronizer.
Referenced by Signal().
uint64_t ns3::Synchronizer::EventEnd | ( | void | ) |
Ask the synchronizer to return the time step between the instant remembered during EventStart and now. Used in conjunction with EventStart to determine the real execution time of a simulation event.
void ns3::Synchronizer::EventStart | ( | void | ) |
Ask the synchronizer to remember what time it is. Typically used with EventEnd to determine the real execution time of a simulation event.
uint64_t ns3::Synchronizer::GetCurrentRealtime | ( | void | ) |
Retrieve the value of the origin of the underlying normalized wall clock time in simulator timestep units.
References DoGetCurrentRealtime().
Referenced by ns3::RealtimeSimulatorImpl::Run(), and ns3::RealtimeSimulatorImpl::ScheduleWithContext().
int64_t ns3::Synchronizer::GetDrift | ( | uint64_t | ts | ) |
Retrieve the difference between the real time clock used to synchronize the simulation and the simulation time (in simulator timestep units).
ts | Simulation timestep from the simulator interpreted as current time in the simulator. |
References DoGetDrift().
uint64_t ns3::Synchronizer::GetOrigin | ( | void | ) |
Retrieve the value of the origin of the simulation time in simulator timestep units.
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static |
This method returns the TypeId associated to ns3::Synchronizer.
No Attributes defined for this type.
No TraceSources defined for this type.
Reimplemented from ns3::Object.
References ns3::TypeId::SetParent().
bool ns3::Synchronizer::Realtime | ( | void | ) |
Return true if this synchronizer is actually synchronizing to a realtime clock. The simulator sometimes needs to know this.
References DoRealtime().
void ns3::Synchronizer::SetCondition | ( | bool | cond | ) |
Set the condition variable that tells a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time.
References DoSetCondition().
void ns3::Synchronizer::SetOrigin | ( | uint64_t | ts | ) |
Establish a correspondence between a simulation time and the synchronizer real time.
This method is expected to be called at the "instant" before simulation begins. At this point, simulation time = 0, and a set = 0 in this method. We then associate this time with the current value of the real time clock that will be used to actually perform the synchronization.
Subclasses are expected to implement the corresponding DoSetOrigin pure virtual method to do the actual real-time-clock-specific work of making the correspondence mentioned above.
ts | The simulation time we should use as the origin (in simulator timestep units). |
References DoSetOrigin().
Referenced by ns3::RealtimeSimulatorImpl::Run().
void ns3::Synchronizer::Signal | ( | void | ) |
Tell a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time. This will cause the thread to wake and return to the simulator proper where it can get its bearings.
References DoSignal().
Referenced by ns3::RealtimeSimulatorImpl::Schedule(), ns3::RealtimeSimulatorImpl::ScheduleNow(), and ns3::RealtimeSimulatorImpl::ScheduleWithContext().
bool ns3::Synchronizer::Synchronize | ( | uint64_t | tsCurrent, |
uint64_t | tsDelay | ||
) |
Wait until the real time is in sync with the specified simulation time or until the synchronizer is Sigalled.
This is where the real work of synchronization is done. The Time passed in as a parameter is the simulation time. The job of Synchronize is to translate from simulation time to synchronizer time (in a perfect world this is the same time) and then figure out how long in real-time it needs to wait until that synchronizer / simulation time comes around.
Subclasses are expected to implement the corresponding DoSynchronize pure virtual method to do the actual real-time-clock-specific work of waiting (either busy-waiting or sleeping, or some combination thereof) until the requested simulation time.
tsCurrent | The current simulation time (in simulator timestep units). |
tsDelay | The simulation time we need to wait for (in simulator timestep units). |
References DoSynchronize().
Referenced by ns3::RealtimeSimulatorImpl::Run().