Base class used for synchronizing the simulation events to some real time "wall clock.". More...
#include "synchronizer.h"
Public Member Functions | |
Synchronizer () | |
Constructor. | |
~Synchronizer () override | |
Destructor. | |
uint64_t | EventEnd () |
Ask the synchronizer to return the time step between the instant remembered during EventStart and now. | |
void | EventStart () |
Ask the synchronizer to remember what time it is. | |
uint64_t | GetCurrentRealtime () |
Retrieve the value of the origin of the underlying normalized wall clock 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 Time resolution units). | |
uint64_t | GetOrigin () |
Retrieve the value of the origin of the simulation time in Time.resolution units. | |
bool | Realtime () |
Return true if this synchronizer is actually synchronizing to a realtime clock. | |
void | 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. | |
void | SetOrigin (uint64_t ts) |
Establish a correspondence between a simulation time and the synchronizer real time. | |
void | Signal () |
Tell a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time. | |
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 Signalled. | |
Public Member Functions inherited from ns3::Object | |
Object () | |
Constructor. | |
~Object () override | |
Destructor. | |
void | AggregateObject (Ptr< Object > other) |
Aggregate two Objects together. | |
void | Dispose () |
Dispose of this Object. | |
AggregateIterator | GetAggregateIterator () const |
Get an iterator to the Objects aggregated to this one. | |
TypeId | GetInstanceTypeId () const override |
Get the most derived TypeId for this Object. | |
template<typename T > | |
Ptr< T > | GetObject () const |
Get a pointer to the requested aggregated Object. | |
template<> | |
Ptr< Object > | GetObject () const |
Specialization of () for objects of type ns3::Object. | |
template<typename T > | |
Ptr< T > | GetObject (TypeId tid) const |
Get a pointer to the requested aggregated Object by TypeId. | |
template<> | |
Ptr< Object > | GetObject (TypeId tid) const |
Specialization of (TypeId tid) for objects of type ns3::Object. | |
void | Initialize () |
Invoke DoInitialize on all Objects aggregated to this one. | |
bool | IsInitialized () const |
Check if the object has been initialized. | |
Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter > | |
SimpleRefCount () | |
Default constructor. | |
SimpleRefCount (const SimpleRefCount &o) | |
Copy constructor. | |
uint32_t | GetReferenceCount () const |
Get the reference count of the object. | |
SimpleRefCount & | operator= (const SimpleRefCount &o) |
Assignment operator. | |
void | Ref () const |
Increment the reference count. | |
void | Unref () const |
Decrement the reference count. | |
Public Member Functions inherited from ns3::ObjectBase | |
virtual | ~ObjectBase () |
Virtual destructor. | |
void | GetAttribute (std::string name, AttributeValue &value) const |
Get the value of an attribute, raising fatal errors if unsuccessful. | |
bool | GetAttributeFailSafe (std::string name, AttributeValue &value) const |
Get the value of an attribute without raising errors. | |
virtual TypeId | GetInstanceTypeId () const =0 |
Get the most derived TypeId for this Object. | |
void | SetAttribute (std::string name, const AttributeValue &value) |
Set a single attribute, raising fatal errors if unsuccessful. | |
bool | SetAttributeFailSafe (std::string name, const AttributeValue &value) |
Set a single attribute without raising errors. | |
bool | TraceConnect (std::string name, std::string context, const CallbackBase &cb) |
Connect a TraceSource to a Callback with a context. | |
bool | TraceConnectWithoutContext (std::string name, const CallbackBase &cb) |
Connect a TraceSource to a Callback without a context. | |
bool | TraceDisconnect (std::string name, std::string context, const CallbackBase &cb) |
Disconnect from a TraceSource a Callback previously connected with a context. | |
bool | TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb) |
Disconnect from a TraceSource a Callback previously connected without a context. | |
Static Public Member Functions | |
static TypeId | GetTypeId () |
Get the registered TypeId for this class. | |
Static Public Member Functions inherited from ns3::Object | |
static TypeId | GetTypeId () |
Register this type. | |
Static Public Member Functions inherited from ns3::ObjectBase | |
static TypeId | GetTypeId () |
Get the type ID. | |
Protected Member Functions | |
virtual uint64_t | DoEventEnd ()=0 |
Return the amount of real time elapsed since the last call to EventStart. | |
virtual void | DoEventStart ()=0 |
Record the normalized real time at which the current event is starting execution. | |
virtual uint64_t | DoGetCurrentRealtime ()=0 |
Retrieve the value of the origin of the underlying normalized wall clock time in Time resolution units. | |
virtual int64_t | DoGetDrift (uint64_t ns)=0 |
Get the drift between the real time clock used to synchronize the simulation and the current simulation time. | |
virtual bool | DoRealtime ()=0 |
Return true if this synchronizer is actually synchronizing to a realtime clock. | |
virtual void | DoSetCondition (bool cond)=0 |
Set the condition variable to tell a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time. | |
virtual void | DoSetOrigin (uint64_t ns)=0 |
Establish a correspondence between a simulation time and a wall-clock (real) time. | |
virtual void | DoSignal ()=0 |
Tell a possible simulator thread waiting in the DoSynchronize method that an event has happened which demands a reevaluation of the wait time. | |
virtual bool | DoSynchronize (uint64_t nsCurrent, uint64_t nsDelay)=0 |
Wait until the real time is in sync with the specified simulation time. | |
Protected Member Functions inherited from ns3::Object | |
Object (const Object &o) | |
Copy an Object. | |
virtual void | DoDispose () |
Destructor implementation. | |
virtual void | DoInitialize () |
Initialize() implementation. | |
virtual void | NotifyNewAggregate () |
Notify all Objects aggregated to this one of a new Object being aggregated. | |
Protected Member Functions inherited from ns3::ObjectBase | |
void | ConstructSelf (const AttributeConstructionList &attributes) |
Complete construction of ObjectBase; invoked by derived classes. | |
virtual void | NotifyConstructionCompleted () |
Notifier called once the ObjectBase is fully constructed. | |
Protected Attributes | |
uint64_t | m_realtimeOriginNano |
The real time, in ns, when SetOrigin was called. | |
uint64_t | m_simOriginNano |
The simulation time, in ns, when SetOrigin was called. | |
Private Member Functions | |
uint64_t | NanosecondToTimeStep (uint64_t ns) |
Convert a normalized nanosecond time step into a simulator time step (in Time resolution units). | |
uint64_t | TimeStepToNanosecond (uint64_t ts) |
Convert a simulator time step (in Time resolution units) to a normalized time step in nanosecond units. | |
Additional Inherited Members | |
Related Functions inherited from ns3::ObjectBase | |
static TypeId | GetObjectIid () |
Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly. | |
Base class used for synchronizing the simulation events to some real time "wall clock.".
Introspection did not find any typical Config paths.
The simulation clock is maintained as a 64-bit integer in a unit specified by the user through the Time::SetResolution 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.
No Attributes are defined for this type.
No TraceSources are defined for this type.
Size of this type is 48 bytes (on a 64-bit architecture).
Definition at line 52 of file synchronizer.h.
ns3::Synchronizer::Synchronizer | ( | ) |
|
override |
|
protectedpure virtual |
Return the amount of real time elapsed since the last call to EventStart.
Implemented in ns3::WallClockSynchronizer.
Referenced by EventEnd().
|
protectedpure virtual |
Record the normalized real time at which the current event is starting execution.
Implemented in ns3::WallClockSynchronizer.
Referenced by EventStart().
|
protectedpure virtual |
Retrieve the value of the origin of the underlying normalized wall clock time in Time resolution units.
Subclasses are expected to implement this method to do the actual real-time-clock-specific work of getting the current time.
Implemented in ns3::WallClockSynchronizer.
Referenced by GetCurrentRealtime().
|
protectedpure virtual |
Get the drift between the real time clock used to synchronize the simulation and the current simulation time.
[in] | ns | Simulation time in ns. |
Implemented in ns3::WallClockSynchronizer.
Referenced by GetDrift().
|
protectedpure virtual |
Return true
if this synchronizer is actually synchronizing to a realtime clock.
The simulator sometimes needs to know this.
Subclasses are expected to implement this method to tell the outside world whether or not they are synchronizing to a realtime clock.
true
if locked with realtime, false
if not. Implemented in ns3::WallClockSynchronizer.
Referenced by Realtime().
|
protectedpure virtual |
Set the condition variable to tell a possible simulator thread waiting in the Synchronize method that an event has happened which demands a reevaluation of the wait time.
[in] | cond | The new value for the condition variable. |
Implemented in ns3::WallClockSynchronizer.
Referenced by SetCondition().
|
protectedpure virtual |
Establish a correspondence between a simulation time and a wall-clock (real) time.
There are three timelines involved here: the simulation (virtual) time, the (absolute) wall-clock time and the (relative) synchronizer real time. Calling this method makes a correspondence between the origin of the synchronizer time and the current wall-clock time.
This method is expected to be called at the "instant" before simulation begins. At this point, simulation time = 0, and synchronizer time is 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 this method to do the actual real-time-clock-specific work of making the correspondence mentioned above. for example, this is where the differences between Time parameters and parameters to clock_nanosleep would be dealt with.
[in] | ns | The simulation time we need to use as the origin (normalized to nanosecond units). |
Implemented in ns3::WallClockSynchronizer.
Referenced by SetOrigin().
|
protectedpure virtual |
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().
|
protectedpure virtual |
Wait until the real time is in sync with the specified simulation time.
This is where the real work of synchronization is done. The nsCurrent
argument is the simulation time (in ns). The job of DoSynchronize is to translate from simulation time to synchronizer time (in a perfect world these are 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 this method to do the actual real-time-clock-specific work of waiting (either busy-waiting or sleeping, or some combination) until the requested simulation time.
[in] | nsCurrent | The current simulation time (in nanosecond units). |
[in] | nsDelay | The simulation time we need to wait for (normalized to nanosecond units). |
true
if the function ran to completion, false
if it was interrupted by a Signal. Implemented in ns3::WallClockSynchronizer.
Referenced by Synchronize().
uint64_t ns3::Synchronizer::EventEnd | ( | ) |
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.
Definition at line 128 of file synchronizer.cc.
References DoEventEnd(), NanosecondToTimeStep(), and NS_LOG_FUNCTION.
void ns3::Synchronizer::EventStart | ( | ) |
Ask the synchronizer to remember what time it is.
Typically used with EventEnd to determine the real execution time of a simulation event.
Definition at line 121 of file synchronizer.cc.
References DoEventStart(), and NS_LOG_FUNCTION.
uint64_t ns3::Synchronizer::GetCurrentRealtime | ( | ) |
Retrieve the value of the origin of the underlying normalized wall clock time in simulator timestep units.
Definition at line 62 of file synchronizer.cc.
References DoGetCurrentRealtime(), NanosecondToTimeStep(), and NS_LOG_FUNCTION.
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 Time resolution units).
[in] | ts | Simulation time in Time resolution units. |
Definition at line 84 of file synchronizer.cc.
References DoGetDrift(), NanosecondToTimeStep(), NS_LOG_FUNCTION, and TimeStepToNanosecond().
uint64_t ns3::Synchronizer::GetOrigin | ( | ) |
Retrieve the value of the origin of the simulation time in Time.resolution units.
Definition at line 77 of file synchronizer.cc.
References m_simOriginNano, NanosecondToTimeStep(), and NS_LOG_FUNCTION.
|
static |
Get the registered TypeId for this class.
Definition at line 36 of file synchronizer.cc.
References ns3::TypeId::SetParent().
|
private |
Convert a normalized nanosecond time step into a simulator time step (in Time resolution units).
[in] | ns | The nanosecond count step to be converted |
Definition at line 142 of file synchronizer.cc.
References ns3::Time::GetTimeStep(), ns3::NanoSeconds(), and NS_LOG_FUNCTION.
Referenced by EventEnd(), GetCurrentRealtime(), GetDrift(), and GetOrigin().
bool ns3::Synchronizer::Realtime | ( | ) |
Return true if this synchronizer is actually synchronizing to a realtime clock.
The simulator sometimes needs to know this.
true
if locked with realtime, false
if not. Definition at line 55 of file synchronizer.cc.
References DoRealtime(), and NS_LOG_FUNCTION.
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.
[in] | cond | The new value for the condition variable. |
Definition at line 114 of file synchronizer.cc.
References DoSetCondition(), and NS_LOG_FUNCTION.
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.
[in] | ts | The simulation time we should use as the origin (in Time resolution units). |
Definition at line 69 of file synchronizer.cc.
References DoSetOrigin(), m_simOriginNano, NS_LOG_FUNCTION, and TimeStepToNanosecond().
void ns3::Synchronizer::Signal | ( | ) |
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.
Definition at line 107 of file synchronizer.cc.
References DoSignal(), and NS_LOG_FUNCTION.
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 Signalled.
This is where the real work of synchronization is done. The tsCurrent
argument 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.
[in] | tsCurrent | The current simulation time (in Time resolution units). |
[in] | tsDelay | The simulation time we need to wait for (in Time resolution units). |
true
if the function ran to completion, false
if it was interrupted by a Signal. Definition at line 100 of file synchronizer.cc.
References DoSynchronize(), NS_LOG_FUNCTION, and TimeStepToNanosecond().
|
private |
Convert a simulator time step (in Time resolution units) to a normalized time step in nanosecond units.
[in] | ts | The simulation time step to be normalized. |
Definition at line 135 of file synchronizer.cc.
References NS_LOG_FUNCTION.
Referenced by GetDrift(), SetOrigin(), and Synchronize().
|
protected |
The real time, in ns, when SetOrigin was called.
Definition at line 318 of file synchronizer.h.
Referenced by ns3::WallClockSynchronizer::DoSetOrigin(), and ns3::WallClockSynchronizer::GetNormalizedRealtime().
|
protected |
The simulation time, in ns, when SetOrigin was called.
Definition at line 320 of file synchronizer.h.
Referenced by GetOrigin(), and SetOrigin().