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unison/src/core/model/simulator.h

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/*
* Copyright (c) 2005 INRIA
*
* SPDX-License-Identifier: GPL-2.0-only
*
* Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
*/
#ifndef SIMULATOR_H
#define SIMULATOR_H
#include "event-id.h"
#include "event-impl.h"
#include "make-event.h"
#include "nstime.h"
#include "object-factory.h"
#include <stdint.h>
#include <string>
/**
* @file
* @ingroup simulator
* ns3::Simulator declaration.
*/
namespace ns3
{
class SimulatorImpl;
class Scheduler;
/**
* @ingroup core
* @defgroup simulator Simulator
* @brief Control the virtual time and the execution of simulation events.
*/
/**
* @ingroup simulator
*
* @brief Control the scheduling of simulation events.
*
* The internal 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. Events whose expiration time is
* the same modulo this accuracy are scheduled in FIFO order: the
* first event inserted in the scheduling queue is scheduled to
* expire first.
*
* A simple example of how to use the Simulator class to schedule events
* is shown in sample-simulator.cc:
* @include src/core/examples/sample-simulator.cc
*/
class Simulator
{
public:
// Delete default constructor and destructor to avoid misuse
Simulator() = delete;
~Simulator() = delete;
/**
* @param [in] impl A new simulator implementation.
*
* The simulator provides a mechanism to swap out different implementations.
* For example, the default implementation is a single-threaded simulator
* that performs no realtime synchronization. By calling this method, you
* can substitute in a new simulator implementation that might be multi-
* threaded and synchronize events to a realtime clock.
*
* The simulator implementation can be set when the simulator is not
* running.
*/
static void SetImplementation(Ptr<SimulatorImpl> impl);
/**
* @brief Get the SimulatorImpl singleton.
*
* @internal
* If the SimulatorImpl singleton hasn't been created yet,
* this function does so. At the same time it also creates
* the Scheduler. Both of these respect the global values
* which may have been set from the command line or through
* the Config system.
*
* As a side effect we also call LogSetTimePrinter() and
* LogSetNodePrinter() with the default implementations
* since we can't really do any logging until we have
* a SimulatorImpl and Scheduler.
* @return The SimulatorImpl singleton.
*/
static Ptr<SimulatorImpl> GetImplementation();
/**
* @brief Set the scheduler type with an ObjectFactory.
* @param [in] schedulerFactory The configured ObjectFactory.
*
* The event scheduler can be set at any time: the events scheduled
* in the previous scheduler will be transferred to the new scheduler
* before we start to use it.
*/
static void SetScheduler(ObjectFactory schedulerFactory);
/**
* Execute the events scheduled with ScheduleDestroy().
*
* This method is typically invoked at the end of a simulation
* to avoid false-positive reports by a leak checker.
* After this method has been invoked, it is actually possible
* to restart a new simulation with a set of calls to Simulator::Run,
* Simulator::Schedule and Simulator::ScheduleWithContext.
*/
static void Destroy();
/**
* Check if the simulation should finish.
*
* Reasons to finish are because there are
* no more events lefts to be scheduled, or if simulation
* time has already reached the "stop time" (see Simulator::Stop()).
*
* @return @c true if no more events or stop time reached.
*/
static bool IsFinished();
/**
* Run the simulation.
*
* The simulation will run until one of:
* - No events are present anymore
* - The user called Simulator::Stop
* - The user called Simulator::Stop with a stop time and the
* expiration time of the next event to be processed
* is greater than or equal to the stop time.
*/
static void Run();
/**
* Tell the Simulator the calling event should be the last one
* executed.
*
* If a running event invokes this method, it will be the last
* event executed by the Simulator::Run method before
* returning to the caller.
*/
static void Stop();
/**
* Schedule the time delay until the Simulator should stop.
*
* Force the Simulator::Run method to return to the caller when the
* expiration time of the next event to be processed is greater than
* or equal to the stop time. The stop time is relative to the
* current simulation time.
* @param [in] delay The stop time, relative to the current time.
* @return The stop EventId.
*/
static EventId Stop(const Time& delay);
/**
* Returns the Stop Event, or an invalid event if the simulation
* does not have a scheduled stop time.
* @return The stop EventId.
*/
static EventId GetStopEvent();
/**
* Get the current simulation context.
*
* The simulation context is the ns-3 notion of a Logical Process.
* Events in a single context should only modify state associated with
* that context. Events for objects in other contexts should be
* scheduled with ScheduleWithContext() to track the context switches.
* In other words, events in different contexts should be mutually
* thread safe, by not modify overlapping model state.
*
* In circumstances where the context can't be determined, such as
* during object initialization, the \c enum value \c NO_CONTEXT
* should be used.
*
* @return The current simulation context
*/
static uint32_t GetContext();
/**
* Context enum values.
*
* @internal
* This enum type is fixed to match the representation size
* of simulation context.
*/
enum : uint32_t
{
/**
* Flag for events not associated with any particular context.
*/
NO_CONTEXT = 0xffffffff
};
/**
* Get the number of events executed.
* @returns The total number of events executed.
*/
static uint64_t GetEventCount();
/**
* @name Schedule events (in the same context) to run at a future time.
*/
/** @{ */
/**
* Schedule an event to expire after @p delay.
* This can be thought of as scheduling an event
* for the current simulation time plus the @p delay passed as a
* parameter.
*
* We leverage SFINAE to discard this overload if the second argument is
* convertible to Ptr<EventImpl> or is a function pointer.
*
* @tparam FUNC @deduced Template type for the function to invoke.
* @tparam Ts @deduced Argument types.
* @param [in] delay The relative expiration time of the event.
* @param [in] f The function to invoke.
* @param [in] args Arguments to pass to MakeEvent.
* @returns The id for the scheduled event.
*/
template <typename FUNC,
std::enable_if_t<!std::is_convertible_v<FUNC, Ptr<EventImpl>>, int> = 0,
std::enable_if_t<!std::is_function_v<std::remove_pointer_t<FUNC>>, int> = 0,
typename... Ts>
static EventId Schedule(const Time& delay, FUNC f, Ts&&... args);
/**
* Schedule an event to expire after @p delay.
* This can be thought of as scheduling an event
* for the current simulation time plus the @p delay passed as a
* parameter.
*
* @tparam Us @deduced Formal function argument types.
* @tparam Ts @deduced Actual function argument types.
* When the event expires (when it becomes due to be run), the
* function will be invoked with any supplied arguments.
* @param [in] delay The relative expiration time of the event.
* @param [in] f The function to invoke.
* @param [in] args Arguments to pass to the invoked function.
* @returns The id for the scheduled event.
*/
template <typename... Us, typename... Ts>
static EventId Schedule(const Time& delay, void (*f)(Us...), Ts&&... args);
/** @} */ // Schedule events (in the same context) to run at a future time.
/**
* @name Schedule events (in a different context) to run now or at a future time.
*
* See @ref main-test-sync.cc for example usage.
*/
/** @{ */
/**
* Schedule an event with the given context.
* A context of 0xffffffff means no context is specified.
* This method is thread-safe: it can be called from any thread.
*
* We leverage SFINAE to discard this overload if the second argument is
* convertible to Ptr<EventImpl> or is a function pointer.
*
* @tparam FUNC @deduced Template type for the function to invoke.
* @tparam Ts @deduced Argument types.
* @param [in] context User-specified context parameter
* @param [in] delay The relative expiration time of the event.
* @param [in] f The function to invoke.
* @param [in] args Arguments to pass to MakeEvent.
*/
template <typename FUNC,
std::enable_if_t<!std::is_convertible_v<FUNC, Ptr<EventImpl>>, int> = 0,
std::enable_if_t<!std::is_function_v<std::remove_pointer_t<FUNC>>, int> = 0,
typename... Ts>
static void ScheduleWithContext(uint32_t context, const Time& delay, FUNC f, Ts&&... args);
/**
* Schedule an event with the given context.
* A context of 0xffffffff means no context is specified.
* This method is thread-safe: it can be called from any thread.
*
* @tparam Us @deduced Formal function argument types.
* @tparam Ts @deduced Actual function argument types.
* @param [in] context User-specified context parameter
* @param [in] delay The relative expiration time of the event.
* @param [in] f The function to invoke.
* @param [in] args Arguments to pass to the invoked function.
*/
template <typename... Us, typename... Ts>
static void ScheduleWithContext(uint32_t context,
const Time& delay,
void (*f)(Us...),
Ts&&... args);
/** @} */ // Schedule events (in a different context) to run now or at a future time.
/**
* @name Schedule events (in the same context) to run now.
*/
/** @{ */
/**
* Schedule an event to expire Now. All events scheduled to
* to expire "Now" are scheduled FIFO, after all normal events
* have expired.
*
* We leverage SFINAE to discard this overload if the second argument is
* convertible to Ptr<EventImpl> or is a function pointer.
*
* @tparam FUNC @deduced Template type for the function to invoke.
* @tparam Ts @deduced Actual function argument types.
* @param [in] f The function to invoke.
* @param [in] args Arguments to pass to the invoked function.
* @return The EventId of the scheduled event.
*/
template <typename FUNC,
std::enable_if_t<!std::is_convertible_v<FUNC, Ptr<EventImpl>>, int> = 0,
std::enable_if_t<!std::is_function_v<std::remove_pointer_t<FUNC>>, int> = 0,
typename... Ts>
static EventId ScheduleNow(FUNC f, Ts&&... args);
/**
* Schedule an event to expire Now. All events scheduled to
* to expire "Now" are scheduled FIFO, after all normal events
* have expired.
*
* @tparam Us @deduced Formal function argument types.
* @tparam Ts @deduced Actual function argument types.
* @param [in] f The function to invoke.
* @param [in] args Arguments to pass to MakeEvent.
* @return The EventId of the scheduled event.
*/
template <typename... Us, typename... Ts>
static EventId ScheduleNow(void (*f)(Us...), Ts&&... args);
/** @} */ // Schedule events (in the same context) to run now.
/**
* @name Schedule events to run at the end of the simulation, when Simulator:Destroy() is
* called.
*/
/** @{ */
/**
* Schedule an event to run at the end of the simulation, when Simulator::Destroy() is called.
* All events scheduled to expire at "Destroy" time are scheduled FIFO,
* after all normal events have expired and only when
* Simulator::Destroy is invoked.
*
* We leverage SFINAE to discard this overload if the second argument is
* convertible to Ptr<EventImpl> or is a function pointer.
*
* @tparam FUNC @deduced Template type for the function to invoke.
* @tparam Ts @deduced Actual function argument types.
* @param [in] f The function to invoke.
* @param [in] args Arguments to pass to MakeEvent.
* @return The EventId of the scheduled event.
*/
template <typename FUNC,
std::enable_if_t<!std::is_convertible_v<FUNC, Ptr<EventImpl>>, int> = 0,
std::enable_if_t<!std::is_function_v<std::remove_pointer_t<FUNC>>, int> = 0,
typename... Ts>
static EventId ScheduleDestroy(FUNC f, Ts&&... args);
/**
* Schedule an event to run at the end of the simulation, when Simulator::Destroy() is called.
* All events scheduled to expire at "Destroy" time are scheduled FIFO,
* after all normal events have expired and only when
* Simulator::Destroy is invoked.
*
* @tparam Us @deduced Formal function argument types.
* @tparam Ts @deduced Actual function argument types.
* @param [in] f The function to invoke.
* @param [in] args Arguments to pass to MakeEvent.
* @return The EventId of the scheduled event.
*/
template <typename... Us, typename... Ts>
static EventId ScheduleDestroy(void (*f)(Us...), Ts&&... args);
/** @} */ // Schedule events to run when Simulator:Destroy() is called.
/**
* Remove an event from the event list.
*
* This method has the same visible effect as the
* ns3::EventId::Cancel method
* but its algorithmic complexity is much higher: it has often
* O(log(n)) complexity, sometimes O(n), sometimes worse.
* Note that it is not possible to remove events which were scheduled
* for the "destroy" time. Doing so will result in a program error (crash).
*
* @param [in] id The event to remove from the list of scheduled events.
*/
static void Remove(const EventId& id);
/**
* Set the cancel bit on this event: the event's associated function
* will not be invoked when it expires.
*
* This method has the same visible effect as the
* ns3::Simulator::Remove method but its algorithmic complexity is
* much lower: it has O(1) complexity.
* This method has the exact same semantics as ns3::EventId::Cancel.
* Note that it is not possible to cancel events which were scheduled
* for the "destroy" time. Doing so will result in a program error (crash).
*
* @param [in] id the event to cancel
*/
static void Cancel(const EventId& id);
/**
* Check if an event has already run or been cancelled.
*
* This method has O(1) complexity.
* Note that it is not possible to test for the expiration of
* events which were scheduled for the "destroy" time. Doing so
* will result in a program error (crash).
* An event is said to "expire" when it starts being executed,
* which means that if the code executed by the event calls
* this function, it will get true.
*
* @param [in] id The event to test for expiration.
* @returns @c true if the event has expired, false otherwise.
*/
static bool IsExpired(const EventId& id);
/**
* Return the current simulation virtual time.
*
* @returns The current virtual time.
*/
static Time Now();
/**
* Get the remaining time until this event will execute.
*
* @param [in] id The event id to analyse.
* @return The delay left until the input event id expires.
* if the event is not running, this method returns
* zero.
*/
static Time GetDelayLeft(const EventId& id);
/**
* Get the maximum representable simulation time.
*
* @return The maximum simulation time at which an event
* can be scheduled.
*
* The returned value will always be bigger than or equal to Simulator::Now.
*/
static Time GetMaximumSimulationTime();
/**
* Schedule a future event execution (in the same context).
*
* @param [in] delay Delay until the event expires.
* @param [in] event The event to schedule.
* @returns A unique identifier for the newly-scheduled event.
*/
static EventId Schedule(const Time& delay, const Ptr<EventImpl>& event);
/**
* Schedule a future event execution (in a different context).
* This method is thread-safe: it can be called from any thread.
*
* @param [in] delay Delay until the event expires.
* @param [in] context Event context.
* @param [in] event The event to schedule.
*/
static void ScheduleWithContext(uint32_t context, const Time& delay, EventImpl* event);
/**
* Schedule an event to run at the end of the simulation, after
* the Stop() time or condition has been reached.
*
* @param [in] event The event to schedule.
* @returns A unique identifier for the newly-scheduled event.
*/
static EventId ScheduleDestroy(const Ptr<EventImpl>& event);
/**
* Schedule an event to run at the current virtual time.
*
* @param [in] event The event to schedule.
* @returns A unique identifier for the newly-scheduled event.
*/
static EventId ScheduleNow(const Ptr<EventImpl>& event);
/**
* Get the system id of this simulator.
*
* The system id is the identifier for this simulator instance
* in a distributed simulation. For MPI this is the MPI rank.
* @return The system id for this simulator.
*/
static uint32_t GetSystemId();
private:
/**
* Implementation of the various Schedule methods.
* @param [in] delay Delay until the event should execute.
* @param [in] event The event to execute.
* @return The EventId.
*/
static EventId DoSchedule(const Time& delay, EventImpl* event);
/**
* Implementation of the various ScheduleNow methods.
* @param [in] event The event to execute.
* @return The EventId.
*/
static EventId DoScheduleNow(EventImpl* event);
/**
* Implementation of the various ScheduleDestroy methods.
* @param [in] event The event to execute.
* @return The EventId.
*/
static EventId DoScheduleDestroy(EventImpl* event);
/**
* Stop event (if present)
*/
static EventId m_stopEvent;
// end of class Simulator
};
/**
* @ingroup simulator
* @brief 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":
* @code
* Simulator::Schedule (Seconds (2.0) - Now (), &my_function);
* @endcode
* @return The current simulation time.
*/
Time Now();
} // namespace ns3
/********************************************************************
* Implementation of the templates declared above.
********************************************************************/
namespace ns3
{
// Doxygen has trouble with static template functions in a class:
// it treats the in-class declaration as different from the
// out of class definition, so makes two entries in the member list. Ugh
template <typename FUNC,
std::enable_if_t<!std::is_convertible_v<FUNC, Ptr<EventImpl>>, int>,
std::enable_if_t<!std::is_function_v<std::remove_pointer_t<FUNC>>, int>,
typename... Ts>
EventId
Simulator::Schedule(const Time& delay, FUNC f, Ts&&... args)
{
return DoSchedule(delay, MakeEvent(f, std::forward<Ts>(args)...));
}
template <typename... Us, typename... Ts>
EventId
Simulator::Schedule(const Time& delay, void (*f)(Us...), Ts&&... args)
{
return DoSchedule(delay, MakeEvent(f, std::forward<Ts>(args)...));
}
template <typename FUNC,
std::enable_if_t<!std::is_convertible_v<FUNC, Ptr<EventImpl>>, int>,
std::enable_if_t<!std::is_function_v<std::remove_pointer_t<FUNC>>, int>,
typename... Ts>
void
Simulator::ScheduleWithContext(uint32_t context, const Time& delay, FUNC f, Ts&&... args)
{
return ScheduleWithContext(context, delay, MakeEvent(f, std::forward<Ts>(args)...));
}
template <typename... Us, typename... Ts>
void
Simulator::ScheduleWithContext(uint32_t context, const Time& delay, void (*f)(Us...), Ts&&... args)
{
return ScheduleWithContext(context, delay, MakeEvent(f, std::forward<Ts>(args)...));
}
template <typename FUNC,
std::enable_if_t<!std::is_convertible_v<FUNC, Ptr<EventImpl>>, int>,
std::enable_if_t<!std::is_function_v<std::remove_pointer_t<FUNC>>, int>,
typename... Ts>
EventId
Simulator::ScheduleNow(FUNC f, Ts&&... args)
{
return DoScheduleNow(MakeEvent(f, std::forward<Ts>(args)...));
}
template <typename... Us, typename... Ts>
EventId
Simulator::ScheduleNow(void (*f)(Us...), Ts&&... args)
{
return DoScheduleNow(MakeEvent(f, std::forward<Ts>(args)...));
}
template <typename FUNC,
std::enable_if_t<!std::is_convertible_v<FUNC, Ptr<EventImpl>>, int>,
std::enable_if_t<!std::is_function_v<std::remove_pointer_t<FUNC>>, int>,
typename... Ts>
EventId
Simulator::ScheduleDestroy(FUNC f, Ts&&... args)
{
return DoScheduleDestroy(MakeEvent(f, std::forward<Ts>(args)...));
}
template <typename... Us, typename... Ts>
EventId
Simulator::ScheduleDestroy(void (*f)(Us...), Ts&&... args)
{
return DoScheduleDestroy(MakeEvent(f, std::forward<Ts>(args)...));
}
} // namespace ns3
#endif /* SIMULATOR_H */