181 protected:

   181 protected:

   182 /**

   182 /**

   183  * @brief Establish a correspondence between a simulation time and a 

   183  * @brief Establish a correspondence between a simulation time and a 

   184  * wall-clock (real) time.

   184  * wall-clock (real) time.

   185  *

   185  *

   188  * There are three timelines involved here:  the simulation time, the 

   186  * There are three timelines involved here:  the simulation time, the 

   189  * (absolute) wall-clock time and the (relative) synchronizer real time.

   187  * (absolute) wall-clock time and the (relative) synchronizer real time.

   190  * Calling this method makes a correspondence between the origin of the

   188  * Calling this method makes a correspondence between the origin of the

   191  * synchronizer time and the current wall-clock time.

   189  * synchronizer time and the current wall-clock time.

   192  *

   190  *

   210 

   208 

   211 /**

   209 /**

   212  * @brief Return true if this synchronizer is actually synchronizing to a

   210  * @brief Return true if this synchronizer is actually synchronizing to a

   213  * realtime clock.  The simulator sometimes needs to know this.

   211  * realtime clock.  The simulator sometimes needs to know this.

   214  *

   212  *

   217  * Subclasses are expected to implement this method to tell the outside world

   213  * Subclasses are expected to implement this method to tell the outside world

   218  * whether or not they are synchronizing to a realtime clock.

   214  * whether or not they are synchronizing to a realtime clock.

   219  *

   215  *

   220  * @returns True if locked with realtime, false if not.

   216  * @returns True if locked with realtime, false if not.

   221  */

   217  */

   223 

   219 

   224 /**

   220 /**

   225  * @brief Retrieve the value of the origin of the underlying normalized wall

   221  * @brief Retrieve the value of the origin of the underlying normalized wall

   226  * clock time in simulator timestep units.

   222  * clock time in simulator timestep units.

   227  *

   223  *

   230  * Subclasses are expected to implement this method to do the actual

   224  * Subclasses are expected to implement this method to do the actual

   231  * real-time-clock-specific work of getting the current time.

   225  * real-time-clock-specific work of getting the current time.

   232  *

   226  *

   233  * @returns The normalized wall clock time (in nanosecond units).

   227  * @returns The normalized wall clock time (in nanosecond units).

   234  * @see TimeStepPrecision::Get

   228  * @see TimeStepPrecision::Get

   237   virtual uint64_t DoGetCurrentRealtime (void) = 0;

   231   virtual uint64_t DoGetCurrentRealtime (void) = 0;

   238 

   232 

   239 /**

   233 /**

   240  * @brief Wait until the real time is in sync with the specified simulation

   234  * @brief Wait until the real time is in sync with the specified simulation

   241  * time.

   235  * time.

   244  *

   236  *

   245  * This is where the real work of synchronization is done.  The Time passed

   237  * This is where the real work of synchronization is done.  The Time passed

   246  * in as a parameter is the simulation time.  The job of Synchronize is to

   238  * in as a parameter is the simulation time.  The job of Synchronize is to

   247  * translate from simulation time to synchronizer time (in a perfect world

   239  * translate from simulation time to synchronizer time (in a perfect world

   248  * this is the same time) and then figure out how long in real-time it needs

   240  * this is the same time) and then figure out how long in real-time it needs

   284 

   276 

   285 /**

   277 /**

   286  * @brief Declaration of method used to retrieve drift between the real time

   278  * @brief Declaration of method used to retrieve drift between the real time

   287  * clock used to synchronize the simulation and the current simulation time.

   279  * clock used to synchronize the simulation and the current simulation time.

   288  *

   280  *

   291  * @param ns Simulation timestep from the simulator normalized to nanosecond 

   281  * @param ns Simulation timestep from the simulator normalized to nanosecond 

   292  * steps.

   282  * steps.

   293  * @returns Drift in nanosecond units.

   283  * @returns Drift in nanosecond units.

   294  * @see TimeStepPrecision::Get

   284  * @see TimeStepPrecision::Get

   295  * @see Synchronizer::SetOrigin

   285  * @see Synchronizer::SetOrigin

   306 private:

   296 private:

   307 /**

   297 /**

   308  * @brief Convert a simulator time step (which can be steps of time in a 

   298  * @brief Convert a simulator time step (which can be steps of time in a 

   309  * user-specified unit) to a normalized time step in nanosecond units.

   299  * user-specified unit) to a normalized time step in nanosecond units.

   310  *

   300  *

   313  * @param ts The simulation time step to be normalized.

   301  * @param ts The simulation time step to be normalized.

   314  * @returns The simulation time step normalized to nanosecond units.

   302  * @returns The simulation time step normalized to nanosecond units.

   315  * @see TimeStepPrecision::Get

   303  * @see TimeStepPrecision::Get

   316  */

   304  */

   317   uint64_t TimeStepToNanosecond (uint64_t ts);

   305   uint64_t TimeStepToNanosecond (uint64_t ts);

   318 

   306 

   319 /**

   307 /**

   320  * @brief Convert a normalized nanosecond count into a simulator time step

   308  * @brief Convert a normalized nanosecond count into a simulator time step

   321  * (which can be steps of time in a user-specified unit).

   309  * (which can be steps of time in a user-specified unit).

   322  *

   310  *

   325  * @param ns The nanosecond count step to be converted

   311  * @param ns The nanosecond count step to be converted

   326  * @returns The simulation time step to be interpreted in appropriate units.

   312  * @returns The simulation time step to be interpreted in appropriate units.

   327  * @see TimeStepPrecision::Get

   313  * @see TimeStepPrecision::Get

   328  */

   314  */

   329   uint64_t NanosecondToTimeStep (uint64_t ns);

   315   uint64_t NanosecondToTimeStep (uint64_t ns);