/* Copyright (c) 2012 Massachusetts Institute of Technology
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "model/optical_graph/OpticalGraph.h"
#include "model/OpticalModel.h"
#include "model/optical_graph/OpticalNode.h"
#include "model/optical_graph/OpticalLaser.h"
#include "model/optical_graph/OpticalModulator.h"
#include "model/optical_graph/OpticalFilter.h"
#include "model/optical_graph/OpticalDetector.h"
#include "model/optical_graph/OpticalWavelength.h"
namespace DSENT
{
// Initialize the next visited number to be one above the initial number
// used by OpticalNode
int OpticalGraph::msTreeNum = OpticalNode::OPTICAL_NODE_INIT_VISITED_NUM + 1;
OpticalGraph::OpticalGraph(const String& instance_name_, OpticalModel* model_)
: m_instance_name_(instance_name_), m_model_(model_)
{
}
OpticalGraph::~OpticalGraph()
{
}
const String& OpticalGraph::getInstanceName() const
{
return m_instance_name_;
}
//-------------------------------------------------------------------------
// Perform Datapath power optimization
//-------------------------------------------------------------------------
bool OpticalGraph::performPowerOpt(OpticalNode* node_, const WavelengthGroup& wavelengths_, unsigned int number_detectors_, double util_)
{
// Total number of iterations
unsigned int number_iterations = 1250;
// Maximum IL + ER
double IL_ER_max = 10;
// Figure out the step size used in the sweep
double step = (double) (IL_ER_max / sqrt(2 * number_iterations));
// Assume it is possible
bool possible = true;
// Begin optical data path power optimization
Log::printLine(getInstanceName() + " -> Beginning optical data path power optimization");
// Trace the specified wavelengths
OpticalWavelength* wavelength = traceWavelength(wavelengths_, node_);
// For each data path found in the wavelength
const vector<OpticalDataPath>* data_paths = wavelength->getDataPaths();
for (unsigned int i = 0; i < data_paths->size(); ++i)
{
const OpticalDataPath& data_path = data_paths->at(i);
// Default to worst possible modulator
double best_power = 1e99;
double best_IL = IL_ER_max - step;
double best_ER = step;
// Perform power optimization for this data path
Log::printLine(getInstanceName() + " -> Optimize data path - Laser = " + data_path.laser->getInstanceName()
+ ", Modulator = " + data_path.modulator->getInstanceName());
if (data_path.modulator->canOptimizeLoss())
{
// Iterate over IL and ER to find optimal set of IL and ER
for (double IL = step; IL < IL_ER_max; IL += step)
{
for (double ER = step; ER <= (IL_ER_max - IL); ER += step)
{
// Ask the modulator to try this new ER and IL
bool success = data_path.modulator->setModulatorSpec(IL, ER);
// If the modulator was successful
if (success)
{
double laser_power = wavelength->getLaserPower(number_detectors_);
double modulator_power = data_path.modulator->getPower(util_);
double total_power = laser_power + modulator_power;
// If this is the new lowest power point
if (total_power < best_power)
{
best_power = total_power;
best_IL = IL;
best_ER = ER;
}
}
}
}
// Set IL and ER to the best ones we found
bool success = data_path.modulator->setModulatorSpec(best_IL, best_ER);
// If the best one we found was still not possible...
possible = possible && success;
// Print best IL and ER
Log::printLine(getInstanceName() + " -> Best IL=" + (String) best_IL + ", Best ER=" + (String) best_ER +
", Best Laser/Mod Power=" + (String) best_power);
}
else
{
// Perform power optimization for this data path
Log::printLine(getInstanceName() + " -> Data path not set to allow optimization");
}
}
// End optical data path power optimization
Log::printLine(getInstanceName() + " -> End optical data path power optimization");
delete wavelength;
return possible;
}
//-------------------------------------------------------------------------
// Trace wavelength(s), returning a wavelength data structure
//-------------------------------------------------------------------------
OpticalWavelength* OpticalGraph::traceWavelength(const WavelengthGroup& wavelengths_, OpticalNode* node_)
{
setTreeNum(getTreeNum() + 1);
OpticalWavelength* wavelength = new OpticalWavelength("TraceWavelength", wavelengths_);
return traceWavelength(wavelength, node_, NULL, NULL, 0.0);
}
OpticalWavelength* OpticalGraph::traceWavelength(OpticalWavelength* wavelength_, OpticalNode* node_, OpticalLaser* laser_, OpticalModulator* modulator_, double loss_)
{
// If the node has already been visited, don't do anything!
if (node_->getVisitedNum() != getTreeNum())
{
// Set the new parity for this node
node_->setVisitedNum(getTreeNum());
// Calculate the loss of the current path
double current_loss = loss_ + node_->getLoss();
// Check if the current node is a laser, modulator or detector
if(node_->getType() == OpticalNode::LASER)
{
// Set the laser lighting up the wavelength
ASSERT(laser_ == NULL, "[Error] " + getInstanceName() + " -> Multiple " +
"Lasers lighting up the wavelength!");
laser_ = (OpticalLaser*) node_;
}
else if (node_->getType() == OpticalNode::MODULATOR)
{
// Check that the path already lit up by a laser and there are no
// modulators already driving data
ASSERT(laser_ != NULL, "[Error] " + getInstanceName() + " -> Wavelength reaches a " +
"modulator (" + node_->getInstanceName() + ") prior to being lit up by a laser!");
ASSERT(modulator_ == NULL, "[Error] " + getInstanceName() + " -> Two modulators are driving" +
" the same optical data path (" + node_->getInstanceName() + ")!");
modulator_ = (OpticalModulator*) node_;
}
else if (node_->getType() == OpticalNode::DETECTOR)
{
// Check that the path is both lit up by a laser and there is
// a modulator driving data
ASSERT(laser_ != NULL, "[Error] " + getInstanceName() + " -> Wavelength reaches a " +
"detector (" + node_->getInstanceName() + ") prior to being lit up by a laser!");
ASSERT(modulator_ != NULL, "[Error] " + getInstanceName() + " -> Wavelength reaches a " +
"detector (" + node_->getInstanceName() + ") prior to being driven by a modulator!");
// Add a detector to the wavelength
wavelength_->addDataPath(laser_, modulator_, (OpticalDetector*) node_, current_loss);
}
// Traverse downstream nodes to calculate the delay through each downstream path
vector<OpticalNode*>* d_nodes = node_->getDownstreamNodes();
bool trace_downstream = (node_->getType() != OpticalNode::DETECTOR);
// Do special things when traversing filters
if (node_->getType() == OpticalNode::FILTER)
{
OpticalFilter* filter_node = (OpticalFilter*) node_;
if (filter_node->isDropped(wavelength_->getWavelengths()))
traceWavelength(wavelength_, filter_node->getDropPort(), laser_, modulator_, loss_ + filter_node->getDropLoss());
// If the filter is not modeled as a complete drop, continue tracing downstream
trace_downstream = !filter_node->getDropAll();
}
if (trace_downstream)
{
// Trace downstream nodes
for (unsigned int i = 0; i < d_nodes->size(); ++i)
traceWavelength(wavelength_, d_nodes->at(i), laser_, modulator_, current_loss);
}
}
return wavelength_;
}
//-------------------------------------------------------------------------
OpticalGraph::OpticalGraph(const OpticalGraph& /* graph_ */)
{
// Disabled
}
OpticalModel* OpticalGraph::getModel()
{
return m_model_;
}
void OpticalGraph::setTreeNum(int tree_num_)
{
msTreeNum = tree_num_;
return;
}
int OpticalGraph::getTreeNum()
{
return msTreeNum;
}
} // namespace DSENT