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bus_impl_dragon.cpp
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bus_impl_dragon.cpp
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#include "bus_impl_dragon.hpp"
#include <unistd.h>
using namespace std;
bool dragon_bus_debug = false;
bool BusImplDragon::checkCacheBlocked(unsigned int indexWithTag, int pid) {
// Find the address in the unordered_map
auto it = cacheBlocked.find(indexWithTag);
return false;
}
void BusImplDragon::addCacheBlocked(unsigned int indexWithTag, int pid) {
// add the address in the unordered_map processorModifiedCache if does not exist
cacheBlocked.insert({indexWithTag, pid});
}
void BusImplDragon::removeCacheBlocked(unsigned int indexWithTag, int pid) {
// remove the address in the unordered_map processorModifiedCache if it exist
auto it = cacheBlocked.find(indexWithTag);
if (it != cacheBlocked.end()) {
cacheBlocked.erase(it);
}
}
void BusImplDragon::executeCycle() {
if (dragon_bus_debug)
cout << "execute bus cycle--"
<< "busqueuesize: " << busQueue.size() << " memqueuesize: " << memRequests.size()
<< " curr request " << (currReq == nullptr) << endl;
if (dragon_bus_debug) {
for (const auto &pair : cacheBlocked) {
std::cout << "{" << pair.first << ": " << pair.second << "} ";
}
std::cout << std::endl;
}
if (currReq == nullptr && busQueue.empty() && memRequests.empty()) {
return;
}
// pop if no current request
if (currReq == nullptr && !busQueue.empty()) {
if (dragon_bus_debug)
cout << "from execute cycle: -- busqueue is " << busQueue.size() << endl;
currReq = busQueue.front();
busQueue.pop();
processRequest(currReq);
}
// decrement current request if there is one
if (currReq != nullptr) {
currReq->countdown--;
if (currReq->countdown == 0) {
if (currReq->isToMemOrCache) {
// this request is going to mem next (100)
memRequests[currReq->pid] = currReq;
} else {
// this request is going to cache (finished the last 2n, done)
// sanity check: this is the only place where request is set to done
currReq->done = true;
// unlock cache blocked over here.
}
if (currReq->pid == -2) {
removeCacheBlocked(currReq->address / wordsPerBlock, currReq->pid);
}
currReq = nullptr;
return;
}
}
// decrement memory accesses
for (int i = 0; i < memRequests.size(); i++) {
auto req = memRequests[i];
if (req == nullptr) continue;
req->countdown--;
if (req->countdown == 0) {
req->countdown = 2 * wordsPerBlock;
req->isToMemOrCache = false;
// this last 2n request is still tagged to the original processor in the bus map
busQueue.push(req);
// remove the request from memory, its now in the bus
memRequests[i] = nullptr;
}
}
}
void BusImplDragon::processBusRd(shared_ptr<Request> request) {
// need to check the line is shared
if (dragon_bus_debug) cout << "processing BusRd" << endl;
if (request->pid == -1) {
// countdown of passing through the bus only
request->countdown = 2 * wordsPerBlock;
request->isToMemOrCache = false;
trafficInBytes += 4 * wordsPerBlock;
return;
}
// check if any other processor has it in M state
// sanity check : if there exists the block in M state then they need to flush it
// otherwise, everyone who has the block MUST match memory. so 100 + 2n
bool isModified = false; // used to decide where the request goes
bool isShared = false; // used to decide the new state of the current processor
// check whether the line is shared
for (auto p : this->processors) {
// skip if the processor is the current processor
if (p->getPID() == request->pid) {
continue;
}
State pState = p->getState(request->address);
isShared |= (pState == M || pState == E || pState == Sm || pState == Sc);
}
for (auto p : this->processors) {
State pState = p->getState(request->address);
if (isShared) {
if (pState == M) {
p->setState(request->address, Sm);
} else if (pState == E) {
p->setState(request->address, Sc);
}
}
}
if (dragon_bus_debug) cout << "processingRd" << request->pid << endl;
State newState = isShared ? Sc : E;
if (newState == Sc) {
numShared++;
} else if (newState == E) {
numPrivate++;
}
processors[request->pid]->addCacheLine(request->address, newState);
if (isShared) { // for dragon, if its shared, it will be 2n else it will be 2n + 100
// this case is 2n
// this request is spending 2n on the bus, and then going to memory
request->countdown = 2 * wordsPerBlock;
request->isToMemOrCache = false;
trafficInBytes += 4 * wordsPerBlock;
} else {
// load from memory, this case is 100 + 2n
request->countdown = 100;
request->isToMemOrCache = false;
memRequests[request->pid] = request;
currReq = nullptr;
}
if (dragon_bus_debug) cout << "processingRd" << request->pid << endl;
}
void BusImplDragon::processBusUpd(shared_ptr<Request> request) {
if (dragon_bus_debug) cout << "processing BusUpd" << endl;
if (request->pid == -2) {
if (dragon_bus_debug) cout << "request does goes through here" << endl;
request->countdown = 2;
request->isToMemOrCache = false;
trafficInBytes += 4;
return;
}
// sanity check : if there exists the block in M state then they need to flush it
// otherwise, everyone who has the block MUST match memory. so 100 + 2n
bool isModified = false; // used to decide where the request goes
bool isShared = false; // used to decide the new state of the current processor
// check whether the line is shared
for (auto p : this->processors) {
// skip if the processor is the current processor
if (p->getPID() == request->pid) {
continue;
}
State pState = p->getState(request->address);
isShared |= (pState == M || pState == E || pState == Sm || pState == Sc);
}
// check for request pid
if (request->pid != -1 && request->pid != -2) { // this will be from the I state
for (auto p : this->processors) {
State pState = p->getState(request->address);
if (isShared) {
p->setState(request->address, M);
} else {
p->setState(request->address, Sm);
}
}
if (dragon_bus_debug) cout << "processingUpd " << request->pid << endl;
State newState = isShared ? Sm : M;
if (newState == Sm) {
numShared++;
} else if (newState == M) {
numPrivate++;
}
processors[request->pid]->addCacheLine(request->address, newState);
if (isShared) { //for dragon, if its shared, it will be 2n else it will be 2n + 100
// this case is 2n
// this request is spending 2n on the bus, and then going to memory
request->countdown = 2 * wordsPerBlock;
request->isToMemOrCache = false;
trafficInBytes += 4 * wordsPerBlock;
} else {
// load from memory, this case is 100 + 2n
request->countdown = 100;
request->isToMemOrCache = false;
memRequests[request->pid] = request;
currReq = nullptr;
}
} else { // sending message only
request->countdown = 2;
request->isToMemOrCache = false;
currReq = nullptr;
}
}
void BusImplDragon::processRequest(shared_ptr<Request> request) {
if (dragon_bus_debug) cout << "This is from the dragon child class" << endl;
if (!request->isToMemOrCache) return; // this is going back to cache, nothing to do
if (request->type == BusRd) {
processBusRd(request);
} else if (request->type == BusUpd) {
processBusUpd(request);
}
}
void BusImplDragon::updateOtherCachesToSc(unsigned int address, int pid) {
for (auto p : this->processors) {
// skip if the processor is the current processor
if (p->getPID() == pid) {
continue;
}
State pState = p->getState(address);
if (pState == Sm) {
p->setState(address, Sc);
}
}
}