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#include "cache.h"
#include "definitions.h"
#include "response.h"
#include "utils.h"
#include <bits/stdc++.h>
Cache::Cache(Storage *lower, int delay)
{
this->data = new std::vector<std::array<signed int, LINE_SIZE>>;
this->data->resize(L1_CACHE_SIZE);
this->delay = delay;
this->is_waiting = false;
this->lower = lower;
this->meta.fill({-1, -1});
this->requester = IDLE;
this->wait_time = this->delay;
}
Cache::~Cache() { delete this->data; }
Response Cache::write(Accessor accessor, signed int data, int address)
{
Response r = WAIT;
/* Do this first--then process the first cycle immediately. */
if (this->requester == IDLE)
this->requester = accessor;
if (this->requester == accessor) {
fetch_resource(address);
if (this->is_waiting)
r = BLOCKED;
else if (this->wait_time == 0) {
int tag, index, offset;
get_bit_fields(address, &tag, &index, &offset);
this->data->at(index).at(offset) = data;
this->meta[index].at(1) = 1;
r = OK;
}
}
return r;
}
Response Cache::read(
Accessor accessor, int address, std::array<signed int, LINE_SIZE> &data)
{
return WAIT;
}
void Cache::fetch_resource(int expected)
{
Response r = OK;
int tag, index, offset;
std::array<signed int, LINE_SIZE> actual;
std::array<int, 2> *meta;
get_bit_fields(expected, &tag, &index, &offset);
meta = &this->meta.at(index);
if (meta->at(0) != tag) {
// address not in cache
if (meta->at(1) >= 0) {
// occupant is dirty
// TODO
r = WAIT;
} else {
actual = this->data->at(index);
r = this->lower->read(L1CACHE, expected, actual);
if (r == OK) {
meta->at(0) = tag;
meta->at(1) = -1;
}
}
}
this->is_waiting = (r == OK) ? false : true;
}
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