Add bitset field to cache.h for keeping track of write/validity

3 files changed, 31 insertions, 5 deletions

diff --git a/inc/cache.h b/inc/cache.h
index f1fb942..0c86e97 100644
--- a/inc/cache.h
+++ b/inc/cache.h
@@ -1,6 +1,9 @@
 #ifndef CACHE_H
 #define CACHE_H
-#include <storage.h>
+#include "definitions.h"
+#include "storage.h"
+#include <array>
+#include <bitset>
 
 class Cache : public Storage
 {
@@ -19,6 +22,15 @@ class Cache : public Storage
 
 	Response write(Accessor accessor, signed int data, int address) override;
 	Response read(Accessor accessor, int address) override;
+
+  private:
+	/**
+	 * An array of paired bits.
+	 * If the least significant bit of an element is set, the corresponding
+	 * element in `data` is invalid. If the most significant bit of an element
+	 * is set, the corresponding element in `data` is dirty.
+	 */
+	std::array<std::bitset<2>, L1_CACHE_SIZE> stat;
 };
 
 #endif /* CACHE_H_INCLUDED */
diff --git a/src/storage/cache.cc b/src/storage/cache.cc
index bbefb2a..bf1126a 100644
--- a/src/storage/cache.cc
+++ b/src/storage/cache.cc
@@ -6,17 +6,31 @@
 Cache::Cache(int lines, Storage *lower, int delay)
 {
 	this->data = new std::vector<std::array<signed int, LINE_SIZE>>;
-	this->data->resize(lines);
+	this->data->resize(L1_CACHE_SIZE);
 	this->lower = lower;
 	this->delay = delay;
-	this->lower = nullptr;
+	for (int i = 0; i < L1_CACHE_SIZE; ++i)
+		this->stat[i] = 0b01;
 }
 
 Cache::~Cache() { delete this->data; }
 
 Response Cache::write(Accessor accessor, signed int data, int address)
 {
-	return WAIT;
+	Response r = WAIT;
+
+	/* Do this first--then process the first cycle immediately. */
+	if (this->requester == IDLE)
+		this->requester = accessor;
+
+	if (this->requester == accessor) {
+		if (this->wait_time == 0) {
+			this->do_write(data, address);
+			r = OK;
+		}
+	}
+
+	return r;
 }
 
 Response Cache::read(Accessor accessor, int address) { return WAIT; }
diff --git a/src/utils/utils.cc b/src/utils/utils.cc
index b4bdb2f..52be177 100644
--- a/src/utils/utils.cc
+++ b/src/utils/utils.cc
@@ -1,5 +1,5 @@
-#include "definitions.h"
 #include "utils.h"
+#include "definitions.h"
 
 void get_bit_fields(int address, int *tag, int *index, int *offset)
 {