Move do_write to dram.h, is_blocked flag

6 files changed, 39 insertions, 15 deletions

diff --git a/inc/cache.h b/inc/cache.h
index 4e4b48d..a317f5d 100644
--- a/inc/cache.h
+++ b/inc/cache.h
@@ -28,6 +28,13 @@ class Cache : public Storage
 
   private:
 	/**
+	 * Fetches `address` from a lower level of storage if it is not already
+	 * present. If it is not, temporarily sets the is_blocked attribute of this
+	 * cache level to true.
+	 * @param the address that must be present in cache.
+	 */
+	void fetch_resource(int address);
+	/**
 	 * 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
diff --git a/inc/dram.h b/inc/dram.h
index 1061d6b..20221b7 100644
--- a/inc/dram.h
+++ b/inc/dram.h
@@ -19,7 +19,15 @@ class Dram : public Storage
 	Response read(Accessor accessor, int address, std::array<signed int, LINE_SIZE>& data) override;
 
 	private:
+	/**
+	 * Helper for `write`.
+	 */
+	void do_write(signed int, int);
+	/**
+	 * Helper for `read`.
+	 */
 	void do_read(std::array<signed int, LINE_SIZE>& data_line, int address);
 };
 
 #endif /* DRAM_H_INCLUDED */
+
diff --git a/inc/storage.h b/inc/storage.h
index 1fb41b0..9707041 100644
--- a/inc/storage.h
+++ b/inc/storage.h
@@ -32,7 +32,10 @@ class Storage
 	 * @return a status code reflecting the state of the request, and the
 	 * data being returned.
 	 */
-	virtual Response read(Accessor accessor, int address, std::array<signed int, LINE_SIZE>& data) = 0;
+	virtual Response read(
+		Accessor accessor,
+		int address,
+		std::array<signed int, LINE_SIZE> &data) = 0;
 	/**
 	 * Sidedoor view of `lines` of memory starting at `base`.
 	 * @param The base line to start getting memory from.
@@ -48,10 +51,6 @@ class Storage
 
   protected:
 	/**
-	 * Helper for `write`.
-	 */
-	void do_write(signed int, int);
-	/**
 	 * The data currently stored in this level of storage.
 	 */
 	std::vector<std::array<signed int, LINE_SIZE>> *data;
@@ -73,6 +72,11 @@ class Storage
 	 * The number of cycles until the current request is completed.
 	 */
 	int wait_time;
+	/**
+	 * A flag indicating whether this level of storage is currently blocked by a
+	 * lower level.
+	 */
+	int is_blocked;
 };
 
 #endif /* STORAGE_H_INCLUDED */
diff --git a/src/storage/cache.cc b/src/storage/cache.cc
index cf954b0..e0eaf58 100644
--- a/src/storage/cache.cc
+++ b/src/storage/cache.cc
@@ -24,8 +24,9 @@ Response Cache::write(Accessor accessor, signed int data, int address)
 		this->requester = accessor;
 
 	if (this->requester == accessor) {
+		fetch_resource(address);
 		if (this->wait_time == 0) {
-			this->do_write(data, address);
+			// this->do_write(data, address);
 			r = OK;
 		}
 	}
@@ -34,3 +35,7 @@ Response Cache::write(Accessor accessor, signed int data, int address)
 }
 
 Response Cache::read(Accessor accessor, int address, std::array<signed int, LINE_SIZE>& data) { return WAIT; }
+
+void Cache::fetch_resource(int address) {
+
+}
diff --git a/src/storage/dram.cc b/src/storage/dram.cc
index 0db4c35..e3f3c9a 100644
--- a/src/storage/dram.cc
+++ b/src/storage/dram.cc
@@ -15,6 +15,14 @@ Dram::Dram(int lines, int delay)
 
 Dram::~Dram() { delete this->data; }
 
+void Dram::do_write(signed data, int address)
+{
+	int line = address / LINE_SIZE;
+	int word = address % LINE_SIZE;
+
+	this->data->at(line).at(word) = data;
+}
+
 Response Dram::write(Accessor accessor, signed int data, int address)
 {
 	Response r = WAIT;
diff --git a/src/storage/storage.cc b/src/storage/storage.cc
index e3067a2..f382b3e 100644
--- a/src/storage/storage.cc
+++ b/src/storage/storage.cc
@@ -13,20 +13,12 @@ Storage::view(int base, int lines)
 	return ret;
 }
 
-void Storage::do_write(signed data, int address)
-{
-	int line = address / LINE_SIZE;
-	int word = address % LINE_SIZE;
-
-	this->data->at(line).at(word) = data;
-}
-
 void Storage::resolve()
 {
 	if (this->wait_time == 0) {
 		this->requester = IDLE;
 		this->wait_time = delay;
-	} else if (this->requester != IDLE) {
+	} else if (this->requester != IDLE && !this->is_blocked) {
 		--this->wait_time;
 	}
 }