Cache Snooping Simulation

This project simulates a basic cache snooping protocol in a multiprocessor system. It demonstrates how multiple CPU cores with private caches interact with a shared memory through a bus, maintaining cache coherence.

Overview

• Memory.java: Represents the main memory as a map from addresses to data.
• CoreCache.java: Simulates a private cache for each core, storing cache lines as address-data pairs.
• Bus.java: Acts as the communication medium between caches and memory. It handles read and write transactions, checks caches for data, and updates memory and all caches on writes.

How It Works

1. Read Operation:

   • The bus checks all core caches for the requested address.
   • If found in any cache, it returns the cached data.
   • If not found, it reads from memory.

2. Write Operation:

   • The bus writes the data to memory.
   • It then updates all core caches with the new data for the given address, simulating a snooping protocol where all caches observe the write.

Example Usage

1. Create a Bus instance with a transaction ID, data, address, and operation ("READ" or "WRITE").
2. Add core caches to the bus using addCoreCaches(coreId).
3. Use checkOperation() to perform the transaction (read or write).

Notes

• This is a simplified simulation for educational purposes. It does not implement advanced cache coherence protocols (like MESI), but demonstrates the basic idea of snooping and cache updates.
• The simulation uses Long for addresses and byte[] for data, but can be adapted for other types.

Requirements

• Java 8 or higher

Compilation

Compile all Java files:

javac CacheSnooping/*.java