Introduction
In the world of blockchain, Ethereum is a popular platform with its own programming language - Solidity. The Ethereum Virtual Machine (EVM) is a crucial component of the Ethereum platform as it allows the execution of smart contracts. In this article, we will delve deeper into the Ethereum Virtual Machine, its architecture, and how it works.
What is the Ethereum Virtual Machine (EVM)?
The Ethereum Virtual Machine (EVM) is a runtime environment that executes smart contracts on the Ethereum network. It is a sandboxed environment that ensures the security of the network by isolating the execution of smart contracts from the rest of the network. The EVM is responsible for executing code in a deterministic and secure manner.
Architecture of the Ethereum Virtual Machine
The Ethereum Virtual Machine is a stack-based architecture, which means that it uses a Last-In-First-Out (LIFO) data structure to store and retrieve data. The EVM is designed to be a platform-independent virtual machine, which means that it can run on any computer without any modification. The EVM has four main components:
Stack
The stack is a data structure used by the EVM to store and retrieve data. The stack operates on the LIFO principle, which means that the last item pushed onto the stack is the first item to be popped off the stack.
Memory
The memory is a byte array used by the EVM to store data during execution. The memory is a linear array of bytes that can be read from and written to during execution.
Storage
The storage is a key-value data store used by the EVM to store persistent data. The storage is similar to a database and can be read from and written to during execution. The storage is stored on the blockchain and is accessible to all nodes on the network.
Program Counter
The program counter is a register that keeps track of the current instruction being executed. The program counter is incremented after each instruction is executed, and the next instruction is fetched from memory.
How the Ethereum Virtual Machine works
The Ethereum Virtual Machine executes bytecode, which is generated by compiling smart contracts written in Solidity. The bytecode is then deployed to the Ethereum network and executed by the EVM. The following steps outline how the EVM executes smart contracts:
The contract is compiled into bytecode.
The bytecode is deployed to the Ethereum network.
The EVM receives the bytecode and executes it.
The EVM reads the bytecode instruction by instruction.
The EVM pushes and pops data onto and from the stack as required by the instructions.
The EVM stores and retrieves data from the memory as required by the instructions.
The EVM stores and retrieves data from the storage as required by the instructions.
The EVM updates the program counter after each instruction is executed.
The EVM stops execution when it reaches the end of the bytecode or encounters an error.
Benefits of the Ethereum Virtual Machine
The Ethereum Virtual Machine offers several benefits, including:
Decentralization
The EVM ensures the decentralization of the Ethereum network by allowing nodes to execute smart contracts in a secure and deterministic manner. The EVM ensures that the smart contracts are executed in the same way on all nodes on the network, which ensures the integrity of the network.
Security
The EVM is designed to be a sandboxed environment that ensures the security of the Ethereum network. The EVM ensures that the execution of smart contracts is isolated from the rest of the network, which prevents malicious actors from accessing or modifying the smart contracts.
Flexibility
The EVM is a platform-independent virtual machine that can run on any computer without any modification. This flexibility allows developers to write smart contracts in any programming language and deploy them to the Ethereum network.
How is data stored?
The Ethereum protocol uses two distinct data types – permanent data and ephemeral data. Permanent data, such as a transaction, is recorded in Ethereum’s tree-like data structure and will never be altered. Ephemeral data, such as a wallet’s balance, is recorded and changed in response to new transactions.
EVM’s opcodes use contract memory to retrieve data. Contract state memory is stored at the contract address and is not persistent. A variable’s position in a smart contract’s storage array is determined by its order in the code. If a given variable is 256 bits or less, the EVM will try to fit multiple variables in the space. When a contract inherits another contract, the storage variables of the base contract are stored in the first slots in the order of inheritance.
Whereas contract memory is impermanent, contract storage is stored indefinitely. Contract storage is like a public database where values can be read externally without the need to send a transaction. Still, contract storage is expensive compared to contract state memory.
Conclusion
The Ethereum Virtual Machine is a crucial component of the Ethereum platform that allows the execution of smart contracts. The EVM is a stack-based architecture that uses a Last-In-First-Out data structure to store and retrieve data. The EVM is designed to be a platform-independent virtual machine, which means that it can run on any computer without any modification. The EVM offers several benefits, including decentralization, security, and flexibility. The EVM is a powerful tool for developers looking to create decentralized applications on the Ethereum network. Understanding the architecture of the EVM, how it works, and its benefits is essential for anyone looking to develop on the Ethereum platform.