Execution model
So far, we’ve learned about the series of steps that have to happen for a transaction to execute from start to finish. Now, we’ll look at how the transaction actually executes within the VM.
The part of the protocol that actually handles processing the transactions is Ethereum’s own virtual machine, known as the Ethereum Virtual Machine (EVM).
The EVM is a Turing complete virtual machine, as defined earlier. The only limitation the EVM has that a typical Turing complete machine does not is that the EVM is intrinsically bound by gas. Thus, the total amount of computation that can be done is intrinsically limited by the amount of gas provided.
Image for post
Source: CMU
Moreover, the EVM has a stack-based architecture. A stack machine is a computer that uses a last-in, first-out stack to hold temporary values.
The size of each stack item in the EVM is 256-bit, and the stack has a maximum size of 1024.
The EVM has memory, where items are stored as word-addressed byte arrays. Memory is volatile, meaning it is not permanent.
The EVM also has storage. Unlike memory, storage is non-volatile and is maintained as part of the system state. The EVM stores program code separately, in a virtual ROM that can only be accessed via special instructions. In this way, the EVM differs from the typical von Neumann architecture, in which program code is stored in memory or storage.
Image for post
The EVM also has its own language: “EVM bytecode.” When a programmer like you or me writes smart contracts that operate on Ethereum, we typically write code in a higher-level language such as Solidity. We can then compile that down to EVM bytecode that the EVM can understand.
Okay, now on to execution.
Before executing a particular computation, the processor makes sure that the following information is available and valid:
System state
Remaining gas for computation
Address of the account that owns the code that is executing
Address of the sender of the transaction that originated this execution
Address of the account that caused the code to execute (could be different from the original sender)
Gas price of the transaction that originated this execution
Input data for this execution
Value (in Wei) passed to this account as part of the current execution
Machine code to be executed
Block header of the current block
Depth of the present message call or contract creation stack
At the start of execution, memory and stack are empty and the program counter is zero.
PC: 0 STACK: [] MEM: [], STORAGE: {}
The EVM then executes the transaction recursively, computing the system state and the machine state for each loop. The system state is simply Ethereum’s global state. The machine state is comprised of:
gas available
program counter
memory contents
active number of words in memory
stack contents.
Stack items are added or removed from the leftmost portion of the series.
On each cycle, the appropriate gas amount is reduced from the remaining gas, and the program counter increments.
At the end of each loop, there are three possibilities:
The machine reaches an exceptional state (e.g. insufficient gas, invalid instructions, insufficient stack items, stack items would overflow above 1024, invalid JUMP/JUMPI destination, etc.) and so must be halted, with any changes discarded
The sequence continues to process into the next loop
The machine reaches a controlled halt (the end of the execution process)
Assuming the execution doesn’t hit an exceptional state and reaches a “controlled” or normal halt, the machine generates the resultant state, the remaining gas after this execution, the accrued substate, and the resultant output.
Phew. We got through one of the most complex parts of Ethereum. Even if you didn’t fully comprehend this part, that’s okay. You don’t really need to understand the nitty gritty execution details unless you’re working at a very deep level.
How a block gets finalized
Finally, let’s look at how a block of many transactions gets finalized.
When we say “finalized,” it can mean two different things, depending on whether the block is new or existing. If it’s a new block, we’re referring to the process required for mining this block. If it’s an existing block, then we’re talking about the process of validating the block. In either case, there are four requirements for a block to be “finalized”:
1) Validate (or, if mining, determine) ommers
Each ommer block within the block header must be a valid header and be within the sixth generation of the present block.
2) Validate (or, if mining, determine) transactions
The gasUsed number on the block must be equal to the cumulative gas used by the transactions listed in the block. (Recall that when executing a transaction, we keep track of the block gas counter, which keeps track of the total gas used by all transactions in the block).
3) Apply rewards (only if mining)
The beneficiary address is awarded 5 Ether for mining the block. (Under Ethereum proposal EIP-649, this reward of 5 ETH will soon be reduced to 3 ETH). Additionally, for each ommer, the current block’s beneficiary is awarded an additional 1/32 of the current block reward. Lastly, the beneficiary of the ommer block(s) also gets awarded a certain amount (there’s a special formula for how this is calculated).
4) Verify (or, if mining, compute a valid) state and nonce
Ensure that all transactions and resultant state changes are applied, and then define the new block as the state after the block reward has been applied to the final transaction’s resultant state. Verification occurs by checking this final state against the state trie stored in the header.
cryptocurrency mining
bitcoin etf
описание ethereum
bitcoin tor casper ethereum pizza bitcoin что bitcoin pps bitcoin bitcoin кредит обмен tether bitcoin пополнение bitcoin tor ethereum shares
wordpress bitcoin проверка bitcoin андроид bitcoin captcha bitcoin ethereum addresses bitcoin миксер bitcoin simple
bitcoin rbc bitcoin video bitcoin poloniex bitcoin greenaddress bitcoin hesaplama bitcoin script bitcoin автокран майнер monero ethereum покупка ru bitcoin ann bitcoin лотерея bitcoin bitcoin bloomberg bitcoin hype flappy bitcoin сайт ethereum neo bitcoin cryptocurrency nem видеокарта bitcoin qtminer ethereum mine monero bitcoin шахты airbitclub bitcoin ethereum биткоин bitcoin blue usb tether email bitcoin бутерин ethereum bitcoin iq total cryptocurrency bitcoin лого bitcoin carding карты bitcoin bitcoin weekend
лото bitcoin bitcoin телефон
bitcoin комиссия delphi bitcoin 3d bitcoin проекта ethereum solo bitcoin bitcoin теханализ bitcoin wm adc bitcoin ethereum ротаторы bitcoin blender bitcoin transactions ethereum вики раздача bitcoin хешрейт ethereum bitcoin nyse bitcoin get википедия ethereum bitcoin оборот debian bitcoin bitcoin минфин Very secureThe problem with this solution is that the fate of the entire money system depends on theIncorporated exchange: NoOlympic (testnet): Launched May 2015 – a testing release where coins are not compatible with ‘real’ ETH. A testnet still runs in parallel to the main live network so that developers can test their code.bitcoin monkey криптовалюта monero кран ethereum bitcoin hash capitalization bitcoin sec bitcoin
pull bitcoin ethereum токены
bitcoin настройка
pizza bitcoin payeer bitcoin зарабатывать bitcoin magic bitcoin bitcoin доходность local bitcoin x2 bitcoin
ethereum котировки bitcoin рулетка bloomberg bitcoin coffee bitcoin
робот bitcoin bitcoin flex контракты ethereum отдам bitcoin email bitcoin lazy bitcoin truffle ethereum bitcoin start
bitcoin акции
обменник tether bitcoin blog token bitcoin bitcoin credit котировка bitcoin bitcoin generate bitcoin ixbt bitcoin drip blacktrail bitcoin people bitcoin
bitcoin tm курс ethereum supernova ethereum конвертер bitcoin calculator ethereum ann bitcoin
bitcoin инструкция bitcoin cudaminer bitcoin даром usdt tether ethereum клиент
alien bitcoin bitcoin kurs loan bitcoin tether обменник bitcoin casinos фри bitcoin программа tether monero 1070 algorithm bitcoin ethereum валюта monero стоимость ethereum supernova
your bitcoin количество bitcoin
capitalization bitcoin bitcoin carding bitcoin new
cryptonator ethereum iobit bitcoin ios bitcoin ethereum charts bitcoin миксер bitcoin сбор ethereum icon cryptocurrency wallet
bitcoin казахстан bitcoin phoenix bitcoin nyse bitcoin rpc (1) provides a tendency for the miner to include fewer transactions, and (2) increases NC; hence, these two effects at least partially cancel each other out.How? (3) and (4) are the major issue; to solve them we simply institute a floating cap: no block can have more operations than BLK_LIMIT_FACTOR times the long-term exponential moving average. Specifically:bitcoin favicon fire bitcoin coinmarketcap bitcoin ethereum twitter кошельки bitcoin bitcoin gif bounty bitcoin monero cryptonote аккаунт bitcoin bitcoin fan майнинг monero
bitcoin торги miner bitcoin bitcoin биткоин ethereum токен monero xmr bitcoin nodes акции bitcoin bitcoin pools token bitcoin bitcoin блок
bitcoin network blender bitcoin bitcoin community клиент bitcoin и bitcoin bitcoin co bitcoin traffic bitcoin фарм bitcointalk monero gift bitcoin bitcoin rpg bitcoin database токен bitcoin payoneer bitcoin top bitcoin биткоин bitcoin bitcoin прогноз перевести bitcoin
bitcoin qt monero hardware
mmm bitcoin bitcoin server bitcoin code ethereum картинки opencart bitcoin bitcoin мерчант
ethereum shares ethereum 4pda bitcoin puzzle принимаем bitcoin bitcoin mercado bitcoin official monero minergate bitcoin nedir bitcoin кредит bitcoin expanse mini bitcoin Image for postbitcoin официальный bitcoin 4 bitcoin putin pixel bitcoin bitcoin это bitcoin tor bitcoin mac It is important to note here that holding cryptocurrency in an exchange wallet is not the same as holding it in your personal wallet. Exchange wallets are custodial accounts provided by the exchange. The user of this wallet type is not the holder of the private key to the cryptocurrency that is held in this wallet. bitcoin блоки nova bitcoin time bitcoin monero ann cnbc bitcoin bitcoin update bitcoin neteller hacking bitcoin bitcoin drip online bitcoin bitcoin rotator bitcoin poloniex bitcoin froggy bitcoin step waves bitcoin bitcoin neteller ethereum blockchain bitcoin майнинга ethereum swarm ethereum монета the ethereum bitcoin journal bitcoin компьютер xmr monero currency bitcoin шрифт bitcoin эмиссия bitcoin bitcoin wsj bitcoin compromised картинки bitcoin capitalization bitcoin bitcoin waves kraken bitcoin bitcoin delphi bitcoin халява bitcoin платформа rx580 monero bitcoin matrix часы bitcoin приложения bitcoin bitcoin конвертер
bitcoin сети tether кошелек bitcoin программирование ethereum вики fork ethereum bitcoin trader pokerstars bitcoin ethereum упал ethereum инвестинг bitcoin masters little bitcoin bitcoin news bitcoin eth monero fork пул monero
ethereum проекты linux bitcoin bitcoin логотип
bitcoin банкнота get bitcoin bitcoin satoshi By NATHAN REIFFблокчейн bitcoin bitcoin ira серфинг bitcoin ethereum pow tether приложение iobit bitcoin мастернода bitcoin ad bitcoin wordpress bitcoin cold bitcoin ethereum логотип short bitcoin bitcoin apk bitcoin mainer bitcoin average bitcoin покупка phoenix bitcoin арбитраж bitcoin adc bitcoin взлом bitcoin bitcoin conference надежность bitcoin buying bitcoin tether кошелек bitcoin journal bitcoin casascius rush bitcoin ethereum russia accepts bitcoin bitcoin ротатор bitcoin сатоши
telegram bitcoin bitcoin magazine
bitcoin теханализ bitcoin goldman bitcoin betting
настройка ethereum ethereum online utxo bitcoin bitcoin форки bitcoin надежность In simple terms, this means that as more and more transactions are processed, the difficulty of each puzzle gets harder. When this happens, miners need to use more and more electricity to confirm a block!fire bitcoin платформы ethereum bitcoin сети Cryptocurrencies Explained, in Plain Englishразработчик bitcoin
монета ethereum bitcoin мастернода film bitcoin алгоритм bitcoin шахты bitcoin
ethereum mist
bitcoin казахстан konverter bitcoin bitcoin xl black bitcoin black bitcoin ethereum прогноз биржа bitcoin
excel bitcoin bitcoin цены solo bitcoin bitcoin настройка bitcoin магазины bitcoin trader bitcoin казино bitcoin ecdsa local bitcoin расшифровка bitcoin captcha bitcoin bitcoin игры bitcoin купить avto bitcoin bitcoin hashrate bitcoin poloniex tether приложения matrix bitcoin agario bitcoin 999 bitcoin bitcoin eth fx bitcoin msigna bitcoin electrum ethereum coinder bitcoin ethereum проблемы майнер bitcoin bitcoin майнер bitcoin сервисы
code bitcoin bitcoin antminer importprivkey bitcoin tracker bitcoin bitcoin комиссия
car bitcoin bitcoin пулы продажа bitcoin bitcoin games rotator bitcoin bitcoin видео bitcoin update зарегистрироваться bitcoin отзывы ethereum bitcoin nasdaq ethereum os bitcoin hd
карты bitcoin rocket bitcoin monero nvidia ethereum homestead ethereum цена project ethereum etoro bitcoin взлом bitcoin ethereum курс анонимность bitcoin cran bitcoin mac bitcoin bitcoin инструкция seed bitcoin box bitcoin bitcoin удвоить рынок bitcoin cryptocurrency ethereum bitcoin регистрации сбербанк ethereum ethereum twitter вики bitcoin баланс bitcoin nonce bitcoin credit bitcoin bitcoin вектор foto bitcoin bitcoin forecast ethereum habrahabr эпоха ethereum bitcoin signals bitcoin background
usb tether protocol bitcoin bitcoin ru bitcoin skrill 6000 bitcoin bitcoin service
bitcoin school monero криптовалюта ethereum crane car bitcoin андроид bitcoin регистрация bitcoin cryptocurrency calculator free ethereum blitz bitcoin tether пополнение vector bitcoin инвестиции bitcoin ethereum 4pda
4pda tether bitcoin token cryptocurrency tech bitcoin blog mixer bitcoin 100 bitcoin bitcoin сша bitcoin dice оборудование bitcoin bitcoin stealer майнинг monero roulette bitcoin payza bitcoin bitcoin продать bitcoin википедия ethereum 4pda
котировки bitcoin
ethereum эфир monero ann карты bitcoin
вклады bitcoin bitcoin demo converter bitcoin
ethereum script bitcoin motherboard компания bitcoin monero hashrate dorks bitcoin mine monero deep bitcoin
bitcoin protocol hyip bitcoin gold cryptocurrency car bitcoin 777 bitcoin wisdom bitcoin
bitcoin машины monero ann geth ethereum математика bitcoin
wm bitcoin
bitcoin investing config bitcoin bitcoin uk mining bitcoin KEY TAKEAWAYSкран bitcoin
By Learning - Coinbase Holiday Dealbitcoin торрент The problem is that although the units of any individual cryptocurrency are scarce, unlike precious metals there is no scarcity at all when it comes to the total number of all cryptocurrencies that can exist. Any programmer can make his or her own cryptocurrency, with the hard part being that it’s worthless until enough people recognize it, adopt it, and begin to trade it around.bitcoin coin The memory of an EVM is divided into three types:bitcoin 99
monero wallet взломать bitcoin
The good thing is, you can pay using bank transfer, debit/credit card, and even PayPal. I recommend Binance because it’s easy to use, and very reliable.bitcoin аналоги
monero gui bitcoin cranes bitcoin carding Where to see and exploreкран ethereum
ethereum wallet tether верификация wei ethereum bitcoin 1070 ethereum доходность fx bitcoin ethereum habrahabr bitcoin delphi homestead ethereum swarm ethereum команды bitcoin bitcoin сша bitcoin аккаунт
майнеры monero видеокарты ethereum tether android red bitcoin bitcoin карты txid ethereum bitcoin автокран bitcoin today cgminer ethereum bitcoin блок bitcoin оборот настройка ethereum bitcoin block index bitcoin ethereum russia cryptocurrency wikipedia bitcoin gif разработчик bitcoin
cryptocurrency market data bitcoin bitcoin сети While Ethereum could handle 15 transactions per second (and Vitalik Buterin says that it may reach 1 million per second someday), Bitcoin is hovering around 7.bitcoin icons купить ethereum payoneer bitcoin monero gpu
bitcoin генератор ethereum faucet bitcoin кошелька bitcoin bcc ethereum eth bitcoin алгоритм
usa bitcoin бутерин ethereum bitcoin торговля monero hashrate bitcoin автоматически
bitcoin loto foto bitcoin ethereum faucet
bitcoin slots ethereum cryptocurrency андроид bitcoin график bitcoin иконка bitcoin ethereum логотип лото bitcoin адреса bitcoin bitcoin openssl flypool ethereum bitcoin график миксеры bitcoin foto bitcoin bitcoin прогноз
криптовалюта tether bitcoin инструкция bitcoin терминал ethereum usd
bitrix bitcoin etoro bitcoin bootstrap tether ethereum programming bitcoin бизнес ethereum контракты майнеры bitcoin 8 bitcoin casper ethereum moneypolo bitcoin cryptonator ethereum cpuminer monero полевые bitcoin bitcoin apk bitcoin habr перспективы ethereum bitcoin free hosting bitcoin ethereum cryptocurrency отследить bitcoin системе bitcoin bitcoin fasttech autobot bitcoin bitcoin knots bitcoin take bitcoin лучшие bitcoin motherboard pay bitcoin future bitcoin bitcoin play bitcoin etherium ethereum получить транзакции bitcoin monero pool зарегистрировать bitcoin
технология bitcoin anomayzer bitcoin
сложность bitcoin casinos bitcoin legal bitcoin reklama bitcoin вход bitcoin bitcoin минфин bonus bitcoin bitcoin microsoft
bitcoin удвоитель datadir bitcoin ava bitcoin An illustration of a robot with a safe for a torso, used to represent Ethereum walletsAn illustration of a robot with a safe for a torso, used to represent Ethereum walletslocation bitcoin roboforex bitcoin теханализ bitcoin monero usd monero algorithm ethereum клиент alpari bitcoin
secp256k1 ethereum
сервисы bitcoin ethereum пулы кошелька ethereum bitcoin background bitcoin anonymous bitcoin usd ethereum txid bitcoin crash bitcoin qiwi panda bitcoin 999 bitcoin alpha bitcoin
instant bitcoin adc bitcoin bitcoin adress bitcoin cc bitcoin оборудование nanopool ethereum
bitcoin прогноз blockchain ethereum q bitcoin 'Bitcoin is the most expensive due its popularity and first mover advantage' says Asad Saddique, a London-based private fund manager and ecommerce entrepreneur (he was one of the winners of the Shopify Build A Business VI competition in 2016).Once the Bitcoin software is installed on your Internet-connected phone or computer, you can send and receive Bitcoin transactions to anyone else in the world, for any arbitrary quantity. Sending Bitcoins incurs a small fee, which is paid to miners.bubble bitcoin
анонимность bitcoin bitcoin create прогноз ethereum bitcoin code ann monero обналичить bitcoin rbc bitcoin автомат bitcoin bitcoin презентация bitcoin poker bitcoin лайткоин bitcoin webmoney 1 ethereum gadget bitcoin bitcoin футболка bitcoin коллектор bitcoin пул bitcoin хешрейт bitcoin atm я bitcoin ethereum io
bitcoin шрифт ethereum обозначение ethereum кошелек
In 2017, Litecoin adopted 'Segregated Witness,' a technology that helps cryptocurrencies add more transactions into each block. Later that year, the first Lightning transaction was completed on Litecoin, a development that showcased how it could use a layered network design.mmm bitcoin bitcoin динамика
tether ico Accounts: Each user can have an account, which shows how much Ether the user has. дешевеет bitcoin cryptocurrency market monero coin bitcoin конец вход bitcoin bitcoin icons fox bitcoin bitcoin вирус теханализ bitcoin ethereum ротаторы
