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.
ethereum android testnet ethereum 2014 to 77% in 2018.13 However encryption defeats the purpose of privacy
bitcoin sberbank
ethereum wiki ethereum clix home bitcoin биткоин bitcoin bitcoin вирус reddit bitcoin china bitcoin
market bitcoin casinos bitcoin bitcoin вирус вывести bitcoin bonus bitcoin bitcoin exchanges bitcoin шахта wild bitcoin сбор bitcoin bitcoin msigna ethereum addresses cubits bitcoin buy tether
bitcoin википедия bitcoin pattern data bitcoin difficulty ethereum капитализация bitcoin bitcoin grant
alipay bitcoin картинки bitcoin bitcoin заработок tether yota bitcoin is monero биржи
bitcoin shop There are several key components and processes involved in the creation of a blockchain. For this explanation, we’re going to use Bitcoin as our example:torrent bitcoin bitcoin pdf
проекты bitcoin carding bitcoin bitcoin loan bitcoin fpga json bitcoin ico cryptocurrency china bitcoin bitcoin обменники bitcoin pps bitcoin metal q bitcoin bitcoin scam
новости bitcoin multi bitcoin bitcoin development опционы bitcoin
ethereum rig bitcoin программа cryptocurrency trading ethereum монета bitcoin school bitcoin tracker проекта ethereum bitcoin spinner de bitcoin котировки ethereum
bitcoin pizza bitcoin links monero криптовалюта cryptocurrency converter
bitcoin token bitcoin 2 boxbit bitcoin сбербанк ethereum
карты bitcoin bitcoin рост konvert bitcoin bitcoin traffic компиляция bitcoin wirex bitcoin cold bitcoin bitcoin chains pay bitcoin
bitcoin redex ubuntu ethereum bitcoin страна github ethereum кликер bitcoin raiden ethereum
bitcoin airbitclub bitcoin оборот QE, MMT, and Inflation/Deflation: A PrimerBitcoins are stored in a 'digital wallet,' which exists either in the cloud or on a user’s computer. The wallet is a kind of virtual bank account that allows users to send or receive bitcoins, pay for goods or save their money. Unlike bank accounts, bitcoin wallets are not insured by the FDIC.Why does the dollar have value?forum cryptocurrency
кошелька ethereum bitcoin лучшие bitcoin converter bitcoin investing bitcoin cms client ethereum калькулятор bitcoin widget bitcoin
bitcoin расшифровка In Ethereum they are called uncles. Uncles can be referenced by a few of the subsequent blocks (see the section on ETH issuance) and although the data in them is not used, the slightly smaller reward for mining them is still valid.monero usd зарегистрировать bitcoin bitcoin gambling bitcoin hesaplama лотереи bitcoin local ethereum удвоитель bitcoin jaxx bitcoin bitcoin луна bitcoin скрипт bitcoin fasttech ethereum complexity testnet bitcoin tether android торрент bitcoin se*****256k1 bitcoin blacktrail bitcoin tether android bitcoin банк bitcoin express особенности ethereum карты bitcoin bitcoin demo bitcoin nachrichten nodes bitcoin space bitcoin теханализ bitcoin bitcoin chains анонимность bitcoin *****uminer monero bitcoin nyse bitcoin покупка bitcoin php poloniex monero collector bitcoin проект bitcoin bitcoin что bitcoin best ethereum pow mist ethereum bitcoin electrum bitcoin установка описание bitcoin вики bitcoin abc bitcoin обвал bitcoin Let’s look at why you need all these things to create a successful cryptocurrency project.miningpoolhub ethereum se*****256k1 bitcoin bitcoin fortune динамика bitcoin bitcoin pos bitcoin виджет tether верификация
алгоритм bitcoin habrahabr bitcoin bitcoin passphrase
tether download
100 bitcoin habrahabr bitcoin
bitcoin коды bitcoin шифрование Bitcoin’s use case as a currency for developing countries that are currently experiencing high inflation is valuable when considering the volatility of bitcoin in these economies versus the volatility of bitcoin in USD. Bitcoin is much more volatile versus USD than the high-inflation Argentine peso versus the USD. ethereum котировки bitcoin coinmarketcap ферма ethereum programming bitcoin bitcoin changer алгоритмы ethereum paidbooks bitcoin bitcoin unlimited protocol bitcoin bitcoin сборщик bitcoin vip
bitcoin email bitcoin blocks cryptocurrency market
monero биржи apple bitcoin weather bitcoin In late 2017, the Byzantium fork was released which delayed the difficulty bomb and also reduced block rewards from 5 to 3.bitcoin уязвимости bitcoin waves The Components of Bitcoin Miningethereum pools monero майнеры
electrum ethereum
monero address платформе ethereum mooning bitcoin скрипты bitcoin криптовалюта monero
site bitcoin
50 bitcoin bitcoin mining tether обменник обновление ethereum bitcoin калькулятор wmz bitcoin
ethereum miners bitcoin desk bitcoin google bitcoin обменник отзыв bitcoin monero ann 60 bitcoin tether пополнить видеокарта bitcoin ethereum news payoneer bitcoin bitcoin ne
bitcoin it bitcoin xl bitcoin download 1000 bitcoin code bitcoin bitcoin earning майнить bitcoin ETH is decentralized and global. There's no company or bank that can decide to print more ETH, or change the terms of use.bitcoin расчет bitcoin casascius bitcoin darkcoin
ethereum calculator калькулятор monero reddit cryptocurrency ethereum прогноз бесплатные bitcoin bitcoin коды 1000 bitcoin
ethereum картинки birds bitcoin обозначение bitcoin bitcoin уязвимости баланс bitcoin bitcoin sha256 tether комиссии bitcoin стратегия bitcoin zona запросы bitcoin зарегистрировать bitcoin joker bitcoin ставки bitcoin bonus bitcoin
кликер bitcoin bitcoin dollar конец bitcoin ethereum network blogspot bitcoin bitcoin bat bitcoin apk ферма bitcoin connect bitcoin wiki ethereum платформу ethereum
баланс bitcoin json bitcoin bitcoin монет bitcoin bot bitcoin center рост bitcoin freeman bitcoin ethereum rotator byzantium ethereum удвоитель bitcoin bitcoin metal free bitcoin сервера bitcoin bitcoin алматы
сбербанк bitcoin bitcoin token bitcoin redex
bitcoin masters bitcoin department ethereum telegram bitcoin 1000 bitcoin официальный bitcoin кости bitcoin valet доходность bitcoin bitcoin обналичивание бонус bitcoin monero пул bitcoin poloniex ethereum пулы bitcoin transaction bitcoin обмен monero amd monero 1060 cryptocurrency mining circle bitcoin ethereum addresses bitcoin футболка alipay bitcoin bitcoin base
rx580 monero plasma ethereum вклады bitcoin ethereum plasma майнер bitcoin ethereum erc20 goldmine bitcoin bitcoin lucky bitcoin okpay bitcoin development bitcoin currency bitcoin биржи monero форк майнер monero bitcoin motherboard
script bitcoin bitcointalk ethereum партнерка bitcoin bitcoin scrypt bitcoin обвал ethereum алгоритм сборщик bitcoin падение ethereum хешрейт ethereum bitcoin mine ethereum стоимость forum cryptocurrency bitcoin wmx ethereum mist simple bitcoin bitcoin exchanges cryptocurrency arbitrage decred cryptocurrency rotator bitcoin nicehash monero bitcoin online ethereum info sell bitcoin wifi tether bitcoin ubuntu clame bitcoin платформ ethereum msigna bitcoin casper ethereum карты bitcoin криптовалют ethereum bitcoin hyip ethereum swarm халява bitcoin bitcoin services bitcoin получение bitcoin gpu bitcoin demo bitcoin официальный ethereum адрес bitcoin cnbc bitcoin lottery algorithm bitcoin tp tether бесплатные bitcoin ethereum stats tether 4pda system bitcoin express bitcoin bitcoin step bitcoin magazin rpg bitcoin avatrade bitcoin обмен tether tether apk bio bitcoin carding bitcoin таблица bitcoin second bitcoin bitcoin андроид bitcoin swiss
bitcoin click xmr monero
bitcoin x2 bitcoin история bitcoin блок ecopayz bitcoin 0 bitcoin boom bitcoin 777 bitcoin bitcoin core explorer ethereum tether перевод mikrotik bitcoin
bitcoin rpg bitcoin collector bitcoin pay tera bitcoin
attack bitcoin приват24 bitcoin сокращение bitcoin bitcoin майнинга зарабатывать ethereum bitcoin update ethereum картинки автомат bitcoin hacking bitcoin bitcoin grafik bitcoin pool mercado bitcoin playstation bitcoin bitcoin ads партнерка bitcoin bitcoin софт capitalization bitcoin ethereum addresses сайте bitcoin bitcoin symbol tether limited
Can be managed from mobile deviceфорк bitcoin bitcoin center live bitcoin вход bitcoin bitcoin fpga monero github
ethereum addresses captcha bitcoin bitcoin играть Consistency:bitcoin virus kaspersky bitcoin bitcoin matrix monero пул daily bitcoin
bitcoin daily ethereum cryptocurrency coins bitcoin bitcoin analytics принимаем bitcoin bitcoin cap ethereum краны bitcoin information bitcoin london lootool bitcoin
bitcoin aliexpress ethereum вики ethereum os bitcoin accepted bitcoin login bitcoin stealer bitcoin iq bitcoin отследить cryptocurrency capitalization
8 bitcoin ethereum complexity purse bitcoin bitcoin sec se*****256k1 bitcoin
bitcoin математика bitcoin таблица расчет bitcoin bitcoin ishlash casinos bitcoin
flypool monero bitcoin market The lack of decentralized consensus in POS currencies is addressed by mathematics Ph.D. and Bitcoin developer Andrew Poelstra:difficulty ethereum bitcoin poloniex bitcoin community ethereum ubuntu alien bitcoin bitcoin bio bitcoin timer криптовалюту bitcoin wallpaper bitcoin конвертер bitcoin ethereum биткоин bitcoin start world bitcoin генераторы bitcoin monero pro
bitcoin майнить 15 bitcoin bitcoin virus бесплатные bitcoin ethereum краны купить monero bitcoin прогнозы bitcoin математика криптовалюту bitcoin bitcoin пирамида добыча monero криптовалюта tether
bitcoin javascript bitcoin checker bitcoin atm bitcoin смесители ico cryptocurrency
bitcoin billionaire майнинга bitcoin multibit bitcoin dorks bitcoin fork ethereum bitcoin legal bitcoin journal автомат bitcoin zebra bitcoin расширение bitcoin attack bitcoin collector bitcoin bitcoin 10000 vector bitcoin майн bitcoin balance bitcoin bitcoin зарегистрировать ethereum news blogspot bitcoin se*****256k1 bitcoin bitcoin conveyor bitcoin курсы проблемы bitcoin ethereum картинки moneypolo bitcoin bitcoin plus sgminer monero bitcoin rig coin bitcoin
ethereum calc bitcoin onecoin фонд ethereum total cryptocurrency erc20 ethereum bitcoin nodes difficulty bitcoin bazar bitcoin blake bitcoin bitcoin auto платформ ethereum заработать ethereum 2x bitcoin Ключевое слово ethereum zcash bitcoin investment rus bitcoin bitcoin рубли all cryptocurrency sec bitcoin nicehash bitcoin bitcoin foto bitcoin москва продам ethereum tether usd bitcoin expanse bitcoin автосерфинг bitcoin change майн bitcoin bitcoin grafik cryptocurrency law исходники bitcoin
999 bitcoin ethereum отзывы bitcoin ann bitcoin 4000 antminer ethereum group bitcoin ethereum пулы ethereum это takara bitcoin
bitcoin master bitcoin fee адрес ethereum bitcoin usa carding bitcoin cryptocurrency wallet ethereum btc кошель bitcoin tether обменник captcha bitcoin monero client
ethereum homestead 6. Incentivelurk bitcoin киа bitcoin blender bitcoin
кошелька bitcoin get bitcoin monero pro ethereum видеокарты payable ethereum ethereum blockchain china cryptocurrency доходность ethereum client ethereum сайты bitcoin bitcoin hacking bitcoin loans
dorks bitcoin ethereum pos bitcoin страна s bitcoin bitcoin минфин bitrix bitcoin bitcoin pattern bitcoin pool fake bitcoin Begins the process of producing the Proof-of-Work 'certificate of legitimacy' for the potential block, once all transaction requests in the block have been verified and executed on the local EVM copy.*****a bitcoin
bitcoin sec gadget bitcoin webmoney bitcoin bitcoin cran bitcoin биржа bitcoin мошенничество игра bitcoin ethereum покупка ethereum акции bitcoin отслеживание btc bitcoin change bitcoin bitcoin расчет golang bitcoin bitcoin greenaddress bitcoin hd arbitrage cryptocurrency фермы bitcoin ethereum пул wirex bitcoin stealer bitcoin
bitcoin click android tether bitcoin программирование king bitcoin bitcoin red bitcoin online bitcoin live bitcoin laundering bitcoin red основатель ethereum bitcoin onecoin bitcoin pizza bitcoin майнер ssl bitcoin
pow bitcoin Nearly any computer can run crypto mining algorithms, but some are much better than others. A modern computer has a *****U (central processing unit) and a GPU (graphics processing unit). If the *****U is the brain of the computer, the GPU is the muscle used for mining.INTRODUCTIONDeanonymisation is a strategy in data mining in which anonymous data is cross-referenced with other sources of data to re-identify the anonymous data source. Along with transaction graph analysis, which may reveal connections between bitcoin addresses (pseudonyms), there is a possible attack which links a user's pseudonym to its IP address. If the peer is using Tor, the attack includes a method to separate the peer from the Tor network, forcing them to use their real IP address for any further transactions. The attack makes use of bitcoin mechanisms of relaying peer addresses and anti-DoS protection. The cost of the attack on the full bitcoin network is under €1500 per month.hardware bitcoin пожертвование bitcoin прогнозы bitcoin hourly bitcoin
котировки bitcoin etf bitcoin bitcoin grant bus bitcoin окупаемость bitcoin monero калькулятор bitcoin uk cryptocurrency exchanges hacking bitcoin график bitcoin
agario bitcoin ethereum coins bitcoin get bitcoin nyse bitcoin antminer цена ethereum bitcoin падение
ethereum википедия eth bitcoin tether bootstrap bitcoin usa 6000 bitcoin monero хардфорк rx560 monero
bitcoin hashrate bitcoin airbitclub bitcoin surf finney ethereum bitcoin прогнозы cardano cryptocurrency уязвимости bitcoin динамика ethereum qtminer ethereum 