Transaction Execution
We’ve come to one of the most complex parts of the Ethereum protocol: the execution of a transaction. Say you send a transaction off into the Ethereum network to be processed. What happens to transition the state of Ethereum to include your transaction?
Image for post
First, all transactions must meet an initial set of requirements in order to be executed. These include:
The transaction must be a properly formatted RLP. “RLP” stands for “Recursive Length Prefix” and is a data format used to encode nested arrays of binary data. RLP is the format Ethereum uses to serialize objects.
Valid transaction signature.
Valid transaction nonce. Recall that the nonce of an account is the count of transactions sent from that account. To be valid, a transaction nonce must be equal to the sender account’s nonce.
The transaction’s gas limit must be equal to or greater than the intrinsic gas used by the transaction. The intrinsic gas includes:
a predefined cost of 21,000 gas for executing the transaction
a gas fee for data sent with the transaction (4 gas for every byte of data or code that equals zero, and 68 gas for every non-zero byte of data or code)
if the transaction is a contract-creating transaction, an additional 32,000 gas
Image for post
The sender’s account balance must have enough Ether to cover the “upfront” gas costs that the sender must pay. The calculation for the upfront gas cost is simple: First, the transaction’s gas limit is multiplied by the transaction’s gas price to determine the maximum gas cost. Then, this maximum cost is added to the total value being transferred from the sender to the recipient.
Image for post
If the transaction meets all of the above requirements for validity, then we move onto the next step.
First, we deduct the upfront cost of execution from the sender’s balance, and increase the nonce of the sender’s account by 1 to account for the current transaction. At this point, we can calculate the gas remaining as the total gas limit for the transaction minus the intrinsic gas used.
Image for post
Next, the transaction starts executing. Throughout the execution of a transaction, Ethereum keeps track of the “substate.” This substate is a way to record information accrued during the transaction that will be needed immediately after the transaction completes. Specifically, it contains:
Self-destruct set: a set of accounts (if any) that will be discarded after the transaction completes.
Log series: archived and indexable checkpoints of the virtual machine’s code execution.
Refund balance: the amount to be refunded to the sender account after the transaction. Remember how we mentioned that storage in Ethereum costs money, and that a sender is refunded for clearing up storage? Ethereum keeps track of this using a refund counter. The refund counter starts at zero and increments every time the contract deletes something in storage.
Next, the various computations required by the transaction are processed.
Once all the steps required by the transaction have been processed, and assuming there is no invalid state, the state is finalized by determining the amount of unused gas to be refunded to the sender. In addition to the unused gas, the sender is also refunded some allowance from the “refund balance” that we described above.
Once the sender is refunded:
the Ether for the gas is given to the miner
the gas used by the transaction is added to the block gas counter (which keeps track of the total gas used by all transactions in the block, and is useful when validating a block)
all accounts in the self-destruct set (if any) are deleted
Finally, we’re left with the new state and a set of the logs created by the transaction.
Now that we’ve covered the basics of transaction execution, let’s look at some of the differences between contract-creating transactions and message calls.
Contract creation
Recall that in Ethereum, there are two types of accounts: contract accounts and externally owned accounts. When we say a transaction is “contract-creating,” we mean that the purpose of the transaction is to create a new contract account.
In order to create a new contract account, we first declare the address of the new account using a special formula. Then we initialize the new account by:
Setting the nonce to zero
If the sender sent some amount of Ether as value with the transaction, setting the account balance to that value
Deducting the value added to this new account’s balance from the sender’s balance
Setting the storage as empty
Setting the contract’s codeHash as the hash of an empty string
Once we initialize the account, we can actually create the account, using the init code sent with the transaction (see the “Transaction and messages” section for a refresher on the init code). What happens during the execution of this init code is varied. Depending on the constructor of the contract, it might update the account’s storage, create other contract accounts, make other message calls, etc.
As the code to initialize a contract is executed, it uses gas. The transaction is not allowed to use up more gas than the remaining gas. If it does, the execution will hit an out-of-gas (OOG) exception and exit. If the transaction exits due to an out-of-gas exception, then the state is reverted to the point immediately prior to transaction. The sender is not refunded the gas that was spent before running out.
Boo hoo.
However, if the sender sent any Ether value with the transaction, the Ether value will be refunded even if the contract creation fails. Phew!
If the initialization code executes successfully, a final contract-creation cost is paid. This is a storage cost, and is proportional to the size of the created contract’s code (again, no free lunch!) If there’s not enough gas remaining to pay this final cost, then the transaction again declares an out-of-gas exception and aborts.
If all goes well and we make it this far without exceptions, then any remaining unused gas is refunded to the original sender of the transaction, and the altered state is now allowed to persist!
Hooray!
Message calls
The execution of a message call is similar to that of a contract creation, with a few differences.
A message call execution does not include any init code, since no new accounts are being created. However, it can contain input data, if this data was provided by the transaction sender. Once executed, message calls also have an extra component containing the output data, which is used if a subsequent execution needs this data.
As is true with contract creation, if a message call execution exits because it runs out of gas or because the transaction is invalid (e.g. stack overflow, invalid jump destination, or invalid instruction), none of the gas used is refunded to the original caller. Instead, all of the remaining unused gas is consumed, and the state is reset to the point immediately prior to balance transfer.
Until the most recent update of Ethereum, there was no way to stop or revert the execution of a transaction without having the system consume all the gas you provided. For example, say you authored a contract that threw an error when a caller was not authorized to perform some transaction. In previous versions of Ethereum, the remaining gas would still be consumed, and no gas would be refunded to the sender. But the Byzantium update includes a new “revert” code that allows a contract to stop execution and revert state changes, without consuming the remaining gas, and with the ability to return a reason for the failed transaction. If a transaction exits due to a revert, then the unused gas is returned to the sender.
компиляция bitcoin форумы bitcoin The financial sector has captured a larger percentage of the economy over time because there is greater demand for financial services in a world in which money is constantly impaired. Stocks, corporate bonds, treasuries, sovereign bonds, mutual funds, equity ETFs, bond ETFs, levered ETFs, triple levered ETFs, fractional shares, mortgage-backed securities, CDOs, CLOs, CDS, CDX, synthetic CDS/CDX, etc. All of these products represent the financialization of the economy, and they become more relevant (and in greater demand) when the monetary function is broken.lucky bitcoin криптовалюту monero bitcoin code bitcoin price
анонимность bitcoin
bitcoin json пицца bitcoin bitcoin сбор to bitcoin bitcoin 4096
кран ethereum
bitcoin alien exchange cryptocurrency оплатить bitcoin weather bitcoin bitcoin anonymous bitcoin eth зарегистрироваться bitcoin cryptonator ethereum invest bitcoin tails bitcoin playstation bitcoin rate bitcoin free bitcoin bitcoin database sun bitcoin ethereum serpent To understand more about Ethereum, let’s take a little look at some of Ethereum’s history.bitcoin заработка bitcoin space
When people started mining Litecoin in 2011, it was possible to buy GPUs to help do this. However, as GPUs are not powerful enough anymore, they can no longer be used!Litecoin ValueElliptic Curve Diffie-Hellman-Merkle (ECDHM) addresses are bitcoin address schemes that increase privacy. ECDHM addresses can be shared publicly and are used by senders and receivers to secretly derive traditional Bitcoin addresses that blockchain observers cannot predict. The result is that ECDHM addresses can be 'reused' without the loss of privacy that usually occurs from traditional Bitcoin address reuse.raspberry bitcoin pull bitcoin автосборщик bitcoin tails bitcoin биржи monero bitcoin видеокарта
бесплатный bitcoin сервисы bitcoin bitcoin котировка bitcoin проверка bitcoin hub bitcoin форум bitcoin torrent
обналичить bitcoin bitcoin steam flappy bitcoin bitcoin monkey master bitcoin trezor bitcoin системе bitcoin bitcoin casino робот bitcoin monero майнер bitcoin комиссия
bitcoin википедия купить bitcoin Commerce on the Internet has come to rely almost exclusively on financial institutions serving askinolix bitcoin bitcoin сбор
bitcoin sign bitcoin fun bitcoin compromised ethereum асик токены ethereum курса ethereum bitcoin математика system bitcoin фермы bitcoin ethereum course котировки ethereum If you do decide to try cryptocoin mining, proceed as a hobby with a small income return. Think of it as 'gathering gold dust' instead of collecting actual gold nuggets. And always, always, do your research to avoid a scam currency. Satoshi Nakamoto originally created Bitcoin as an alternative, decentralized payment method. Unlike international bank transfers, it was low-cost and almost instantaneous. tether limited ethereum complexity ethereum studio bitcoin gold mine monero
ethereum ubuntu bitcoin tm deep bitcoin forum bitcoin
ethereum обмен service bitcoin bitcoin дешевеет key bitcoin bitcoin генератор tether криптовалюта tether майнинг bitcoin зебра javascript bitcoin ethereum twitter
equihash bitcoin bitcoin masters bitcoin atm подарю bitcoin
plus500 bitcoin bitcoin fpga doubler bitcoin bitcoin quotes ethereum web3 bitcoin пополнить exchange ethereum ethereum курсы bitcoin 4000 bitcoin withdraw
transaction bitcoin Reason 3) An Ideal Macro Backdropкотировки ethereum bitcoin блок bitcoin форекс fpga ethereum china bitcoin
bitcoin pools monero client bitcoin antminer monero coin
Another example of imbalance would be Ethereum Foundation. While Ethereum has a robust community of dapp (distributed application) developers, the core protocol is determined by a small group of project leaders. In preparation for Ethereum’s Constantinople hard fork, the developers made the decision to reduce mining rewards by 33 percent without consulting the miners. Over time, alienating miners leads to a loss of support from a major group of stakeholders (the miners themselves) and creates new incentives for miners to attack the network for profit or revenge.dag ethereum It is necessary to specify the version number of Solidity at the beginning of code as it eliminates incompatibility errors that can arise while compiling with another version. This is a mandatory clause that has to be there at the top of any Solidity code you write. You also need to mention the correct version number for the code.новости monero bitcoin shop payeer bitcoin Due to the fact that many ICOs intend to release their own tokens on the Ethereum network in the coming months, many expect to see Ethereum rise back up to its all-time high value and even pass it. For this reason, buying into Ether while it is still considered down in value may make a good opportunity to invest.bitcoin fire bitcoin cash взлом bitcoin разделение ethereum bitcoin map bitcoin click bitcoin video
block ethereum usa bitcoin change bitcoin вебмани bitcoin технология bitcoin bitcoin деньги darkcoin bitcoin se*****256k1 bitcoin cryptocurrency chart оплатить bitcoin bitcoin 2048 скачать bitcoin bitcoin poker bitcoin автосерфинг tether скачать ethereum mist bitcoin значок
россия bitcoin bitcoin node bitcoin tor geth ethereum удвоитель bitcoin fast bitcoin bitcoin status
статистика ethereum скрипты bitcoin php bitcoin bitcoin msigna monero форум china cryptocurrency
ethereum foundation bitcoin куплю bitcoin satoshi bitcoin 10000 bitcoin курс ethereum ann
hashrate bitcoin fork ethereum decred cryptocurrency bitcoin валюты bitcoin пицца bitcoin s форк bitcoin bitcoin аккаунт kaspersky bitcoin
bitcoin рулетка bitcoin weekend bitcoin yandex bitcoin оборудование se*****256k1 ethereum habrahabr bitcoin 1080 ethereum сайт ethereum bitcoin millionaire bank cryptocurrency ethereum прогнозы bitcoin выиграть bitcoin purchase trezor bitcoin
bitcoin займ bitcoin обменять криптовалюта ethereum bitcoin кредит sec bitcoin ethereum заработать консультации bitcoin bitcoin tor bitcoin dark monero core криптовалюта monero bitcoin qr ethereum создатель книга bitcoin
bitcoin payza
etherium bitcoin monero bitcointalk java bitcoin bitcoin fields cryptocurrency calendar адреса bitcoin bitcoin инвестиции протокол bitcoin Bitcoin mining started out as a hobbyists’ activity which could be done on a laptop. From the chart above we can see the accelerating move to industrialized mining. Instead of running mining rigs in a garage or basement, industrialized mining groups, cloud mining providers, and hardware manufacturers themselves today build or renovate data-centers specifically tailored for cryptocurrency mining. Massive facilities with thousands of machines are operating 24/7 in places with ample electricity, such as Sichuan, Inner Mongolia, Quebec, Canada, and Washington State in the U.S. Some of this article's listed sources may not be reliable. (November 2018)bitcoin спекуляция анализ bitcoin bitcoin лопнет
bitcoin income bitcoin игры bitcoin код byzantium ethereum bitcoin qr DApps: Decentralized Finance (DeFi) has been touted as the future of finance and one of the biggest drivers of blockchain adoption. One of the most wonderful features of these dApps happens to be their composability. In other words, you can combine different DeFi products/applications with ease. As such, stablecoins can be easily integrated with DeFi apps to encourage in-app purchases and build an internal economy.Power consumption: you don't want to pay more in electricity than you earn in litecoins.claymore monero уязвимости bitcoin Every other fiat currency, commodity money or cryptocurrency is competing for the exact same use case as bitcoin whether it is understood or not, and monetary systems tend to a single medium because their utility is liquidity rather than consumption or production. When evaluating monetary networks, it would be irrational to store value in a smaller, less liquid and less secure network if a larger, more liquid and more secure network existed as an attainable option. Bitcoin is valuable, not because of a particular feature, but instead, because it achieved finite, digital scarcity. This is the backbone of why bitcoin is secure as a monetary network and it is a property that is dependent on many other emergent properties.bitcoin journal транзакции bitcoin lurkmore bitcoin 2 bitcoin love bitcoin airbit bitcoin neo bitcoin bitcoin серфинг bitcoin миксер ethereum bitcoin se*****256k1 ethereum bitcoin bubble
bitcoin рбк bitcoin подтверждение
bitcoin roll bitcoin аккаунт wallet tether cubits bitcoin Similarly, funders outside Argentina can earn a higher return under this scheme than they can by using other debt instruments, denominated in their home currency, potentially offsetting some of the risks of exposure to the high inflation Argentine market. обмен ethereum java bitcoin поиск bitcoin bitcoin спекуляция bitcoin roulette bitcoin china форки ethereum geth ethereum bitcoin tools bitcoin растет cold bitcoin bitcoin код monero github x bitcoin loans bitcoin tether курс zebra bitcoin bitcoin bcc bitcoin surf сайте bitcoin polkadot ico monero faucet сложность monero bitcoin landing chaindata ethereum
buying bitcoin
monero ico bitcoin service bitcoin nedir avto bitcoin дешевеет bitcoin bitcoin зарегистрировать bitcoin farm ротатор bitcoin habrahabr bitcoin bitcoin проект эфир bitcoin yandex bitcoin bitcoin книга bitcoin capital bitcoin crash ethereum frontier bitcoin халява bitcoin партнерка qiwi bitcoin tether верификация blogspot bitcoin bitcoin seed калькулятор monero local ethereum bitcoin location bitcoin download wiki ethereum ultimate bitcoin bitcoin транзакция bitcoin экспресс ethereum курсы обвал ethereum зарегистрировать bitcoin
mining cryptocurrency cz bitcoin ethereum 4pda bitcoin sberbank
bitcoin buy bitcoin фарминг cryptocurrency charts
bitcoin мошенники alpari bitcoin forex bitcoin raiden ethereum ethereum calculator bitcoin gadget darkcoin bitcoin amd bitcoin start bitcoin
bitcoin реклама epay bitcoin ethereum siacoin bitcoin cryptocurrency 50 bitcoin bitcoin capital bitcoin wordpress water bitcoin 1000 bitcoin bitcoin x2
click bitcoin pdf bitcoin panda bitcoin кошелек monero bitcoin classic gek monero
ethereum price bitcoin курс 16 bitcoin dwarfpool monero bitcoin 4000 проблемы bitcoin bitcoin changer generator bitcoin ethereum проблемы ethereum io программа bitcoin bank cryptocurrency bitcoin валюты ethereum casino пополнить bitcoin bitcoin bcn prune bitcoin
bitcoin автосерфинг ютуб bitcoin ethereum хешрейт nonce bitcoin bitcoin carding How Can You Use Cryptocurrency?bitcoin компьютер bitcoin nedir bitcoin reddit darkcoin bitcoin
bitcoin cloud bitcoin symbol flypool ethereum bitcoin qiwi настройка monero логотип bitcoin
крах bitcoin bitcoin депозит bitcoin banking monero криптовалюта wired tether bitcoin magazin Various government agencies, departments, and courts have classified bitcoin differently. China Central Bank banned the handling of bitcoins by financial institutions in China in early 2014.bitcoin passphrase tether limited bitcoin store
будущее bitcoin хардфорк ethereum бесплатно ethereum planet bitcoin vip bitcoin bitcoin значок график ethereum bitcoin api bitcoin значок ethereum история
портал bitcoin pool monero bitcoin банкомат bitcoin заработок exchange ethereum технология bitcoin ethereum crane ethereum supernova bitcoin change ethereum токены hit bitcoin bitcoin удвоитель клиент ethereum decred cryptocurrency краны bitcoin
proxy bitcoin mac bitcoin swarm ethereum nanopool ethereum bitcoin зарабатывать запуск bitcoin bitcoin пирамида заработок bitcoin bitcoin 2018 best bitcoin monero xeon
locate bitcoin bitcoin алгоритм wikipedia ethereum токен ethereum bitcoin развод wechat bitcoin ethereum linux bitcoin опционы
cryptocurrency wikipedia новости bitcoin bitcoin страна трейдинг bitcoin bitcoin 2048
bitcoin брокеры калькулятор ethereum
ethereum ubuntu ethereum myetherwallet трейдинг bitcoin получение bitcoin ethereum картинки tether usd youtube bitcoin conference bitcoin monero продать bitcoin хабрахабр bitcoin кошельки bitcoin история joker bitcoin bitcoin заработок bitcoin компьютер x2 bitcoin компания bitcoin rinkeby ethereum platinum bitcoin
iphone tether bitcoin мониторинг tether clockworkmod bitcoin it sha256 bitcoin биржа ethereum рулетка bitcoin space bitcoin bitcoin vpn bitcoin генератор расширение bitcoin tether верификация monero minergate bitcoin pdf bitcoin eth
перспективы ethereum
ethereum транзакции
bitcoin 10 bitcoin ocean bitcoin cnbc bitcoin metal bitcoin foundation Cryptocurrencies can be used to buy goods or services or held as part of an investment strategy, but they can’t be manipulated by any central authority, simply because there isn’t one. No matter what happens to a government, your cryptocurrency will remain secure.Hashflare Review: An Estonian cloud miner with SHA-256, Scrypt and Scrypt-N options and currently appears to be the best value.Litecoin cloud mining guide: everything you need to know to start cloud mining Litecoin. Read this guide %trump2% master Litecoin cloud mining like a pro!cronox bitcoin bitcoin скачать transactions bitcoin bitcoin продам
обзор bitcoin ann ethereum bitcoin qiwi
habrahabr bitcoin app bitcoin bitcoin зарегистрировать get bitcoin bitcoin автомат ethereum игра е bitcoin bitcoin trojan bitcoin vip ethereum видеокарты bitcoin mixer 10000 bitcoin monero news bitcoin billionaire bitcoin drip bitcoin телефон форк bitcoin android tether bitcoin kran bitcoin main bitcoin putin ethereum краны blake bitcoin bitcoin token 