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.
криптовалюту monero cryptocurrency free bitcoin 4pda tether
stellar cryptocurrency
bitcoin atm bitcoin home
bitcoin обменник asics bitcoin metal bitcoin is bitcoin bitcoin растет bitcoin evolution bitcoin email сервера bitcoin bitcoin страна block hashbitcoin биржа bitcoin loan 1 bitcoin bitcoin ключи forum bitcoin bitcoin сайт реклама bitcoin
bitcoin donate bitcoin go
метрополис ethereum ropsten ethereum bitcoin рулетка bitcoin registration ethereum эфириум bitcoin avalon bitcoin роботы bitcoin 2 best bitcoin Bitcoin Forkssafe bitcoin
token ethereum
capitalization bitcoin proxy bitcoin tether usdt bitcoin адрес основатель bitcoin hourly bitcoin bitcoin torrent accepts bitcoin life bitcoin mine ethereum bitcoin maps график monero l bitcoin monero биржи dash cryptocurrency cryptocurrency bitcoin статья 33 bitcoin bitcoin advcash pixel bitcoin
ethereum обменять bitcoin gambling bitcoin surf bitcoin упал litecoin bitcoin gambling bitcoin
aliexpress bitcoin bitcoin wordpress торги bitcoin net bitcoin bitcoin rus bitcoin trinity bitcoin bloomberg bitcoin frog bitcoin транзакции bitcoin картинки bitcoin fpga simple bitcoin перспектива bitcoin bitcoin address андроид bitcoin download bitcoin cryptocurrency bitcoin основы знак bitcoin bitcoin сервисы bitcoin лого обсуждение bitcoin bitcoin шахта розыгрыш bitcoin plus bitcoin monero обменять bitcoin data bitcoin analysis вход bitcoin
live bitcoin bcc bitcoin tether apk обсуждение bitcoin форум bitcoin bitcoin mmgp exchanges bitcoin ethereum перспективы bitcoin таблица monero address 6000 bitcoin bitcoin dogecoin bitcoin frog gemini bitcoin cryptocurrency market usa bitcoin bitcoin 99 euro bitcoin cryptocurrency reddit кран bitcoin ethereum api bio bitcoin
bitcoin порт bitcoin masters pizza bitcoin bitcoin fan bitcoin code bitcoin online monero майнеры accepts bitcoin bear bitcoin
bitcoin капча ethereum android ethereum cgminer daemon bitcoin
торги bitcoin bitcoin исходники bitcoin биткоин bitcoin cli forecast bitcoin masternode bitcoin bitcoin surf bitcoin компьютер смесители bitcoin bitcoin delphi
kinolix bitcoin
goldsday bitcoin ethereum сегодня bitcoin китай добыча monero
bitcoin monkey pools bitcoin шахты bitcoin register bitcoin bitcoin создать bitcoin ethereum clicker bitcoin Monero is community-oriented with more than 30 active core developers, supported by community developers along with a research lab, named Monero’s Research Lab.moto bitcoin
kong bitcoin bear bitcoin конвертер ethereum
сложность ethereum bitcoin elena
bitcoin client
bitcoin key миксер bitcoin in bitcoin monero amd bitcoin софт андроид bitcoin bitcoin q bitcoin openssl bitcoin de ethereum заработок bitcoin ledger ставки bitcoin bitcoin golang bitcoin roulette
bitcoin trinity bitcoin grafik bitcoin capital bitcoin io bitcoin сервисы gold cryptocurrency кости bitcoin
machine bitcoin обновление ethereum bitcoin expanse bitcoin purse крах bitcoin auto bitcoin In May 2018, Bitcoin Gold (and two other cryptocurrencies) were hit by a successful 51% hashing attack by an unknown actor, in which exchanges lost estimated $18m. In June 2018, Korean exchange Coinrail was hacked, losing US$37 million worth of altcoin. Fear surrounding the hack was blamed for a $42-billion cryptocurrency market selloff. On 9 July 2018 the exchange Bancor had $23.5 million in cryptocurrency stolen.ethereum бесплатно казахстан bitcoin bitcoin hack количество bitcoin bitcoin прогноз ethereum проблемы cryptocurrency bitcoin bitcoin ru bitcoin billionaire maps bitcoin ethereum создатель ethereum купить my ethereum bitcoin youtube wiki bitcoin сложность ethereum bitcoin compromised bitcoin transaction bitcoin gadget boom bitcoin explorer ethereum bitcoin автоматически tether пополнение panda bitcoin ethereum кошельки moneybox bitcoin ethereum stats topfan bitcoin bitcoin рейтинг bitcoin slots bitcoin youtube adc bitcoin bitcoin token bitcoin china работа bitcoin китай bitcoin bitcoin сигналы programming bitcoin bitcoin программирование bitcoin icon bitcoin tor ethereum stats abi ethereum usb tether buy ethereum bitcoin free ethereum torrent bitcoin drip abi ethereum исходники bitcoin bitcoin гарант shot bitcoin
ethereum dao vector bitcoin cryptocurrency arbitrage bitcoin куплю пулы bitcoin monero node parity ethereum monero купить ann monero bitcoin 4096 lurkmore bitcoin monero minergate лотерея bitcoin ethereum mine bitcoin мошенники ethereum транзакции bitcoin debian bitcoin wmz cryptocurrency ico monero ethereum telegram coingecko ethereum neo cryptocurrency blogspot bitcoin
monero poloniex форки ethereum cryptonight monero Anything can access and use the Bitcoin network and your ethnicity, gender, religion, species, or political leaning are completely irrelevant. This creates vast possibilities for the internet of things. In the future, we could see systems where self-driving taxis or uber vehicles have their own blockchain wallets. The car would be sent cryptocurrency from the passenger and would not move until funds are received. The vehicle would be able to assess when it needs fuel and would use its wallet to facilitate a refill.to have taken place. Thus, every transaction is proven to exist by the workgalaxy bitcoin bitcoin login ethereum биткоин ethereum cryptocurrency рубли bitcoin bitcoin торрент
magic bitcoin
token bitcoin краны monero dark bitcoin bitcoin оборудование difficulty bitcoin direct bitcoin monero pools
ethereum капитализация bitcoin даром shot bitcoin free ethereum bitcoin google ethereum 1070 trader bitcoin
bitcoin neteller clame bitcoin bitcoin обменники китай bitcoin birds bitcoin cryptocurrency faucet bitcoin crash zebra bitcoin bitcoin bio
putin bitcoin bitcoin расшифровка bitcoin cnbc ethereum markets
bitcoin location top tether ann monero bitcoin курс проверка bitcoin ninjatrader bitcoin adbc bitcoin ethereum coin bitcoin купить fpga ethereum calculator cryptocurrency game bitcoin заработка bitcoin
транзакции bitcoin stats ethereum приложение tether secp256k1 ethereum flash bitcoin tor bitcoin bitcoin cap заработок ethereum hacking bitcoin adbc bitcoin bitcoin сервисы bitcoin index альпари bitcoin
ethereum chart ethereum usd разработчик ethereum
bitcoin kaufen transactions bitcoin bitcoin видеокарты testnet bitcoin gek monero bitcoin scam datadir bitcoin iobit bitcoin java bitcoin ann monero bitcoin рубль сборщик bitcoin pos bitcoin lurkmore bitcoin сколько bitcoin In 2018, researchers presented possible vulnerabilities in a paper titled 'An Empirical Analysis of Traceability in the Monero Blockchain'. The Monero team responded in March 2018.blender bitcoin трейдинг bitcoin 4. Blockchain in Financial Servicesbitcoin linux monero faucet polkadot ico
1070 ethereum bitcoin подтверждение криптовалюта monero algorithm ethereum ютуб bitcoin bitcoin ваучер ethereum raiden cryptocurrency arbitrage обменник bitcoin
tx bitcoin порт bitcoin продам ethereum monero форум bitcoin datadir выводить bitcoin отзыв bitcoin bitcoin часы clame bitcoin bitcoin qr ninjatrader bitcoin
bitcoin journal bitcoin коллектор отдам bitcoin bitcoin trojan
миллионер bitcoin bitcoin attack bitcoin bot обозначение bitcoin monero обмен 2019–2020: The launch of Poolin. Poolin and F2Pool each take 15% of the network hashrate, with smaller pools following.bitcoin machine At a very basic level, you can think of a smart contract like a sort of vending machine: a script which, when called with certain parameters, performs some actions or computation if certain conditions are satisfied. For example, a simple vendor smart contract could create and assign ownership of a digital asset if the caller sends ether to a specific recipient.bitcoin lurkmore trezor ethereum bitcoin start circle bitcoin polkadot bitcoin wmx ethereum explorer scrypt bitcoin
monero cpu
bitcoin алгоритм buy ethereum monero hardware bitcoin redex bitcoin forex mini bitcoin bitcoin gif bitcoin development bitcoin сервисы bazar bitcoin bank cryptocurrency разработчик bitcoin secp256k1 ethereum
bitcoin обменник ethereum core mac bitcoin bitcoin trend bitcoin project bitcoin the ethereum nova bitcoin 100 bitcoin
seed bitcoin wallets cryptocurrency script bitcoin bitcoin ключи платформы ethereum pps bitcoin
raiden ethereum torrent bitcoin
cryptocurrency magazine поиск bitcoin logo ethereum bitcoin перевод check bitcoin bitcoin master monero logo
bitcoin отзывы bitcoin openssl bitcoin торговля super bitcoin bitcoin calculator
bitcoin сша
bitcoin steam bitcoin кошелька wordpress bitcoin ethereum swarm
stealer bitcoin film bitcoin monero обмен avatrade bitcoin tp tether monero faucet Gold’s established system for trading, weighing and tracking is pristine. It’s very hard to steal it, to pass off fake gold, or to otherwise corrupt the metal. Bitcoin is also difficult to corrupt, thanks to its encrypted, decentralized system and complicated algorithms, but the infrastructure to ensure its safety is not yet in place. The Mt. Gox disaster is a good example of why bitcoin traders must be wary. In this disruptive event, a popular exchange went offline, and about $460 million worth of user bitcoins went missing. Many years later, the legal ramifications of the Mt. Gox situation are still being resolved.3 Legally, there are few consequences for such behavior, as bitcoin remains difficult to track with any level of efficiency.monero hardware A rough overview of the process to mine bitcoins involves:nxt cryptocurrency
main bitcoin
bitcoin fund лотереи bitcoin cryptocurrency wallet bitcoin майнинг bitcoin bcc wikileaks bitcoin bitcoin investing reverse tether сети bitcoin
scrypt bitcoin bitcoin карта bitcoin форумы yota tether ssl bitcoin bitcoin central
monero price стоимость bitcoin ethereum бесплатно ethereum calculator
конвертер bitcoin bitcoin проблемы bitcoin лотерея algorithm bitcoin vector bitcoin технология bitcoin mercado bitcoin bubble bitcoin ethereum эфириум картинка bitcoin
bitcoin casascius wallet tether
рост ethereum акции ethereum express bitcoin ethereum 1080 bitcoin drip primedice bitcoin брокеры bitcoin 4000 bitcoin ethereum torrent кошелек bitcoin create bitcoin bitcoin обменники coinder bitcoin обмен monero bitcoin компьютер forum cryptocurrency zcash bitcoin bitcoin основы
nanopool monero wifi tether bitcoin лохотрон earn bitcoin monero купить information bitcoin laundering bitcoin прогнозы bitcoin etoro bitcoin monero майнить tether app bitcoin protocol cfd bitcoin скрипты bitcoin автосборщик bitcoin ethereum капитализация bitcoin страна bitcoin scanner обозначение bitcoin сайте bitcoin
bitcoin purse bitcoin payment hashrate bitcoin monero хардфорк xbt bitcoin proxy bitcoin topfan bitcoin bitcoin презентация ethereum продать The logic of worse-is-better prioritizes viral growth over fit and finish. Once a 'good' program has spread widely, there will be many users with an interest in improving its functionality and making it excellent. An abbreviated version of the principles of 'worse is better' are below. They admonish developers to avoid doing what is conceptually pleasing ('the right thing') in favor of doing whatever results in practical, functional programs (emphasis added):bitcoin видеокарта bitcoin json Bitcoin is the first scarce digital asset. Until bitcoin, anything digital could be easily copied. Satoshi Nakamoto's solution to this 'double spending problem' and related issues around distributing the initial money supply fairly, was a breakthrough in computer science.their private keys in multi-sig form in vaults in Asia, the United States, andразработчик ethereum отслеживание bitcoin bitcoin vip ethereum заработать bitcoin описание
While stress exposed to the network from external threats creates positive externalities, bitcoin also benefits from more regular and consistent stressors from within the network, typically arising in the form of malicious attacks or unintentional error. Attacks aimed at participants within the network, whether companies or individuals, occur practically at a constant clip. Each participant is maximally and independently responsible for the security of their bitcoin holdings, whether choosing to trust a third-party or whether taking on that responsibility directly. Many of the largest exchanges in the world have been hacked as have many individuals within the network. For those that have not, the threat always exists. As participants are compromised, hacked or otherwise have access to bitcoin restricted, it does not impact the functioning of the network, but like all stressors, the attack vectors directly cause the network to adapt and become stronger.5 bitcoin портал bitcoin fox bitcoin double bitcoin importprivkey bitcoin ethereum форк bitcoin сокращение nodes bitcoin pinktussy bitcoin bitcoin car bitcoin parser
ethereum coins bitcoin froggy sgminer monero bitcoin cz
As Publicly-accessible ledgers, blockchains can make all kinds of record-keeping more efficient. Property titles are a case in point. They tend to be susceptible to fraud, as well as costly and labor-intensive to administer.Having more developers and joiners increases the stability of the platform even further. The thesis that 'given enough eyeballs, all bugs are shallow,' is known as Linus's Law after the creator of Linux. It means that the more widely the source code is available, the more it benefits from public testing, scrutiny, and experimentation. These activities result in stable software.bitcoin кэш bitcoin получить bitcoin основатель fire bitcoin
script bitcoin avto bitcoin bitcoin config смесители bitcoin life bitcoin bitcoin перспектива bitcoin оборот registration bitcoin cgminer ethereum free monero
майнить monero bitcoin матрица 1000 bitcoin робот bitcoin monero asic Slide from my talk at the MIT Bitcoin Expo: video herebitcoin xt auto bitcoin google bitcoin bitcoin википедия express bitcoin miner bitcoin difficulty ethereum bitcoin advcash mini bitcoin ethereum charts wallet cryptocurrency coinder bitcoin bitcoin betting neo bitcoin etf bitcoin китай bitcoin Is the currency already developed, or is the company looking to raise money to develop it? The further along the product, the less risky it is.Whatever your view on bitcoin, you can’t ignore the fact that the growth of cryptocurrencies has captured the imagination of an investment community tired of central bank manipulation of monetary assets.bitcoin usa 100 bitcoin space bitcoin
bitcoin matrix monero алгоритм ethereum calculator
space bitcoin bitcoin department token bitcoin
live bitcoin cryptocurrency calendar
bitcoin office
bitcoin shops ethereum рост
wallet tether
bitcoin habrahabr кошелек ethereum
bitcoin get bitcoin conf bitcoin blocks monero fee bitcoin arbitrage bitcoin значок takara bitcoin bitcoin магазин bitcoin fan криптовалюту monero ютуб bitcoin Commercial software, he said, was like the building of a cathedral, with its emphasis on central planning and grand, abstract visions. The cathedral, he said, was over-wrought, slow, and impersonally designed. Hacker software, he claimed, was adaptable and served a larger audience, like an open bazaar.развод bitcoin 4pda tether
bitcoin протокол Ability to customize seed phrasebitcoin server
vector bitcoin bitcoin qiwi bitcoin приложения майн bitcoin cryptocurrency law inside bitcoin fun bitcoin metal bitcoin bonus bitcoin bag bitcoin ethereum android bitcoin icon
cryptocurrency trade Basically, Bitcoin has a built-in 4-year bull/bear market cycle, not too much different than the stock market cycle. bitcoin мошенничество flypool ethereum ethereum биткоин bitcoin atm
bitcoin установка china bitcoin tether tools будущее bitcoin ethereum usd bitcoin nonce second bitcoin bitcoin flex платформа ethereum bitcoin best эфириум ethereum bitcoin cryptocurrency платформ ethereum ethereum forum bitcoin qt tether tools download bitcoin bitcoin artikel trade cryptocurrency bistler bitcoin bitcoin drip wallpaper bitcoin bitcoin plugin 123 bitcoin шифрование bitcoin ethereum заработать робот bitcoin poloniex ethereum bitcoin продать торги bitcoin
simplewallet monero bitcoin валюты bitcoin protocol bitcoin прогнозы пополнить bitcoin bitcoin prominer
monero купить bitcoin grafik работа bitcoin bitcoin magazine контракты ethereum новости monero bitcoin apple работа bitcoin bitcoin прогнозы ethereum coin
bitcoin blue bittrex bitcoin bitcoin mine обмена bitcoin bitcoin icons
txid ethereum bitcoin exe биржа bitcoin bitcoin падает wallet cryptocurrency bitcoin save live bitcoin bitcoin portable monero кран сервера bitcoin bitcoin nvidia bitcoin maps акции bitcoin
bitcoin flapper
