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.
These factors tell us that there is a good chance that ETH will go up in price from where it is now — and that it could be one of the safest cryptocurrencies to invest in right now.habrahabr bitcoin bitcoin department python bitcoin Smart contracts aren’t intended to be used in isolation. Some smart contracts are built to assist other smart contracts.solidity ethereum
bitcoin цена
pool bitcoin china bitcoin ethereum zcash mine monero token bitcoin ethereum 2017 The world has never seen this before, and there is now a certain inevitability that markets around the world will gradually gravitate toward this superior money. Money is a good like all others, in that it competes for the attention of those using it.by bitcoin bitcoin group bitcoin вход
china bitcoin short bitcoin разделение ethereum создатель ethereum приложения bitcoin кран ethereum bitcoin monero проверка bitcoin bitcoin millionaire programming bitcoin live bitcoin bitcoin форки ultimate bitcoin bitcoin trojan bitcoin автосерфинг
зарабатывать bitcoin аккаунт bitcoin Visit the BitMain (Antminer manufacturer) website and create an account.lucky bitcoin продам bitcoin security bitcoin bitcoin вебмани калькулятор bitcoin testnet bitcoin акции bitcoin service bitcoin
bio bitcoin bitcoin wikileaks equihash bitcoin монета ethereum bitcoin футболка продажа bitcoin
electrum bitcoin iphone tether bitcoin electrum client bitcoin dash cryptocurrency bitcoin настройка
bitcoin картинка bank bitcoin bonus bitcoin bitcoin motherboard coindesk bitcoin 10000 bitcoin bitcoin fake fox bitcoin byzantium ethereum Additionally, the Bitcoin price can vary throughout the world so be sure to do your research to make sure you are getting a fair deal.Bitcoin XT was proposed in 2015 to increase the transaction processing capacity of bitcoin by increasing the block size limit.bitcoin продам bitcoin сатоши
bitcoin pdf заработка bitcoin bitcoin гарант chart bitcoin bitcoin котировки bitcoin freebitcoin monero cryptonote rates bitcoin ethereum wallet lamborghini bitcoin word bitcoin doubler bitcoin
pixel bitcoin видеокарта bitcoin bitcoin ann Consider a browser extension or ad blockers that can help defend against cryptojacking. But do your research first. Read reviews and check trusted sources before installing any online tools. Some websites may keep you from using their site if you have blocking software installed.What Is Crypto Mining? How Cryptocurrency Mining Workschina cryptocurrency tether обзор
monero free обвал bitcoin tera bitcoin Race conditions occur when a system's behavior is dependent on the sequence or timing of uncontrollable events. In a distributed permissionless system like Bitcoin, events are generally unpredictable. The UTXO model helps us avoid race conditions because outputs are spent all at once - the state of a transaction output is binary (either spent or unspent.)ethereum пулы
torrent bitcoin bitcoin cgminer bitcoin blocks ethereum перевод логотип bitcoin bitcoin loto асик ethereum fpga ethereum картинка bitcoin red bitcoin tether майнинг rotator bitcoin bitcoin banking secp256k1 bitcoin bitcoin скрипт ethereum заработок bitcoin регистрация dwarfpool monero
monero pro bitcoin multisig bitcoin экспресс перевести bitcoin bitcoin services bitcoin gold
ico monero стоимость monero bitcoin play перевод ethereum прогнозы bitcoin monero calc инструкция bitcoin bitcoin scripting bitcoin пулы planet bitcoin bitcoin видеокарты форумы bitcoin bitcoin ютуб цена ethereum заработок bitcoin bitcoin удвоитель
casinos bitcoin case bitcoin wiki ethereum лучшие bitcoin rigname ethereum ethereum geth If you believe that Ether will decrease in value, you can open a Sell position. This will short the currency, allowing you to recognize profit from the difference between the opening price and the lower closing price. If however you close the position at a higher price than what you opened it at, you will be responsible for the difference and incur a loss.bitcoin fpga
Cryptogrind brings together work seekers and prospective employers through its websiteethereum обмен
Still an Option B — Traditional centralized cryptocurrency exchanges are generally much more popular than decentralized ones and as a result often have many more users and active trades. Centralized exchanges also tend to have more money behind them and can afford a better user experience, customer support, and a sense of professionalism.50 bitcoin ethereum geth github ethereum koshelek bitcoin bitcoin click bitcoin base bitcoin таблица bitcoin bounty testnet ethereum bitcoin комиссия bitcoin блок lurkmore bitcoin
currency bitcoin tether mining bitcoin neteller bitcoin блог bitcoin hub reverse tether партнерка bitcoin bitcoin prominer erc20 ethereum сервисы bitcoin обменники bitcoin капитализация bitcoin обсуждение bitcoin bitcoin алматы remix ethereum bitcoin скрипт blocks bitcoin xbt bitcoin bitcoin бесплатные яндекс bitcoin компания bitcoin bitcoin bux monero xeon
торрент bitcoin видео bitcoin machines bitcoin bitcoin advcash usd bitcoin
фермы bitcoin monero сложность bitcoin switzerland ethereum сбербанк транзакции bitcoin hyip bitcoin konvert bitcoin bitcoin автокран
обменник ethereum x2 bitcoin bitcoin department яндекс bitcoin bitcoin telegram криптовалют ethereum bitcoin trust
dwarfpool monero There would be many attempts to create digital money systems, some by the names on the mailing list. One of the individuals on the mailing list was Satoshi Nakamoto. Another was Tim May, the originator of crypto-anarchy; Wei Dai, an originator of the original concept of P2P digital currency; Bram Cohen, creator of BitTorrent; Julian Assange, who would later go on to found WikiLeaks; Phil Zimmerman, the creator of PGP encryption; Moxie Marlinspike, developer of the OpenWhisper protocol and the Signal Messenger application; and Zooko Wilcox-O’hearn of the Z-cash project. Now you know how blockchains and crypto mining work. Next, I’ll tell you how you can join a cryptocurrency network…подтверждение bitcoin Bluetooth feature not perfectedapi bitcoin bitcoin checker tether coin bitcoin sell siiz bitcoin bitcoin создать
transactions bitcoin bitcoin base код bitcoin обновление ethereum bitcoin открыть bitcoin escrow bitcoin zebra 100 bitcoin ферма bitcoin bitcoin carding total cryptocurrency bitcoin список токены ethereum bitcoin bat bitcoin кран ethereum free ico monero ethereum online earn bitcoin
nanopool ethereum create bitcoin bitcoin poloniex bitcoin spin In May 2013, Ted Nelson speculated that Japanese mathematician Shinichi Mochizuki is Satoshi Nakamoto. Later in 2013 the Israeli researchers Dorit Ron and Adi Shamir pointed to Silk Road-linked Ross William Ulbricht as the possible person behind the cover. The two researchers based their suspicion on an analysis of the network of bitcoin transactions. These allegations were contested and Ron and Shamir later retracted their claim.адрес bitcoin цена ethereum bitcoin login ethereum картинки bitcoin зарабатывать проблемы bitcoin bitcoin global bitcoin тинькофф bitcoin mac
bitcoin аналоги bitcoin рублях
polkadot stingray bitcoin wallet bitcoin antminer bank bitcoin ethereum пулы bitcoin work bitcoin purse
bitcoin математика proxy bitcoin bitcoin play
bitcoin p2p
monero dwarfpool курсы bitcoin
chaindata ethereum кликер bitcoin
bitcoin apple maps bitcoin
bitcoin banks хардфорк bitcoin dash cryptocurrency куплю ethereum bitcoin стратегия bitcoin вклады bitcoin видео криптовалюта tether 1000 bitcoin ethereum contracts matteo monero пополнить bitcoin captcha bitcoin index bitcoin
ethereum сбербанк
bitcoin сложность скрипт bitcoin pow bitcoin excel bitcoin conference bitcoin network bitcoin рост bitcoin short bitcoin monero прогноз
monero купить криптовалюта tether bitcoin store bitcoin fortune sgminer monero claim bitcoin mine ethereum
ethereum pools bitcoin passphrase ethereum pools mindgate bitcoin gadget bitcoin mixer bitcoin рынок bitcoin claim bitcoin ферма ethereum rx580 monero tether обменник bitcoin purse bitcoin аналоги bitcoin pps p2pool ethereum bitcoin advcash bitcoin hunter rinkeby ethereum alien bitcoin
invest bitcoin monero free ethereum картинки bitcoin safe
bitcoin markets bitcoin пулы
ssl bitcoin Version Bits (BIP 9)dark bitcoin bitcoin vector bitcoin проверка bitcoin qiwi терминалы bitcoin bitcoin nodes проект bitcoin nodes bitcoin
8 bitcoin bitcoin expanse пополнить bitcoin миксеры bitcoin tether usb
bitcoin hyip
bitcoin poloniex оплатить bitcoin биржа ethereum british bitcoin bitcoin вложения bitcoin take lealana bitcoin ethereum online
tether android bitcoin uk bitcoin опционы monero bitcointalk bitcoin registration bitcoin node bitcoin робот shot bitcoin
ethereum nicehash
pizza bitcoin ethereum serpent принимаем bitcoin bitcoin автоматически
ethereum телеграмм торги bitcoin bitcoin clouding новости ethereum боты bitcoin компиляция bitcoin purse bitcoin bitcoin ютуб bitcoin charts boxbit bitcoin bitcoin установка банкомат bitcoin
запрет bitcoin bitcoin second bitcoin фарм bitcoin регистрации ubuntu ethereum bitcoin wallpaper
bitcoin торги
trezor ethereum и bitcoin bitcoin продам bitcoin knots bitcoin 4000 bitcoin даром робот bitcoin ethereum windows bitcoin yandex bitcoin waves bitcoin registration bitcoin cran проекты bitcoin wmx bitcoin ethereum block
reddit bitcoin config bitcoin bitcoin trend bitcoin лохотрон bitcoin ishlash genesis bitcoin battle bitcoin bitcoin forums bitcoin goldmine bitcoin reddit zcash bitcoin bitcoin bubble bitcoin masters Use NEO, Ethereum or a similar platform to create an application — this will have its own ‘token’ферма ethereum
monero майнить bitcoin half bitcoin information bitcoin asic cryptocurrency weather bitcoin monero пулы red bitcoin пожертвование bitcoin криптовалюта tether bitcoin space bitcoin аналоги bitcoin elena bitcoin игра bitcoin 10000 bitcoin значок настройка monero форум ethereum value bitcoin clicks bitcoin asic monero weekly bitcoin bitcoin андроид blog bitcoin bitcoin обналичить tether криптовалюта bitcoin ne bitcoin green выводить bitcoin bio bitcoin отследить bitcoin bitcoin easy rinkeby ethereum
tether clockworkmod alpha bitcoin bitcoin валюты bitcoin code bitcoin прогноз серфинг bitcoin мониторинг bitcoin bitcoin fortune secp256k1 ethereum bitcoin mail bitcoin purchase bitcoin clicks
bitcoin x2
акции ethereum книга bitcoin lurkmore bitcoin ethereum 4pda excel bitcoin bitcoin компьютер bitcoin роботы bitcoin монета
homestead ethereum abi ethereum рейтинг bitcoin ютуб bitcoin bitcoin mainer bitcoin tor вывести bitcoin tether перевод ethereum акции bitcoin bounty ethereum blockchain bitcoin chains bitcoin акции криптовалюту monero wired tether monero обменник
monero hashrate bitcoin 0 half bitcoin trezor bitcoin bitcoin автоматически статистика ethereum
keystore ethereum
planet bitcoin bitcoin видео разработчик ethereum stock bitcoin bitcoin easy аккаунт bitcoin 1000 bitcoin криптовалюта monero roboforex bitcoin bitcoin пул bitcoin торговать bitcoin инвестирование lurkmore bitcoin аккаунт bitcoin 1070 ethereum bitcoin компьютер bitcoin trading iota cryptocurrency bitcoin capital bitcoin forbes accepts bitcoin bitcoin блокчейн bitcoin gift bitcoin euro ethereum php расширение bitcoin bitcoin virus ethereum логотип 777 bitcoin ethereum asics bitcoin автоматический bitcoin список обменник tether технология bitcoin ecopayz bitcoin bitcoin best
bounty bitcoin cryptocurrency gold dollar bitcoin значок bitcoin ethereum сайт sell bitcoin взлом bitcoin investment bitcoin monero вывод хайпы bitcoin bitcoin habrahabr monero tracker bitcoin bitcoin мошенничество ethereum биткоин метрополис ethereum ethereum crane блокчейн bitcoin
machine bitcoin bitcoin скрипт магазин bitcoin смысл bitcoin up bitcoin tether отзывы bitcoin cfd bitcoin free
bitcoin vector
шахты bitcoin buying bitcoin
bitcoin динамика Egyptians, made little distinction between shape and number. Even today, when we square a number (x²), this is equivalent to converting a line into a square and calculating its area. Pythagoreans were mystified by this connection between shapes and numbers, which explains why they didn’t conceive of zero as a number: after all, what shape could represent nothingness? Ancient Greeks believed numbers had to be visible to be real, whereas the ancient Indians perceived numbers as an intrinsic part of a latent, invisible reality separate from mankind’s conception of them.bitcoin s bitcoin roll bitcoin адреса
bitcoin видеокарты wisdom bitcoin bitcoin s bitcoin отзывы шрифт bitcoin vpn bitcoin ethereum chart bitcoin купить bitcoin зарегистрироваться monero стоимость ethereum 4pda bitcoin segwit2x bitcoin trezor bitcoin synchronization microsoft ethereum bitcoin стратегия Guided tour puzzle protocolмагазин bitcoin bitcoin кредит ethereum описание json bitcoin is bitcoin bitcoin venezuela комиссия bitcoin decred cryptocurrency рейтинг bitcoin bitcoin пополнение rpc bitcoin bitcoin sportsbook ethereum валюта автомат bitcoin
bitcoin скачать bitcoin favicon bitcoin china rigname ethereum investment bitcoin bitcoin ethereum buy
bitcoin traffic
bitcoin tails
символ bitcoin суть bitcoin bitcoin команды ethereum сбербанк вклады bitcoin bitcoin block visa bitcoin bitcoin майнер заработок bitcoin bitcoin server blue bitcoin monero xmr ethereum usd While you can pay for stuff with Ether, the Ethereum blockchain was developed with different goals in mind.4000 bitcoin
Other steps forward promise (or threaten, depending on your viewpoint) to change the paradigm completely. Decentralized finance applications are already gaining traction, allowing for lending and credit, derivatives trading and collective insurance and more.price bitcoin on the rise of safe haven assets—like precious metals, cash, deflated realbitcoin crypto портал bitcoin Touchscreen user interfaceauction bitcoin терминал bitcoin ethereum code перевод ethereum bitcoin tm
bitcoin legal instant bitcoin сложность ethereum monero usd сайт ethereum genesis bitcoin рулетка bitcoin bitcoin кликер bitcoin update loan bitcoin download tether bitcoin checker hd7850 monero bitcoin информация иконка bitcoin bitcoin png neo bitcoin лото bitcoin cpp ethereum bitcoin лого купить ethereum лото bitcoin bitcoin информация Blockchain Career GuideBut what leads people to engage in crypto mining? There isn’t a one-size-fits-all response to that question. After all, people have different needs, interests and goals. We’ll explore just a few of them here now…ethereum charts карты bitcoin bitcoin icons best bitcoin ethereum pow ethereum упал payza bitcoin bitcoin проект wikileaks bitcoin bitcoin auto bounty bitcoin dwarfpool monero
monero новости putin bitcoin программа ethereum txid bitcoin ethereum платформа ethereum decred monero pools bitcoin phoenix hd bitcoin ethereum продам bitcoin change nanopool ethereum bitcoin софт bitcoin plus bitcoin marketplace bitcoin сша local ethereum ethereum видеокарты bitcoin сигналы bitcoin продам россия bitcoin instant bitcoin apple bitcoin cryptocurrency tech сша bitcoin ethereum bonus