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.
space bitcoin bitcoin reklama dwarfpool monero bitcoin gif кредит bitcoin bitcoin converter space bitcoin half bitcoin bitcoin бесплатные миксеры bitcoin bitcoin x bitcoin delphi
падение ethereum
gold cryptocurrency
bitcoin dance cold bitcoin bitcoin лотереи курс ethereum карты bitcoin bitcoin puzzle покер bitcoin monero сложность bitcoin автоматически приложение tether обсуждение bitcoin cryptocurrency reddit bitcoin banking ethereum метрополис ico bitcoin monero майнеры программа ethereum segwit bitcoin bitcoin boxbit trade cryptocurrency
bitcoin department bitcoin генераторы
bitcoin etherium bitcoin symbol bitcoin wmz
эфир ethereum Backup your entire bitcoin wallet early and often. In case of a computer failure, a history of regular backups may be the only way to recover the currency in the digital wallet. Make sure to backup all the wallet.dat files and then store the backup at multiple secure locations (like on a USB, on the hard drive, and on CDs). Not only this, set a strong password on the backup.Other solutions include storing private keys offline, on paper or a hard disk (or other electronic equipment) that is not connected to the Internet. But losing physical custody (or either the paper or electronic equipment) is a real possibility, and in those cases recovery of the cryptocurrency holdings can be impossible. For individual holders of bitcoin, the possibility of losing private keys is a risk; for institutional investors, though, it represents an even more significant risk. The latter go to extreme lengths to guard against this danger. Some major investors have even been known to distribute portions of a paper wallet across numerous storage units in different locations.ethereum контракт майнинг tether bitcoin pump bitcoin fasttech bitcoin прогнозы bitcoin создать monero hashrate flash bitcoin форк ethereum
валюта tether bitcoin favicon bitcoin elena боты bitcoin bitcoin курсы pow bitcoin адрес ethereum сервисы bitcoin пулы bitcoin
blocks bitcoin bitcoin доходность ethereum rig исходники bitcoin cryptocurrency trading bitcoin бот дешевеет bitcoin bitcoin capital cryptocurrency news usd bitcoin
best cryptocurrency обменники ethereum форумы bitcoin bitcoin auto kraken bitcoin bitcoin paw платформы ethereum cpa bitcoin bitcoin 99 кости bitcoin home bitcoin bitcoin wallet bitcoin доллар bitcoin мошенничество monero news bitcoin euro bitcoin currency korbit bitcoin home bitcoin ethereum история instaforex bitcoin анонимность bitcoin bitcoin фильм iso bitcoin difficulty monero
bux bitcoin bitcoin cranes nanopool ethereum bitcoin исходники bitcoin pool курс bitcoin monero hardware bitcoin genesis bitcoin пирамиды логотип bitcoin bitcoin google cryptocurrency market bitcoin linux hardware bitcoin ethereum siacoin flash bitcoin ethereum платформа bitcoin комбайн bitcoin course bitcoin получить bitcoin fan bitcoin core location bitcoin monero simplewallet bitcoin freebitcoin daemon monero bitcoin click ethereum ios котировка bitcoin сбербанк bitcoin stock bitcoin курс tether jaxx monero transactions bitcoin
bitcoin virus bitcoin alliance dwarfpool monero If you already know Bitcoin, Litecoin is very similar, the two main differences being that it has faster confirmation times and it uses a different hashing algorithm.cryptocurrency dash bitcoin pay bitcoin zone bitcoin coingecko bitcoin комиссия bitcoin рулетка bitcoin уязвимости android tether bitcoin ann 2016 bitcoin cryptocurrency chaindata ethereum ethereum сбербанк перевести bitcoin blitz bitcoin добыча bitcoin bitcoin ne bitcoin сборщик alpari bitcoin loan bitcoin stock bitcoin установка bitcoin bear bitcoin cryptocurrency exchange bitcoin cgminer
coingecko bitcoin app bitcoin multiply bitcoin
ethereum geth monero minergate видеокарты bitcoin bitcoin xyz erc20 ethereum bitcoin nvidia
ютуб bitcoin основатель ethereum mt5 bitcoin homestead ethereum cryptocurrency calendar ethereum os bitcoin minecraft alien bitcoin ad bitcoin capitalization cryptocurrency forum bitcoin monero dwarfpool сложность ethereum red bitcoin
bitcoin сбор
bitcoin stealer bitcoin прогноз ethereum перевод monero rur rpg bitcoin взломать bitcoin bitcoin nasdaq cryptocurrency trade bitcoin donate ethereum асик bitcoin plus500 bitcoin nvidia
bitcoin russia bitcoin daily ethereum parity bitcoin minecraft ethereum game bitcoin stealer bitcoin blue bitcoin swiss
Any rule that adds required, explicit centralization. For example, a change requiring that all blocks be signed by some central organization.video bitcoin eos cryptocurrency bitcoin lion 3d bitcoin ethereum core forum cryptocurrency tether верификация explorer ethereum
bitcoin blue сбор bitcoin bitcoin ishlash cryptocurrency ico bitcoin обозреватель tether bootstrap monero proxy demo bitcoin bitcoin даром кошелек tether credit bitcoin проблемы bitcoin разработчик bitcoin abc bitcoin bitcoin nvidia robot bitcoin bitcoin valet bitcoin транзакции monero windows ethereum project bitcoin flapper bitcoin вход mining bitcoin bitcoin гарант blockchain ethereum bitcoin capitalization cryptonator ethereum ethereum russia bitfenix bitcoin ethereum siacoin
пополнить bitcoin
mining bitcoin 999 bitcoin bitcoin gif падение ethereum bitcoin income взлом bitcoin bitcoin упал
bitcoin billionaire
tether кошелек bitcoin demo ethereum complexity ethereum stats брокеры bitcoin банкомат bitcoin 2x bitcoin Check if the previous block referenced by the block exists and is valid.'Node operators' are the owners and managers of nodes that run the protocol. Most node operators don’t want to write much software, and it’s a technical challenge for anyone to independently write compatible implementations of any consensus protocol even if they have a specification. As a result, node operators rely on software repositories (usually hosted on Microsoft/Github servers) to provide them with the software they choose to run.Ring signaturesimproving Bitcoin's liquidity and utility as a monetary asset. Through successive bubbles, Bitcoinbitcoin logo bitcoin address Most exchanges accept payments via bank transfers or credit cards, and some are willing to work with Paypal transfers. They typically charge fees for each transaction, which include the cost for using the bitcoin network.рубли bitcoin Stallman, the GNU creator, says the difference between free and open source software is a moral one: 'Most discussion of ‘open source’ pays no attention to right and wrong, only to popularity and success.'bitcoin king bitcoin antminer lealana bitcoin bitcoin base bitcoin microsoft создатель ethereum bitcoin bitrix
mac bitcoin криптовалюты ethereum
bitcoin минфин
bitcoin комиссия подарю bitcoin
cryptocurrency capitalization cpuminer monero loans bitcoin fork ethereum secp256k1 bitcoin
bitcoin ne bitcoin dark дешевеет bitcoin cryptocurrency bitcoin bitcoin heist
apple bitcoin monero обмен вывод monero
bitcoin nedir bitcoin investment bitcoin хардфорк форк bitcoin monero криптовалюта ultimate bitcoin ethereum io bitcoin links
bitcoin пицца
bitcoin wordpress bitcoin bow At a very basic level, 'staking' means locking your crypto assets in a proof-of-stake blockchain for a certain period of time. These locked assets are used to achieve consensus, which is required to secure the network and ensure the validity of every new transaction to be written to the blockchain. Those who stake their coins in a PoS blockchain are usually called 'validators.' For locking their assets and providing services to the blockchain, validators are rewarded with new coins from the network.The most recognized form of cryptocurrency, Bitcoin, was created in 2008 and has seen its value increase exponentially in the past year. In just twelve months, the value of one Bitcoin skyrocketed from about $800 in January 2017 to over $13,000 shortly after the end of the year.bitcoin 2018 bitcoin россия
bitcoin conf ethereum developer preev bitcoin робот bitcoin bitcoin block bitcoin word coinbase ethereum виталик ethereum opencart bitcoin bitcoin fox faucet ethereum bitcoin презентация 33 bitcoin arbitrage cryptocurrency дешевеет bitcoin курс tether bitcoin 20 sha256 bitcoin bitcoin qazanmaq bitcoin india bitcoin автоматом bitcoin arbitrage приложение bitcoin ethereum телеграмм nova bitcoin bitcoin теханализ rise cryptocurrency курс bitcoin ico cryptocurrency рубли bitcoin bitcoin приват24
finney ethereum
tor bitcoin обзор bitcoin bitcoin switzerland free bitcoin cap bitcoin bestchange bitcoin antminer bitcoin bitcoin парад ethereum usd ebay bitcoin ethereum github bitcoin 0 bitcoin rpg bitcoin video ethereum asic комиссия bitcoin bitcoin фирмы Should I Buy Ethereum? All You Need to Make An Informed Decisionанонимность bitcoin bitcoin monkey solo bitcoin bitcoin trading bitcoin safe ethereum addresses бесплатный bitcoin moon ethereum bitcoin forbes bitcoin explorer
bitcoin algorithm кран monero bitcoin регистрации gold cryptocurrency cgminer bitcoin cryptocurrency mining bitcoin ann кран ethereum bitcoin freebie ethereum debian ethereum настройка ecdsa bitcoin bitcoin formula bitcoin stellar компьютер bitcoin miningpoolhub ethereum ethereum decred conference bitcoin bitcoin earn
раздача bitcoin bitcoin shop dollar bitcoin etoro bitcoin bitcoin пицца bitcoin block bitcoin genesis monero обменник bitcoin матрица bitcoin форк падение bitcoin валюта monero tracker bitcoin bitcoin faucets вложения bitcoin bitcoin usd сервера bitcoin bitcoin ann ethereum биткоин tether gps tp tether ethereum usd bitcoin slots оборудование bitcoin calculator ethereum ecopayz bitcoin plus500 bitcoin bitcoin synchronization bitcoin vip bitcoin окупаемость
alpha bitcoin зарегистрироваться bitcoin bitcoin рейтинг ethereum алгоритм bitcoin spend
bitcoin что купить bitcoin сайте bitcoin bitcoin ocean bux bitcoin
pro100business bitcoin ethereum упал bitcoin motherboard protocol bitcoin bitcoin buy x2 bitcoin monero майнить
monero usd виталий ethereum китай bitcoin консультации bitcoin bitcoin instagram сколько bitcoin lightning bitcoin bitcoin usa сайт ethereum arbitrage cryptocurrency
battle bitcoin pplns monero icon bitcoin wild bitcoin your bitcoin лохотрон bitcoin
bitcoin testnet future bitcoin yota tether расшифровка bitcoin bitcoin status antminer bitcoin почему bitcoin bitcoin accelerator
bitcoin card goldmine bitcoin r bitcoin cryptocurrency это bitcoin mac
bitcoin betting bestexchange bitcoin bitcoin reddit monero windows ethereum usd bitcoin express bitcoin journal bitcoin компания bitcoin шифрование io tether web3 ethereum регистрация bitcoin пулы bitcoin
bitcoin скачать bitcoin paper roboforex bitcoin
ethereum api новый bitcoin
ethereum телеграмм cryptocurrency calendar кредиты bitcoin tether транскрипция ethereum mining bitcoin laundering monero fee bitcoin вконтакте брокеры bitcoin
bitcoin loan bitcoin dynamics
bitcoin кредиты bitcoin мерчант wei ethereum bitcoin quotes сбор bitcoin pool bitcoin
tether wifi bitcoin 123 0 bitcoin trading bitcoin bitcoin start bitrix bitcoin cryptocurrency ico ethereum crane
bitcoin биржа ethereum создатель Similarly, there are protocols like the Lightning Network and other smart contract concepts that are built on top of Bitcoin, which increase Bitcoin’s scalability. Lightning can perform tons of quick transactions between counterparties, and reconcile them with Bitcoin’s blockchain in one batch transaction. This reduces the fees and bandwidth limitations per small transaction.bitcoin timer bitcoin открыть bitcoin bitcointalk ethereum 1070 bitcoin описание кошель bitcoin ethereum видеокарты bitcoin pdf pixel bitcoin easy bitcoin bitcoin school ethereum price bitcoin withdrawal daily bitcoin bitcoin node bitcoin unlimited bitcoin super status bitcoin bitcoin skrill ethereum проект bitcoin code bitcoin agario bitcoin galaxy A hot wallet refers to keeping single-signature wallets with private keys kept on an online computer or mobile phone. Most bitcoin wallet software out there is a hot wallet. The bitcoins are easy to spend but are maximally vulnerable to malware or hackers. Hot wallets may be appropriate for small amounts and day-to-day spending.usb tether short bitcoin tether 4pda Forcing everyone to live in a world in which money loses value creates a negatively reinforcing feedback loop; by eliminating the very possibility of saving money as a winning proposition, it makes all outcomes far more negative in aggregate. Just holding money is a non-credible threat when money is engineered to lose its value. People still do it, but it’s a losing hand by default. So is perpetual risk-taking as a forced substitute to saving. Effectively, all hands become losing hands when one of the options is not winning by saving money. Recall that each individual with money has already taken risk to get it in the first place. A positive incentive to save (and not invest) is not equivalent to rewarding people for not taking risk, quite the opposite. It is rewarding people who have already taken risk with the option of merely holding money without the express promise of its purchasing power declining in the future.майнеры ethereum ecdsa bitcoin monero xmr ethereum майнеры bitcoin stellar win bitcoin lealana bitcoin tor bitcoin
bitcoin prices скачать bitcoin client bitcoin робот bitcoin кошелька bitcoin
captcha bitcoin monero стоимость ethereum code
mine monero monero майнинг bitcoin parser fx bitcoin bitcoin 2x ethereum wallet bitcoin flip
