Ping

Utility

0x657849c4d05f...0ba1d071a047

FrontierContract #867Exact Bytecode MatchEdit this contract

Deployed September 5, 2015 (11 years ago)Block 189,361

Ping, half of a cross-contract return value test

Frontier EraVerified Source

Historical Significance

An early mainnet example of inter-contract communication in Solidity. Part of a systematic tutorial series that documented learning Solidity from scratch during Ethereum's first months.

Context

Frontier and Homestead era deployment.

Key Facts

Deployer

Cyrus Adkisson(0xcf684d...ad1bac)

Deployment Block

189,361

Deployment Date

Sep 5, 2015, 05:45 PM

Code Size

1.2 KB

Gas at Deploy

333,946

Transactions by Year

20152

Deployment Transaction: 0x552578d82039336c...2c11361180c9f681

Description

One half of a two-contract experiment in whether an Ethereum contract can read a non constant return value from another contract, which web3 and geth could not do at the time. Ping holds the address of a Pong, calls into it transactionally, and stores what comes back so it can be read afterwards.

Source Verified

SolidityExact bytecode match(1,277 bytes)

Compiler: v0.1.3+

View verification proof

Exact creation bytecode match. Author Cyrus Adkisson published source at https://github.com/cyrusadkisson/solidity-baby-steps/blob/master/contracts/45_ping.sol. Batch-matched against 357 deploy TXs from deployer 0xcf684dfb8304729355b58315e8019b1aa2ad1bac.

Historian Categories

Experimental

Heuristic Analysis

The following characteristics were detected through bytecode analysis and may not be accurate.

Detected Type: Utility

Frontier Era

The initial release of Ethereum. A bare-bones implementation for technical users.

Block span: 0 — 1,149,999

July 30, 2015 — March 14, 2016

Bytecode Overview

Opcodes1,277

Unique Opcodes97

Jump Instructions35

Storage Operations20

Verified Source Available

Source verified through compiler archaeology and exact bytecode matching.

View Verification Proof

Show source code (Solidity)

// Submitted by EthereumHistory (ethereumhistory.com)
// Contracts can get non-constant return values from functions in other contracts. (Whereas you can't from web3/geth.)
// These two contracts are meant to test this. Like so:

// 1. Deploy Pong with a pongval.
// 2. Deploy Ping, giving it the address of Pong.
// 3. Call Ping.getPongvalRemote() using a sendTransaction...
// 4. ... which retreives the value of pongval from Pong.
// 5. If successful Ping.getPongval() should return the value from step 1.

contract PongvalRetriever {
 	int8 pongval_tx_retrieval_attempted = 0;
	function getPongvalTransactional() public returns (int8){	// tells Ping how to interact with Pong.
		pongval_tx_retrieval_attempted = -1;
		return pongval_tx_retrieval_attempted;
	}
}

contract Ping is PongvalRetriever {

 	int8 pongval;
	PongvalRetriever pvr;
    address creator;

	/*********
 	 Step 2: Deploy Ping, giving it the address of Pong.
 	 *********/
    function Ping(PongvalRetriever _pongAddress) 
    {
        creator = msg.sender; 	
        pongval = -1;							
        pvr = _pongAddress;
    }

	/*********
     Step 3: Transactionally retrieve pongval from Pong. 
     *********/

	function getPongvalRemote() 
	{
		pongval = pvr.getPongvalTransactional();
	}
	
	/*********
     Step 5: Get pongval (which was previously retrieved from Pong via transaction)
     *********/
     
    function getPongvalConstant() constant returns (int8)
    {
    	return pongval;
    }
	
  
// -----------------------------------------------------------------------------------------------------------------	
	
	/*********
     Functions to get and set pongAddress just in case
     *********/
    
    function setPongAddress(PongvalRetriever _pongAddress)
	{
		pvr = _pongAddress;
	}
	
	function getPongAddress() constant returns (address)
	{
		return pvr;
	}
    
    /****
	 For double-checking this contract's address
	 ****/
	function getAddress() returns (address)
	{
		return this;
	}
    
    /*********
     Standard kill() function to recover funds 
     *********/
    
    function kill()
    { 
        if (msg.sender == creator)
            suicide(creator);  // kills this contract and sends remaining funds back to creator
    }
}


/*

var _pongAddress =  web3.toBigNumber( '0x4d6412ebac502b70776a902c03f8775b3007f70d') ;

var pingContract = web3.eth.contract([{
    "constant": false,
    "inputs": [],
    "name": "getAddress",
    "outputs": [{
        "name": "",
        "type": "address"
    }],
    "type": "function"
}, {
    "constant": false,
    "inputs": [{
        "name": "_pongAddress",
        "type": "address"
    }],
    "name": "setPongAddress",
    "outputs": [],
    "type": "function"
}, {
    "constant": false,
    "inputs": [],
    "name": "getPongvalRemote",
    "outputs": [],
    "type": "function"
}, {
    "constant": true,
    "inputs": [],
    "name": "getPongvalConstant",
    "outputs": [{
        "name": "",
        "type": "int8"
    }],
    "type": "function"
}, {
    "constant": false,
    "inputs": [],
    "name": "kill",
    "outputs": [],
    "type": "function"
}, {
    "constant": true,
    "inputs": [],
    "name": "getPongAddress",
    "outputs": [{
        "name": "",
        "type": "address"
    }],
    "type": "function"
}, {
    "constant": false,
    "inputs": [],
    "name": "getPongvalTransactional",
    "outputs": [{
        "name": "",
        "type": "int8"
    }],
    "type": "function"
}, {
    "inputs": [{
        "name": "_pongAddress",
        "type": "address"
    }],
    "type": "constructor"
}]);
var ping = pingContract.new(
    _pongAddress, {
        from: web3.eth.accounts[0],
        data: '60606040526000600060006101000a81548160ff02191690837f01000000000000000000000000000000000000000000000000000000000000009081020402179055506040516020806104dd8339016040526060805190602001505b33600160006101000a81548173ffffffffffffffffffffffffffffffffffffffff021916908302179055507fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff600060016101000a81548160ff02191690837f010000000000000000000000000000000000000000000000000000000000000090810204021790555080600060026101000a81548173ffffffffffffffffffffffffffffffffffffffff021916908302179055505b506103be8061011f6000396000f3006060604052361561007f576000357c01000000000000000000000000000000000000000000000000000000009004806338cc48311461008157806339df1608146100b85780633af94817146100cb57806340193d17146100d857806341c0e1b5146100fc578063fab43cb114610109578063fb5d5729146101405761007f565b005b61008c600450610272565b604051808273ffffffffffffffffffffffffffffffffffffffff16815260200191505060405180910390f35b6100c9600480359060200150610214565b005b6100d66004506102f8565b005b6100e36004506101f8565b604051808260000b815260200191505060405180910390f35b610107600450610164565b005b610114600450610243565b604051808273ffffffffffffffffffffffffffffffffffffffff16815260200191505060405180910390f35b61014b60045061027f565b604051808260000b815260200191505060405180910390f35b600160009054906101000a900473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff163373ffffffffffffffffffffffffffffffffffffffff1614156101f557600160009054906101000a900473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff16ff5b5b565b6000600060019054906101000a900460000b9050610211565b90565b80600060026101000a81548173ffffffffffffffffffffffffffffffffffffffff021916908302179055505b50565b6000600060029054906101000a900473ffffffffffffffffffffffffffffffffffffffff16905061026f565b90565b600030905061027c565b90565b60007fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff600060006101000a81548160ff02191690837f0100000000000000000000000000000000000000000000000000000000000000908102040217905550600060009054906101000a900460000b90506102f5565b90565b600060029054906101000a900473ffffffffffffffffffffffffffffffffffffffff1673ffffffffffffffffffffffffffffffffffffffff1663fb5d5729604051817c01000000000000000000000000000000000000000000000000000000000281526004018090506020604051808303816000876161da5a03f1156100025750505060405151600060016101000a81548160ff02191690837f01000000000000000000000000000000000000000000000000000000000000009081020402179055505b56',
        gas: 1000000
    },
    function(e, contract) {
        if (typeof contract.address != 'undefined') {
            console.log(e, contract);
            console.log('Contract mined! address: ' + contract.address + ' transactionHash: ' + contract.transactionHash);
        }
    });
    
> Contract mined! Address: 0x17368ba7a5e05d4204edc1692dc875fbacf90245
[object Object]
> 
> pong.getPongvalConstant();
-87		// pong knows its pongval									
> ping.getPongvalConstant();
-1		// ping doesn't know the new value yet
> ping.getPongvalRemote.sendTransaction({from:eth.coinbase,gas:1000000});
"0xaad73ff006032e59d8a84055528f1361e6cfe02a7cf44acf61fcaed334b3a097"
> ping.getPongvalConstant();
-87     // now ping knows the pongval from the transactional return value.
> 
    
    */

External Links

Etherscan Verified Source (if any)

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