thinking and modular organization of Go-ethereum
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Ethereum's goal is to build a centralized platform for running smart contracts based on blockchain technology.
# # One. Blockchain technology
Blockchain belongs to a kind of centralized digital bookkeeping technology, and blockchain data is maintained by nodes that are not trusted by each other, and each node replicates a complete record.
# Two.
First visit GitHub on the Go Language development client URL: Https://github.com/ethereum/go-ethereum
Installing Ethereum Https://github.com/ethereum/go-ethereum/wiki/Building-Ethereum
Install on Mac
Brew Tap
(1) what is Ethereum.
Ethereum is a decentralized, intelligent contract platform supported by Ether's crypto currency. (2) have heard of Ethereum, but what is geth,mist,ethminer,mix.
Geth: The go implementation of the Ethereum node is the basis for any interaction with the Ether
Preface
Since go Ethereum is the most widely used Ethereum client, subsequent source analysis is analyzed from this code on GitHub.
Build Go ethereum debugging environment
Windows 64bit
First download go install package to install, because go website is wall, so download from the address below.
https://studygolang.com/dl/golang/go1.9.1.windows-amd64.msi
After ins
Account
The account plays a central role in Ethereum. There are two types of accounts: external accounts (EOAS) and contract accounts. We'll focus on the external account here, which will be referred to as the account. Contract accounts are referred to as contracts and are discussed specifically in the contract chapters. The general concept of putting both external and contractual accounts into accounts is justified, since these entities are so-calle
Exception Reason:1, wrote a cycle of death, this is the most likely.2, the operation of large data volume, resulting in the status of suspended animation.Solution: Managed Debug Assistants in Debug---Exceptions, remove ContextSwitchDeadlock a front hook.Exception information: The CLR cannot convert from COM context 0x645e18 to COM context 0x645f88, which has lasted for 60 seconds. The thread that owns the target context/unit is most likely to perform
1.WPF multithreaded Modification UI Example:// Start thread Modify UI, throw exception ThreadPool.QueueUserWorkItem ((q) += {" Zhang San "null);Solution: Modify the UI by using the Dispatcher.begininvoke+ delegate methodEncapsulating code that modifies the UI in a delegate// Start thread processing New true; // set to a background thread, the background thread exits automatically when the main thread ends, otherwise the program cannot end Thread1. Start ();//threading methods, modifying butt
Let's look at the code first:var s = "Test"; var len=s.length;We know that the string declared in JavaScript like above is not an object, but since S is not an object, why is there a property of length?The reason is that in JavaScript, whenever you reference a property of a string (numeric, Boolean, and so on), JS converts the string to an object by calling new string (s), which inherits the string's method and is used to handle the property's reference. Once the attribute reference is finished,
1. Create a complextype.xsd file under the D:/xml practice directory2. Download the XJC tool, which can be downloaded at the following link:http://download.csdn.net/detail/u013998070/85696673. Open the command line and adjust to the bin directory of the XJC ToolkitIf you do not know what you need to enter, you can simply enter the XJC command to view it, as followsAfter you clear the relevant commands, enter the following instructions to generate the target Java codeThe schema that
I tried some of the methods offered online, and finally I solved some problems with SQL.
1 Select the problematic database in the Query Analyzer and enter:Exec sp_configure ' allow updates ', 1--Allows the system tables to be updated.
Reconfigure with OVERRIDE
2. Run the following SQL statement:UPDATE sysobjects Set uid=1--all objects in the database are assigned to the user dbo
3. Execute the following SQL statement:
Exec sp_configure ' allow updates ', 0--Shutdown system Table update
Re
This is a creation in
Article, where the information may have evolved or changed.
After learning from various sources, we decided to start building a private chain environment based on Ethereum Go-ethereum. Because my computer system for WIN8, in order to avoid the window environment too many inexplicable problems, deliberately through the VM built a ubuntu16.04 version of the virtual system. The following
SQL database user cannot delete, prompting "the user cannot be dropped because the selected user owns the object" workaroundDue to the error of the MSSQL200 database, I restored an original database to the current SQL, at this time I came to the user, want to restore the user deleted, but the result is prompted "because the selected user has an object, so the user cannot be removed"Because PB automatically establishes the table with the logged-in user
Error: The calling thread cannot access this object because another thread owns the objectMain window Create thread, multithreading cannot call control directlyThe thread created by the main window Public MainWindow () { InitializeComponent (); New Thread (listenchange); T.start (); }Line Cheng: Public void Listenchange () { // Create a ListView item is not written, here is just an example of
Title, when a WPF child thread accesses the UI thread, assigns a value to the UI's control, and if it does not, it reports the exception: "The calling thread cannot access this object because another thread owns the object." ”The solution is as follows: // method One this. Dispatcher.invoke (Action)delegate() {// your code }); // Method Two App.Current.Dispatcher.Invoke (Action)delegate(
Ethereum History
For recent history, please see the Taylor gerring blog post. Birth
At the same time, Vitalik began working with Dr. Gavin Wood to create Ethereum. In April 2014, Gavin published the Ethereum Yellow Book as a technical note for Ethereum virtual machines. As specified in the Yellow Book, the
Error When deleting a user:
MSG 15138, level16, state 1, line 1
The Database Principal owns a schemain the database, and cannot be dropped.
Solution (SSMs ):
1. Find the user's schema
2. Find the db_owner In the schema and change the schema owner from test6 to DBO or another user.
3. delete user test6
Or use the following statement to delete the file:
--- Query the schema owned by user test6 as db_owner
Use DBA;
Select
successful. You think people are casual, in fact, it is not so. There are things that you can see only by standing on that level.In this world, there is no shortage of wise people, but wise men.6.What I want to say is that good things are always fought and sacrificed to get.Will all the good things in the world be automatically put into your arms? Will the pie in the sky just fall into my open mouth? Especially the poor people like me, my competitors are the strength of my rich, they stand high
Tags: Database SQL Server 2008When using SQL Server to Do data mining, the user can not access the problem, so to the corresponding database add a login user Zhang, and give the appropriate permissions. When debugging, found that there is still a problem, so want to delete this user Zhang, and create a new user. An error message appears : The database principal has a schema in the database and cannot be deleted. (Microsoft SQL Server, error : 15138) Solution:Delete the schema for this user, an
In doing some testing, it may be necessary to build a private ethereum network to facilitate control and to get to the real test work faster.While the Ethereum nodes can link to each other need to meet 1) the same protocol version 2) the same networkid, so the most convenient way to build a private network is to use the--networkid option in the Geth command to set a different networkid from the main network
In Ethereum (1): In the steps to build the Ethereum private chain on CentOS 6.5 we set up the Ethereum private chain, this time we will create accounts, mining and transfer operations in this private chain environment.
First of all, to review the construction process, the more important part of our talk.
We used the last step in the build./geth--rpc--rpccorsdoma
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