. NET parallel (multicore) programming series seven shared data issues and solutions overview

Preface: The previous article introduced some basic knowledge of parallel programming, from this beginning, will talk about the actual encounter some problems in parallel programming, the next few will talk about data sharing problem.

The topics in this article are as follows:

Data competition

Solution proposal

Sequential Execution Solution

Data invariant Solutions

Before we begin, let's take a look at an interesting example:

 class BankAccount 
 {
 public int Balance 
 {
 get; 
 Set 
} 
} 
 class App 
 {
 static void Main (string[] args) 
 {
//Create the bank account ins        Tance 
 BankAccount account = new BankAccount (); 
        Create an array of tasks 
 task[] tasks = new TASK[10]; 
 for (int i = 0; i < i++) 
 {
///Create a new task 
 Tasks[i] = new Task (() =&G T 
 {
//Enter a loop for 1000 balance updates 
 for (int j = 0; J < 10 00; J + +) 
 {
//update the Balance 
 account. Balance = account. Balance + 1; 
} 
}); 
//Start the new task 
 Tasks[i]. Start ();        
} 
//Wait for all of the tasks to complete 
 Task.waitall (tasks); 
 Write out the counter value 
        Console.WriteLine ("Expected value {0}, Counter value: {1}", 
 10000, account. Balance);        
//wait for input before exiting 
 Console.WriteLine ("Press ENTER to finish"); 
 Console.ReadLine (); 
} 
}