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.NET 9 new features-C#13 new lock types and semantics

Popularity：308 ℃/2025-01-22 16:08:28

In C# 13, new lock types and semantics are introduced, mainly used to enhance the synchronization mechanism in multi-threaded programming.

Traditionally, C# useslockKeywords and arbitraryobjectInstances cooperate to achieve mutually exclusive access between threads. However, this approach may have performance bottlenecks and potential deadlock risks.

To this end, C# 13 introduces new lock types in .NET 9, providing a more efficient and safe thread synchronization mechanism.

It is a structure specially designed for thread synchronization and provides an improved API to achieve more efficient thread synchronization operations.

For example,()Methods can enter an exclusive scope, thereby replacing the traditionallockKeywords.

Main application scenarios

The new lock types and semantics are mainly applicable to the following scenarios:

  1. Multi-threaded applications with high performance requirements: In a high-concurrency environment that requires frequent locking and unlocking,Provides a more efficient locking mechanism and reduces context switching overhead.

  2. Complex synchronization requirements: For applications that require fine-grained control over locking behavior, the new lock type provides a more flexible API that can meet complex synchronization requirements.

  3. avoid deadlock: Through new lock semantics, functions such as timeout and cancellation can be more easily implemented, reducing the possibility of deadlocks.

Sample code

The following is usedSample code that demonstrates how to safely update shared resources in a multi-threaded environment:

using System;
using ;
using ;

public class Account
{
    private decimal _balance;
    private Lock _balanceLock = new Lock();

    public Account(decimal initialBalance)
    {
        _balance = initialBalance;
    }

    public void Debit(decimal amount)
    {
        if (amount <= 0)
            throw new ArgumentException("Amount must be positive", nameof(amount));

        using (_balanceLock.EnterScope())
        {
            if (_balance < amount)
                throw new InvalidOperationException("Insufficient funds");

            _balance -= amount;
        }
    }

    public void Credit(decimal amount)
    {
        if (amount <= 0)
            throw new ArgumentException("Amount must be positive", nameof(amount));

        using (_balanceLock.EnterScope())
        {
            _balance += amount;
        }
    }

    public decimal GetBalance()
    {
        using (_balanceLock.EnterScope())
        {
            return _balance;
        }
    }
}

public class Program
{
    public static async Task Main()
    {
        var account = new Account(1000m);

        var tasks = new Task[10];
        for (int i = 0; i < ; i++)
        {
            tasks[i] = (() =>
            {
                for (int j = 0; j < 100; j++)
                {
                    (10);
                    (10);
                }
            });
        }

        await (tasks);

        ($"Final balance: {()}");
    }
}

In the above code:

  • Accountkind: Represents a bank account, including debit, credit, and methods for obtaining balance.

  • _balanceLockField: use newLocktype, make sure to_balanceField access is thread-safe.

  • EnterScope()method: Used to enter an exclusive locking scope to ensure that access to shared resources within this scope is mutually exclusive.

  • usingstatement: Ensure that the lock is automatically released when the scope ends to prevent deadlock.

by using newtype, the code implements more efficient thread synchronization and avoids the traditionallockPerformance issues and potential risks that keywords may bring.

The implementation is based on the following key concepts:

  1. private lock object：It is a type specially designed for thread synchronization, avoiding the disadvantages of using general objects as locks.

  2. Scope management:passEnterScope()Method, enter a locked scope to ensure that access to shared resources within the scope is thread-safe.

  3. automatic release:useusingstatement to ensure that the lock is automatically released when the scope ends.

 

In C# 13, new lock types and semantics are introduced, mainly used to enhance the synchronization mechanism in multi-threaded programming.

 

Zhou Guoqing

2025/1/7

 
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