C multithreaded lock collation record

ManualResetEvent

new ManualResetEvent(true) // Don't block at first

WaitOne();// Wait for the signal

Reset(); // Threads will block in WaitOne Call location （ Generally, I like to package this , Name it Lock,Set Then for Unlock

Set();// Threads don't block ,WaitOne Directly through

AutoResetEvent

new AutoResetEvent(false) // Don't block at first , Here and Manual It's the opposite

Call once Set, unblocked , When WaitOne After passing through a thread , Automatic re blocking , Equivalent to internal automatic Reset 了

Mutex

similar AutoResetEvent

ReleaseMutex（Set） Release when you're in

A thread passes WaitOne It will immediately block (Reset)

lock

Common are lock One static object perhaps object

Whether static or not mainly depends on whether you care about static variables or variables of the current instance

Monitor

lock(obj) Itself is equivalent to

Monitor.Enter(obj);

Monitor.Exit(obj);

Interlocked

Thread safe simple variable operation

public int State
{
get => Interlocked.Increment(ref _state);
}

SpinLock

C# Thread lock （ spinlocks SpinLock、 The mutex Mutex、 Hybrid lock Monitor | lock）_xujianjun229 The blog of -CSDN Blog _c# Thread lock

Spin lock refers to when a thread is acquiring a lock object , If the lock has been acquired by another thread , Then this thread will wait circularly , Keep getting the lock , Until we get the lock . It is suitable for scenarios with very short atomic operation time

advantage ： Avoid thread context switching . Higher performance .

shortcoming ： If you wait a long time , Will consume a lot of CPU resources . And multiple waiting threads , It's not that the longer you wait, the first you get the lock , May wait forever .

private static SpinLock _spinLock = new SpinLock();
private static int incrValue = 0;// Shared resources
private void Run()
{
bool locked = false;
_spinLock.Enter(ref locked);// Get the lock
incrValue++; // Secure logical computation
if (locked) // Release the lock
_spinLock.Exit();
}

ReaderWriterLockSlim Read-write lock

.NET Synchronous and asynchronous lock （ReaderWriterLockSlim）（ 8、 ... and ）_mb5fe09d2d96fc4 Technology blog _51CTO Blog

ReaderWriterLockSlim.EnterUpgradeableReadLock Method （System.Threading） | Microsoft documentation (microsoft.com)

EnterUpgradeableReadLock Mainly for , Need to read , Also write about

SemaphoreSlim

Set a quantity when constructing , Limit the number of incoming threads

SemaphoreSlim class (System.Threading) | Microsoft Docs

CancellationTokenSource

This is not a lock . I just saw By the way .

C# Use CancellationTokenSource Cancel multithreading _tnblog Technology sharing ～ The blog of -CSDN Blog _cancellationtokensource

CancellationTokenSource cts = new CancellationTokenSource();

Call before executing the main logic in the thread ：

cts.Token.ThrowIfCancellationRequested();

Somewhere called cts.Cancel(true);

When the thread executes ThrowIfCancellationRequested The location of , It throws an exception , Exit the thread directly

If the thread has executed to ThrowIfCancellationRequested After that ,cts It doesn't work .