Both lock and mutex are synchronization primitives in C# that help prevent race conditions and ensure thread safety. However, they differ in their implementation and usage:
Lock:
- Implementation: A lock is a syntactic sugar provided by C# that simplifies the use of a Monitor class. It's a convenient way to acquire and release a lock on a specific object.
- Usage: You use
lock
with a specific object as the argument. This object acts as a lock, ensuring that only one thread can execute code within thelock
block at a time. - Example:
public class Counter
{
private int count = 0;
public void Increment()
{
lock (this)
{
count++;
}
}
}
Mutex:
- Implementation: A mutex is a more powerful synchronization primitive that can be used across multiple processes. It's implemented using the Mutex class in C#.
- Usage: You create a mutex with a unique name. Threads can acquire and release the mutex using its methods. If another thread already holds the mutex, a thread attempting to acquire it will block until the mutex is released.
- Example:
using System.Threading;
public class MyMutex
{
private Mutex mutex = new Mutex(false, "MyMutexName");
public void DoSomething()
{
// Acquire the mutex
if (mutex.WaitOne(Timeout.Infinite))
{
try
{
// Critical section
// ...
}
finally
{
// Release the mutex
mutex.ReleaseMutex();
}
}
}
}
Key Differences:
- Scope: Locks are scoped to a specific object, while mutexes can be used across multiple processes.
- Implementation: Locks are built on the Monitor class, while mutexes are implemented using the Mutex class.
- Usage: Locks are simpler to use, while mutexes provide more flexibility and control.
In summary, lock is a convenient way to synchronize access to an object within a single process, while mutex is a more powerful and versatile mechanism for synchronization across multiple processes.