问题
What is the Mutex and semaphore in C#? Where we need to implement?
How can we work with them in multithreading?
回答1:
You should start at MSDN.
- System.Threading.Mutex: A synchronization primitive that can also be used for interprocess synchronization.
- System.Threading.Semaphore: Limits the number of threads that can access a resource or pool of resources concurrently.
Generally you only use a Mutex across processes, e.g. if you have a resource that multiple applications must share, or if you want to build a single-instanced app (i.e. only allow 1 copy to be running at one time).
A semaphore allows you to limit access to a specific number of simultaneous threads, so that you could have, for example, a maximum of two threads executing a specific code path at a time.
回答2:
You might want to check out the lock statement. It can handle the vast majority of thread synchonization tasks in C#
class Test {
private static object Lock = new object();
public function Synchronized()
{
lock(Lock)
{
// Only one thread at a time is able to enter this section
}
}
}
The lock statement is implemented by calling Monitor.Enter and Monitor.Exit. It is equivalent to the following code:
Monitor.Enter(Lock);
try
{
// Only one thread at a time is able to enter this section
}
finally
{
Monitor.Exit(Lock);
}
回答3:
I'd start by reading this: http://www.albahari.com/threading/part2.aspx#_Synchronization_Essentials and then bolster it with the MSDN links bobbymcr posted.
来源:https://stackoverflow.com/questions/1553012/what-is-the-mutex-and-semaphore-in-c-where-we-need-to-implement