进程间如何做到互斥？

wangchen_0626

进程间如何做到互斥？ [复制链接]

gpio寄存器都是以组的形式出现（一个寄存器对应一组gpio.pin），我们的多个驱动会用到同一组gpio的不同pin来做一些使能复位等控制，那么会出现对不同pin但同组即同寄存器操作的状况吗？在同一进程下，我们可以用线程同步的互斥体来避免冲突。如果是进程呢？进程会遇到这种情况吗？进程是在什么情况下做的切换呢？有可能在执行gpio操作的代码（读-改-写）中间做切换吗？

jobezxy

一样的，CREATEMUTEX。这个是全局的。

daizhi1970

如果是两个应用程序，怎么定义一个全局的互斥体对象。

力量

用有名mutex
CreateMutex的时候有个参数Name
两个应用程序用同一个Name就可以了

zhufuzhufu

有个ID号啊！

niuhuang123

pb help里对CREATEMUTEX的解说。所以只要指定一个同样的名字，就可以实现进程间的互斥了。

A handle to the mutex object indicates success. If the named mutex object existed before the function call, the function returns a handle to the existing object and GetLastError returns ERROR_ALREADY_EXISTS. Otherwise, the caller created the mutex. NULL indicates failure. To get extended error information, call GetLastError.

Two or more processes can call CreateMutex to create the same named mutex. The first process actually creates the mutex, and subsequent processes open a handle to the existing mutex. This enables multiple processes to get handles of the same mutex, while relieving you of the responsibility of ensuring that the creating process is started first. When using this technique, set the bInitialOwner flag to FALSE; otherwise, it can be difficult to be certain which process has initial ownership.

Multiple processes can have handles of the same mutex object, enabling use of the object for interprocess synchronization. To provide object sharing, a process can specify the name of a mutex object in a call to the CreateMutex function.

Use the CloseHandle function to close the handle. The system closes the handle automatically when the process terminates. The mutex object is destroyed when its last handle has been closed.