信号量

在内部，有一种保护每个视图的信号量，它称为Collection信号量。

Internally , there is a semaphore protecting each view called the Collection semaphore .

在Linux中，我们使用sempost（）来释放信号量。

In Linux , sem_post () is used to release semaphore .

value（信号量计数器）是这个信号量的初始值。

Value ( semaphore count ) is the initial value of the semaphore .

在进程之间，可以使用SystemV信号量。

Between processes , System V semaphores can be used .

记住，超时操作在SystemV信号量中并不适用。

Remember that the timeout option is not available in System V semaphore .

key应该指向想要打开的信号量集的key值。

Key should point to the semaphore set key , which you want to open .

key是一个惟一的标识符，不同的进程使用它来标识这个信号量集。

The key is a unique identifier that is used by different processes to identify this semaphore set .

关于每个SystemV信号量的原型，请参阅本文中有关信号量一节的内容。

Refer to the section on semaphores in this article for the prototype for each of these System V semaphores .

在Linux中，semwait（）用来获取对信号量的访问。

In Linux , sem_wait () is used to acquire the semaphore access .

Linux内核中信号量机制的研究与实现

Research and Realization on Semaphore Mechanism in Linux Kerne

在Linux中，进程之间有名事件对象所实现的功能可以使用SystemV信号量实现。

In Linux , the named event objects functionality between processes can be achieved by using a System V semaphore .

为了在Linux实现与Windows中有名事件对象相同的功能，可以使用SystemV信号量或信号。

To achieve functionality of named event objects in Linux , System V semaphore or signals can be used .

基于信号量的Linux多线程同步研究

Research on Linux Multithread Synchronization Based on Semaphore

当然，解决方案是使用finally来释放信号量许可证，这是一个很简单却容易被遗忘的方法。

The solution , of course , is to use finally to release the semaphore permit ; an easy enough but all-too-often-forgotten approach .

Debugcapturetimeout=10给每个信号量超时消息加时间戳。

Debug_capture_timeout = 10 time stamps each semaphore timeout message .

“showstat”命令将报告信号量超时信息。

The'show stat'command will record semaphore timeout information .

信号量机制在Linux中的实现

Implementation of Semaphore Mechanism in Linux

Windows信号量是一些计数器变量，允许有限个线程/进程访问共享资源。

Windows semaphores are count variables allowing a limited number of threads / processes to access the shared resource .

定义在kernel/semaphore.c中，它用于获取信号量sem。

Defined in kernel / semaphore . c , it is used to acquire the semaphore sem .

注意，在SystemV信号量中，key被用来惟一标识信号量；在Windows中，信号量是使用一个名称来标识的。

Notice that in System V semaphores , key is used to uniquely identify the semaphore ; in Windows , the semaphore is identified by a name .

利用信号量、消息等系统功能提高CPU的使用效率。

It improves the efficiency of CPU usage by providing semaphore , message and other system functions .

它的核心原理是，一个信号量是一个单精度的整形数值，此数值结合了一双函数集称为P和V。

At its core , a semaphore is a single integer value combined with a pair of functions that are typically called P and V.

用信号量机制与PV操作解决进程同步互斥问题的方法Windows下的线程互斥和同步

Achieve Mutual Exclusion in Process Synchronization with Signal Mechanism and PV Operation Line Procedure Mutually-exclusive and Synchronization under Windows

如果并没有请求上一个信号量计数器的值，那么这个参数可以是NULL。

The parameter can be NULL if the previous semaphore count value is not required .

等待函数中的超时：当在一个等待函数中使用时，可以为Windows信号量对象指定超时值。

Timeout in wait functions : When used in one of the wait functions , timeout value can be specified for Windows semaphore objects .

在Linux中，条件变量和POSIX信号量都是自动重置类型的。

In Linux , conditional variable and POSIX semaphores are of the auto-reset type .

TIMEOUT=nDomino服务器控制台报告信号量超时消息的速率（毫秒数）。

TIMEOUT = n Rate at which the Domino server console reports semaphore timeout messages in milliseconds .

在Linux上，在相同进程的不同线程之间，则只使用POSIX信号量。

On Linux , POSIX semaphores are used only between the threads of same process .

在Linux中，POSIX信号量和SystemV信号量也都是异步的，不过pthreads条件变量不是异步的。

In Linux , POSIX semaphores and System V semaphores are asynchronous but pthreads conditional variables are not asynchronous .

本文给出了信号量的具体含义并提出用P，V原语实现进程互斥的一般模型。

In this paper , We give specific meaning of semaphores and put forward a general model to achieve process mutual exclusion with P , V primitive .