epoll com

In the network programming of Linux, the new event triggering mechanism is-epoll. The biggest benefit compared to Select,epoll is that it does not reduce efficiency as the number of monitoring FD increases. Because in a select implementation in the kernel, it is handled by polling, the more the number of FD polled, the more natural time consuming. Also, in the Linux/posix_types.h header file there is such a

the user State and then pass it to the kernel. However, it is only supported in the 2.6 kernel. Epoll is more suitable for handling a large number of FD, and there are not many cases of active FD. After all, FD is a large number of serial operations. ========================================================== ================================== I do not know much about select, poll, and epoll.

Turn from: http://blog.csdn.net/tianmohust/article/details/6677985 i). Epoll Introduction Epoll is currently in Linux under the development of large-scale concurrent network programs popular candidates, Epoll in the Linux2.6 kernel formally introduced, and select similar, in fact, I/O multiplexing technology just , and nothing mysterious. In fact, the design of

When using Epoll, if you call fork to create a child process after calling Epoll_create, the parent-child process has a copy of its own Epoll instance, but in the kernel, they refer to the same instance. When a child process adds, modifies, and deletes a file descriptor to its own Epoll instance, it can affect the epoll_wait of the parent process. So there will b

the file descriptor, so there is no limit, and the following 3 disadvantages of the Select are also applicable to poll. Epoll Epoll was born in the Linux 2.6 kernel and is considered to be the best Linux2.6 multiplex Io multiplexing method under the performance. Epoll Features: Epoll does not have the maximum concurre

Epoll is a particularly important concept that is often used to handle concurrency problems on the server side. When the number of online services is more and more, will lead to system resources tight, I/O efficiency is more and more slow, this time should consider epoll. Epoll is the Linux kernel's improved poll for handling large numbers of handles and is a Lin

the difference between Epoll and Select/pollThe select,poll,epoll is a mechanism for IO multiplexing. I/O multiplexing is a mechanism by which multiple descriptors can be monitored, and once a descriptor is ready, the program can be notified of the appropriate action. The essence of select is 32 bits with 32 integers, that is, the 32*32= 1024来 identifier, and the FD value is 1-1024. When the value of FD exc

(a) functionRPC (remote function call) provides services for client-side calls to functions on the remote server side through the network.The Rpc-server side needs to provide high throughput capability and support large concurrent connections.(ii) Design ideas Epoll Monitor multiple connection fd for IO multiplexing 1) Epoll does not have the maximum concurrent connection limit, the maximum ca

First, what is EpollEpoll is an improved poll of the Linux kernel for processing large-volume file descriptors, an enhanced version of the multiplexed IO interface select/poll under Linux, which significantly increases the CPU utilization of the program in cases where there are only a few active instances of a large number of concurrent connections. Another reason is that when getting an event, it does not need to traverse the entire set of descriptors that are being listened to, as long as it t

I recently learned the I/O model and suddenly thought of the I/O model of epoll. To study this problem, we must first know which I/O models are commonly used. Common Io models are as follows: Blocking IO: The program is blocked until Io is available. The simplest I/O model. The recvfrom receiving function you call usually belongs to this model. Non-blocking IO: The program returns immediately after calling the IO function, regardless of whether the

Advantages of Epoll:1. Support a process to open a large number of socket descriptors (FD)Select the most unbearable is a process opened by the FD is a certain limit, set by Fd_setsize, the default value is 2048. It is obviously too small for the number of connected IM servers that need to be supported. At this time you can choose to modify the macro and then recompile the kernel, but the data also pointed out that this will bring down the network eff

Tags: Lin callback memory Support problem object Create List LinuxWhen developing high-performance network programs, Windows developers say that Iocp,linux developers will say Epoll. We all know that Epoll is an IO multiplexing technology that can handle millions of socket handles very efficiently, much more efficiently than previous select and poll. We use the epoll