trigamous relationship

works on the last two layers of the OSI, the physical layer and the data link layer, and the physical layer defines the electrical and optical signals, line States, clock benchmarks, data encoding, and circuitry needed for data transmission and reception, and provides a standard interface to the data link layer device. The physical layer of the chip is called PHY. The data link layer provides the functions of addressing mechanism, data frame construction, data error checking, Transmission contr

. So the filter, Interceptor, Service () method, the execution order of the DISPATC () method should be like this, roughly draw a picture: Actually very good test, write a filter, an interceptor, and then in these methods are added a breakpoint, all the way down the F8 came to a conclusion.　　Summary: The interceptor work is really useful in the authentication of the request authority, in the project I am involved in, the third party's remote invocation of each request needs to participate in the

In spring, the dependencies of each module are described through a simple IOC configuration file, which centralizes and understands these externalities, and when we use other Component Services, we only need to understand and configure these dependencies in the configuration file, that is, the interface is concerned, and the specific implementation of the service, After using the interface definition to leave, it is not the focus of application development concern. For application development, y

Role:Copy the SSH public key of the current machine to another machine. In order to realize from the current machine can ssh without password landing to other machinesUsage:1) Write the IP address you want to add to a file. For example, host2) Save the script as an SH file, such as Install_ssh.sh set the operational permissions3) rewrite the password settings in the script. Only a few password are supported at the moment.4) Run the commandSH install_ssh.sh Code:#!/bin/shauto_ssh_copy_id () {Loca

.　② key implementations: Determines that the child process exits the cycle of creating the child process , leaving the opportunity for the creation process to the parent process only ."Programming Experiment" build process fanProcess_swing.c#include #include#includeintMainintargcChar*argv[]) { intCounter = (ARGC 2) ?2: Atoi (argv[1]); pid_t pid; inti =0; //build Process Fan for(i =1; i) {PID=Fork (); if(PID 0) {perror ("Fork Error"); Exit (1); }Else if(PID = =0) {//the child process e

more complex things Redis can help a lot (think at timeline caching).And, of course, you have to talk about your specific application needs in the end. Redis has more data structures and supports richer data operations than memcached, usually in memcached, you need to get the data to the client for similar modifications and set it back. This greatly increases the number of network IO and the volume of data. In Redis, these complex operations are often as efficient as the general get/set. So, if

, for the system, or the same process, But it's already another program. (But some of the Exec class functions also allow the inheritance of information such as environment variables.) ）So the process's storage image is replaced by the new program (that is, the socket address structure with the other address is lost), but since the open file descriptor persists even after exec, we can call Getpeername (FD ...). ) Get the IP and port number of the peerGenerally speaking: Before calling exec to op

the file: The user must have at least R, w permissions on the file Iv. Basic permissions for a user to create a file: Permissions required for the directory: The user must have w,x permissions in the directory, with a focus on W. The basic permissions for users to enter a directory and run a command in that directory: Permissions required by the directory: the user must have at least X permission on the directory; Permissions required by the file: the user must

10 for outputLed_on ();PRINTK ("Hello on!\n");return 0;}static void __exit led_exit (void)//module unload function{Led_off ();Iounmap ((void *) virt); To undo a mapping relationshipPRINTK ("led off!\n");}Module_init (Led_init);Module_exit (Led_exit);Module_license ("GPL");Module_author ("litingtingModule_version ("2015-5-26");3 MakefileIfneq ($ (kernelrelease),)Obj-m: =VIR.OElseKerneldir: =/home/litingting/gec2440/linux-2.6.30.4AllMake-c $ (Kerneldir) m=$ (PWD) modules Arch=arm cross_compile=ar

(1) if a C + + program uses a header file with the suffix ". h", then you do not have to declare the namespace in the program, only the file contains the header file, (2) the C + + standard requires the system to provide a header file without the suffix ". Instead of using the suffix ". h" in the header file, prefix c with the corresponding header filename in C:(3) Custom header file usually with suffix ". h", System standard library file without suffix ". h".(4) because the standard library is

object individually through the session. When you use the following methods:? 1 2 3 4 session.load (Address. class new long ( 1 session.save (address); session.update (address); session.delete (address); The throws Org.hibernate.MappingException:Unknow entity class:xx.xxx.Address. The value type has no OID and cannot be persisted independently, and its life cycle depends on the life cycle of the object that owns the persisted class.　　 Two, map co

Prepare () in the thread to create a Looper, and then use Loop () to handle Messagesuntil the loop terminates. Most of the interactions with message loops are through Handler. The following is a typical threading Implementation with Looper. Class Looperthread extends Thread {public Handler Mhandler; public void Run () { looper.prepare (); Mhandler = new Handler () {public voidhandlemessage (Message msg) { //process in

1. DTOs are the data structures used to transform the background data structure (JavaBean) into a user-friendly representation, while at the same time preventing the potential danger of back-office traffic being delivered directly to the foreground.2. The converter interface provided by the Springbot framework can be used: Org.springframework.core.convert.converter.Converter, to implement conversion of entity classes and DTOs3. DTOs are reasonable allocations should be: an entity corresponds to

Hibernate Relational Mapping Directory│├─ One-Way Association│├─One way foreign key unidirectional Association│├─One-to- primary key one-way Association│├─Single connection table one-way Association│├─one-to-many foreign key unidirectional association│├─one-to-many connection Table unidirectional Association│├─multi-to-one foreign key one-way Association│├─multiple-to-one connection table one-way Association│└─Many-to-many one-way associations└─ bidirectional correlation├─One-to-one foreign key

The correspondence between action and URL in spring in Web. XML, this configuration: NBSP;NBSP;NBSP;NBSP;NBSP; servlet-mapping > servlet-name Spring Servlet-name Url-pattern>*. HTML Url-pattern> Thus, we can see that to enter into Logincontroller, we need to enter in the browser: localhost:8080/springmybatis/background/To_login . HTML The background, to_loggin, and HTML, respectively, are configured in the controller and Web. Xml. The corr

│││webelement.py│││__init__.py│││├─ie│││service.py│││webdriver.py│││__init__.py│├─opera│││options.py│││webdriver.py│││__init__.py│├─phantomjs│││service.py│││webdriver.py│││__init__.py│├─remote│││command.py│││errorhandler.py│││file_detector.py│││getattribute.js│││isdisplayed.js│││mobile.py│││remote_connection.py│││switch_to.py│││utils.py│││webdriver.py│││webelement.py│││__init__.py│├─safari│││service.py│││webdriver.py│││__init__.py│├─support│││abstract_event_listener.py│││color.py│││events.py│││e

based on different. The allocation of IP addresses is based on network topology, and the allocation of MAC addresses is based on the manufacturer.4. The addressing protocol layer is different. The IP address is applied to the third layer of the OSI, the network layer, while the MAC address is applied to the second layer of the OSI, the data link layer. The Data Link layer protocol enables data to be passed from one node to another on the same link (via MAC address), while the Network layer prot

written in the configuration file, the file descriptor in the configuration file path is written in/etc/security/limits.conf* Soft Nofile 32768 Maximum number of file descriptors that can be opened (soft limit)* Hard Nofile 65536 maximum number of file descriptors that can be opened (rigid link)* Soft Nproc 32768 Maximum number of processes that can be used by a single user (soft limit)* Hard Nproc 65536 maximum number of processes that can be used by a single user (rigid limit)Or you can write

written in the configuration file, the file descriptor in the configuration file path is written in/etc/security/limits.conf* Soft Nofile 32768 Maximum number of file descriptors that can be opened (soft limit)* Hard Nofile 65536 maximum number of file descriptors that can be opened (rigid link)* Soft Nproc 32768 Maximum number of processes that can be used by a single user (soft limit)* Hard Nproc 65536 maximum number of processes that can be used by a single user (rigid limit)Or you can write

process, and the ID of the leader process is the same as the ID of the process group. The process group ID of the Setgpid (pid_t pid,pit_t pgid) function PID process is set to Pgid. If these two numbers are equal, then the process specified by the PID becomes the leader process, but the process only assigns the leader process to itself or its child processes. If pid=0, the caller's ID is used. If pgid==0, the process ID specified by the PID is used as the leader ID. In most job control shells,