ELF file format and example analysis

ELF (Executable and Linkable Format) Compiled source code on Linux o file is the target file. The structure of the target file is very similar to that of the executable file. The executable file is obtained by linking the corresponding library through the linker elf. For the convenience of description, the storage formats of the two are not d ...

Posted by aod on Tue, 19 Apr 2022 05:20:59 +0300

ABB Robot socket communication guide

1, Introduction In industrial automation, the most commonly used is profinet. Industrial equipment can send or receive data reliably in real time (1ms or less) with one network cable through configuration. profinet is similar to profibus+ethernet. However, for ordinary computers, profinet communication with ABB robots cannot be realized, and s ...

Posted by daiwa on Tue, 19 Apr 2022 02:02:43 +0300

Multi thread synchronization mechanism

Multi thread synchronization mechanism (thread safety) Whether the program is thread safe: whether the method of the program is a synchronous method. When viewing the source code of a class in the future, if the method in the class is a synchronous method, it means that the class is thread safe. (when this kind of operation is in progress, it ...

Posted by lalabored on Tue, 19 Apr 2022 01:11:55 +0300

Regular expression of re library for python learning

Regular expression is a special character sequence, which can help you easily check whether a string matches a pattern. python is implemented by re module re. The search () method is used to search the string for the first occurrence of a regular expression pattern Search for non-existent strings and return None, import re re.search("dawn"," ...

Posted by thefisherman on Mon, 18 Apr 2022 00:13:26 +0300

Detailed explanation of Lambda expression

5.Lambda expression 5.1 experience Lambda expression [understanding] Code demonstration /* Swimming interface */ interface Swimming { void swim(); } public class TestSwimming { public static void main(String[] args) { // Implemented through anonymous inner classes goSwimming(new Swimming() { @Overrid ...

Posted by jarv on Sun, 17 Apr 2022 21:28:53 +0300

Active information collection: ARP based host discovery

Active information collection: ARP based host discovery ARP protocol (address resolution protocol) belongs to the protocol of data link layer, which is mainly responsible for obtaining the data link layer address (MAC) according to the network layer address (IP). Ethernet protocol stipulates that if a host in the same LAN wants to communicat ...

Posted by BlueSkyIS on Sun, 17 Apr 2022 13:19:03 +0300

Deep understanding and use of Spring AOP

Spring AOP 1, Introduction Aspect oriented programming (AOP) provides a supplement to Object-oriented Programming (OOP). The core unit of Object-oriented Programming is class, but the core unit of aspect oriented programming is aspects. Different from the object-oriented sequential process, AOP adopts a horizontal aspect approach and injects ...

Posted by bslevin on Sat, 16 Apr 2022 22:46:44 +0300

Actual combat: use Alibaba Arthas tool to analyze CPU soaring

Arthas is an open-source Java diagnostic tool of Alibaba. Compared with the built-in diagnostic tool of JDK, it is more user-friendly and powerful. It can locate many problems with one click, decompile classes with one click to view the source code, and even carry out hot repair of production code directly, so as to realize the one-stop service ...

Posted by Lee on Sat, 16 Apr 2022 14:18:57 +0300

[CSDN Software Engineer competency certification learning selection] teach you to read the source code of Cpython

CSDN Software Engineer competency certification (hereinafter referred to as c-series certification) is a competency certification standard formulated and launched by CSDN. C series certification has gone through nearly a year of actual offline research, investigation, iteration and testing, and sorted out various technical skills required in th ...

Posted by travelerBT on Fri, 15 Apr 2022 23:07:03 +0300

C++ linux semaphore not completed to be continued

brief introduction A semaphore is essentially a counter used to coordinate the reading / writing of shared data objects by multiple processes (including but not limited to parent-child processes). It is not for the purpose of transmitting data. It is mainly used to protect shared resources (shared memory, message queue, socket connection pool, ...

Posted by amob005 on Fri, 15 Apr 2022 15:34:10 +0300