• Java language asynchronous non blocking design pattern (principle)


    There are 2 articles in this series to popularize the asynchronous non blocking mode of Java language. Principles explains the principle of asynchronous non blocking model and the basic characteristics of the core design pattern “promise”. The application section will show richer application scenarios, introduce promise variants, such as exception handling and scheduling strategies, and […]

  • How does Java handle null values more gracefully?


    Source: sigma blog https://lrwinx.github.io/ 2019-12-17 09:39:00 In my several years of development experience, I often see that there are null value judgments everywhere in the project. These judgments will make people feel confused. Its emergence is likely to have nothing to do with the current business logic. But it will give you a headache. Sometimes, […]

  • Advantages and disadvantages of concurrent programming (-)


    1.Why concurrency For a long time, the development of hardware has been extremely rapid, and there is also a very famous “Moore’s law“. It may be strange that it is clearly discussed why concurrent programming involves the development of hardware. The relationship should be the hardware foundation provided by the development of multi-core CPU for […]

  • Some basic concepts involved in swoole


    IO (input / output) In computers, input / output (i.e. IO) refers to the communication between information processing systems (such as computers) and the external world (which can be people or other information processing systems). Input refers to the signal or data received by the system, and output refers to the data or signal sent […]

  • Effective c# (5) – exception handling


    Programs always make mistakes, because even if developers do it carefully, unexpected things will happen. Making the code stable in case of exceptions is a key skill that every c# programmer should master.. net framework design guidelines suggests that if the method cannot complete the operation requested by the caller, you can consider throwing an […]

  • Operating system — privilege level switch


    There are four levels of privilege level, from high to low: level 0, level 1, level 2 and level 3. Switching privilege level refers to transferring from level 0 to level 1, or from level 1 to level 3. In short, it refers to the transfer from one privilege level to another different privilege level. […]

  • Basic concepts of Java concurrency


    1. Concurrency and parallelism for instance Concurrency: the key to concurrency is the ability to handle multiple tasks, but not necessarily at the same time Example 1: when eating, the phone rings, stop eating temporarily, and continue eating after answering the phone Example 2: one person eats three steamed buns Parallelism: the key to parallelism […]

  • Enrich your log information: get line number and other information from Python call stack


    Log printing or message uploading in the program, such as Kafka message, etc. Among the frequently uploaded messages, the file name, line number, upper layer caller and other specific positioning messages in the stack information need to be uploaded. Python provides the following two methods: sys._getframe, basic method inspect.currentframeIn addition to the recommended method, providesys._getframeMethod, […]

  • How to select webclient, httpclient, Httpwebrequest in. Net


    When we call restapi with. Net, we usually have three options:WebClient, HttpWebRequest,HttpClientIn this article, we will discuss how to use these three methods to call the restapi. I will also provide corresponding code cases to help you better understand the concepts and usage of these three methods. In short: HttpWebRequestIt is a relatively low-level way […]

  • JS function arguments and application of higher order functions


    Function member – arguments Arguments: the collection of all arguments (class array object) passed in when the function is called Arguments. Callee: an attribute of arguments that points to the function itself Function name. Caller: the caller of the function. If it is called globally, the returned caller is null. Function name. Length: number of […]

  • Design pattern learning 16 (Java implementation) — command mode


    Write in front Take notes on learning design patterns Improve the flexible use of design patterns Learning address https://www.bilibili.com/vide… https://www.bilibili.com/vide… Reference articles http://c.biancheng.net/view/1… Project source codehttps://gitee.com/zhuang-kang/DesignPattern 18. Command mode 18.1 definition and characteristics of command mode The command mode is defined as follows:Encapsulating a request as an object separates the responsibility of issuing the request […]

  • [translation] some theories of modern go


    Translated from < a theory of modern go > by Peter bourgon 2017 / 06 / 09 Original link The conclusion is as follows Global state has huge side effects — > package level variables and init functions need to be avoided Part1 Go is easy to read The only best attribute of the go […]