


How to use the operating system API to detect Socket connection disconnection?
Apr 02, 2025 am 11:51 AMExplore the API for Socket connection disconnect detection
Many developers encounter this problem when programming the network: How to reliably determine whether a Socket connection has been disconnected? Especially after the client actively closes the connection, how does the server sense the termination of the connection? This article will dive into the APIs provided by the operating system and how to use these APIs to detect disconnection of Socket connections.
The title of the article is "What API does the operating system provide to let us know if a socket connection is disconnected?" This is the core issue of this article. The questioner pointed out that after TCP four waves completed, the client (A) that actively closed the connection knew that the connection had been closed, but the server (B) that passively closed the connection could be sensed, and whether the operating system provided the corresponding API provisioning layer query. The questioner believes that the server application layer cannot directly perceive the four waves of the underlying operating system, and the operating system should provide corresponding APIs to solve this problem.
The questioner's doubts about not finding relevant APIs in Python are actually not a problem unique to Python. The key is to understand the mechanism of TCP connection shutdown and how the operating system exposes this information to the application layer.
The recv() function is mentioned in the answer. The recv() function is not only used to receive data, but its return value also contains important information about the connection status. The recv() function returns 0 when the peer has completed an ordered shutdown (i.e., four waves) and there is no more data to receive. This is the important basis for the application layer to determine that the Socket connection has been disconnected. Therefore, by monitoring the return value of the recv() function, the application layer can detect whether the Socket connection has been disconnected. It should be noted that recv() returns -1 and sets errno to indicate that an error has occurred and further judgment is needed based on the specific value of errno. This is different from the normal shutdown state after four waves are completed. In this way, the application layer can monitor the connection status without directly relying on the four wave details inside the operating system.
The above is the detailed content of How to use the operating system API to detect Socket connection disconnection?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

User voice input is captured and sent to the PHP backend through the MediaRecorder API of the front-end JavaScript; 2. PHP saves the audio as a temporary file and calls STTAPI (such as Google or Baidu voice recognition) to convert it into text; 3. PHP sends the text to an AI service (such as OpenAIGPT) to obtain intelligent reply; 4. PHP then calls TTSAPI (such as Baidu or Google voice synthesis) to convert the reply to a voice file; 5. PHP streams the voice file back to the front-end to play, completing interaction. The entire process is dominated by PHP to ensure seamless connection between all links.

To realize text error correction and syntax optimization with AI, you need to follow the following steps: 1. Select a suitable AI model or API, such as Baidu, Tencent API or open source NLP library; 2. Call the API through PHP's curl or Guzzle and process the return results; 3. Display error correction information in the application and allow users to choose whether to adopt it; 4. Use php-l and PHP_CodeSniffer for syntax detection and code optimization; 5. Continuously collect feedback and update the model or rules to improve the effect. When choosing AIAPI, focus on evaluating accuracy, response speed, price and support for PHP. Code optimization should follow PSR specifications, use cache reasonably, avoid circular queries, review code regularly, and use X

To enable PHP containers to support automatic construction, the core lies in configuring the continuous integration (CI) process. 1. Use Dockerfile to define the PHP environment, including basic image, extension installation, dependency management and permission settings; 2. Configure CI/CD tools such as GitLabCI, and define the build, test and deployment stages through the .gitlab-ci.yml file to achieve automatic construction, testing and deployment; 3. Integrate test frameworks such as PHPUnit to ensure that tests are automatically run after code changes; 4. Use automated deployment strategies such as Kubernetes to define deployment configuration through the deployment.yaml file; 5. Optimize Dockerfile and adopt multi-stage construction

Use Seaborn's jointplot to quickly visualize the relationship and distribution between two variables; 2. The basic scatter plot is implemented by sns.jointplot(data=tips,x="total_bill",y="tip",kind="scatter"), the center is a scatter plot, and the histogram is displayed on the upper and lower and right sides; 3. Add regression lines and density information to a kind="reg", and combine marginal_kws to set the edge plot style; 4. When the data volume is large, it is recommended to use "hex"

To build a PHP content payment platform, it is necessary to build a user management, content management, payment and permission control system. First, establish a user authentication system and use JWT to achieve lightweight authentication; second, design the backend management interface and database fields to manage paid content; third, integrate Alipay or WeChat payment and ensure process security; fourth, control user access rights through session or cookies. Choosing the Laravel framework can improve development efficiency, use watermarks and user management to prevent content theft, optimize performance requires coordinated improvement of code, database, cache and server configuration, and clear policies must be formulated and malicious behaviors must be prevented.

To integrate AI sentiment computing technology into PHP applications, the core is to use cloud services AIAPI (such as Google, AWS, and Azure) for sentiment analysis, send text through HTTP requests and parse returned JSON results, and store emotional data into the database, thereby realizing automated processing and data insights of user feedback. The specific steps include: 1. Select a suitable AI sentiment analysis API, considering accuracy, cost, language support and integration complexity; 2. Use Guzzle or curl to send requests, store sentiment scores, labels, and intensity information; 3. Build a visual dashboard to support priority sorting, trend analysis, product iteration direction and user segmentation; 4. Respond to technical challenges, such as API call restrictions and numbers

String lists can be merged with join() method, such as ''.join(words) to get "HelloworldfromPython"; 2. Number lists must be converted to strings with map(str, numbers) or [str(x)forxinnumbers] before joining; 3. Any type list can be directly converted to strings with brackets and quotes, suitable for debugging; 4. Custom formats can be implemented by generator expressions combined with join(), such as '|'.join(f"[{item}]"foriteminitems) output"[a]|[

Pythoncanbeoptimizedformemory-boundoperationsbyreducingoverheadthroughgenerators,efficientdatastructures,andmanagingobjectlifetimes.First,usegeneratorsinsteadofliststoprocesslargedatasetsoneitematatime,avoidingloadingeverythingintomemory.Second,choos
