Unlock issues

If a process adds a lock to the table, and later the process does not unlock it normally for some reason. . So how to deal with it? For example, there is a power outage. . .

东东 2021-07-12 17:48:56 0  2  1229

Why can't the Linux file be unlocked if it is locked? ?

The files in the apache2 folder under etc are all locked. Last night, someone said that executing this command would unlock sudo chmod 777 /etc/apache2, but it still didn’t work after trying it. I am using the ubuntu16.04 version.

怪我咯 2017-06-10 09:48:58 0  1  899

How to interpret this semaphore?

What exactly does the lock function here mean? ? Why is sembuf.sem_op -1 instead of 1 when unlocked? ?

習慣沉默 2017-06-07 09:24:21 0  1  805

linux - How to understand mutex locks and condition variables?

The following code is from "Unix/Linux Programming Practice Tutorial". Its function is to use two threads to count the number of words in two files respectively, and calculate the total number in the main thread. The following is a running screenshot: But after watching it for a long time,...

仅有的幸福 2017-06-12 09:24:46 0  1  1221

[Must-read for front-end job hunting] Selected front-end development interview questions and answers_Outline

Front-end development interview knowledge points outline: 1. HTML&CSS: Understanding of Web standards, browser kernel differences, compatibility, hacks, basic CSS skills: layout, box model, selector priority and use, HTML5, CSS3, mobile terminal adaptation 2. JavaScript: Data type, object-ori...

天蓬老师 2017-11-13 12:02:37 1  3  1571

How to split paragraphs composed of multiple user information by different users in python?

Name: a002ID: ffd7eb90-3705-4248-8c21-f3d579ccc54dDisplay Name: Email: .com.cnFirst Name: a002Last Name: liDepartment: Title: Description: Account Disabled: falseAccount Unlocked At: 2017-04-24 07:...

世界只因有你 2017-05-18 10:51:32 0  4  675

Use redis to design a mechanism to mark a certain data in a locked state

The program goes to the database to read 10 data with run_status=0 every time. When a task is executed, the database updates the field run_status=-1 to indicate that the task is locked. Of course, after the task execution is completed, run_status=0, indicating that the lock has been unlocked. Now co...

迷茫 2017-06-26 10:49:39 0  1  1227

mysql optimization - mysql innodb table lock, beg the DBA expert for answers

Questions: 1. When transactions are not enabled in innodb and autocommit=1, will update and delete cause table locks? I opened two mysql sessions in the terminal, and table t has a total of 3.5 million rows of data. Execute separately: {code...} Execute at the same time, my understanding: {code...} ...

PHP中文网 2017-05-25 15:08:06 0  1  758

Changing orientation causes video to close when playing HTML5 video on Safari iOS

I'm using React and HTML5's <video> tag to render a video, and when I open the website on my iPhone, the video plays in the native iOS Safari video player. However, when I change the orientation to watch the video in landscape mode, the video turns off. Do I need to implement some configuratio...

P粉413307845 2023-08-30 20:49:37 0  1  633

Buttons on mobile remain focused or active, causing issues with CSS animations

I'm trying to achieve an animation every time I click a button, it works fine on desktop but I can't achieve the same effect on mobile. I have to click the button first, then click somewhere else to de-focus the CSS, then click the button again to get the animation effect. Below is the code snippet....

P粉043295337 2023-08-28 15:14:37 0  1  513

vue.js/bootstrap: onclick event method not called, error "Variable not found: updateDocument"

I'm new to front-end development but have basic understanding of HTML5, CSS and Javascript. I created a vue.js project and added bootstrap and axios. My application loads data and displays them. However, once I click the "Show", "Update" or "Delete" button, I get "...

P粉757640504 2023-09-09 20:06:48 0  1  858

Ways to fix issue 2003 (HY000): Unable to connect to MySQL server 'db_mysql:3306' (111)

I recently tried to containerize my FastAPIPython server (also for replication/doubling purposes). Before, I had just a MySQL server in a Docker container and everything was fine, but when I also made my web server a service, it couldn't connect to the MySQL server, so now the application doesn't wo...

P粉178132828 2023-09-05 11:18:47 0  1  771

Experiment with sorting after query limit

So this is my first question here, please forgive me if something is wrong. I'm trying to make a sort query based on constraints. So there is a Customers table with 90 records. I want to first perform a query limited to 3 records, and then sort the results of this query by a column called ContactNam...

P粉237125700 2023-09-05 14:46:42 0  1  700

CSS Grid: Create new row when child content overflows column width

I have a two column layout based on CSS grid. When the content of the second column exceeds 1fr I want to create a new row. As it currently stands, the content simply overflows the column. One requirement of this layout is that the items in the right menu column are in one row. I achieve this with: ...

P粉212114661 2023-09-05 15:18:28 0  1  593

PHP full text search functionality using AND, OR and NOT operators

Newbie question: I'm trying to implement a full text search on a search string using php and eloquent. $searchstring="+(victimsuspect)+crime-covid";$searchresult=RssItem::whereRaw("MATCH(description)AGAINST('$searchstring'INBOOLEANMODE)")->ge

P粉076987386 2023-09-05 15:06:32 0  1  552

Shortest way to convert all PHP types to string

I'm writing a general system that I hope can one day be applied to fields like medicine (i.e. it's "scientific"). I think the best way is to represent all the data in php with strings (true will be "true", false will be "false" and so on). The reason for this is that in...

P粉369196603 2023-09-05 15:34:44 0  1  979

How to get average of DATETIME column in MySQL while grouping by other columns

I'm creating and populating a MySQL table using the following query: SETtime_zone='+00:00';CREATETABLEtimestamp_n_datetime(idINT,timeDATETIME,avg_timeDATETIME);INSERTINTOtimestamp_n_datetime(id,time,avg_time)VALUES("1","2023-01-0310:

P粉460377540 2023-09-05 11:46:21 0  1  495

Multi-device (mobile phone) synchronization - React Native

I'm trying to create a Lightshow that will launch on all users' mobile devices at the same time (can have up to 2000-3000 users). All users will use the Internet (Wi-Fi or mobile data). In our FE we use Apollo for subscriptions and it works like a charm. But the problem is, user A can get subscribed...

P粉151466081 2023-09-05 11:58:38 0  1  682