locking

问题 I want to implement record locking functionality in my Yii2 application. If one user opens update link/record (Ex. http://localhost/myproject/backend/web/user/update/1 ) then another user cannot able to access thislink and user will get an ALERT message saying " This record already opened by another user ". So the record/page should lock for another user. (Same like MS Excel locking) Once first user finishes and leaves from that record/page then it should unlock and another user can read

问题 I want explicitly provide an order on how MySql InnoDB should acquire locks for rows. If this is possible there shouldn't be any dead locks just stalling. (If we follow the convention.) First, the databse should lock all rows found in table "models" in ascending order. Then all rows in the second table "colors" should get locked in ascending order. Is there a way to control the database to lock table "models" first and then "colors"? Given for example: start transaction; select * from models

问题 A simple and seemingly reliable way to do locking under bash is: exec 9>>lockfile flock 9 However, bash notoriously propagates such a fd lock to all forked stuff including executed programs etc. Is there any way to tell bash not to duplicate the fd? It's great that the lock is attached to a fd which gets removed when the program terminates, no matter how it gets terminated. I know I can do stuff like: run_some_prog 9>&- But that is quite tedious. Is there any better solution? 回答1: You can use

问题 Let's suppose I got two different threads, T1 and T2, accessing concurrently the same database and fetching data from the same table. Now on thread startup I need to fetch data from the table and store the rows into a collection, that I will then use to perform some work elsewhere. I don't want the two threads to be able to process the same data, because it will result in duplicated (and long) work. To be more concrete, this is an enterprise application that needs to load some records at

问题 Let's assume I declared two maps and want to assign it in two different goroutines in error group. I don't perform any reads/write. Should I protect assign operation with lock or I can omit it? UPD3: In the Java Concurrency In Practice Brian Goetz's Part I Chapter 3 Shared Objects , mentioned: Locking is not just about mutual exclusion; it is also memory visibility. To ensure that all threads see the most up-to-date values of shared mutable variables, the reading and writing threads must

问题 EDIT: The issue here wan't the fact it was locked via GP, it was that it was being run as a service under a service account and it didn't have access to the interactive desktop I have a C# application that needs to check for when a user's session is locked, I'm using Microsoft.Win32.SystemEvents.SessionSwitch and this works fine when a user manually locks the machine. The problem is that when the machine is locked via a group policy (User Configuration > Policies > Administrative Templates >

问题 Background with example: We are building a stream processing application that receives a stream of data, runs algorithms on the data and stores the results in a database. As an example for this question let's use a stream of purchases. Each purchase has the geo-location of the purchase (store location or IP based location). The stream of purchases is coming from a Kafka topic. We now want to process that stream of data and output some statistics. For example, we want to see the average

问题 Is it possible to force the user to lock a file in eclipse before they edit anything? I am using subclipse with tortoise svn. 回答1: To get this functionality for your entire project open up the root directory of your project in your file explorer. Right-Click--> Properties --> Subversion Tab --> Properties... --> New Choose svn:needs-lock Check apply property recursively Click Ok Now subclipse with force you to get a lock before editing a file. 来源： https://stackoverflow.com/questions/6266738

问题 I am just now starting to dig into Teradata's locking features and Google is fairly convoluted with explanations on this. Hopefully, I can get a very simple and streamlined answer from SE. After encountering numerous issues with identity columns in Teradata, I've decided to create a mechanism that mimics Oracle's sequence. To do this, I am creating a table with two fields, one that holds a table name and the other that stores its last-used sequence. I am going to then create a stored

问题 upd: Let me rephrase my question shortly. There are N double numbers. There are N dedicated threads each of them update own double number ( _cachedProduct in the example below). Somehow I need to have sum of these numbers and I need IndexUpdated event to be raised ASAP after any double number is changed (it would be nice if such event can be raised in 10 µs or less). Below is how I tried to implement this task =============================================== To calculate stock exchange index I