race-condition

问题 My understanding is that due to the Global Interpreter Lock in cPython, only one thread can ever be executed at any one time. Does this or does this not automatically protected against race conditions, such as the lost update problem? Just to be clear, I am asking from a theoretical perspective. I would never write threaded code without synchronization. 回答1: Due to the GIL, there is only ever one thread per process active to execute Python bytecode; the bytecode evaluation loop is protected

问题 I have seen the terms contention and race are used interchangeably when it comes to thread's state(at critical section). Are they same? 回答1: "Contention" usually refers to the situation where two or more threads need to lock the same lock. We say that the lock is "contested" or maybe, "heavily contested," if there is a significant probability of any thread being forced to wait when it tries to acquire the lock. "Race," "Race condition," and "Data race" are phrases whose meanings have changed

问题 In my Electron application, I am seeing weird behavior. In Windows, sometimes the renderer process executes before the initialization of Electron finishes, which is causing the issue in a startup. For eg: I set up a sequelize database and register IPC channels in the constructor of Main.ts file, so as per my knowledge, app.on('ready') event should be fired once the constructor finishes execution but sometimes in Windows OS only, ready events fires even before the database setup, and my

问题 I've read an article about multithreading in Python where they trying to use Synchronization to solve race condition issue. And I've run the example code below to reproduce race condition issue: import threading # global variable x x = 0 def increment(): """ function to increment global variable x """ global x x += 1 def thread_task(): """ task for thread calls increment function 100000 times. """ for _ in range(100000): increment() def main_task(): global x # setting global variable x as 0 x

问题 I'm using a SemaphoreSlim with a FIFO behaviour and now I want to add to it a Starve(int amount) method to remove threads from the pool, sort of the opposite to Release() . If there are any running tasks, they will of course continue until they are done, since for the moment the semaphore is not keeping track of what is actually running and "owes" the semaphore a release call. The reason is that the user will dynamically control how many processes are allowed at any time for a given semaphore

问题 We have a table that looks like this: appointment_id | team_id ----------------|--------- 1001 | 1 1005 | 4 1009 | 7 In this table appointment_id is the primary index and team_id is just a regular index. The code for creating the table: CREATE TABLE `appointment_primary_teams` ( `appointment_id` int(11) NOT NULL, `team_id` int(11) NOT NULL, PRIMARY KEY (`appointment_id`), KEY `team_id` (`team_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; However, occasionally the below code fails: // Even

问题 I searched in many web pages to find what phrase exact should I place in settings.json in VS Code Golang extension (released by Microsoft) to add a build flag (in my case, race detector)? I added: "go.buildFlags": ["-race"], in extension's settings.json but still when debugging, in a function that definitely generates a race condition, the debugging console does not denote something like: Found 1 data race(s) which the go compiler usually indicates when executing the same file via go run

问题 This question already has answers here : File.Move Does Not Work - File Already Exists (9 answers) Closed 9 days ago . I'm developing a multi threaded application. I have somewhere in my code : File.Delete(sidetapedata); File.Move(sidetapedata2, sidetapedata); //sidetapedata and sidetapedata2 are two file paths that correspond to sidetapedata.txt and sidetaptdata2.txt in some directory. The second line sometimes runs fine and other times, it throws an IOException : Cannot create a file when

问题 This question already has answers here : File.Move Does Not Work - File Already Exists (9 answers) Closed 9 days ago . I'm developing a multi threaded application. I have somewhere in my code : File.Delete(sidetapedata); File.Move(sidetapedata2, sidetapedata); //sidetapedata and sidetapedata2 are two file paths that correspond to sidetapedata.txt and sidetaptdata2.txt in some directory. The second line sometimes runs fine and other times, it throws an IOException : Cannot create a file when

问题 Today, when I was working on my android project, I saw this weird behavior of my app. When I click on an icon and move to a different activity, which would basically insert another child into the node to which first activity was listening to. But to my surprise, when return back, everything in the screen was doubled. When I refresh the view, it again would become normal. I repeated it many times, thinking it may be a glitch. But same result every time. When I look into database, new child was