This happens because pandas optimizes away copies when one input is empty, so they share the same memory.
To prevent linkage without forcing a deep copy, enable Copy-on-Write in pandas 2.x:
I think resources based access control is something beyond a role based access control. With roles, a user is bound to a permanent identification. it is very limiting when you work in environment where one account is shared across multiple applications.
With resources based access control, a user have permission to resources based on specific specific target. For example, a user can be owner of one store and a simple manager of a different store without being globally labelled a manager or a store owner.
Another exemple is a aws, your account doesn't directly have access to all features in services, you create a IAM user and give a specific permission on a specific resources to that IAM user. It makes it easier to introduce new authorities and permissions without touching the core of your auth. Instead of (user , user role) you have (user, target, permissions of user in the target).
It makes it also really easy to have real-time access control. Still, case of a store manager and owner, a manager can have access to create product now for example, and on the next request no longer have access to it, while still have access to other permissions in the store, all that without needing to affect the global identify of the user in any way.
It's important to mention that this can lead to larger queries for permissions. For exemple, instead of just checking if a user has a specific role, you need to check if a user a a specific permission on a specific target. But with a good caching layer, it's way more powerful in every single way compared to role based access control.
/* If element has a sibling immediately after it, remove its right radius */
.item.active:has(+ .item.active) {
border-top-right-radius: 0;
border-bottom-right-radius: 0;
}
/* and the left radius of the adjacent active siblings in the group */
.item.active + .item.active {
border-top-left-radius: 0;
border-bottom-left-radius: 0;
}
An Addition to "https://stackoverflow.com/a/79786806/31654810", "fstream file(argv[1], ios::in | ios::app);" didn't work for me when I tried running it but you could open the file in just ios::in mode and when you want to append, you can create another fstream or ofstream in append mode to actually write it.
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
using namespace std;
void testFile(const char *fileName)
{
fstream file(fileName, ios::in);
string line, word;
while (getline(file, line))
{
istringstream checker_str(line);
if (checker_str >> word && word == "ret")
{
cout << "Message: " << "\033[92msuccess: \033[0m" << "\"ret\" keyword was already written." << endl;
return;
}
}
//cout << "Message: " << "\033[93mwarning: \033[0m" << "\"ret\" keyword was not written." << endl;
cout << "Message: " << "\033[93mwarning: \033[0m" << "\"ret\" keyword was not written and has been written for you." << endl;
ofstream file1(fileName, ios::app);
file1 << "\nret";
return;
}
int main(){
testFile("no_ret.txt");
testFile("Yes_Ret.txt");
return 0;
}
This would be the right code referenced/inspired from "https://stackoverflow.com/a/79786806/31654810".
You class from image dont recognize class.getresource(url) because the image are located with mistake, you have to put your images on src/main/resources and you have to compile the resources with maven. Grettings
In C23, <stdalign.h> provides no content. There is no alignas macro, no alignof macro, and no __alignas_is_defined or __alignof_is_defined macros.
In C++, both alignas and alignof are keywords, and the C++ standard forbids C++ standard library headers from defining macros with names that are C++ keywords. So <stdalign.h> in C++ must not define an alignas macro or an alignof macro. eel.is
What <stdalign.h> can still provide in C++23 are the feature-test macros. __alignas_is_defined is present but deprecated in C++23, and __alignof_is_defined is also provided via the “same as C header” wording and is being explicitly tracked so it can be deprecated as well. Both expand to 1. GitHub
For reference, the current C++ working draft points <stdalign.h> at C23’s header, which is empty, so including it in C++ has no effect. The general prohibition on keyword-named macros remains in force. eel.is
I think that the idea that you might have to swap to Controller when "development becomes more serious" is silly. Controllers aren´t inherently more serious or clean. They prescribe you an architecture. Minimal API gives you much more freedom. For example it is much easier to swap out a few routes depending on deployments. Whats more clean depends on how you use either.
For the most part people using Controllers also throw together a lot of methods that somehow loosely connect to some arbitrary word. Sometimes the word is HomeController. What's "Home" supposed to be? Well... just about anything on this "Home" page that just so happens to have 15 sub menus. Seen this a lot.
There is absolutely no issue mixing controllers and minimal API. In fact you probably do it already if you use controllers without knowing it. As a lot of stuff like 3rd party login, or openapi docs will use minimal API under the hood. You just did not write the minimal API part yourself.
The issue isn't with VtValue itself. We were calling GetLightParamValue(), which does some additional steps before returning the value. Including throwing away types it doesn't recognize. Calling Get() avoids those extra steps and solves the problem in this case.
Thanks for the help. You can't imagine how useful your answer was to me.
I would be picking at least 7 different workarounds if I didn't reach you.
Just to clarify and let the step-by-step guide:
Pick an option: User-assigned or System-assigned managed identity. I had picked System-assigned one.
To enable managed identity you need to go to "Identity" section in the left panel. You can simply enable system-assigned or create a user-assigned one and add it to the the list.
Go to your DevOps organization settings and add this identity as a new user to the whole organization (you might have to give it admin permissions).
Now you can select the managed identity in this HTTP request block as Authorization header.
After upgrading to Windows 11, I encountered the "The emulator process for AVD Nexus_6_API_33 has terminated" error, so I checked the idea.log file, searched online, and eventually found the solution involving a missing C++ file that needed to be updated.
The emulator may require certain DLLs that are not present so I have downloaded the latest supported redistributed version from this link:
After upgrading to Windows 11, I encountered the "The emulator process for AVD Nexus_6_API_33 has terminated" error, so I checked the idea.log file, searched online, and eventually found the solution involving a missing C++ file that needed to be updated.
Which version of LCOV are you using?
What do you see, when you run lcov --summary ....Client/Web.UI/coverage/lcov.info (_.e., ask lcov to summarize your .info file).
You may want to add --branch and/or --mcdc - depending on your lcov version and the source of your coverage data.
For anyone conquering the same demons as I am: I did actually find a concrete difference between the two functions: I found a library that used eglCreateImageKHR to import DMABUFs using the EXT_image_dma_buf_import EGL extension. It was using OpenGL ES as its rendering API. Replicating this in my OpenGL application would raise an unexplainable EGL_BAD_PARAMETER error. When I replaced it with eglCreateImage instead, it finally worked. As such my best guess is that eglCreateImageKHR might be more an OpenGL ES thing or be related in some way to it that the non khr suffix version isn't.
After upgrading to Windows 11, I encountered the "The emulator process for AVD Nexus_6_API_33 has terminated" error, so I checked the idea.log file, searched online, and eventually found the solution involving a missing C++ file that needed to be updated.
After upgrading to Windows 11, I encountered the "The emulator process for AVD Nexus_6_API_33 has terminated" error, so I checked the idea.log file, searched online, and eventually found the solution involving a missing C++ file that needed to be updated.
The emulator may require certain DLLs that are not present so I have downloaded the latest supported redistributed version from this link:
It sounds like from what Bryan was asking, he wanted to access the selected items from a multiselect choice field in OnEdit or OnSave of the SharePointIntegration object, which is before the item actually loads, which is why he needed it from the SharePoint list as well and not the Choice DataCard. I needed this as well, as I use the Variable that I store the data from a Gallery field to show/hide other fields, and these show/hides wouldn't work when going to edit or View the Form since they are based on the table Variable that stores the Gallery. Here's what worked for me:
OnView/OnEdit: In these modes, the SharePointIntegration.Selected object represents the current item. You can access the multi-select column's value from this object. For example, if your multi-select column is named "Categories", the DefaultSelectedItems property would be set to SharePointIntegration.Selected.Categories.
The "Resource ID" fields are meant for native Android Apps only. Flutter doesn't have this option since flutter apps are built with widgets, not native controls. The robot simply wouldn't find them inside your app. You can use Firebase Test Labs to run your flutter integration tests though.
module AdminUsers
class CustomSessionsController < ActiveAdmin::Devise::SessionsController
include ::ActiveAdmin::Devise::Controller
def create
#Add new logic here
end
end
The solution I found here is to open an interactive shell in the target directory, and grab the PATH from there. Afterwards I can call `:os.find_executable(~c"elixir", path)`:
As two filters are of different types (here team and player) belong to different collection, we cannot combine those filters. So need to use two different filters- one to retrieve specific team(team filter) and second to get specific player using team filter.
Because I'm cross-compiling, I needed to use the TOOLCHAIN_TARGET_TASK.
Also, the application that I was developing needed the static library, so I needed to find in the Yocto build where the static libraries were being built.
Searching through the build history for the sysroot of interest (in my case riscv64-oe-linux), I found all of the related packages that were built as a result of adding openssl to my yocto build.
Digging in further, I found that the static libs are built as part of openssl-staticdev.
So in summary, I needed to add the following
TOOLCHAIN_TARGET_TASK:append = " openssl-staticdev"
I encountered the same error and discovered it was due to an Xcode settings issue. In my case, I had to set the project's 'Project Format' value to Xcode 16. If this value is not set to Xcode 16, the object version in your pbxproj file will be 70 instead of 77.
Either all changes happen, or none do (It avoids leaving the system in a half-changed state)
1 - Backup folder : It script that if any step fails, everything is rolled back to its original state using a backup folder.
Rollback Logic : Backup the Original File and Directory, Creates a subfolder inside the backup folder, Copies the original file into that subfolder. Deletes the backup file and folder since everything succeeded.
<?php
//there is a folder that cannot be registered as an account.
$backupfolder = 'backupfolder';
$oldname = $_SESSION['oldname'];
$newname = $_POST['newname'];
$oldFile = "./$oldname/$oldname.php";
$newFile = "./$oldname/$newname.php";
$oldDir = "./$oldname";
$newDir = "./$newname";
mkdir("$backupFolder/$oldname");
copy($oldFile, "$backupFolder/$oldname/$oldname.php");
if (file_exists($oldFile) && rename($oldFile, $newFile)) {
if (file_exists($oldDir) && rename($oldDir, $newDir)) {
try {
$conn->beginTransaction();
$update1 = $conn->prepare("UPDATE table1 SET name=? WHERE name=?");
$update1->execute([$newname, $oldname]);
$update2 = $conn->prepare("UPDATE table2 SET name=? WHERE name=?");
$update2->execute([$newname, $oldname]);
if ($update1->rowCount() > 0 && $update2->rowCount() > 0) {
$conn->commit();
unlink("$backupFolder/$oldname/$oldname.php");
rmdir("$backupFolder/$oldname");
echo 'changed !';
} else {
throw new Exception();
}
} catch (Exception $e) {
$conn->rollBack();
rename($newDir, $oldDir);
copy("$backupFolder/$oldname/$oldname.php", $oldFile);
echo 'didnt change !';
}
} else {
copy("$backupFolder/$oldname/$oldname.php", $oldFile);
echo 'didnt change !';
}
} else {
copy("$backupFolder/$oldname/$oldname.php", $oldFile);
echo 'didnt change !';
}
?>
2 - Flags for Tracking Progress : it uses a flags array to track which steps succeed.
Rollback Logic : If the database update fails, It checks if the directory was renamed and renames it back, It checks if the file was renamed and renames it back.
I encountered the same error and discovered it was due to an Xcode settings issue. In my case, I had to set the project's 'Project Format' value to Xcode 16. If this value is not set to Xcode 16, the object version in your pbxproj file will be 70 instead of 77.
This issue happens because, starting September 26, 2025, Render’s free tier blocks outbound traffic on traditional SMTP ports 25, 465, and 587.
Emails fail with a 500 Internal Server Error even if credentials and configuration are correct. To fix this, use port 2525, which remains open on the free tier and is supported by SMTP2GO.
After switching to port 2525, email sending works normally without changing any other part of your setup. No upgrade required unless you want to use standard ports.
The only workaround I can think of is @froadie's workaround to his own problem link, where he ended up changing his macro to write output to a particular cell within the workbook.
When you use the flags FLAG_ACTIVITY_NEW_TASKand FLAG_ACTIVITY_CLEAR_TASK together, this causes Android to remove all Activity intances in the target task and create a new instance of the target Activity.
The goal of the code you've shown is not clear. If you already have an instance of FirstActivity, why are you creating a new instance of FirstActivity? What is it you are trying to do here? Please give more context.
@JustinBlaber
After writing 2 comments about it, I choose to just write a answer...
Even tho my response is kinda late... There is really good github repository from a guy called Obko. (https://github.com/ObKo/stm32-cmake/tree/master) There is everything except the OBJECT stuff in there, but it might be helpful still. In order to understand the usage of the OBJECT libraries more better you could just create some test-project with your STM32CubeMX. Just create for the board of your choice a little project, but make sure you select "CMake" as Toolchain and create it once.
It doesnt matter if you use the STM32IDE or VSCode with the original STM32 Extension for it. Then you will see a folder named cmake/stm32cubemx// with one toolchain file and one bigger file. The bigger file is the one you are looking for. There is everything ST uses split up into OBJECT libraries which are circuarly depending on each other. Pretty neat.
The error "npm error could not determine executable to run" when executing npx tailwindcss init "-p" after installing tailwindcss and @tailwindcss/vite suggests an incompatibility or a change in the expected command for initializing Tailwind CSS, particularly with the latest versions (like Tailwind CSS v4).
We are trying to put a background image in the sense of a watermark in the certification of completion report for LMS. In PRD it looks good but uploading to LMS the image is just not shown in the output of the report. We have tried different way to add it but none was solving the issue. Do you have any hint on that?
getch() returns two keystrokes for arrow keys. First an extended-key prefix (0 or 224), then the actual code ('H','P','K','M'). Your loop prints the board before reading the full arrow key, so the first getch() reads only the prefix (no move happens), the loop iterates and prints again, and only then the second getch() reads the real arrow code—making it look like the board prints twice. Fix it by swallowing the prefix and printing after you handle the move.
The issue has been identified. Updates were being made to the wrong appsetting file. Updates were being made to Windows appsetting rather than the Linux appsetting. So the application was still using a mongodb connection string of 'localhost:27017' rather than the correct one (as displayed in my original post).
Appreciate all the responses for helping me looking into the problem.
Die Deprecation Warning verschwindet in TYPO3 v12+, indem Sie auf die Request-Attribute zugreifen (siehe Code unten). Für abwärtskompatiblen Code verwenden Sie eine Versionsprüfung.
Bonus-Tipp für PHP 8.2: Bei TYPO3 mit PHP 8.2 können auch 'Creation of dynamic property' Warnings auftreten. Lösungen: Properties explizit deklarieren oder das AllowDynamicProperties-Attribut verwenden.
Weitere Infos: docs.typo3.org im TYPO3 v12 Changelog.
THis message indicates you need to increase the disk volume as it has reached the threshold defined witn environment variable `DISK_USE_WARNING_PERCENTAGE` as stated in https://docs.weaviate.io/deploy/configuration/env-vars
Today, my Visual Studio 2026 Insider completely stopped launching. I repeatedly told it not to display error messages. After that, the splash screen would only appear upon startup, then immediately disappear. I ran the entire recovery mode, but that didn't help. Then I went into the Cache directory and renamed it. That didn't help either. Then I renamed both 18.0_[letters-numbers] directories (to hide them and then, if necessary, bring them back) and launched Visual Studio – everything started normally.
You need to install Windows Workflow Foundation (WF) support in Visual Studio — it’s not included by default in newer versions of Visual Studio (like 2022).Without it, workflow projects (.xaml or .xamlx) will fail to build, showing XamlBuildTask errors.
Steps to install Windows Workflow Foundation in Visual Studio 2022
Open Visual Studio Installer-> Modify your Visual Studio installation
For detecting the zoom with the roam option, try using one of the roam event listeners. For me, graphRoam did the job (for my graph type chart). Its params include a "zoom" property that shows you the current zoom-level.
After Aparslan's comment about version mismatch, I tried to rollback my C# and C# dev extensions from current versions to previous versions (C# Dev - v1.50.51 & C# 2.90.60) and the issue got fixed. IDK, but according to dotnet.microsoft.com, I'm using the latest version. And 9.0.9.sdk110-1 is the latest version on arch repositories.
Commonly you can get the data with these usage id and pages from microsoft :
https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/windows-precision-touchpad-required-hid-top-level-collections#windows-precision-touchpad-input-reports
https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchpad-windows-precision-touchpad-collection
Member Description Page ID Mandatory/Optional
X X coordinate of contact position 0x01 0x30 Mandatory for T Optional for C
Y Y coordinate of contact position 0x01 0x31 Mandatory for T Optional for C
X/Y
The X and Y values report the coordinates of a given contact. A Windows Precision Touchpad should report one point for each contact. The following global items should be specified for both the X and Y usages:
Logical minimum & Logical maximum (ensuring greater than or equal to 300DPI input resolution).
Note The entire logical coordinate range should be reportable across both the X and Y axis.
Physical minimum & Physical maximum (see Device Integration - Size).
Unit & unit exponent.
The coordinate 0,0 (x, y values) indicates the top left corner of the touchpad.
---
https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/hidpi/ns-hidpi-_hidp_value_caps
Coordinates are in array if valueCaps[i].UsagePage = 1 and valueCaps[i].NotRange.Usage = 0x30 (x), valueCaps[i].NotRange.Usage = 0x30 (y)
xLogicalMin, yLogicalMin, xLogicalMax, yLogicalMax are in valueCaps[i] array
xLogicalMin = valueCaps[i].LogicalMin;
xLogicalMax = valueCaps[i].LogicalMax;
xPhysicalMin = valueCaps[i].PhysicalMin;
xPhysicalMax = valueCaps[i].PhysicalMax;
Apparently xLogicalMax, xLogicalMax are more in line with the parameters of the Touchpad.
Sample
https://stackoverflow.com/questions/47005610/x-and-y-coordinate-from-precision-touchpad-with-raw-input?noredirect=1
I had a similiar issue and noticed that I needed the following to be true:
Although I had installed WSL, I was missing an important individual component, make sure within the Visual Studio installer that you have installed the "C++ CMake tools for Linux" (in addition to the "Linux and embedded development with C++" workload)
Have WSL installed and set it up as a Remote Connection within visual studio. To do this follow the instructions on this page
Hostname: localhost OR the IP address of wsl, this can be found using the following command in PowerShell/Command Prompt
wsl hostname -I
Username and Password --> the same as your WSL login details
With legacy Excel such as Excel 2013 this formula works in my sample file. The formula must be entered as an arrayformula with ctrl+shift+enter if someone doesn't work with Office 365 or Excel for the web or Excel 2024.
I had a similar issue on Linux and in my case was due to another library (xaringanthemer) enabling showtext behind the scenes. For folks having a similar issues, try running
If you're still hitting CPU or RAM limits consider using i.e. Tsung which is known for producing higher throughput from the same hardware. But be aware that you won't be able to create more than 65535 because this is the maximum number of TCP ports
I know this is an old question but these extra characters could be byte markers for data aggregation; you may need to de-aggregate the stream in the Lambda if the producer is aggregating the data into Kinesis.
I believe this is because it executes using the account set as the default in your browser when you are signed into multiple accounts. I ran into a similar issue, and it work by using another browser signed in only to the account that I used to create the script. Typically the account you login to first is set as the default automatically and you don't have control over switching the default account. You would have to sign out of all accounts and sign in to the account you want to be the default first.
Well, to tell the truth, both MVC and WebFlux are equally well supported — no bias here.
But the real magic of the reactive stack lies in the fact that it’s fully asynchronous straight out of the box. Every DataFetcher runs asynchronously, and queries (including all those nested subqueries) that are invoked in parallel actually execute in parallel. This help a lot according to my experience :)
That gives you an impactful performance boost, especially when you start playing with GraphQL namespacing techniques — where multiple query segments can resolve simultaneously without blocking the main thread.
Another day, another WebFlux win. GraphQL Java defines subscriptions as reactive-stream Publishers, so Flux/Mono it is — or Observable, if you’re still dabbling in the dark arts of RxJava. 🧙♂️
I'm not sure if it's actual solution but may be worth trying. I copied the text from Bluetooth Serial Port GPS receiver docs about how to make it work on Windows 11 (link has screenshots, scroll to the bottom, to "Facing problems" section of FAQ)
Windows 11 has modified the Bluetooth device listing and the Balloon Live sensor must now be paired via the “old” Device pairing dialog.
In the “Bluetooth & Devices” section, scroll down and select “More devices and printer settings”
In the new “Devices and Printers” dialog, select “Add a device”
I heavily use this pattern. It is very helpful to quickly navigate to certain elements. It improves readability.
You can break the component into smaller components, but sometimes it not possible or doesnt make sense. Eg. <Header> component renders <Logo>, <Menu>, <Search>, <UserIcon>, <SettingsMenu>. There components cant be further broken down. So Header component has to render all these components. And if these components take 3 props each then already return statement will span over 15 lines. Instead I put these into renderLogo(), renderMenu(), renderSearch()... It becomes so easy to read and navigate.
I highly recommend others to use this pattern as well.
The Stack Overflow question sought a workaround for achieving atomicity and memory ordering (fencing) in a multithreaded C++ application when restricted to the old gcc 4.4 compiler without C++11 features. The accepted solution advises using the available standard library feature, std::mutex, to protect the shared variable, noting that while it's an "overkill" for simple atomic operations, it reliably ensures thread-safe access under those specific constraints. Privacy Fence Augusta
I would probably break down the app, assuming that not all code is required at the initial load.
One way to do this, is to have web components that handles the data loading through a data service so that components aren't registered and templates aren't fetched before they are needed.
This was probably due to windows server maintenance / regular restarts in our organization while the job was running. Active batch couldn't track the running process so it reported Lost exit code description
Was facing above error because i was using jfrog server as host but the expected host is "reponame.host". For eg if the registry name is "test-jfrog-registry" and the host name is "abc.jfrog.io" then the right host would be test-jfrog-registry.abc.jfrog.io and not abc.jfrog.io/test-jfrog-registry
Correct command echo $JFROG_TOKEN | docker login test-jfrog-registry.abc.jfrog.io --username $JFROG_USERNAME --password-stdin
I had the same crash after adding a custom attribute for my View. Turned out attribute's name conflicted with some system attribute, so I had to add prefix to it
What i understood is ur app becomes slow because it is waiting for the whole file to load and then it shows you the save as dialog box.
So ur UI feels like blocked or stuck ....So if this is the problem then , Instead of using Angular httpclient to fetch the file, you must let the browser to handle the download directly.
public void download(....){
// dont return Response Entity<ByteArrayResource> ....
instead
response.setContentType("text/csv");
response.setHeader( your header);
response.setContentLength(butes.length);
ServletOutputStream os = response.getOutputStream();
os.write();
os.flush()
os.close();
/*Pls. check the code before use ... just giving you an idea*/
// this approach streams the bytes directly to the HTTP response and browser confuses with the input type and transfer the control on client side that "what you want my boss"
}
and make some changes in front end side too
because you r using
this.http.get(url,{
// some code
})
mand
if(event.type== ..response){
saveAs(...)
}
means first download the file / load the file and then use ..only then after u would able to do save as
This is over ten years late, but I found a workaround for this. I discovered through debugging the notification of row validation errors that the "binding group" representing the whole row was not marked to notify on validation error. Since my row validation (based on another example here on StackOverflow) had already discovered the binding group, it was a simple matter to force notification by setting the "NotifyOnValidationError" for the binding group to true.
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
if (value is BindingGroup bindingGroup && bindingGroup.Items.Count > 0)
{
bindingGroup.NotifyOnValidationError = true;
// Insert validation code here.
}
return ValidationResult.ValidResult;
}
Ideally, this would be handled through XAML markup, but I don't see where that could be done for rows.
Apex debugger on VSCode is reading the log you provide. It will stop when the line of the log reaches a breakpoint in VSCode that matches the log.
If it is not stopping, it could be a number of reasons:
Your log is incomplete: Sometimes, with very very long logs, Salesforce logs are incomplete.
Your test is failing before reaching your breakpoints (to debug this, set a breakpoint at the very beginning of your testSetup method and see if it hits the breakpoint, or run the test normally to see in which line it fails)
Complex flows, for example: method -> trigger -> flow -> trigger -> flow (etc.). The debugger sometimes hickups and cannot follow the execution.
Your code is incomplete: You might not have available in your project all the code running in your org. The debugger can get lost as well.
In my experience, the debugger is generally working, but sometimes it just doesn't work. In those cases, I reduce my test to just some lines, try again to see if it works, and then add code to the test in smaller steps.
On a side note, you are using Test.startTest in your @testSetup method. This isn't advisable, and could be messing with your debugger as well.
Thanks to @IanAbbott in the comments, I now understand why waking 1 waiter would be incorrect. Assuming a semaphore with 2 waiters (and thus a count of -1), here is how sem_post waking only 1 waiter, followed by another sem_post, would behave:
poster waiter 1 waiter 2
in sem_wait() in sem_wait()
sem_post() called
sem->count = 1
previous count -1
=> wake 1 waiter
gets woken up
sem->count = 0
returns from sem_wait()
...
sem_post() called again
sem->count++ (so 1)
previous count 0
=> no futex_wake
Waking all waiters ensures that the waiter that fails to grab the semaphore will decrement it to -1 again and not leave it at 0, indicating there are still waiters to be woken up on the next sem_post.
I should also note that it would not be correct to do the less naïve change of waking 2 (resp. N) waiters, since the same situation described above could arise again with 3 or more (resp. N+1 or more) waiters, if an additional (resp. N-1 additional) sem_post races its way before the woken up waiters attempt to grab the semaphore.
Implementations such as musl and glibc seem to implement semaphores differently, with a separate waiters count, and are thus able to wake only 1 waiter in sem_post when possible (i.e. in the absence of concurrent updates, I assume):
When debugging Python code in Visual Studio Code (VS Code) and want to view the full call stack, the process mainly involves configuring your launch.json file and using the VS Code Debug Console effectively.
Open the Run and Debug Panel
Click on the Run and Debug icon on the left sidebar or press Ctrl + Shift + D.
Select “create a launch.json file” if you don’t already have one.
Edit Your launch.json
Add or modify your configuration like this:
Setting "justMyCode": false ensures that VS Code displays the full call stack, including library and framework code — not just your own Python files.
Viewing the Full Stack Trace
When an error or exception occurs, open the CALL STACK panel (right side of the Debug view).
It will list all function calls leading to the current point, from external libraries to your script.
You can click any frame in the stack to view the exact line of code that was executed.
For unhandled exceptions or runtime errors, the Debug Console or Terminal will also display a full traceback:
Traceback (most recent call last):
File "main.py", line 20, in <module>
run_app()
File "app.py", line 12, in run_app
start_server()
...
Exception: Something went wrong
