Aligned | Memory alignment wrappers , useful for avoiding false sharing | Collaboration library
kandi X-RAY | Aligned Summary
kandi X-RAY | Aligned Summary
Memory alignment wrappers, useful for avoiding false sharing.
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of Aligned
Aligned Key Features
Aligned Examples and Code Snippets
Community Discussions
Trending Discussions on Aligned
QUESTION
In C++20, we got the capability to sleep on atomic variables, waiting for their value to change.
We do so by using the std::atomic::wait method.
Unfortunately, while wait has been standardized, wait_for and wait_until are not. Meaning that we cannot sleep on an atomic variable with a timeout.
Sleeping on an atomic variable is anyway implemented behind the scenes with WaitOnAddress on Windows and the futex system call on Linux.
Working around the above problem (no way to sleep on an atomic variable with a timeout), I could pass the memory address of an std::atomic to WaitOnAddress on Windows and it will (kinda) work with no UB, as the function gets void* as a parameter, and it's valid to cast std::atomic to void*
On Linux, it is unclear whether it's ok to mix std::atomic with futex. futex gets either a uint32_t* or a int32_t* (depending which manual you read), and casting std::atomic to u/int* is UB. On the other hand, the manual says
The uaddr argument points to the futex word. On all platforms, futexes are four-byte integers that must be aligned on a four- byte boundary. The operation to perform on the futex is specified in the futex_op argument; val is a value whose meaning and purpose depends on futex_op.
Hinting that alignas(4) std::atomic should work, and it doesn't matter which integer type is it is as long as the type has the size of 4 bytes and the alignment of 4.
Also, I have seen many places where this trick of combining atomics and futexes is implemented, including boost and TBB.
So what is the best way to sleep on an atomic variable with a timeout in a non UB way? Do we have to implement our own atomic class with OS primitives to achieve it correctly?
(Solutions like mixing atomics and condition variables exist, but sub-optimal)
...ANSWER
Answered 2021-Jun-15 at 20:48You shouldn't necessarily have to implement a full custom atomic API, it should actually be safe to simply pull out a pointer to the underlying data from the atomic and pass it to the system.
Since std::atomic does not offer some equivalent of native_handle like other synchronization primitives offer, you're going to be stuck doing some implementation-specific hacks to try to get it to interface with the native API.
For the most part, it's reasonably safe to assume that first member of these types in implementations will be the same as the T type -- at least for integral values [1]. This is an assurance that will make it possible to extract out this value.
... and casting
std::atomictou/int*is UB
This isn't actually the case.
std::atomic is guaranteed by the standard to be Standard-Layout Type. One helpful but often esoteric properties of standard layout types is that it is safe to reinterpret_cast a T to a value or reference of the first sub-object (e.g. the first member of the std::atomic).
As long as we can guarantee that the std::atomic contains only the u/int as a member (or at least, as its first member), then it's completely safe to extract out the type in this manner:
QUESTION
A part of my form contains QGroupBox (Status Box) with 4 child QGroupBoxes arranged in a grid layout (2x2). Two bottom QGroupBoxes (Widget 1 Box and Widget 2 Box) contain widgets of fixed size (with set minimumSize and maximumSize) so they're non-resizable at all in both directions. Because of that rigid size constraints top row of QGroupBoxes (Summary Box and Helper Box) can only be resized in vertical direction.
And here comes the troublesome part. Top-left QGroupBox (Summary Box) have grid layout 5x3 while top-right (Helper Box) have vertical layout with 6 rows. If I have naive widget placement as shown on picture 1 Qt is enlarging vertical size of both labels in top row to make height of both QGroupBoxes equal (see red arrows on picture 1).
This is definitely that I don't want so I've added vertical spacer to the bottom of Summary Box and from the first glance it worked (picture 2). But only from the first glance... What you see is the minimum height of my whole form and the bottom side of spacer and last QCheckBox in the Helper Box seems to be aligned.
If I'm expanding my form vertically this spacer grows a bit and that causes the increase of height of both top QGroupBoxes. As a result spacing between QCheckBoxes increases too and we can also see that top and bottom spacing are unequal for the top-right box (see red arrows on picture 3).
I've tried to play with sizeType for my vertical spacer. If I set it to Minimum or MinimumExpanding then the spacer doesn't grow on resize (and doesn't shrink, too) but it appears to be expanded to the size as on picture 3 (corrupting spacings between QCheckBoxes too). If I set it to Maximum, Preferred or Expanding then I observe the same behavior as described above for picture 3.
What is the proper way to achieve alignment for two QGroupBoxes in a row of grid without affecting spacing between elements (e. g. in that case make vertical spacer to fit only single row of grid layout and never expand/shrink)?
ANSWER
Answered 2021-Jun-15 at 17:18Items will be aligned if both QGroupBoxes have same count of children and each row have at least one child with Expanding vertical policy. Instead of spacer use QWidget
I removed unrelated widgets and reduces number of rows to 4 for demonstration purposes (less xml).
QUESTION
I'm trying to understand how the "fetch" phase of the CPU pipeline interacts with memory.
Let's say I have these instructions:
...ANSWER
Answered 2021-Jun-15 at 16:34It varies between implementations, but generally, this is managed by the cache coherency protocol of the multiprocessor. In simplest terms, what happens is that when CPU1 writes to a memory location, that location will be invalidated in every other cache in the system. So that write will invalidate the line in CPU2's instruction cache as well as any (partially) decoded instructions in CPU2's uop cache (if it has such a thing). So when CPU2 goes to fetch/execute the next instruction, all those caches will miss and it will stall while things are refetched. Depending on the cache coherency protocol, that may involve waiting for the write to get to memory, or may fetch the modified data directly from CPU1's dcache, or things might go via some shared cache.
QUESTION
I'd like to run a simple neural network model which uses Keras on a Rasperry microcontroller. I get a problem when I use a layer. The code is defined like this:
...ANSWER
Answered 2021-May-25 at 01:08I had the same problem, man. I want to transplant tflite to the development board of CEVA. There is no problem in compiling. In the process of running, there is also an error in AddBuiltin(full_connect). At present, the only possible situation I guess is that some devices can not support tflite.
QUESTION
I have customized a progress bar when I scroll down. According to the content the progress bar gets increased with fixed and scroll up the bar get decreased.
When I tried with position: fixed it is breaking out of the container level. It should come inside the container level with left and right aligned.
Note: I want it to be done in position: fixed
Thank you for anyone help and time, I appreciate it.
...ANSWER
Answered 2021-Jun-15 at 08:03The issue is because using position: fixed takes the element out of the document flow. As such it has no reference to its parent for CSS to be able to calculate inherited dimensions.
In this case you can create the behaviour you require by manually calculating the percentage width as an explicit pixel value using the width of .container.
Also note that the if condition around the moveTrackingBar() function definition is redundant and can be removed.
QUESTION
Following script is a combination of RSI and Higher High and Lower Low script. The issue is that the HH LL labels are aligned for the price not on the RSI Line. How to align the labels to the RSI line? It is basically showing the Higher Highs and Lower Lows of RSI. The labels need to stick on to the respective RSI line.
...ANSWER
Answered 2021-Jun-15 at 09:25Changed the location.belowbar and location.abovebar with location.absolute and the plotshapes display (ex: if _hl is true, plot at the RSI level, otherwise pass)
QUESTION
I want to deal with an abstraction where I can store f1, f2, f3, f4, f5... where
...ANSWER
Answered 2021-Jun-13 at 04:23You can store them with a GADT, like this:
QUESTION
I have three TextSpan children as per the image attached - with the middle TextSpan object a larger font size.
I want all three TextSpan objects to be centered against the background parent.
When the fonts are all the same size they are aligned along the center horizontally. However when I increase the font size of one TextSpan, only the larger text object remains centered and the smaller two fonts fall to the larger font's base)...
I have tried different alignment properties but cannot work it out. Can this be done with TextSpan text?
Thanks!
...ANSWER
Answered 2021-Jun-15 at 07:20You can use WidgetSpans to make sure all your elements(text or not) are vertically centered
QUESTION
How do I align the Color views in a straight line with the text to the side?
To look like so (text aligned leading):
█ red
█ green
█ blue
Or this (text aligned center):
█ red
█ green
█ blue
Current code:
...ANSWER
Answered 2021-Jun-15 at 01:08I think this should align your text and fix your issue.
QUESTION
I really need your help. I would like all my prices to show on the same line. Right now, the price shows below the product name, and depending on the length of the name, the price shows after.
Can I somehow force the prices to get aligned on the same line?
You can check http://dansupplies.dk to see what I mean. The first box has 4 products, and these prices should be on the same line.
My “related products” that show on the product page also needs this fix, if it’s possible of course.
Big high five!
...ANSWER
Answered 2021-Jun-14 at 21:14The most simple solution would be to add a min-height to the .woocommerce-loop-product__title class.
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install Aligned
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page
