大约有 48,000 项符合查询结果（耗时：0.0729秒） [XML]
Why does pthread_cond_wait have spurious wakeups?
... operations.
In the following comp.programming.threads discussion, he expands on the thinking behind the design:
Patrick Doyle wrote:
> In article , Tom Payne wrote:
> >Kaz Kylheku wrote:
> >: It is so because implementations can sometimes not avoid inserting
> >: the...
Round to 5 (or other number) in Python
...
I don't know of a standard function in Python, but this works for me:
Python 2
def myround(x, base=5):
return int(base * round(float(x)/base))
Python3
def myround(x, base=5):
return base * round(x/base)
It is easy to see why the a...
java.lang.UnsupportedClassVersionError: Bad version number in .class file?
... suggestions on the web indicate that the code was compiled in one version and executed in another version (new on old). However, I only have one version of JRE on my system. If I run the commands:
...
How to call an async method from a getter or setter?
...int (2) wouldn't work in that case. Just implement INotifyPropertyChanged, and then decide whether you want the old value returned or default(T) while the asynchronous update is in flight.
– Stephen Cleary
Nov 19 '13 at 11:57
...
Docker - a way to give access to a host USB or serial device?
...in /dev/bus/usb, you can mount this in the container using privileged mode and the volumes option. For example:
docker run -t -i --privileged -v /dev/bus/usb:/dev/bus/usb ubuntu bash
Note that as the name implies, --privileged is insecure and should be handled with care.
...
Should I instantiate instance variables on declaration or in the constructor?
...he compiler.
The first variant is more readable.
You can't have exception handling with the first variant.
There is additionally the initialization block, which is as well put in the constructor(s) by the compiler:
{
a = new A();
}
Check Sun's explanation and advice
From this tutorial:
...
What does threadsafe mean?
...ently I tried to Access a textbox from a thread (other than the UI thread) and an exception was thrown. It said something about the "code not being thread safe" and so I ended up writing a delegate (sample from MSDN helped) and calling it instead.
...
Stopping scripters from slamming your website
...at does the design, writes the product descriptions, podcasts, blog posts, and moderates the forums. I work with CSS/HTML and am only barely familiar with other technologies. I work closely with the developers and have talked through all of the answers here (and many other ideas we've had).
...
How to create a MySQL hierarchical recursive query
... (select @pv := '19') initialisation
where find_in_set(parent_id, @pv)
and length(@pv := concat(@pv, ',', id))
Here is a fiddle.
Here, the value specified in @pv := '19' should be set to the id of the parent you want to select all the descendants of.
This will work also if a parent has m...
Quickly reading very large tables as dataframes
...ahead of time, the table does not contain any column headers or row names, and does not have any pathological characters that I have to worry about.
...