A small note about static linking Boost, so as not to forget.

Initial data:

• OS Windows
• MSVC 2017 64bit
• Boost 1.68.0
• CMake project

I propose to consider several ways to synchronize threads and processes that are most commonly used in Java. They differ in implementation and use cases. We will consider all methods on interesting examples.

Critical section

This method is suitable for you if:

• parallel threads work with a shared resource;
• requires synchronization between threads, not processes;

This method of synchronization is called resource synchronization ("open – close" synchronization). The idea of this method is that each object in Java has an associated monitor . A monitor is a kind of tool to control access to an object.

Напишем небольшое приложение для получения максимального числа из нескольких полей QLineEdit.

This means that we will have several QLineEdit fields, let's say 4 pieces into which numbers will be entered. And there will be the fifth field QLineEdit in which the result will be displayed. We also have a QPushButton button, by clicking we will get values from all QLineEdit fields and among them we will look for the maximum number that has been entered into these fields.

The application will look like this

There was a need to obtain a large amount of data from the database for the subsequent work of the user with them (Reference book of goods in a particular store).

For the code do not kick much. Programming for me is a hobby for the mind.

The query itself takes a long time. For this, we do it in the stream, display the endless ProgressBar to the user with the sentence "Lean back and wait." :-)

Let's write a small example of an application in which a button will be moved using property animations. To do this, we use the QSequentialAnimationGroup and QPropertyAnimation classes.

QSequentialAnimationGroup is a class that combines several animations into one group, which allows you to automatically start one animation when the previous QPropertyAnimation has completed.

Animation will be launched by pressing the button and this button will move in the window as shown in the image.

And here is an article on the boost of my some accumulated materials. I offer you the option of writing a console program with support for the console menu, which is implemented using boost::program_options .

boost::program_options is responsible for processing the arguments passed to the program and sets all the necessary variables without the need to implement long logic from if else branches. This is already implemented inside boost::program_optons .

Suppose our program takes the following data as arguments

• input file path
• output file path
  
• the size of the block being processed, no matter why, we will not do anything with it, just have such a parameter in the program.
  

Also, the program will have a help menu, which will be the console menu.

The figure below shows the use of this program.

After talking with one of the users, I decided to change the policy regarding advertising on the site, although I am not sure about that.

I myself am not pleased with the abundance of advertising banners, but I would like to receive sufficient income from the site in order to switch to part-time work and put more effort into the development of the site. I really enjoy the site, it's interesting. But at the moment you have to choose between a hobby and a job.

I added authorization on the site through Facebook.

At the same time collected a couple of pitfalls.

Before Facebook , I already added in authorization through the social network VKontakte and Google . And here I needed to create a privacy policy page, since Facebook requires this page and also requires a user agreement, but I provided a privacy policy page. I think that with the growth of the site I will add a full-fledged page of the user agreement, although it is unknown when it will be. However, the site rules are described in sufficient detail.

Also came across a strict need for https from the site. Generally, if you consider that I have https from Let`s Encrypt , I didn’t think that there would be any problem, but as it turned out, by default django-social-auth forms the return address with HTTP protocol, and for using HTTPS You need to specify this in the settings.

And now let's see how this is done.

Consider a small example of the formation of a JSON document from, for example, the text and the title of this text.

For example, the text has:

• Title - First Title
• Content - First Content

And so on

We will add this text to QJsonObject, which we will add to the QJsonArray text array. The array of objects will be in the general working QJsonObject, which we will save to a file.

We will do all this through a graphical interface in which we have:

• QLineEdit - titleLineEdit - contains the title of the text to add
• QTextEdit - contentTextEdit - contains the contents of the text to add
• QTextEdit - jsonDocumentTextEdit - JSON document preview
• QPushButton - addButton - button to add new text in JSON
• QPushButton - clearButton - button to remove all texts from the current QJsonObject
• QPushButton - saveButton - button to save JSON document to file
• QPushButton - loadButton - button to read JSON from file

In this case, we will be able to read the JSON file and add additional texts to the read file.

The application will look like this.

Gave free time to correct private messages on the site. This functionality is not used very often, so I do not make great efforts to improve it, although it is time to bring this functionality to adequate work.

Previously, there was a very big flaw, which was that the dialogue counter with unread messages was not shown, which led to the fact that the users who were sent the message simply did not pay attention to it, because they did not know about it.

Now I finally fixed this flaw. And in the framework of the previous code I will show which corrections were added.