Managarm: A Fully Asynchronous OS Based on Modern C++

C++20 and future C++ standards are expected to massively improve the ergonomics of asynchronous I/O within the C++ ecosystem. Yet, the vast majority of current operating systems (OSes) were designed without considering asynchronous I/O to be a first-class citizen. For example, Linux is only able to perform general-purpose asynchronous I/O since the recent addition of io_uring. Even with this new asynchronous mechanism in place, many I/O operations still have to fall back to a thread-based emulation within the kernel.

In this talk, we present Managarm, an OS designed around C++20 coroutines and the upcoming C++ sender/receiver model. Its main goal is to fully support asynchronous I/O through the entire system. All I/O operations are asynchronous in Managarm, with a single blocking system call to wait for their completion. The OS implements primitive asynchronous operations using (a variant of) the C++ sender/receiver model. These primitives comprise the system call layer and basic asynchronous data structures. We discuss how this low-level functionality can be integrated into high-level C++ code that is based on coroutines. High-level coroutine code constitutes the majority of the system and enables fully asynchronous drivers and servers. This approach enables high programmer productivity and excellent performance at the same time. At the end of the talk, we discuss open challenges for system programming that C++20 does not solve yet and give a perspective on vital future work in this area.

https://github.com/CppCon/CppCon2020/blob/main/Presentations/managarm_a_fully_asynchronous_operating_system_powered_by_modern_cpp/managarm_a_fully_asynchronous_operating_system_powered_by_modern_cpp__alexander_van_der_grinten__cppcon_2020.pdf

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Managarm: A Fully Asynchronous OS Based on Modern C++
Tamale  Moses

Tamale Moses

1624240146

How to Run C/C++ in Sublime Text?

C and C++ are the most powerful programming language in the world. Most of the super fast and complex libraries and algorithms are written in C or C++. Most powerful Kernel programs are also written in C. So, there is no way to skip it.

In programming competitions, most programmers prefer to write code in C or C++. Tourist is considered the worlds top programming contestant of all ages who write code in C++.

During programming competitions, programmers prefer to use a lightweight editor to focus on coding and algorithm designing. VimSublime Text, and Notepad++ are the most common editors for us. Apart from the competition, many software developers and professionals love to use Sublime Text just because of its flexibility.

I have discussed the steps we need to complete in this blog post before running a C/C++ code in Sublime Text. We will take the inputs from an input file and print outputs to an output file without using freopen file related functions in C/C++.

#cpp #c #c-programming #sublimetext #c++ #c/c++

Dicey Issues in C/C++

If you are familiar with C/C++then you must have come across some unusual things and if you haven’t, then you are about to. The below codes are checked twice before adding, so feel free to share this article with your friends. The following displays some of the issues:

  1. Using multiple variables in the print function
  2. Comparing Signed integer with unsigned integer
  3. Putting a semicolon at the end of the loop statement
  4. C preprocessor doesn’t need a semicolon
  5. Size of the string matters
  6. Macros and equations aren’t good friends
  7. Never compare Floating data type with double data type
  8. Arrays have a boundary
  9. Character constants are different from string literals
  10. Difference between single(=) and double(==) equal signs.

The below code generates no error since a print function can take any number of inputs but creates a mismatch with the variables. The print function is used to display characters, strings, integers, float, octal, and hexadecimal values onto the output screen. The format specifier is used to display the value of a variable.

  1. %d indicates Integer Format Specifier
  2. %f indicates Float Format Specifier
  3. %c indicates Character Format Specifier
  4. %s indicates String Format Specifier
  5. %u indicates Unsigned Integer Format Specifier
  6. %ld indicates Long Int Format Specifier

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A signed integer is a 32-bit datum that encodes an integer in the range [-2147483648 to 2147483647]. An unsigned integer is a 32-bit datum that encodes a non-negative integer in the range [0 to 4294967295]. The signed integer is represented in twos-complement notation. In the below code the signed integer will be converted to the maximum unsigned integer then compared with the unsigned integer.

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#problems-with-c #dicey-issues-in-c #c-programming #c++ #c #cplusplus

Sadie  Ratke

Sadie Ratke

1590582240

Modern C++ development with Visual Studio

Join us for a demo packed session on the latest improvements in Visual Studio 2019, including new C++20 features, cross-platform CMake integration, and support for Visual Studio Codespaces.

#c #c# #c++ #programming-c

Ari  Bogisich

Ari Bogisich

1590587580

Loops in C++ | For, While, and Do While Loops in C++

In this Video We are going to see how to use Loops in C++. We will see How to use For, While, and Do While Loops in C++.
C++ is general purpose, compiled, object-oriented programming language and its concepts served as the basis for several other languages such as Java, Python, Ruby, Perl etc.

#c #c# #c++ #programming-c

Ari  Bogisich

Ari Bogisich

1589816580

Using isdigit() in C/C++

In this article, we’ll take a look at using the isdigit() function in C/C++. This is a very simple way to check if any value is a digit or not. Let’s look at how to use this function, using some simple examples.

#c programming #c++ #c #c#