Lecture

Advanced Types in C: Unions and Bit Fields

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

In course

CS-202: Computer systems

This course will teach operating systems and networks in an integrated fashion,emphasising the fundamental concepts and techniques that make their interaction possible/practical. Core lectures will be coupled with C programming lectures and assignments for ...

Description

This lecture covers advanced types and keywords in the C programming language, focusing on unions and bit fields. The instructor begins by discussing various type modifiers, including extern, static, register, restrict, and volatile, explaining their specific uses and implications. The concept of unions is introduced, illustrating how they allow multiple interpretations of the same memory location, with examples demonstrating their syntax and potential pitfalls. The instructor emphasizes the importance of maintaining consistency when using unions, as the last assigned type must be compatible with subsequent accesses. The lecture also touches on the advantages of unions over generic pointers in certain scenarios. Additionally, bit fields are explained, showcasing how they enable precise control over memory usage by specifying the number of bits for each field. The instructor concludes with a brief overview of bit manipulation operators, highlighting their relevance in working with advanced types in C.

Instructors (2)

Jean-Cédric Chappelier

Jean-Cédric Chappelier is currently senior researcher and lecturer in Computational Linguistics at the Ecole Polytechnique Fédérale de Lausanne (Switzerland). He holds an Ms.Sci. and a Ph.D. in Computer Science from the Ecole Nationale Supérieure des Télécommunications de Paris (France).

Edouard Bugnion

Edouard Bugnion joined EPFL in 2012, where his focus is on datacenter systems. His areas of interest include operating systems, datacenter infrastructure (systems and networking), and computer architecture. Before joining EPFL, Edouard spent 18 years in the US, where he studied at Stanford and co-founded two startups: VMware and Nuova Systems (acquired by Cisco). At VMware from 1998 until 2005, he played many roles including CTO. At Nuova/Cisco from 2005 until 2011, he helped build the core engineering team and became the VP/CTO of Ciscos Server, Access, and Virtualization Technology Group, a group that brought to market Ciscos Unified Computing System (UCS) platform for virtualized datacenters. Prof. Bugnion is a Fellow of the ACM. Together with his colleagues, he received the ACM Software System Award for VMware 1.0 in 2009. His paper Disco: Running Commodity Operating Systems on Scalable Multiprocessors" received a Best Paper Award at SOSP '97 and was entered into the ACM SIGOPS Hall of Fame Award in 2008. At EPFL, he received the OSDI 2014 Best Paper Award for his work on the IX dataplane operating system

Official source

Ontological neighbourhood

Theoretical computer science

Programming language theory: High-level programming languages

Related concepts (32)

Object-oriented programming

Object-Oriented Programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or properties), and the code is in the form of procedures (often known as methods). A common feature of objects is that procedures (or methods) are attached to them and can access and modify the object's data fields. In this brand of OOP, there is usually a special name such as or used to refer to the current object.

Data structure

In computer science, a data structure is a data organization, management, and storage format that is usually chosen for efficient access to data. More precisely, a data structure is a collection of data values, the relationships among them, and the functions or operations that can be applied to the data, i.e., it is an algebraic structure about data. Data structures serve as the basis for abstract data types (ADT). The ADT defines the logical form of the data type. The data structure implements the physical form of the data type.

C (programming language)

C (pronounced 'siː – like the letter c) is a general-purpose computer programming language. It was created in the 1970s by Dennis Ritchie, and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted CPUs. It has found lasting use in operating systems, device drivers, protocol stacks, though decreasingly for application software. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems.

Array (data structure)

In computer science, an array is a data structure consisting of a collection of elements (values or variables), of same memory size, each identified by at least one array index or key. An array is stored such that the position of each element can be computed from its index tuple by a mathematical formula. The simplest type of data structure is a linear array, also called one-dimensional array. For example, an array of ten 32-bit (4-byte) integer variables, with indices 0 through 9, may be stored as ten words at memory addresses 2000, 2004, 2008, .

C Sharp (programming language)

C# (pronounced ) is a general-purpose high-level programming language supporting multiple paradigms. C# encompasses static typing, strong typing, lexically scoped, imperative, declarative, functional, generic, object-oriented (class-based), and component-oriented programming disciplines. The C# programming language was designed by Anders Hejlsberg from Microsoft in 2000 and was later approved as an international standard by Ecma (ECMA-334) in 2002 and ISO/IEC (ISO/IEC 23270) in 2003. Microsoft introduced C# along with .

Related lectures (64)

Advanced C Data Types

Covers advanced data types and memory management in C programming, emphasizing type consistency and dynamic array allocation.

C Programming Concepts: Debugging and Memory Management

Covers essential C programming concepts, including memory management, debugging techniques, and practical applications in programming projects.

Arrays in C: Advanced Data Types

Discusses advanced data types in C, focusing on arrays and their characteristics.

Dynamic Arrays in C: Implementation and Memory Management

Discusses the implementation and management of dynamic arrays in C programming, focusing on memory allocation and safe access methods.

Pointers and Arrays: Arithmetic, Buffer Overflow