Lecture

Transactional Memory: Two-phase Locking and Invisible Reads

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.

Description

This lecture provides a historical perspective on databases, theory, language, architecture, and hardware related to transactional memory. It covers the two-phase locking mechanism, the TM API, and the concept of invisible reads. The instructor discusses the importance of transactional memory in the context of multi-core processors and presents different approaches such as DSTM. The lecture explores contention managers and the implications of aborting transactions, emphasizing the challenges and benefits of using transactional memory in modern computing systems.

Official source

Ontological neighbourhood

Computer engineering

High-performance computing: Distributed computing

Related concepts (32)

Concurrency control

In information technology and computer science, especially in the fields of computer programming, operating systems, multiprocessors, and databases, concurrency control ensures that correct results for concurrent operations are generated, while getting those results as quickly as possible. Computer systems, both software and hardware, consist of modules, or components. Each component is designed to operate correctly, i.e., to obey or to meet certain consistency rules.

Multi-core processor

A multi-core processor is a microprocessor on a single integrated circuit with two or more separate processing units, called cores, each of which reads and executes program instructions. The instructions are ordinary CPU instructions (such as add, move data, and branch) but the single processor can run instructions on separate cores at the same time, increasing overall speed for programs that support multithreading or other parallel computing techniques.

Parallel computing

Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling.

Multiversion concurrency control

Multiversion concurrency control (MCC or MVCC), is a concurrency control method commonly used by database management systems to provide concurrent access to the database and in programming languages to implement transactional memory. Without concurrency control, if someone is reading from a database at the same time as someone else is writing to it, it is possible that the reader will see a half-written or inconsistent piece of data.

Optimistic concurrency control

Optimistic concurrency control (OCC), also known as optimistic locking, is a concurrency control method applied to transactional systems such as relational database management systems and software transactional memory. OCC assumes that multiple transactions can frequently complete without interfering with each other. While running, transactions use data resources without acquiring locks on those resources. Before committing, each transaction verifies that no other transaction has modified the data it has read.

Related lectures (64)

Scalable Synchronization Mechanisms for Manycore Operating Systems

Explores scalable synchronization mechanisms for many-core operating systems, focusing on the challenges of handling data growth and regressions in OS.

Concurrency with Futures

Explores futures as a structured approach to concurrency, simplifying parallel tasks and input-output operations.

Transaction Management & Concurrency Control

Explores transaction management, concurrency control, ACID properties, anomalies, and conflict serializability in database systems.

Parallel Computing: Principles and OpenMP

Covers the principles of parallel computing and introduces OpenMP for creating concurrent code from serial code.

Distributed Transactions: Architectures and Protocols