Software transactional memory

<p>In <a href="/facts/Computer_science/lN3pEyPz">computer science</a>, software transactional memory (STM) is a <a href="/facts/Concurrency_control/JWnmhVd5">concurrency control</a> mechanism analogous to <a href="/facts/Database_transaction/q1Etrsl8">database transactions</a> for controlling access to <a href="/facts/Shared_memory_(interprocess_communication)/zmpH7WuV">shared memory</a> in <a href="/facts/Concurrent_computing/yVzQBPr9">concurrent computing</a>. It is an alternative to <a href="/facts/Lock_(computer_science)/e3a9gnJT">lock-based synchronization</a>. STM is a strategy implemented in software, rather than as a hardware component. A transaction in this context occurs when a piece of code executes a series of reads and writes to shared memory. These reads and writes logically occur at a single instant in time; intermediate states are not visible to other (successful) transactions. The idea of providing hardware support for transactions originated in a 1986 paper by <a href="/facts/Tom_Knight_(scientist)/4TS2pC0L">Tom Knight</a>. The idea was popularized by <a href="/facts/Maurice_Herlihy/QvzHk8u9">Maurice Herlihy</a> and <a href="/facts/J._Eliot_B._Moss/QbG51AAm">J. Eliot B. Moss</a>. In 1995, <a href="/facts/Nir_Shavit/mW2QX3bD">Nir Shavit</a> and Dan Touitou extended this idea to software-only transactional memory (STM). Since 2005, STM has been the focus of intense research and support for practical implementations is growing.
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Software transactional memory open-in-new

Software transactional memory