Referans say\u0131m\u0131, bilgisayar programlamada bellek kaynaklar\u0131n\u0131n tahsisini ve serbest b\u0131rak\u0131lmas\u0131n\u0131 otomatik olarak y\u00f6netmek i\u00e7in kullan\u0131lan bir haf\u0131za y\u00f6netimi tekni\u011fidir. Bellekteki belirli bir nesneye i\u015faret eden referanslar\u0131n veya i\u015faret\u00e7ilerin say\u0131s\u0131n\u0131n izlenmesini i\u00e7erir. Referans say\u0131s\u0131 s\u0131f\u0131ra d\u00fc\u015ft\u00fc\u011f\u00fcnde, bu nesneye daha fazla referans olmad\u0131\u011f\u0131n\u0131 g\u00f6sterir, nesnenin kaplad\u0131\u011f\u0131 haf\u0131za otomatik olarak serbest b\u0131rak\u0131l\u0131r. Bu teknik, bellek s\u0131z\u0131nt\u0131lar\u0131n\u0131 \u00f6nlemek ve bellek kullan\u0131m\u0131n\u0131 verimli bir \u015fekilde y\u00f6netmek i\u00e7in \u00e7e\u015fitli programlama dillerinde ve sistemlerinde yayg\u0131n olarak kullan\u0131lmaktad\u0131r.<\/p>\n
Referans sayma kavram\u0131, bilgisayar programlaman\u0131n ilk g\u00fcnlerine kadar uzan\u0131r. \u0130lk bahsedilenlerden biri, 1950'lerin sonlar\u0131nda geli\u015ftirilen ve \u00e7\u00f6p toplama i\u00e7in referans say\u0131m\u0131n\u0131n kullan\u0131ld\u0131\u011f\u0131 Lisp programlama diline kadar uzanabilir. Programlama dilleri geli\u015ftik\u00e7e referans sayma, bellek y\u00f6netimi tekniklerinde temel bir kavram haline geldi.<\/p>\n
Referans say\u0131m\u0131, belirli bir nesneye yap\u0131lan referanslar\u0131n veya i\u015faret\u00e7ilerin say\u0131s\u0131n\u0131n korunmas\u0131n\u0131 i\u00e7erir. Nesneye her referans olu\u015fturuldu\u011funda referans say\u0131s\u0131 art\u0131r\u0131l\u0131r. Tersine, bir referans silindi\u011finde veya kapsam d\u0131\u015f\u0131na \u00e7\u0131kt\u0131\u011f\u0131nda referans say\u0131s\u0131 azalt\u0131l\u0131r. Referans say\u0131s\u0131n\u0131n s\u0131f\u0131ra ula\u015fmas\u0131, nesneye art\u0131k eri\u015filemedi\u011fi ve belle\u011finin g\u00fcvenli bir \u015fekilde yeniden konumland\u0131r\u0131labilece\u011fi anlam\u0131na gelir.<\/p>\n
Referans say\u0131m\u0131n\u0131n i\u00e7 yap\u0131s\u0131 tipik olarak iki ana bile\u015feni i\u00e7erir: referans say\u0131m\u0131 ve ger\u00e7ek nesne. Her nesne, olu\u015fturulduktan sonra ba\u015flang\u0131\u00e7ta bir olarak ayarlanan bir referans say\u0131s\u0131 de\u011fi\u015fkeni i\u00e7erir. Nesneye referanslar olu\u015fturulduk\u00e7a referans say\u0131s\u0131 art\u0131r\u0131l\u0131r. Referanslar kald\u0131r\u0131ld\u0131\u011f\u0131nda say\u0131 azalt\u0131l\u0131r. Say\u0131m s\u0131f\u0131ra ula\u015ft\u0131\u011f\u0131nda, bir serbest b\u0131rakma rutini tetiklenir ve nesneyle ili\u015fkili bellek serbest b\u0131rak\u0131l\u0131r.<\/p>\n
Referans say\u0131m\u0131, onu \u00e7ekici bir haf\u0131za y\u00f6netimi tekni\u011fi haline getiren birka\u00e7 temel \u00f6zellik sunar:<\/p>\n
Deterministik Bellek Y\u00f6netimi:<\/strong> Referans say\u0131m\u0131, deterministik bellek y\u00f6netimine izin verir, \u00e7\u00fcnk\u00fc bellek art\u0131k ihtiya\u00e7 duyulmad\u0131\u011f\u0131 anda serbest b\u0131rak\u0131l\u0131r ve bellek s\u0131z\u0131nt\u0131lar\u0131 \u00f6nlenir.<\/p>\n<\/li>\n D\u00fc\u015f\u00fck havai:<\/strong> Referans say\u0131m\u0131yla ilgili ek y\u00fck, di\u011fer bellek y\u00f6netimi teknikleriyle kar\u015f\u0131la\u015ft\u0131r\u0131ld\u0131\u011f\u0131nda genellikle d\u00fc\u015f\u00fckt\u00fcr.<\/p>\n<\/li>\n Ger\u00e7ek Zamanl\u0131 Avantajlar:<\/strong> Referans say\u0131m\u0131, \u00f6ng\u00f6r\u00fclebilir bellek davran\u0131\u015f\u0131n\u0131n \u00e7ok \u00f6nemli oldu\u011fu ger\u00e7ek zamanl\u0131 sistemlerde avantajl\u0131 olabilir.<\/p>\n<\/li>\n<\/ul>\n Referans say\u0131m\u0131na ili\u015fkin, her biri kendine has \u00f6zelliklere sahip olan birka\u00e7 varyasyon ve yakla\u015f\u0131m vard\u0131r:<\/p>\n Basit Referans Say\u0131m\u0131:<\/strong> Daha \u00f6nce a\u00e7\u0131kland\u0131\u011f\u0131 gibi referans say\u0131m\u0131n\u0131n temel bi\u00e7imi.<\/p>\n<\/li>\n Ertelenmi\u015f Referans Say\u0131m\u0131:<\/strong> Bu yakla\u015f\u0131m, s\u0131k s\u0131k yap\u0131lan tahsislerin y\u00fck\u00fcn\u00fc en aza indirmek i\u00e7in fiili tahsisin program\u0131n y\u00fcr\u00fct\u00fclmesinde belirli bir noktaya kadar ertelenmesini i\u00e7erir.<\/p>\n<\/li>\n<\/ol>\n Referans say\u0131m\u0131, nesnelerin sahipli\u011finin ve \u00f6mr\u00fcn\u00fcn a\u00e7\u0131k\u00e7a y\u00f6netilmesinin gerekti\u011fi senaryolarda yayg\u0131n olarak kullan\u0131l\u0131r. Ancak zorluklar da yok de\u011fil:<\/p>\n Dairesel Referanslar:<\/strong> Referans say\u0131m\u0131, nesnelerin birbirine referans verdi\u011fi d\u00f6ng\u00fcsel referanslarla sorun ya\u015far ve bu da bellek s\u0131z\u0131nt\u0131lar\u0131na yol a\u00e7ar. Bu sorunu \u00e7\u00f6zmek i\u00e7in \u201c\u00e7\u00f6p toplama\u201d d\u00f6ng\u00fcleri gibi teknikler kullan\u0131labilir.<\/p>\n<\/li>\n Performans Etkisi:<\/strong> Referans say\u0131mlar\u0131n\u0131n s\u0131k s\u0131k art\u0131r\u0131lmas\u0131 ve azalt\u0131lmas\u0131, \u00f6zellikle \u00e7ok i\u015f par\u00e7ac\u0131kl\u0131 ortamlarda performans\u0131 etkileyebilir. Atomik i\u015flemler gibi optimizasyonlar bunu azaltabilir.<\/p>\n<\/li>\n<\/ul>\nReferans Sayma T\u00fcrleri<\/h2>\n
\n
Referans Saymay\u0131 Kullanma Yollar\u0131, Sorunlar ve \u00c7\u00f6z\u00fcmleri<\/h2>\n
\n
Ana \u00d6zellikler ve Benzer Terimlerle Kar\u015f\u0131la\u015ft\u0131rmalar<\/h2>\n