{"id":195,"date":"2018-05-02T00:37:53","date_gmt":"2018-05-01T21:37:53","guid":{"rendered":"http:\/\/talhacelik.com.tr\/?p=195"},"modified":"2018-05-02T00:52:17","modified_gmt":"2018-05-01T21:52:17","slug":"mpi-functions-mpi_send-mpi_recv","status":"publish","type":"post","link":"https:\/\/talhacelik.com.tr\/index.php\/2018\/05\/02\/mpi-functions-mpi_send-mpi_recv\/","title":{"rendered":"MPI Functions (MPI_Send & MPI_Recv)"},"content":{"rendered":"

Paralel programlamada processler aras\u0131nda veri\u00a0 al\u0131\u015f-veri\u015fi olduk\u00e7a \u00f6nemlidir. Seri bir halde yaz\u0131lm\u0131\u015f kodu paralel olarak \u00e7al\u0131\u015ft\u0131rabilir duruma getirirken hangi process\u2019in hangi i\u015fi nerede, \u00a0nas\u0131l ve ne \u015fekilde yapaca\u011f\u0131n\u0131 belirlemek gerekmektedir.<\/p>\n

Tabii bu i\u015flem \u00f6rnekte de oldu\u011fu gibi manuel olarak yap\u0131lmaktad\u0131r. Fakat t\u00fcretilmi\u015f fonksiyonlarda veri al\u0131\u015f-veri\u015fi otomatik olarak yap\u0131lacakt\u0131r.<\/p>\n

MPI k\u00fct\u00fcphanesinin en temel iki fonksiyonu MPI_Send() ve MPI_Recv()<\/strong> dir. \u0130simlerinden de anla\u015f\u0131laca\u011f\u0131 \u00fczere MPI_Send() datay\u0131 hedefe g\u00f6ndermek amac\u0131 ile kullan\u0131lmakta, MPI_Recv() ise g\u00f6nderilen datan\u0131n al\u0131nmas\u0131n\u0131 sa\u011flamaktad\u0131r.<\/p>\n

<\/code>MPI_Send<\/span>(<\/span>\r\n    void<\/span>*<\/span> data<\/span>,<\/span>\r\n    int<\/span> count<\/span>,<\/span>\r\n    MPI_Datatype<\/span> datatype<\/span>,<\/span>\r\n    int<\/span> destination<\/span>,<\/span>\r\n    int<\/span> tag<\/span>,<\/span>\r\n    MPI_Comm<\/span> communicator<\/span>)<\/span><\/code><\/pre>\n
MPI_Recv<\/span>(<\/span>\r\n    void<\/span>*<\/span> data<\/span>,<\/span>\r\n    int<\/span> count<\/span>,<\/span>\r\n    MPI_Datatype<\/span> datatype<\/span>,<\/span>\r\n    int<\/span> source<\/span>,<\/span>\r\n    int<\/span> tag<\/span>,<\/span>\r\n    MPI_Comm<\/span> communicator<\/span>,<\/span>\r\n    MPI_Status<\/span>*<\/span> status<\/span>)<\/span><\/code><\/pre>\n
 <\/p>\n
void *data\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 : G\u00f6nderilecek olan veri, RAM \u00fczerindeki adresler ile \u00e7al\u0131\u015ft\u0131\u011f\u0131 i\u00e7in pointer yap\u0131da.<\/em><\/p>\n
int count\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0: G\u00f6nderilecek olan verinin adedi.<\/em><\/p>\n
MPI_Datatype datatype\u00a0 \u00a0 : G\u00f6nderilecek olan verinin tipi.<\/em><\/p>\n
int destination\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 : Veriyi alacak olan processin numaras\u0131.<\/em><\/p>\n
int tag\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 : Verinin numaras\u0131. <\/em><\/p>\n
MPI_Comm \u00a0com\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0: Processlerin i\u00e7inde bulundu\u011fu evren.<\/em><\/p>\n
\u00a0<\/em><\/p>\n
Fonksiyonlar\u0131n parametrelerini okurken anla\u015f\u0131lmas\u0131 zor olan k\u0131s\u0131mlardan biri MPI_Datatype.\u00a0<\/strong>Bu anahtar kelime ile processler aras\u0131nda dola\u015fan verinin tipini MPI k\u00fct\u00fcphanesinin kendince belirlemi\u015f oldu\u011fu bir veri tipi ile birlikte kullanmak durumunday\u0131z.<\/p>\n
\"\"
Go to book<\/a><\/figcaption><\/figure>\n
MPI K\u00fct\u00fcphanesine ait veri tipleri ve C deki karl\u0131\u015f\u0131klar\u0131<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
MPI_SHORT<\/td>\nshort int<\/td>\n<\/tr>\n
MPI_INT<\/td>\nint<\/td>\n<\/tr>\n
MPI_LONG<\/td>\nlong int<\/td>\n<\/tr>\n
MPI_LONG_LONG<\/td>\nlong long int<\/td>\n<\/tr>\n
MPI_UNSIGNED_CHAR<\/td>\nunsigned char<\/td>\n<\/tr>\n
MPI_UNSIGNED_SHORT<\/td>\nunsigned short int<\/td>\n<\/tr>\n
MPI_UNSIGNED<\/td>\nunsigned int<\/td>\n<\/tr>\n
MPI_UNSIGNED_LONG<\/td>\nunsigned long int<\/td>\n<\/tr>\n
MPI_UNSIGNED_LONG_LONG<\/td>\nunsigned long long int<\/td>\n<\/tr>\n
MPI_FLOAT<\/td>\nfloat<\/td>\n<\/tr>\n
MPI_DOUBLE<\/td>\ndouble<\/td>\n<\/tr>\n
MPI_LONG_DOUBLE<\/td>\nlong double<\/td>\n<\/tr>\n
MPI_BYTE<\/td>\nchar<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\u00d6rnek olarak 0 ve 1 numaral\u0131 processler aras\u0131nda number de\u011fi\u015fkeninin al\u0131\u015f-veri\u015fini yapan bir C kodu.<\/p>\n
int<\/span> world_rank<\/span>; \/\/ worker (process) numaras\u0131n\u0131 tutacak de\u011fi\u015fken<\/span>\r\nMPI_Comm_rank<\/span>(<\/span>MPI_COMM_WORLD<\/span>,<\/span> &<\/span>world_rank<\/span>); \/\/ aktif evrende \u015fuan \u00e7al\u0131\u015fan worker (process) numaras\u0131n\u0131 getirir <\/span>\r\nint<\/span> world_size<\/span>; \/\/ aktif evrende \u00e7al\u0131\u015fan toplam worker (process) say\u0131s\u0131<\/span>\r\nMPI_Comm_size<\/span>(<\/span>MPI_COMM_WORLD<\/span>,<\/span> &<\/span>world_size<\/span>); \/\/ aktif evrende toplam worker (process) say\u0131s\u0131n\u0131 getirir <\/span>\r\n\r\nint<\/span> number<\/span>;<\/span>\r\nif<\/span> (<\/span>world_rank<\/span> ==<\/span> 0<\/span>)<\/span> {<\/span>\r\n    number<\/span> =<\/span> -<\/span>1<\/span>; \/\/ hedef workera (process) g\u00f6nderilecek data<\/span>\r\n    MPI_Send<\/span>(<\/span>&<\/span>number<\/span>,<\/span> 1<\/span>,<\/span> MPI_INT<\/span>,<\/span> 1<\/span>,<\/span> 0<\/span>,<\/span> MPI_COMM_WORLD<\/span>); \/\/ 0 numaral\u0131 etikete sahip, 1 adet number<\/em> de\u011fi\u015fkenini 1 numaral\u0131 workera yolla  <\/span>\r\n}<\/span> else<\/span> if<\/span> (<\/span>world_rank<\/span> ==<\/span> 1<\/span>)<\/span> {<\/span>\r\n    MPI_Recv<\/span>(<\/span>&<\/span>number<\/span>,<\/span> 1<\/span>,<\/span> MPI_INT<\/span>,<\/span> 0<\/span>,<\/span> 0<\/span>,<\/span> MPI_COMM_WORLD<\/span>,<\/span>\r\n             MPI_STATUS_IGNORE<\/span>);<\/span>\r\n    printf<\/span>(<\/span>\"Process 1 received number %d from process 0<\/span>\\n<\/span>\"<\/span>,<\/span>\r\n           number<\/span>);<\/span>\r\n}\r\n\r\n\r\n<\/span><\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
Paralel programlamada processler aras\u0131nda veri\u00a0 al\u0131\u015f-veri\u015fi olduk\u00e7a \u00f6nemlidir. Seri bir halde yaz\u0131lm\u0131\u015f kodu paralel olarak \u00e7al\u0131\u015ft\u0131rabilir duruma getirirken hangi process\u2019in hangi i\u015fi nerede, \u00a0nas\u0131l ve ne \u015fekilde yapaca\u011f\u0131n\u0131 belirlemek gerekmektedir. Tabii bu i\u015flem \u00f6rnekte de oldu\u011fu gibi manuel olarak yap\u0131lmaktad\u0131r. Fakat t\u00fcretilmi\u015f fonksiyonlarda veri al\u0131\u015f-veri\u015fi otomatik olarak yap\u0131lacakt\u0131r. MPI k\u00fct\u00fcphanesinin en temel iki fonksiyonu MPI_Send() …<\/p>\n","protected":false},"author":1,"featured_media":174,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[3,31,30,4],"_links":{"self":[{"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/195"}],"collection":[{"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=195"}],"version-history":[{"count":18,"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/195\/revisions"}],"predecessor-version":[{"id":301,"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/195\/revisions\/301"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/media\/174"}],"wp:attachment":[{"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=195"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=195"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/talhacelik.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=195"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}