{"id":4183,"date":"2022-12-20T17:39:39","date_gmt":"2022-12-20T20:39:39","guid":{"rendered":"http:\/\/lode.uno\/linux-man\/index.php\/2022\/12\/20\/sleep_on-man9\/"},"modified":"2022-12-20T17:39:39","modified_gmt":"2022-12-20T20:39:39","slug":"sleep_on-man9","status":"publish","type":"post","link":"https:\/\/lode.uno\/linux-man\/2022\/12\/20\/sleep_on-man9\/","title":{"rendered":"sleep_on (man9)"},"content":{"rendered":"

sleep_on<\/h1>\n

NAME<\/a>
SYNOPSIS<\/a>
DESCRIPTION<\/a>
RETURN VALUE<\/a>
AVAILABILITY<\/a>
SEE ALSO<\/a>
AUTHOR<\/a>
BUGS<\/a> <\/p>\n

\n

NAME <\/a> <\/h2>\n

sleep_on \u2212 synchronization using a condition variable<\/p>\n

SYNOPSIS <\/a> <\/h2>\n

#include <\/b><\/p>\n\n\n
<\/td>\n\n

void sleep_on(struct\u00a0wait_queue**<\/b>condition<\/i>)<\/b><\/p>\n<\/td>\n

 <\/td>\n<\/tr>\n<\/table>\n

DESCRIPTION <\/a> <\/h2>\n

The sleep_on<\/b> function provides a means for synchronizing between processes and with interrupt handlers. The condition<\/i> parameter is a pointer to a pointer to the opaque wait_queue type. Initialize the condition variable to zero, then pass a pointer to it to the sleep_on<\/b> function. The basic idea is as follows:<\/p>\n

struct wait_queue*con = 0;<\/p>\n\n\n
<\/td>\n\n

[…]<\/p>\n<\/td>\n<\/tr>\n<\/table>\n

sleep_on(&con);<\/p>\n

While a process is sleeping, it is fully interruptible, no matter what the cpu state when entering the function. The cpu state is restored on being awakened.<\/p>\n

If a null(0) is passed to sleep_on<\/b>, it returns immediately, without sleeping. This is a no-op.<\/p>\n

RETURN VALUE <\/a> <\/h2>\n

The sleep_on<\/b> function only returns when explicitly awakened.<\/p>\n

AVAILABILITY <\/a> <\/h2>\n

Linux 1+<\/p>\n

SEE ALSO <\/a> <\/h2>\n

wake_up<\/b>(9)<\/p>\n

\/usr\/src\/linux\/kernel\/sched.c<\/i><\/p>\n

AUTHOR <\/a> <\/h2>\n

Stephen Williams <\/p>\n

BUGS <\/a> <\/h2>\n

A call to sleep_on(0)<\/i> seems like an interesting way to test for and momentarily allow interrupts, but that is not what happens.<\/p>\n

The sleep_on<\/b> function cannot be called by interrupt handlers.<\/p>\n

The function is not atomic with the condition tests that the driver writer might include, so the code executing the sleep_on<\/b> function is protected from interrupts. Failure to do so generally leads to race conditions.<\/p>\n

\n","protected":false},"excerpt":{"rendered":"

sleep_on \u2212 synchronization using a condition variable <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1222],"tags":[1226,1223,1225,1263],"class_list":["post-4183","post","type-post","status-publish","format-standard","hentry","category-9-rutinas-del-nucleo","tag-1226","tag-kernel","tag-man9","tag-sleep_on"],"gutentor_comment":0,"_links":{"self":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts\/4183","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/comments?post=4183"}],"version-history":[{"count":0,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/posts\/4183\/revisions"}],"wp:attachment":[{"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/media?parent=4183"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/categories?post=4183"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lode.uno\/linux-man\/wp-json\/wp\/v2\/tags?post=4183"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}