X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsd_login_monitor_new.xml;h=b187ad0dbe9536d2e9adf4558849be97bd5d2f3e;hp=de484329a9900c794489d891804c3d08787452f9;hb=667c24a6a86a5a26a906b7477ae81dcf4c73e64e;hpb=595aae376fae21f885ec9af2cac1aaf3ff3e9bee diff --git a/man/sd_login_monitor_new.xml b/man/sd_login_monitor_new.xml index de484329a..b187ad0db 100644 --- a/man/sd_login_monitor_new.xml +++ b/man/sd_login_monitor_new.xml @@ -8,20 +8,20 @@ Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License + You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . --> - + sd_login_monitor_new @@ -47,6 +47,9 @@ sd_login_monitor_unref sd_login_monitor_flush sd_login_monitor_get_fd + sd_login_monitor_get_events + sd_login_monitor_get_timeout + sd_login_monitor Monitor login sessions, seats and users @@ -75,6 +78,17 @@ sd_login_monitor* m + + int sd_login_monitor_get_events + sd_login_monitor* m + + + + int sd_login_monitor_get_timeout + sd_login_monitor* m + uint64_t* timeout_usec + + @@ -82,20 +96,20 @@ Description sd_login_monitor_new() may - be used to monitor login session, users and seats. Via + be used to monitor login sessions, users and seats. Via a monitor object a file descriptor can be integrated into an application defined event loop which is woken up each time a user logs in, logs out or a seat is added or removed, or a session, user, or seat changes state otherwise. The first parameter takes a string - which can be either seat (to get + which can be seat (to get only notifications about seats being added, removed or changed), session (to get only notifications about sessions being created or removed or changed) or uid (to get only notifications when a user changes state in respect to logins). If notifications shall be generated in all - these conditions, NULL may be passed. Note that in + these conditions, NULL may be passed. Note that in the future additional categories may be defined. The second parameter returns a monitor object and needs to be freed with the @@ -121,26 +135,78 @@ application defined event loop, based around poll2 or a similar interface. The application should include - the returned file descriptor as wake up source for - POLLIN events. Whenever a wake-up is triggered the - file descriptor needs to be reset via + the returned file descriptor as wake-up source for the + events mask returned by + sd_login_monitor_get_events(). It + should pass a timeout value as returned by + sd_login_monitor_get_timeout(). Whenever + a wake-up is triggered the file descriptor needs to be + reset via sd_login_monitor_flush(). An application needs to reread the login state with a function like sd_get_seats3 or similar to determine what changed. + + sd_login_monitor_get_events() + will return the poll() mask to + wait for. This function will return a combination of + POLLIN, POLLOUT + and similar to fill into the + .events field of struct + pollfd. + + sd_login_monitor_get_timeout() + will return a timeout value for usage in + poll(). This returns a value in + microseconds since the epoch of CLOCK_MONOTONIC for + timing out poll() in + timeout_usec. See + clock_gettime2 + for details about + CLOCK_MONOTONIC. If there's no + timeout to wait for this will fill in + (uint64_t) -1 instead. Note that + poll() takes a relative timeout + in milliseconds rather than an absolute timeout in + microseconds. To convert the absolute 'us' timeout into + relative 'ms', use code like the following: + + uint64_t t; +int msec; +sd_login_monitor_get_timeout(m, &t); +if (t == (uint64_t) -1) + msec = -1; +else { + struct timespec ts; + uint64_t n; + clock_getttime(CLOCK_MONOTONIC, &ts); + n = (uint64_t) ts.tv_sec * 1000000 + ts.tv_nsec / 1000; + msec = t > n ? (int) ((t - n + 999) / 1000) : 0; +} + + The code above does not do any error checking + for brevity's sake. The calculated msec + integer can be passed directly as + poll()'s timeout + parameter. Return Value On success - sd_login_monitor_new() and - sd_login_monitor_flush() return 0 - or a positive integer. On success + sd_login_monitor_new(), + sd_login_monitor_flush() and + sd_login_monitor_get_timeout() + return 0 or a positive integer. On success sd_login_monitor_get_fd() returns - a Unix file descriptor. On failure, these calls return - a negative errno-style error code. + a Unix file descriptor. On success + sd_login_monitor_get_events() + returns a combination of POLLIN, + POLLOUT and suchlike. On failure, + these calls return a negative errno-style error + code. sd_login_monitor_unref() always returns NULL. @@ -150,10 +216,13 @@ Notes The sd_login_monitor_new(), - sd_login_monitor_unref(), sd_login_monitor_flush() and - sd_login_monitor_get_fd() interfaces - are available as shared library, which can be compiled - and linked to with the + sd_login_monitor_unref(), + sd_login_monitor_flush(), + sd_login_monitor_get_fd(), + sd_login_monitor_get_events() and + sd_login_monitor_get_timeout() + interfaces are available as shared library, which can + be compiled and linked to with the libsystemd-login pkg-config1 file. @@ -164,8 +233,10 @@ systemd1, - sd-login7, - sd_get_seats3 + sd-login3, + sd_get_seats3, + poll2, + clock_gettime2