X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;ds=sidebyside;f=man%2Fsd_notify.xml;h=a15426c1d10c4eba93d8fda1cbc8ffef28b61910;hb=76cc80f42e53215b9039ca99dd35687c7518880a;hp=c52ef533bbe201f47f2f3e4bee38d6c8feedc5c1;hpb=3b22396a4b2767a98172f6915929c47738cb0a1e;p=elogind.git
diff --git a/man/sd_notify.xml b/man/sd_notify.xml
index c52ef533b..a15426c1d 100644
--- a/man/sd_notify.xml
+++ b/man/sd_notify.xml
@@ -1,4 +1,4 @@
-
+
@@ -66,7 +66,7 @@
int sd_notifyfint unset_environmentconst char *format
- ...
+ â¦
@@ -81,7 +81,7 @@
pid_t pidint unset_environmentconst char *format
- ...
+ â¦
@@ -100,7 +100,7 @@
sd_notify() may be called by a service
to notify the service manager about state changes. It can be used
to send arbitrary information, encoded in an
- environment-block-like string. Most importantly it can be used for
+ environment-block-like string. Most importantly, it can be used for
start-up completion notification.If the unset_environment parameter is
@@ -152,19 +152,19 @@
- STATUS=...
+ STATUS=â¦Passes a single-line UTF-8 status string back
to the service manager that describes the service state. This
is free-form and can be used for various purposes: general
state feedback, fsck-like programs could pass completion
- percentages and failing programs could pass a human readable
+ percentages and failing programs could pass a human-readable
error message. Example: STATUS=Completed 66% of file
- system check...
+ system checkâ¦
- ERRNO=...
+ ERRNO=â¦If a service fails, the errno-style error
code, formatted as string. Example: ERRNO=2
@@ -172,7 +172,7 @@
- BUSERROR=...
+ BUSERROR=â¦If a service fails, the D-Bus error-style
error code. Example:
@@ -180,7 +180,7 @@
- MAINPID=...
+ MAINPID=â¦The main process ID (PID) of the service, in
case the service manager did not fork off the process itself.
@@ -194,7 +194,7 @@
watchdog timestamp. This is the keep-alive ping that services
need to issue in regular intervals if
WatchdogSec= is enabled for it. See
- logind.service5
+ elogind.service5
for information how to enable this functionality and
sd_watchdog_enabled3
for the details of how the service can check whether the
@@ -205,28 +205,55 @@
FDSTORE=1
- Stores additional file descriptors in the
- service manager. File descriptors sent this way will be
- maintained per-service by the service manager and be passed
- again using the usual file descriptor passing logic on the
- next invocation of the service (see
- sd_listen_fds3).
- This is useful for implementing service restart schemes where
- services serialize their state to /run,
- push their file descriptors to the system manager, and are
- then restarted, retrieving their state again via socket
- passing and /run. Note that the service
- manager will accept messages for a service only if
- FileDescriptorStoreMax= is set to non-zero
- for it (defaults to zero). See
- logind.service5
- for details. Multiple arrays of file descriptors may be sent
- in separate messages, in which case the arrays are combined.
- Note that the service manager removes duplicate file
- descriptors before passing them to the service. Use
- sd_pid_notify_with_fds() to send messages
- with FDSTORE=1, see
- below.
+ Stores additional file descriptors in the service manager. File
+ descriptors sent this way will be maintained per-service by the service manager
+ and will be passed again using the usual file descriptor passing logic on the next
+ invocation of the service, see
+ sd_listen_fds3.
+ This is useful for implementing service restart schemes where services serialize
+ their state to /run, push their file descriptors to the
+ system manager, and are then restarted, retrieving their state again via socket
+ passing and /run. Note that the service manager will accept
+ messages for a service only if FileDescriptorStoreMax= is set
+ to non-zero for it (defaults to zero, see
+ elogind.service5).
+ File descriptors must be pollable, see
+ epoll_ctl2.
+ Multiple arrays of file descriptors may be sent in separate messages, in which
+ case the arrays are combined. Note that the service manager removes duplicate
+ file descriptors before passing them to the service. Use
+ sd_pid_notify_with_fds() to send messages with
+ FDSTORE=1, see below.
+
+
+
+ FDNAME=â¦
+
+ When used in combination with
+ FDSTORE=1, specifies a name for the
+ submitted file descriptors. This name is passed to the service
+ during activation, and may be queried using
+ sd_listen_fds_with_names3. File
+ descriptors submitted without this field set, will implicitly
+ get the name stored assigned. Note that, if
+ multiple file descriptors are submitted at once, the specified
+ name will be assigned to all of them. In order to assign
+ different names to submitted file descriptors, submit them in
+ separate invocations of
+ sd_pid_notify_with_fds(). The name may
+ consist of any ASCII character, but must not contain control
+ characters or :. It may not be longer than
+ 255 characters. If a submitted name does not follow these
+ restrictions, it is ignored.
+
+
+
+ WATCHDOG_USEC=â¦
+
+ Reset watchdog_usec value during runtime.
+ Notice that this is not available when using sd_event_set_watchdog()
+ or sd_watchdog_enabled().
+ Example : WATCHDOG_USEC=20000000
@@ -238,9 +265,18 @@
Note that elogind will accept status data sent from a
service only if the NotifyAccess= option is
correctly set in the service definition file. See
- logind.service5
+ elogind.service5
for details.
+ Note that sd_notify() notifications may be attributed to units correctly only if either
+ the sending process is still around at the time PID 1 processes the message, or if the sending process is
+ explicitly runtime-tracked by the service manager. The latter is the case if the service manager originally forked
+ off the process, i.e. on all processes that match NotifyAccess= or
+ NotifyAccess=. Conversely, if an auxiliary process of the unit sends an
+ sd_notify() message and immediately exits, the service manager might not be able to properly
+ attribute the message to the unit, and thus will ignore it, even if
+ NotifyAccess= is set for it.
+
sd_notifyf() is similar to
sd_notify() but takes a
printf()-like format string plus
@@ -253,7 +289,7 @@
use as originating PID for the message as first argument. This is
useful to send notification messages on behalf of other processes,
provided the appropriate privileges are available. If the PID
- argument is specified as 0 the process ID of the calling process
+ argument is specified as 0, the process ID of the calling process
is used, in which case the calls are fully equivalent to
sd_notify() and
sd_notifyf().
@@ -290,7 +326,7 @@
- Internally, these functions send a single datagram with the
+ These functions send a single datagram with the
state string as payload to the AF_UNIX socket
referenced in the $NOTIFY_SOCKET environment
variable. If the first character of
@@ -335,7 +371,7 @@
initialization:sd_notifyf(0, "READY=1\n"
- "STATUS=Processing requests...\n"
+ "STATUS=Processing requestsâ¦\n"
"MAINPID=%lu",
(unsigned long) getpid());
@@ -356,20 +392,22 @@
To store an open file descriptor in the service manager,
in order to continue operation after a service restart without
- losing state use FDSTORE=1:
+ losing state, use FDSTORE=1:
- sd_pid_notify_with_fds(0, 0, "FDSTORE=1", &fd, 1);
+ sd_pid_notify_with_fds(0, 0, "FDSTORE=1\nFDNAME=foobar", &fd, 1);See Also
- elogind1,
+ elogind8,
sd-daemon3,
+ sd_listen_fds3,
+ sd_listen_fds_with_names3,
+ sd_watchdog_enabled3,
daemon7,
- logind.service5,
- sd_watchdog_enabled3
+ elogind.service5