diff --git a/man/sd_login_monitor_new.xml b/man/sd_login_monitor_new.xml
index 94428771a8..b187ad0dbe 100644
--- a/man/sd_login_monitor_new.xml
+++ b/man/sd_login_monitor_new.xml
@@ -48,6 +48,7 @@
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
@@ -82,6 +83,12 @@
sd_login_monitor* m
+
+ int sd_login_monitor_get_timeout
+ sd_login_monitor* m
+ uint64_t* timeout_usec
+
+
@@ -130,7 +137,9 @@
or a similar interface. The application should include
the returned file descriptor as wake-up source for the
events mask returned by
- sd_login_monitor_get_events(). Whenever
+ 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
@@ -146,15 +155,51 @@
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 success
sd_login_monitor_get_events()
@@ -173,8 +218,9 @@
The sd_login_monitor_new(),
sd_login_monitor_unref(),
sd_login_monitor_flush(),
- sd_login_monitor_get_fd() and
- sd_login_monitor_get_events()
+ 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
@@ -189,7 +235,8 @@
systemd1,
sd-login3,
sd_get_seats3,
- poll2
+ poll2,
+ clock_gettime2
diff --git a/src/login/libsystemd-login.sym b/src/login/libsystemd-login.sym
index 55a828773b..ce2304a1ba 100644
--- a/src/login/libsystemd-login.sym
+++ b/src/login/libsystemd-login.sym
@@ -62,4 +62,5 @@ global:
LIBSYSTEMD_LOGIN_201 {
global:
sd_login_monitor_get_events;
+ sd_login_monitor_get_timeout;
} LIBSYSTEMD_LOGIN_198;
diff --git a/src/login/sd-login.c b/src/login/sd-login.c
index 861a57166d..7513f76cb3 100644
--- a/src/login/sd-login.c
+++ b/src/login/sd-login.c
@@ -804,5 +804,23 @@ _public_ int sd_login_monitor_get_events(sd_login_monitor *m) {
if (!m)
return -EINVAL;
+ /* For now we will only return POLLIN here, since we don't
+ * need anything else ever for inotify. However, let's have
+ * this API to keep our options open should we later on need
+ * it. */
return POLLIN;
}
+
+_public_ int sd_login_monitor_get_timeout(sd_login_monitor *m, uint64_t *timeout_usec) {
+
+ if (!m)
+ return -EINVAL;
+ if (!timeout_usec)
+ return -EINVAL;
+
+ /* For now we will only return (uint64_t) -1, since we don't
+ * need any timeout. However, let's have this API to keep our
+ * options open should we later on need it. */
+ *timeout_usec = (uint64_t) -1;
+ return 0;
+}
diff --git a/src/login/test-login.c b/src/login/test-login.c
index f639129636..e4d0c93378 100644
--- a/src/login/test-login.c
+++ b/src/login/test-login.c
@@ -183,12 +183,23 @@ int main(int argc, char* argv[]) {
r = sd_login_monitor_new("session", &m);
assert_se(r >= 0);
- zero(pollfd);
- pollfd.fd = sd_login_monitor_get_fd(m);
- pollfd.events = sd_login_monitor_get_events(m);
for (n = 0; n < 5; n++) {
- r = poll(&pollfd, 1, -1);
+ usec_t timeout, nw;
+
+ zero(pollfd);
+ assert_se((pollfd.fd = sd_login_monitor_get_fd(m)) >= 0);
+ assert_se((pollfd.events = sd_login_monitor_get_events(m)) >= 0);
+
+ assert_se(sd_login_monitor_get_timeout(m, &timeout) >= 0);
+
+ nw = now(CLOCK_MONOTONIC);
+
+ r = poll(&pollfd, 1,
+ timeout == (uint64_t) -1 ? -1 :
+ timeout > nw ? (int) ((timeout - nw) / 1000) :
+ 0);
+
assert_se(r >= 0);
sd_login_monitor_flush(m);
diff --git a/src/systemd/sd-login.h b/src/systemd/sd-login.h
index 57255bd4a9..d05424dbf3 100644
--- a/src/systemd/sd-login.h
+++ b/src/systemd/sd-login.h
@@ -23,6 +23,7 @@
***/
#include
+#include
#ifdef __cplusplus
extern "C" {
@@ -159,6 +160,9 @@ int sd_login_monitor_get_fd(sd_login_monitor *m);
/* Get poll() mask to monitor */
int sd_login_monitor_get_events(sd_login_monitor *m);
+/* Get timeout for poll(), as usec value relative to CLOCK_MONOTONIC's epoch */
+int sd_login_monitor_get_timeout(sd_login_monitor *m, uint64_t *timeout_usec);
+
#ifdef __cplusplus
}
#endif