libudev: record and export "age" of device record

8 files changed, 65 insertions, 2 deletions

diff --git a/libudev/docs/libudev-sections.txt b/libudev/docs/libudev-sections.txt
index 05647768fb..7db9c1bba9 100644
--- a/libudev/docs/libudev-sections.txt
+++ b/libudev/docs/libudev-sections.txt
@@ -55,6 +55,7 @@ udev_device_get_devnum
 udev_device_get_action
 udev_device_get_sysattr_value
 udev_device_get_seqnum
+udev_device_get_usec_since_initialized
 </SECTION>
 
 <SECTION>
diff --git a/libudev/exported_symbols b/libudev/exported_symbols
index 9e77fb1be1..2e6a9b7dc0 100644
--- a/libudev/exported_symbols
+++ b/libudev/exported_symbols
@@ -37,6 +37,7 @@ udev_device_get_action
 udev_device_get_driver
 udev_device_get_devnum
 udev_device_get_seqnum
+udev_device_get_usec_since_initialized
 udev_device_get_sysattr_value
 udev_enumerate_new
 udev_enumerate_ref
diff --git a/libudev/libudev-device-private.c b/libudev/libudev-device-private.c
index 36824a7478..3afa82e04f 100644
--- a/libudev/libudev-device-private.c
+++ b/libudev/libudev-device-private.c
@@ -147,6 +147,8 @@ int udev_device_update_db(struct udev_device *udev_device)
 			fprintf(f, "L:%i\n", udev_device_get_devlink_priority(udev_device));
 		if (udev_device_get_watch_handle(udev_device) >= 0)
 			fprintf(f, "W:%i\n", udev_device_get_watch_handle(udev_device));
+		if (udev_device_get_usec_initialized(udev_device) > 0)
+			fprintf(f, "I:%llu\n", udev_device_get_usec_initialized(udev_device));
 		udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
 			if (!udev_list_entry_get_flags(list_entry))
 				continue;
diff --git a/libudev/libudev-device.c b/libudev/libudev-device.c
index 66f806316f..16bee19dff 100644
--- a/libudev/libudev-device.c
+++ b/libudev/libudev-device.c
@@ -63,6 +63,7 @@ struct udev_device {
 	struct udev_list_node sysattr_list;
 	struct udev_list_node tags_list;
 	unsigned long long int seqnum;
+	unsigned long long int usec_initialized;
 	int event_timeout;
 	int timeout;
 	int devlink_priority;
@@ -284,6 +285,9 @@ int udev_device_read_db(struct udev_device *udev_device)
 		case 'W':
 			udev_device_set_watch_handle(udev_device, atoi(val));
 			break;
+		case 'I':
+			udev_device_set_usec_initialized(udev_device, strtoull(val, NULL, 10));
+			break;
 		}
 	}
 	fclose(f);
@@ -1095,6 +1099,44 @@ unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device)
 }
 
 /**
+ * udev_device_get_usec_since_initialized:
+ * @udev_device: udev device
+ *
+ * Return the number of microseconds passed since udev set up the
+ * device for the first time.
+ *
+ * This is only implemented for devices with need to store properties
+ * in the udev database. All other devices return 0 here.
+ *
+ * Returns: the number of microseconds since the device was first seen.
+ **/
+unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device)
+{
+	unsigned long long now;
+
+	if (udev_device == NULL)
+		return 0;
+	if (!udev_device->info_loaded)
+		udev_device_read_db(udev_device);
+	if (udev_device->usec_initialized == 0)
+		return 0;
+	now = usec_monotonic();
+	if (now == 0)
+		return 0;
+	return now - udev_device->usec_initialized;
+}
+
+unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device)
+{
+	return udev_device->usec_initialized;
+}
+
+void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized)
+{
+	udev_device->usec_initialized = usec_initialized;
+}
+
+/**
  * udev_device_get_sysattr_value:
  * @udev_device: udev device
  * @sysattr: attribute name
@@ -1318,7 +1360,7 @@ const char *udev_device_get_id_filename(struct udev_device *udev_device)
  * device node permissions and context, or has renamed a network
  * device.
  *
- * For now, this is only implemented for devices with a device node
+ * This is only implemented for devices with a device node
  * or network interfaces. All other devices return 1 here.
  *
  * Returns: 1 if the device is set up. 0 otherwise.
diff --git a/libudev/libudev-private.h b/libudev/libudev-private.h
index f7b4f90519..f95be53df7 100644
--- a/libudev/libudev-private.h
+++ b/libudev/libudev-private.h
@@ -98,6 +98,8 @@ int udev_device_get_event_timeout(struct udev_device *udev_device);
 int udev_device_set_event_timeout(struct udev_device *udev_device, int event_timeout);
 int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum);
 int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum);
+unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device);
+void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized);
 int udev_device_get_devlink_priority(struct udev_device *udev_device);
 int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio);
 int udev_device_get_watch_handle(struct udev_device *udev_device);
@@ -224,6 +226,7 @@ int util_run_program(struct udev *udev, const char *command, char **envp,
 		     const sigset_t *sigmask, bool reset_prio);
 int util_resolve_subsys_kernel(struct udev *udev, const char *string,
 				      char *result, size_t maxsize, int read_value);
+unsigned long long usec_monotonic(void);
 
 /* libudev-selinux-private.c */
 #ifndef WITH_SELINUX
diff --git a/libudev/libudev-util.c b/libudev/libudev-util.c
index 6c309afd05..51dd017467 100644
--- a/libudev/libudev-util.c
+++ b/libudev/libudev-util.c
@@ -18,6 +18,7 @@
 #include <dirent.h>
 #include <ctype.h>
 #include <fcntl.h>
+#include <time.h>
 #include <sys/stat.h>
 
 #include "libudev.h"
@@ -553,3 +554,15 @@ uint64_t util_string_bloom64(const char *str)
 	bits |= 1LLU << ((hash >> 18) & 63);
 	return bits;
 }
+
+#define USEC_PER_SEC  1000000ULL
+#define NSEC_PER_USEC 1000ULL
+unsigned long long usec_monotonic(void)
+{
+	struct timespec ts;
+
+	if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0)
+		return 0;
+	return (unsigned long long) ts.tv_sec * USEC_PER_SEC +
+	       (unsigned long long) ts.tv_nsec / NSEC_PER_USEC;
+}
diff --git a/libudev/libudev.h b/libudev/libudev.h
index 087991caf4..0abd7c8b0e 100644
--- a/libudev/libudev.h
+++ b/libudev/libudev.h
@@ -97,6 +97,7 @@ const char *udev_device_get_driver(struct udev_device *udev_device);
 dev_t udev_device_get_devnum(struct udev_device *udev_device);
 const char *udev_device_get_action(struct udev_device *udev_device);
 unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device);
+unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device);
 const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr);
 
 /*
diff --git a/libudev/libudev.pc.in b/libudev/libudev.pc.in
index 677d53a97e..f75794ceb8 100644
--- a/libudev/libudev.pc.in
+++ b/libudev/libudev.pc.in
@@ -6,6 +6,6 @@ includedir=@prefix@/include
 Name: libudev
 Description: Library to access udev device information
 Version: @VERSION@
-Libs: -L${libdir} -ludev
+Libs: -L${libdir} -ludev -lrt
 Libs.private: 
 Cflags: -I${includedir}