... will look into some unit and integration testing for all metrics code next in a separate CL.
Review URL: http://codereview.chromium.org/1863002
diff --git a/metrics/Makefile b/metrics/Makefile
index 54b9f53..784ff91 100644
--- a/metrics/Makefile
+++ b/metrics/Makefile
@@ -8,8 +8,7 @@
CCONFIG = $(shell $(PKG_CONFIG) --cflags dbus-1 glib-2.0 dbus-glib-1)
LDCONFIG = $(shell $(PKG_CONFIG) --libs dbus-1 glib-2.0 gthread-2.0 dbus-glib-1)
-CFLAGS = -Wall -Werror -I/usr/include -fPIC -O2 $(CCONFIG)
-CXXFLAGS = $(CFLAGS) -fno-exceptions
+CXXFLAGS += -Wall -Werror -fPIC -fno-exceptions $(CCONFIG)
CLIENT = metrics_client
DAEMON = metrics_daemon
@@ -51,9 +50,6 @@
%.o: %.cc
$(CXX) $(CXXFLAGS) -c $< -o $@
-%.o: %.c
- $(CC) $(CFLAGS) -c $< -o $@
-
# dependencies in addition to those defined by the rules
metrics_daemon.o: \
diff --git a/metrics/metrics_daemon.cc b/metrics/metrics_daemon.cc
index 32581c1..ef973a2 100644
--- a/metrics/metrics_daemon.cc
+++ b/metrics/metrics_daemon.cc
@@ -6,16 +6,39 @@
#include "metrics_library.h"
#include <dbus/dbus-glib-lowlevel.h>
+#include <sys/file.h>
+#include <base/eintr_wrapper.h>
#include <base/logging.h>
#define SAFE_MESSAGE(e) (e.message ? e.message : "unknown error")
#define DBUS_IFACE_CONNMAN_MANAGER "org.moblin.connman.Manager"
#define DBUS_IFACE_POWER_MANAGER "org.chromium.Power.Manager"
+#define DBUS_IFACE_SCREENSAVER_MANAGER "org.chromium.ScreenSaver.Manager"
+#define DBUS_IFACE_SESSION_MANAGER "org.chromium.SessionManagerInterface"
+
+// File to aggregate daily usage before sending to UMA.
+// TODO(petkov): This file should probably live in a user-specific stateful
+// location, e.g., /home/chronos/user.
+static const char kDailyUseRecordFile[] = "/var/log/metrics/daily-usage";
+
+static const int kSecondsPerMinute = 60;
+static const int kMinutesPerHour = 60;
+static const int kHoursPerDay = 24;
+static const int kMinutesPerDay = kHoursPerDay * kMinutesPerHour;
+static const int kSecondsPerDay = kMinutesPerDay * kSecondsPerMinute;
+
+// The daily use monitor is scheduled to a 1-minute interval after
+// initial user activity and then it's exponentially backed off to
+// 10-minute intervals. Although not required, the back off is
+// implemented because the histogram buckets are spaced exponentially
+// anyway and to avoid too frequent metrics daemon process wake-ups
+// and file I/O.
+static const int kUseMonitorIntervalInit = 1 * kSecondsPerMinute;
+static const int kUseMonitorIntervalMax = 10 * kSecondsPerMinute;
// static
-const char*
-MetricsDaemon::dbus_matches_[] = {
+const char* MetricsDaemon::kDBusMatches_[] = {
"type='signal',"
"sender='org.moblin.connman',"
"interface='" DBUS_IFACE_CONNMAN_MANAGER "',"
@@ -26,22 +49,43 @@
"interface='" DBUS_IFACE_POWER_MANAGER "',"
"path='/',"
"member='PowerStateChanged'",
+
+ "type='signal',"
+ "interface='" DBUS_IFACE_SCREENSAVER_MANAGER "',"
+ "path='/',"
+ "member='LockStateChanged'",
+
+ "type='signal',"
+ "sender='org.chromium.SessionManager',"
+ "interface='" DBUS_IFACE_SESSION_MANAGER "',"
+ "path='/org/chromium/SessionManager',"
+ "member='SessionStateChanged'",
};
// static
-const char *
-MetricsDaemon::network_states_[MetricsDaemon::kNumberNetworkStates] = {
+const char* MetricsDaemon::kNetworkStates_[] = {
#define STATE(name, capname) #name,
#include "network_states.h"
};
// static
-const char *
-MetricsDaemon::power_states_[MetricsDaemon::kNumberPowerStates] = {
+const char* MetricsDaemon::kPowerStates_[] = {
#define STATE(name, capname) #name,
#include "power_states.h"
};
+// static
+const char* MetricsDaemon::kScreenSaverStates_[] = {
+#define STATE(name, capname) #name,
+#include "screensaver_states.h"
+};
+
+// static
+const char* MetricsDaemon::kSessionStates_[] = {
+#define STATE(name, capname) #name,
+#include "session_states.h"
+};
+
void MetricsDaemon::Run(bool run_as_daemon, bool testing) {
Init(testing);
if (!run_as_daemon || daemon(0, 0) == 0) {
@@ -51,9 +95,6 @@
void MetricsDaemon::Init(bool testing) {
testing_ = testing;
- network_state_ = kUnknownNetworkState;
- network_state_changed_ = 0;
- power_state_ = kUnknownPowerState;
g_thread_init(NULL);
g_type_init();
@@ -69,9 +110,9 @@
dbus_connection_setup_with_g_main(connection, NULL);
// Registers D-Bus matches for the signals we would like to catch.
- for (unsigned int m = 0; m < sizeof(dbus_matches_) / sizeof(char *); m++) {
- const char* match = dbus_matches_[m];
- LOG(INFO) << "adding dbus match: " << match;
+ for (unsigned int m = 0; m < sizeof(kDBusMatches_) / sizeof(char *); m++) {
+ const char* match = kDBusMatches_[m];
+ DLOG(INFO) << "adding dbus match: " << match;
dbus_bus_add_match(connection, match, &error);
LOG_IF(FATAL, dbus_error_is_set(&error)) <<
"unable to add a match: " << SAFE_MESSAGE(error);
@@ -92,11 +133,12 @@
DBusHandlerResult MetricsDaemon::MessageFilter(DBusConnection* connection,
DBusMessage* message,
void* user_data) {
- LOG(INFO) << "message filter";
+ time_t now = time(NULL);
+ DLOG(INFO) << "message intercepted @ " << now;
int message_type = dbus_message_get_type(message);
if (message_type != DBUS_MESSAGE_TYPE_SIGNAL) {
- LOG(WARNING) << "unexpected message type " << message_type;
+ DLOG(WARNING) << "unexpected message type " << message_type;
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
@@ -109,29 +151,44 @@
DBusMessageIter iter;
dbus_message_iter_init(message, &iter);
if (strcmp(interface, DBUS_IFACE_CONNMAN_MANAGER) == 0) {
- CHECK(strcmp(dbus_message_get_member(message), "StateChanged") == 0);
+ CHECK(strcmp(dbus_message_get_member(message),
+ "StateChanged") == 0);
char *state_name;
dbus_message_iter_get_basic(&iter, &state_name);
- daemon->NetStateChanged(state_name);
+ daemon->NetStateChanged(state_name, now);
} else if (strcmp(interface, DBUS_IFACE_POWER_MANAGER) == 0) {
- CHECK(strcmp(dbus_message_get_member(message), "PowerStateChanged") == 0);
+ CHECK(strcmp(dbus_message_get_member(message),
+ "PowerStateChanged") == 0);
char *state_name;
dbus_message_iter_get_basic(&iter, &state_name);
- daemon->PowerStateChanged(state_name);
+ daemon->PowerStateChanged(state_name, now);
+ } else if (strcmp(interface, DBUS_IFACE_SCREENSAVER_MANAGER) == 0) {
+ CHECK(strcmp(dbus_message_get_member(message),
+ "LockStateChanged") == 0);
+
+ char *state_name;
+ dbus_message_iter_get_basic(&iter, &state_name);
+ daemon->ScreenSaverStateChanged(state_name, now);
+ } else if (strcmp(interface, DBUS_IFACE_SESSION_MANAGER) == 0) {
+ CHECK(strcmp(dbus_message_get_member(message),
+ "SessionStateChanged") == 0);
+
+ char *state_name;
+ dbus_message_iter_get_basic(&iter, &state_name);
+ daemon->SessionStateChanged(state_name, now);
} else {
- LOG(WARNING) << "unexpected interface: " << interface;
+ DLOG(WARNING) << "unexpected interface: " << interface;
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
return DBUS_HANDLER_RESULT_HANDLED;
}
-void MetricsDaemon::NetStateChanged(const char* state_name) {
- LOG(INFO) << "network state: " << state_name;
+void MetricsDaemon::NetStateChanged(const char* state_name, time_t now) {
+ DLOG(INFO) << "network state: " << state_name;
- time_t now = time(NULL);
NetworkState state = LookupNetworkState(state_name);
// Logs the time in seconds between the network going online to
@@ -143,46 +200,225 @@
if (state == kNetworkStateOffline &&
network_state_ == kNetworkStateOnline &&
power_state_ != kPowerStateMem) {
- int online_time = static_cast<int>(now - network_state_changed_);
+ int online_time = static_cast<int>(now - network_state_last_);
PublishMetric("Network.TimeToDrop", online_time,
1, 8 /* hours */ * 60 * 60, 50);
}
network_state_ = state;
- network_state_changed_ = now;
+ network_state_last_ = now;
}
MetricsDaemon::NetworkState
MetricsDaemon::LookupNetworkState(const char* state_name) {
for (int i = 0; i < kNumberNetworkStates; i++) {
- if (strcmp(state_name, network_states_[i]) == 0) {
+ if (strcmp(state_name, kNetworkStates_[i]) == 0) {
return static_cast<NetworkState>(i);
}
}
- LOG(WARNING) << "unknown network connection state: " << state_name;
+ DLOG(WARNING) << "unknown network connection state: " << state_name;
return kUnknownNetworkState;
}
-void MetricsDaemon::PowerStateChanged(const char* state_name) {
- LOG(INFO) << "power state: " << state_name;
+void MetricsDaemon::PowerStateChanged(const char* state_name, time_t now) {
+ DLOG(INFO) << "power state: " << state_name;
power_state_ = LookupPowerState(state_name);
+
+ if (power_state_ != kPowerStateOn)
+ SetUserActiveState(false, now);
}
MetricsDaemon::PowerState
MetricsDaemon::LookupPowerState(const char* state_name) {
for (int i = 0; i < kNumberPowerStates; i++) {
- if (strcmp(state_name, power_states_[i]) == 0) {
+ if (strcmp(state_name, kPowerStates_[i]) == 0) {
return static_cast<PowerState>(i);
}
}
- LOG(WARNING) << "unknown power state: " << state_name;
+ DLOG(WARNING) << "unknown power state: " << state_name;
return kUnknownPowerState;
}
+void MetricsDaemon::ScreenSaverStateChanged(const char* state_name,
+ time_t now) {
+ DLOG(INFO) << "screen-saver state: " << state_name;
+ screensaver_state_ = LookupScreenSaverState(state_name);
+ SetUserActiveState(screensaver_state_ == kScreenSaverStateUnlocked, now);
+}
+
+MetricsDaemon::ScreenSaverState
+MetricsDaemon::LookupScreenSaverState(const char* state_name) {
+ for (int i = 0; i < kNumberScreenSaverStates; i++) {
+ if (strcmp(state_name, kScreenSaverStates_[i]) == 0) {
+ return static_cast<ScreenSaverState>(i);
+ }
+ }
+ DLOG(WARNING) << "unknown screen-saver state: " << state_name;
+ return kUnknownScreenSaverState;
+}
+
+void MetricsDaemon::SessionStateChanged(const char* state_name,
+ time_t now) {
+ DLOG(INFO) << "user session state: " << state_name;
+ session_state_ = LookupSessionState(state_name);
+ SetUserActiveState(session_state_ == kSessionStateStarted, now);
+}
+
+MetricsDaemon::SessionState
+MetricsDaemon::LookupSessionState(const char* state_name) {
+ for (int i = 0; i < kNumberSessionStates; i++) {
+ if (strcmp(state_name, kSessionStates_[i]) == 0) {
+ return static_cast<SessionState>(i);
+ }
+ }
+ DLOG(WARNING) << "unknown user session state: " << state_name;
+ return kUnknownSessionState;
+}
+
+void MetricsDaemon::SetUserActiveState(bool active, time_t now) {
+ DLOG(INFO) << "user: " << (active ? "active" : "inactive");
+
+ // Calculates the seconds of active use since the last update and
+ // the day since Epoch, and logs the usage data.
+ int seconds = user_active_ ? (now - user_active_last_) : 0;
+ int day = now / kSecondsPerDay;
+ LogDailyUseRecord(day, seconds);
+
+ // Schedules a use monitor on inactive->active transitions and
+ // unschedules it on active->inactive transitions.
+ if (!user_active_ && active)
+ ScheduleUseMonitor(kUseMonitorIntervalInit, /* backoff */ false);
+ else if (user_active_ && !active)
+ UnscheduleUseMonitor();
+
+ // Remembers the current active state and the time of the last
+ // activity update.
+ user_active_ = active;
+ user_active_last_ = now;
+}
+
+void MetricsDaemon::LogDailyUseRecord(int day, int seconds) {
+ // If there's no new active use today and the last record in the
+ // usage aggregation file is today, there's nothing to do.
+ if (seconds == 0 && day == daily_use_day_last_)
+ return;
+
+ DLOG(INFO) << "day: " << day << " usage: " << seconds << " seconds";
+ int fd = HANDLE_EINTR(open(kDailyUseRecordFile,
+ O_RDWR | O_CREAT,
+ S_IRUSR | S_IWUSR));
+ if (fd < 0) {
+ DLOG(WARNING) << "Unable to open the daily use file.";
+ return;
+ }
+
+ bool same_day = false;
+ UseRecord record;
+ if (HANDLE_EINTR(read(fd, &record, sizeof(record))) == sizeof(record)) {
+ if (record.day_ == day) {
+ // If there's an existing record for today, aggregates the usage
+ // time.
+ same_day = true;
+ record.seconds_ += seconds;
+ } else {
+ // If there's an existing record for a day in the past, rounds
+ // the usage to the nearest minute and sends it to UMA.
+ int minutes =
+ (record.seconds_ + kSecondsPerMinute / 2) / kSecondsPerMinute;
+ PublishMetric("Logging.DailyUseTime",
+ minutes, 1, kMinutesPerDay, 50);
+
+ // Truncates the usage file to ensure that no duplicate usage is
+ // sent to UMA.
+ LOG_IF(WARNING, HANDLE_EINTR(ftruncate(fd, 0)) != 0);
+ }
+ }
+
+ // Updates the use record in the daily usage file if there's new
+ // usage today.
+ if (seconds > 0) {
+ if (!same_day) {
+ record.day_ = day;
+ record.seconds_ = seconds;
+ }
+ // else an already existing record for the same day will be
+ // overwritten with updated usage below.
+
+ LOG_IF(WARNING, HANDLE_EINTR(lseek(fd, 0, SEEK_SET)) != 0);
+ LOG_IF(WARNING,
+ HANDLE_EINTR(write(fd, &record, sizeof(record))) != sizeof(record));
+ }
+
+ HANDLE_EINTR(close(fd));
+
+ // Remembers the day of the use record in the usage aggregation file
+ // to reduce file I/O. This is not really useful now but potentially
+ // allows frequent LogDailyUseRecord calls with no unnecessary I/O
+ // overhead.
+ daily_use_day_last_ = day;
+}
+
+// static
+gboolean MetricsDaemon::UseMonitorStatic(gpointer data) {
+ return static_cast<MetricsDaemon*>(data)->UseMonitor() ? TRUE : FALSE;
+}
+
+bool MetricsDaemon::UseMonitor() {
+ SetUserActiveState(user_active_, time(NULL));
+
+ // If a new monitor source/instance is scheduled, returns false to
+ // tell GLib to destroy this monitor source/instance. Returns true
+ // otherwise to keep calling back this monitor.
+ return !ScheduleUseMonitor(usemon_interval_ * 2, /* backoff */ true);
+}
+
+bool MetricsDaemon::ScheduleUseMonitor(int interval, bool backoff)
+{
+ // Caps the interval -- the bigger the interval, the more active use
+ // time will be potentially dropped on system shutdown.
+ if (interval > kUseMonitorIntervalMax)
+ interval = kUseMonitorIntervalMax;
+
+ if (backoff) {
+ // Back-off mode is used by the use monitor to reschedule itself
+ // with exponential back-off in time. This mode doesn't create a
+ // new timeout source if the new interval is the same as the old
+ // one. Also, if a new timeout source is created, the old one is
+ // not destroyed explicitly here -- it will be destroyed by GLib
+ // when the monitor returns FALSE (see UseMonitor and
+ // UseMonitorStatic).
+ if (interval == usemon_interval_)
+ return false;
+ } else {
+ UnscheduleUseMonitor();
+ }
+
+ // Schedules a new use monitor for |interval| seconds from now.
+ DLOG(INFO) << "scheduling use monitor in " << interval << " seconds";
+ usemon_source_ = g_timeout_source_new_seconds(interval);
+ g_source_set_callback(usemon_source_, UseMonitorStatic, this,
+ NULL); // No destroy notification.
+ g_source_attach(usemon_source_,
+ NULL); // Default context.
+ usemon_interval_ = interval;
+ return true;
+}
+
+void MetricsDaemon::UnscheduleUseMonitor() {
+ // If there's a use monitor scheduled already, destroys it.
+ if (usemon_source_ == NULL)
+ return;
+
+ DLOG(INFO) << "destroying use monitor";
+ g_source_destroy(usemon_source_);
+ usemon_source_ = NULL;
+ usemon_interval_ = 0;
+}
+
void MetricsDaemon::PublishMetric(const char* name, int sample,
int min, int max, int nbuckets) {
- LOG(INFO) << "received metric: " << name << " " << sample <<
- " " << min << " " << max << " " << nbuckets;
+ DLOG(INFO) << "received metric: " << name << " " << sample << " "
+ << min << " " << max << " " << nbuckets;
if (!testing_) {
MetricsLibrary::SendToChrome(name, sample, min, max, nbuckets);
}
diff --git a/metrics/metrics_daemon.h b/metrics/metrics_daemon.h
index 23f0eb2..99f76d0 100644
--- a/metrics/metrics_daemon.h
+++ b/metrics/metrics_daemon.h
@@ -6,16 +6,23 @@
#define METRICS_DAEMON_H_
#include <dbus/dbus.h>
+#include <glib.h>
#include <time.h>
class MetricsDaemon {
public:
MetricsDaemon()
- : testing_(false),
- network_state_(kUnknownNetworkState),
- network_state_changed_(0),
- power_state_(kUnknownPowerState) {}
+ : network_state_(kUnknownNetworkState),
+ network_state_last_(0),
+ power_state_(kUnknownPowerState),
+ screensaver_state_(kUnknownScreenSaverState),
+ session_state_(kUnknownSessionState),
+ user_active_(false),
+ user_active_last_(0),
+ daily_use_day_last_(0),
+ usemon_interval_(0),
+ usemon_source_(NULL) {}
~MetricsDaemon() {}
// Does all the work. If |run_as_daemon| is true, daemonizes by
@@ -40,6 +47,45 @@
kNumberPowerStates
};
+ // The screen-saver states (see screensaver_states.h).
+ enum ScreenSaverState {
+ kUnknownScreenSaverState = -1, // Initial/unknown screen-saver state.
+#define STATE(name, capname) kScreenSaverState ## capname,
+#include "screensaver_states.h"
+ kNumberScreenSaverStates
+ };
+
+ // The user session states (see session_states.h).
+ enum SessionState {
+ kUnknownSessionState = -1, // Initial/unknown user session state.
+#define STATE(name, capname) kSessionState ## capname,
+#include "session_states.h"
+ kNumberSessionStates
+ };
+
+ // Data record for aggregating daily usage.
+ class UseRecord {
+ public:
+ UseRecord() : day_(0), seconds_(0) {}
+ int day_;
+ int seconds_;
+ };
+
+ // D-Bus message match strings.
+ static const char* kDBusMatches_[];
+
+ // Array of network states.
+ static const char* kNetworkStates_[kNumberNetworkStates];
+
+ // Array of power states.
+ static const char* kPowerStates_[kNumberPowerStates];
+
+ // Array of screen-saver states.
+ static const char* kScreenSaverStates_[kNumberScreenSaverStates];
+
+ // Array of user session states.
+ static const char* kSessionStates_[kNumberSessionStates];
+
// Initializes.
void Init(bool testing);
@@ -52,36 +98,103 @@
void* user_data);
// Processes network state change.
- void NetStateChanged(const char* state_name);
+ void NetStateChanged(const char* state_name, time_t now);
// Given the state name, returns the state id.
NetworkState LookupNetworkState(const char* state_name);
// Processes power state change.
- void PowerStateChanged(const char* state_name);
+ void PowerStateChanged(const char* state_name, time_t now);
// Given the state name, returns the state id.
PowerState LookupPowerState(const char* state_name);
+ // Processes screen-saver state change.
+ void ScreenSaverStateChanged(const char* state_name, time_t now);
+
+ // Given the state name, returns the state id.
+ ScreenSaverState LookupScreenSaverState(const char* state_name);
+
+ // Processes user session state change.
+ void SessionStateChanged(const char* state_name, time_t now);
+
+ // Given the state name, returns the state id.
+ SessionState LookupSessionState(const char* state_name);
+
+ // Updates the user-active state to |active| and logs the usage data
+ // since the last update. If the user has just become active,
+ // reschedule the daily use monitor for more frequent updates --
+ // this is followed by an exponential back-off (see UseMonitor).
+ void SetUserActiveState(bool active, time_t now);
+
+ // Updates the daily usage file, if necessary, by adding |seconds|
+ // of active use to the |day| since Epoch. If there's usage data for
+ // day in the past in the usage file, that data is sent to UMA and
+ // removed from the file. If there's already usage data for |day| in
+ // the usage file, the |seconds| are accumulated.
+ void LogDailyUseRecord(int day, int seconds);
+
+ // Callbacks for the daily use monitor. The daily use monitor uses
+ // LogDailyUseRecord to aggregate current usage data and send it to
+ // UMA, if necessary. It also reschedules itself using an
+ // exponentially bigger interval (up to a certain maximum) -- so
+ // usage is monitored less frequently with longer active use.
+ static gboolean UseMonitorStatic(gpointer data);
+ bool UseMonitor();
+
+ // Schedules or reschedules a daily use monitor for |interval|
+ // seconds from now. |backoff| mode is used by the use monitor to
+ // reschedule itself. If there's a monitor scheduled already and
+ // |backoff| is false, unschedules it first. Doesn't schedule a
+ // monitor for more than kUseMonitorIntervalMax seconds in the
+ // future (see metrics_daemon.cc). Returns true if a new use monitor
+ // was scheduled, false otherwise (note that if |backoff| is false a
+ // new use monitor will always be scheduled).
+ bool ScheduleUseMonitor(int interval, bool backoff);
+
+ // Unschedules a scheduled use monitor, if any.
+ void UnscheduleUseMonitor();
+
// Sends a stat to Chrome for transport to UMA (or prints it for
// testing). See MetricsLibrary::SendToChrome in metrics_library.h
// for a description of the arguments.
void PublishMetric(const char* name, int sample,
int min, int max, int nbuckets);
- // D-Bus message match strings.
- static const char* dbus_matches_[];
+ // Testing mode.
+ bool testing_;
- // Array of network states.
- static const char* network_states_[kNumberNetworkStates];
+ // Current network state.
+ NetworkState network_state_;
- // Array of power states.
- static const char* power_states_[kNumberPowerStates];
+ // Timestamps last network state update.
+ time_t network_state_last_;
- bool testing_; // just testing
- NetworkState network_state_; // current network state
- time_t network_state_changed_; // timestamp last net state change
- PowerState power_state_; // current power state
+ // Current power state.
+ PowerState power_state_;
+
+ // Current screen-saver state.
+ ScreenSaverState screensaver_state_;
+
+ // Current user session state.
+ SessionState session_state_;
+
+ // Is the user currently active: power is on, user session has
+ // started, screen is not locked.
+ bool user_active_;
+
+ // Timestamps last user active update.
+ time_t user_active_last_;
+
+ // Last stored daily use day (since epoch).
+ int daily_use_day_last_;
+
+ // Sleep period until the next daily usage aggregation performed by
+ // the daily use monitor (see ScheduleUseMonitor).
+ int usemon_interval_;
+
+ // Scheduled daily use monitor source (see ScheduleUseMonitor).
+ GSource* usemon_source_;
};
#endif // METRICS_DAEMON_H_
diff --git a/metrics/power_states.h b/metrics/power_states.h
index 413085e..74fbfec 100644
--- a/metrics/power_states.h
+++ b/metrics/power_states.h
@@ -4,18 +4,7 @@
// A table of power states, to be included when building tabular things.
//
-// This file is used to construct two things: an enumerated type in
-// metrics_daemon.h, and a table of structures with state names in
-// metrics_daemon.cc. Including this file ensures that the two tables are
-// always in sync (and saves typing). I don't know of other ways of achieving
-// the same result in C/C++, but it doesn't mean there isn't one.
-
-// Before you include this file, define STATE to do something useful, or else
-// if will be a no-op. STATE will be undefined on exit. Don't worry about
-// collisions for the STATE macro (as long as it's a macro) because the
-// compiler will flag them---in that case, just change the name. If someone is
-// misguided enough to use STATE for something other than a macro, the error
-// messages will be slightly more complicated.
+// See network_states.h for details.
#ifndef STATE
diff --git a/metrics/screensaver_states.h b/metrics/screensaver_states.h
new file mode 100644
index 0000000..340142e
--- /dev/null
+++ b/metrics/screensaver_states.h
@@ -0,0 +1,17 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// A table of screen-saver states, to be included when building tabular things.
+//
+// See network_states.h for details.
+
+
+#ifndef STATE
+#define STATE(name, capname)
+#endif
+
+STATE(locked, Locked)
+STATE(unlocked, Unlocked)
+
+#undef STATE
diff --git a/metrics/session_states.h b/metrics/session_states.h
new file mode 100644
index 0000000..293dbd9
--- /dev/null
+++ b/metrics/session_states.h
@@ -0,0 +1,17 @@
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// A table of user session states, to be included when building tabular things.
+//
+// See network_states.h for details.
+
+
+#ifndef STATE
+#define STATE(name, capname)
+#endif
+
+STATE(started, Started)
+STATE(stopped, Stopped)
+
+#undef STATE
