[gnome-power-manager/gnome-2-32] Adjust dim timeout when necessary

[Richard Hughes <rhughes src gnome org>]

commit 7242cc643cf71f735275fcb0fb95b3a7387a9dac
Author: Tim Liim <tim liim alcatel-lucent com>
Date:   Wed Aug 4 09:46:20 2010 +0100

    Adjust dim timeout when necessary
    
    On slow machines, or machines that have lots to load duing login,
    the current idle time could be bigger than the requested timeout.
    In this case the scheduled idle timeout will never fire, unless
    some user activity (keyboard, mouse) resets the current idle time.
    Instead of relying on user activity to correct this issue, we need
    to adjust timeout, as related to current idle time, so the idle
    timeout will fire as designed.
    
    Signed-off-by: Richard Hughes <richard hughsie com>

 src/gpm-idle.c |   38 ++++++++++++++++++++++++++++++++++++++
 1 files changed, 38 insertions(+), 0 deletions(-)
---
diff --git a/src/gpm-idle.c b/src/gpm-idle.c
index 215cc77..f9fbaf2 100644
--- a/src/gpm-idle.c
+++ b/src/gpm-idle.c
@@ -250,14 +250,52 @@ out:
 }
 
 /**
+ *  gpm_idle_adjust_timeout_dim:
+ *  @idle_time: The new timeout we want to set, in seconds.
+ *  @timeout: Current idle time, in seconds.
+ *
+ *  On slow machines, or machines that have lots to load duing login,
+ *  the current idle time could be bigger than the requested timeout.
+ *  In this case the scheduled idle timeout will never fire, unless
+ *  some user activity (keyboard, mouse) resets the current idle time.
+ *  Instead of relying on user activity to correct this issue, we need
+ *  to adjust timeout, as related to current idle time, so the idle
+ *  timeout will fire as designed.
+ *
+ *  Return value: timeout to set, adjusted acccording to current idle time.
+ **/
+static guint
+gpm_idle_adjust_timeout_dim (guint idle_time, guint timeout)
+{
+	/* allow 2 sec margin for messaging delay. */
+	idle_time += 2;
+
+	/* Double timeout until it's larger than current idle time.
+	 * Give up for ultra slow machines. (86400 sec = 24 hours) */
+	while (timeout < idle_time && timeout < 86400 && timeout > 0) {
+		timeout *= 2;
+	}
+	return timeout;
+}
+
+/**
  * gpm_idle_set_timeout_dim:
  * @timeout: The new timeout we want to set, in seconds
  **/
 gboolean
 gpm_idle_set_timeout_dim (GpmIdle *idle, guint timeout)
 {
+	gint64 idle_time_in_msec;
+	guint timeout_adjusted;
+
 	g_return_val_if_fail (GPM_IS_IDLE (idle), FALSE);
 
+	idle_time_in_msec = gpm_idletime_get_time (idle->priv->idletime);
+	timeout_adjusted  = gpm_idle_adjust_timeout_dim (idle_time_in_msec / 1000, timeout);
+	egg_debug ("Current idle time=%lldms, timeout was %us, becomes %us after adjustment",
+		   idle_time_in_msec, timeout, timeout_adjusted);
+	timeout = timeout_adjusted;
+
 	egg_debug ("Setting dim idle timeout: %ds", timeout);
 	if (idle->priv->timeout_dim != timeout) {
 		idle->priv->timeout_dim = timeout;