From e2c0ce03631fc81651b8bde578e993c25e3291e9 Mon Sep 17 00:00:00 2001
From: Robert Greenwalt <robdroid@android.com>
Date: Fri, 9 Apr 2010 12:31:46 -0700
Subject: Add warning magic to be a bit more reasonable.

Currently warns if you exceed more than 25% and 2*100%*timeUsed/(timeUsed+totalTime)

The formula means that imagining you've got half of the remaining time that you really have,
we will warn you if you would exceed the quota given your rate so far.  It's generous during the
early to mid-life and converges back to the limit as your timeUsed approaches totalTime.

bug:2576057
Change-Id: Id189de5b026f927ef478fd212d61d9e4ab5239e6
---
 .../java/com/android/server/ThrottleService.java   | 44 ++++++++++++++++------
 1 file changed, 33 insertions(+), 11 deletions(-)

diff --git a/services/java/com/android/server/ThrottleService.java b/services/java/com/android/server/ThrottleService.java
index 2fc9249e8e4a..9d4e2263b902 100644
--- a/services/java/com/android/server/ThrottleService.java
+++ b/services/java/com/android/server/ThrottleService.java
@@ -421,18 +421,40 @@ public class ThrottleService extends IThrottleManager.Stub {
             } else {
                 if ((mPolicyNotificationsAllowedMask & NOTIFICATION_WARNING) != 0) {
                     // check if we should warn about throttle
-                    if (currentTotal > (mPolicyThreshold/2) && !mWarningNotificationSent) {
-                        mWarningNotificationSent = true;
-                        mNotificationManager.cancel(com.android.internal.R.drawable.
-                                stat_sys_throttle_warning);
-                        postNotification(com.android.internal.R.string.
-                                throttle_warning_notification_title,
-                                com.android.internal.R.string.
-                                throttle_warning_notification_message,
-                                com.android.internal.R.drawable.stat_sys_throttle_warning,
-                                0);
+                    // pretend we only have 1/2 the time remaining that we actually do
+                    // if our burn rate in the period so far would have us exceed the limit
+                    // in that 1/2 window, warn the user.
+                    // this gets more generous in the early to middle period and converges back
+                    // to the limit as we move toward the period end.
+
+                    // adding another factor - it must be greater than the total cap/4
+                    // else we may get false alarms very early in the period..  in the first
+                    // tenth of a percent of the period if we used more than a tenth of a percent
+                    // of the cap we'd get a warning and that's not desired.
+                    long start = mRecorder.getPeriodStart();
+                    long end = mRecorder.getPeriodEnd();
+                    long periodLength = end - start;
+                    long now = System.currentTimeMillis();
+                    long timeUsed = now - start;
+                    long warningThreshold = 2*mPolicyThreshold*timeUsed/(timeUsed+periodLength);
+                    if ((currentTotal > warningThreshold) && (currentTotal > mPolicyThreshold/4)) {
+                        if (mWarningNotificationSent == false) {
+                            mWarningNotificationSent = true;
+                            mNotificationManager.cancel(com.android.internal.R.drawable.
+                                    stat_sys_throttle_warning);
+                            postNotification(com.android.internal.R.string.
+                                    throttle_warning_notification_title,
+                                    com.android.internal.R.string.
+                                    throttle_warning_notification_message,
+                                    com.android.internal.R.drawable.stat_sys_throttle_warning,
+                                    0);
+                        }
                     } else {
-                        mWarningNotificationSent =false;
+                        if (mWarningNotificationSent == true) {
+                            mNotificationManager.cancel(com.android.internal.R.drawable.
+                                    stat_sys_throttle_warning);
+                            mWarningNotificationSent =false;
+                        }
                     }
                 }
             }
-- 
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