Allow incoming SMS until internal storage is almost full.

Fix for bug 2382830: new incoming SMS should not be rejected when
running low on internal phone storage.

Testing revealed that the /data partition should have at least 256 KiB
available in order to prevent random app crashes (including system apps)
due to SQLite transaction failures. With 256 KiB free, the device should
safely boot without storage full errors. This takes into account the
36-40 KiB that the YAFFS2 filesystem reports as available even after
the partition has been completely filled. I've set the default full
threshold to 1 MiB to provide a generous safety margin.

For this bug, I changed the DeviceStorageMonitorService demon to send
two new hidden notifications for device storage "full" and "not full",
when the free space falls below the full threshold (default 1 MiB,
but configurable as a system setting), in addition to the existing
storage low/okay notifications sent when the storage crosses the threshold
of 90% full (also configurable).

The SMS code was changed to use these new notifications so that it can
accept messages until the data partition has been filled to the maximum
safe capacity rather than stopping when it hits 90% full. There should
be no negative impact on battery life because the additional check in
the storage polling service should be offset by an optimization to cache
the free threshold values which were previously being computed every time
through the loop.

While testing this change, I discovered that SMSDispatcher was being
instantiated twice, the first time in GSMPhone/CDMAPhone, and the second
time in SimSmsInterfaceManager / RuimSmsInterfaceManager. Changed the code
to pass the original SMSDispatcher to the Sim/RuimSmsInterfaceManager
constructor.

Change-Id: Ie0c6d05294778ab6ee42e0fa01313af96d824c77

2 files changed, 38 insertions, 5 deletions

diff --git a/core/java/android/content/Intent.java b/core/java/android/content/Intent.java
index 2acc4a05792a..7154aeee08d4 100644
--- a/core/java/android/content/Intent.java
+++ b/core/java/android/content/Intent.java
@@ -1567,6 +1567,30 @@ public class Intent implements Parcelable, Cloneable {
     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
     public static final String ACTION_DEVICE_STORAGE_OK = "android.intent.action.DEVICE_STORAGE_OK";
     /**
+     * Broadcast Action:  A sticky broadcast that indicates a memory full
+     * condition on the device. This is intended for activities that want
+     * to be able to fill the data partition completely, leaving only
+     * enough free space to prevent system-wide SQLite failures.
+     *
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
+     *
+     * {@hide}
+     */
+    @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
+    public static final String ACTION_DEVICE_STORAGE_FULL = "android.intent.action.DEVICE_STORAGE_FULL";
+    /**
+     * Broadcast Action:  Indicates memory full condition on the device
+     * no longer exists.
+     *
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system.
+     *
+     * {@hide}
+     */
+    @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
+    public static final String ACTION_DEVICE_STORAGE_NOT_FULL = "android.intent.action.DEVICE_STORAGE_NOT_FULL";
+    /**
      * Broadcast Action:  Indicates low memory condition notification acknowledged by user
      * and package management should be started.
      * This is triggered by the user from the ACTION_DEVICE_STORAGE_LOW
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 78a384b65317..7c80420e1a83 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -2961,31 +2961,31 @@ public final class Settings {
         public static final String WTF_IS_FATAL = "wtf_is_fatal";
 
         /**
-         * Maximum age of entries kept by {@link android.os.IDropBox}.
+         * Maximum age of entries kept by {@link com.android.internal.os.IDropBoxManagerService}.
          * @hide
          */
         public static final String DROPBOX_AGE_SECONDS =
                 "dropbox_age_seconds";
         /**
-         * Maximum number of entry files which {@link android.os.IDropBox} will keep around.
+         * Maximum number of entry files which {@link com.android.internal.os.IDropBoxManagerService} will keep around.
          * @hide
          */
         public static final String DROPBOX_MAX_FILES =
                 "dropbox_max_files";
         /**
-         * Maximum amount of disk space used by {@link android.os.IDropBox} no matter what.
+         * Maximum amount of disk space used by {@link com.android.internal.os.IDropBoxManagerService} no matter what.
          * @hide
          */
         public static final String DROPBOX_QUOTA_KB =
                 "dropbox_quota_kb";
         /**
-         * Percent of free disk (excluding reserve) which {@link android.os.IDropBox} will use.
+         * Percent of free disk (excluding reserve) which {@link com.android.internal.os.IDropBoxManagerService} will use.
          * @hide
          */
         public static final String DROPBOX_QUOTA_PERCENT =
                 "dropbox_quota_percent";
         /**
-         * Percent of total disk which {@link android.os.IDropBox} will never dip into.
+         * Percent of total disk which {@link com.android.internal.os.IDropBoxManagerService} will never dip into.
          * @hide
          */
         public static final String DROPBOX_RESERVE_PERCENT =
@@ -3045,6 +3045,15 @@ public final class Settings {
                 "sys_storage_threshold_percentage";
 
         /**
+         * Minimum bytes of free storage on the device before the data
+         * partition is considered full. By default, 1 MB is reserved
+         * to avoid system-wide SQLite disk full exceptions.
+         * @hide
+         */
+        public static final String SYS_STORAGE_FULL_THRESHOLD_BYTES =
+                "sys_storage_full_threshold_bytes";
+
+        /**
          * The interval in milliseconds after which Wi-Fi is considered idle.
          * When idle, it is possible for the device to be switched from Wi-Fi to
          * the mobile data network.