Race in WapPushManager under multi-thread environment

When multiple threads call WapPushManager functions simultaneously,
it might hit race that one thread is closing a SqliteDatabase object
while another thread is using it.

Following is an example:

    Thread A                                    Thread B

call getDatabaseLocked()                          ---
       |                                           |
mDatabase is NULL,so A create Database            ---
       |                                           |
getDatabaseLocked() return the new                ---
created Database                                  ---
       |                                           |
      ---                                 call getDatabaseLocked() and return
      ---                                 the Database created by A
       |                                           |
Call SQLiteDatabase.close()                       ---
close() -> releaseReference()                     ---
the reference count is decreased to 0             ---
       |                                           |
      ---                                  Attempt to call any operation of Database
      ---                                  Object, but hit exception because this
      ---                                  Database Object's reference count is 0

For WapPushManager, seems it always close the database object right after
it open&query it, this is not necessary and would hit above race under multi-thread
environment.

Change-Id: I68fac046f806c8d9328fbe0d9c8a08e6bfddbef1
Signed-off-by: wangbo3 <bo.c.wang@intel.com>
Signed-off-by: chao.bi <chao.bi@intel.com>
Signed-off-by: Zhiquan Liu <zhiquan.liu@intel.com>

1 files changed, 0 insertions, 7 deletions

diff --git a/packages/WAPPushManager/src/com/android/smspush/WapPushManager.java b/packages/WAPPushManager/src/com/android/smspush/WapPushManager.java
index e970367..96d29fd 100644
--- a/packages/WAPPushManager/src/com/android/smspush/WapPushManager.java
+++ b/packages/WAPPushManager/src/com/android/smspush/WapPushManager.java
@@ -185,7 +185,6 @@ public class WapPushManager extends Service {
             WapPushManDBHelper dbh = getDatabase(mContext);
             SQLiteDatabase db = dbh.getReadableDatabase();
             WapPushManDBHelper.queryData lastapp = dbh.queryLastApp(db, app_id, content_type);
-            db.close();
 
             if (lastapp == null) {
                 Log.w(LOG_TAG, "no receiver app found for " + app_id + ":" + content_type);
@@ -284,7 +283,6 @@ public class WapPushManager extends Service {
                 ret = true;
             }
 
-            db.close();
 
             return ret;
         }
@@ -308,7 +306,6 @@ public class WapPushManager extends Service {
             WapPushManDBHelper.queryData lastapp = dbh.queryLastApp(db, x_app_id, content_type);
 
             if (lastapp == null) {
-                db.close();
                 return false;
             }
 
@@ -328,7 +325,6 @@ public class WapPushManager extends Service {
                     + package_name + "." + class_name
                     + ", sq:" + lastapp.installOrder);
 
-            db.close();
 
             return num > 0;
         }
@@ -346,7 +342,6 @@ public class WapPushManager extends Service {
                     + " and class_name=\'" + class_name + "\'";
             int num_removed = db.delete(APPID_TABLE_NAME, where, null);
 
-            db.close();
             if (LOCAL_LOGV) Log.v(LOG_TAG, "deleted " + num_removed + " rows:"
                     + x_app_id + ":" + content_type + " "
                     + package_name + "." + class_name);
@@ -399,7 +394,6 @@ public class WapPushManager extends Service {
         if (LOCAL_LOGV) Log.v(LOG_TAG, "verifyData app id: " + x_app_id + " content type: " +
                 content_type + " lastapp: " + lastapp);
 
-        db.close();
 
         if (lastapp == null) return false;
 
@@ -430,7 +424,6 @@ public class WapPushManager extends Service {
         SQLiteDatabase db = dbh.getReadableDatabase();
         boolean ret = dbh.queryLastApp(db, x_app_id, content_type) != null;
 
-        db.close();
         return ret;
     }