diff options
| -rw-r--r-- | core/java/android/database/sqlite/SQLiteDatabase.java | 2 | ||||
| -rw-r--r-- | core/java/android/provider/Settings.java | 89 |
2 files changed, 46 insertions, 45 deletions
diff --git a/core/java/android/database/sqlite/SQLiteDatabase.java b/core/java/android/database/sqlite/SQLiteDatabase.java index ca7cec2..657bbcc 100644 --- a/core/java/android/database/sqlite/SQLiteDatabase.java +++ b/core/java/android/database/sqlite/SQLiteDatabase.java @@ -1897,7 +1897,7 @@ public class SQLiteDatabase extends SQLiteClosable { samplePercent = 100; } else { samplePercent = (int) (100 * nanos / QUERY_LOG_TIME_IN_NANOS) + 1; - if (mRandom.nextInt(100) < samplePercent) return; + if (mRandom.nextInt(100) >= samplePercent) return; } if (sql.length() > QUERY_LOG_SQL_LENGTH) sql = sql.substring(0, QUERY_LOG_SQL_LENGTH); diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java index c20d338..df40946 100644 --- a/core/java/android/provider/Settings.java +++ b/core/java/android/provider/Settings.java @@ -38,6 +38,7 @@ import android.os.*; import android.telephony.TelephonyManager; import android.text.TextUtils; import android.util.AndroidException; +import android.util.Config; import android.util.Log; import java.net.URISyntaxException; @@ -442,6 +443,7 @@ public final class Settings { public static final String AUTHORITY = "settings"; private static final String TAG = "Settings"; + private static final boolean LOCAL_LOGV = Config.LOGV || false; public static class SettingNotFoundException extends AndroidException { public SettingNotFoundException(String msg) { @@ -478,61 +480,60 @@ public final class Settings { private static class NameValueCache { private final String mVersionSystemProperty; - // the following needs synchronization because this structure is accessed from different - // threads and they could be performing clear(), get(), put() at the same time. - private final Map<String, String> mValues = - Collections.synchronizedMap(new HashMap<String, String>()); - private long mValuesVersion = 0; private final Uri mUri; - NameValueCache(String versionSystemProperty, Uri uri) { + // Must synchronize(mValues) to access mValues and mValuesVersion. + private final HashMap<String, String> mValues = new HashMap<String, String>(); + private long mValuesVersion = 0; + + public NameValueCache(String versionSystemProperty, Uri uri) { mVersionSystemProperty = versionSystemProperty; mUri = uri; } - String getString(ContentResolver cr, String name) { + public String getString(ContentResolver cr, String name) { long newValuesVersion = SystemProperties.getLong(mVersionSystemProperty, 0); - if (mValuesVersion != newValuesVersion) { - mValues.clear(); - mValuesVersion = newValuesVersion; + + synchronized (mValues) { + if (mValuesVersion != newValuesVersion) { + if (LOCAL_LOGV) { + Log.v(TAG, "invalidate [" + mUri.getLastPathSegment() + "]: current " + + newValuesVersion + " != cached " + mValuesVersion); + } + + mValues.clear(); + mValuesVersion = newValuesVersion; + } + + if (mValues.containsKey(name)) { + return mValues.get(name); // Could be null, that's OK -- negative caching + } } - /* - * don't look for the key using containsKey() method because (key, object) mapping - * could be removed from mValues before get() is done like so: - * - * say, mValues contains mapping for "foo" - * Thread# 1 - * performs containsKey("foo") - * receives true - * Thread #2 - * triggers mValues.clear() - * Thread#1 - * since containsKey("foo") = true, performs get("foo") - * receives null - * thats incorrect! - * - * to avoid the above, thread#1 should do get("foo") instead of containsKey("foo") - * since mValues is synchronized, get() will get a consistent value. - * - * we don't want to make this method synchronized tho - because - * holding mutex is not desirable while a call could be made to database. - */ - String value = mValues.get(name); - if (value == null) { - Cursor c = null; - try { - c = cr.query(mUri, new String[] { Settings.NameValueTable.VALUE }, - Settings.NameValueTable.NAME + "=?", new String[]{name}, null); - if (c != null && c.moveToNext()) value = c.getString(0); + + Cursor c = null; + try { + c = cr.query(mUri, new String[] { Settings.NameValueTable.VALUE }, + Settings.NameValueTable.NAME + "=?", new String[]{name}, null); + if (c == null) { + Log.w(TAG, "Can't get key " + name + " from " + mUri); + return null; + } + + String value = c.moveToNext() ? c.getString(0) : null; + synchronized (mValues) { mValues.put(name, value); - } catch (SQLException e) { - // SQL error: return null, but don't cache it. - Log.w(TAG, "Can't get key " + name + " from " + mUri, e); - } finally { - if (c != null) c.close(); } + if (LOCAL_LOGV) { + Log.v(TAG, "cache miss [" + mUri.getLastPathSegment() + "]: " + + name + " = " + (value == null ? "(null)" : value)); + } + return value; + } catch (SQLException e) { + Log.w(TAG, "Can't get key " + name + " from " + mUri, e); + return null; // Return null, but don't cache it. + } finally { + if (c != null) c.close(); } - return value; } } |