Reduce lock contention in ContextImpl (8da0f1e2) · Commits · e / os / android_frameworks_base

core/java/android/app/ContextImpl.java

+156 −75

Original line number	Diff line number	Diff line
		@@ -272,10 +272,17 @@ class ContextImpl extends Context {

		@UnsupportedAppUsage
		private Context mOuterContext;

		private final Object mThemeLock = new Object();

		@UnsupportedAppUsage
		@GuardedBy("mThemeLock")
		private int mThemeResource = 0;

		@UnsupportedAppUsage
		@GuardedBy("mThemeLock")
		private Resources.Theme mTheme = null;

		@UnsupportedAppUsage
		private PackageManager mPackageManager;
		private Context mReceiverRestrictedContext = null;
		@@ -288,7 +295,6 @@ class ContextImpl extends Context {

		private ContentCaptureOptions mContentCaptureOptions = null;

		private final Object mSync = new Object();
		/**
		* Indicates this {@link Context} can not handle UI components properly and is not associated
		* with a {@link Display} instance.
		@@ -340,21 +346,18 @@ class ContextImpl extends Context {
		*/
		private boolean mOwnsToken = false;

		@GuardedBy("mSync")
		private File mDatabasesDir;
		@GuardedBy("mSync")
		@UnsupportedAppUsage
		private File mPreferencesDir;
		@GuardedBy("mSync")
		private File mFilesDir;
		@GuardedBy("mSync")
		private File mCratesDir;
		@GuardedBy("mSync")
		private File mNoBackupFilesDir;
		@GuardedBy("mSync")
		private File mCacheDir;
		@GuardedBy("mSync")
		private File mCodeCacheDir;
		private final Object mDirsLock = new Object();
		private volatile File mDatabasesDir;
		@UnsupportedAppUsage private volatile File mPreferencesDir;
		private volatile File mFilesDir;
		private volatile File mCratesDir;
		private volatile File mNoBackupFilesDir;
		private volatile File[] mExternalFilesDirs;
		private volatile File[] mObbDirs;
		private volatile File mCacheDir;
		private volatile File mCodeCacheDir;
		private volatile File[] mExternalCacheDirs;
		private volatile File[] mExternalMediaDirs;

		// The system service cache for the system services that are cached per-ContextImpl.
		@UnsupportedAppUsage
		@@ -458,7 +461,7 @@ class ContextImpl extends Context {

		@Override
		public void setTheme(int resId) {
		synchronized (mSync) {
		synchronized (mThemeLock) {
		if (mThemeResource != resId) {
		mThemeResource = resId;
		initializeTheme();
		@@ -468,14 +471,14 @@ class ContextImpl extends Context {

		@Override
		public int getThemeResId() {
		synchronized (mSync) {
		synchronized (mThemeLock) {
		return mThemeResource;
		}
		}

		@Override
		public Resources.Theme getTheme() {
		synchronized (mSync) {
		synchronized (mThemeLock) {
		if (mTheme != null) {
		return mTheme;
		}
		@@ -488,6 +491,7 @@ class ContextImpl extends Context {
		}
		}

		@GuardedBy("mThemeLock")
		private void initializeTheme() {
		if (mTheme == null) {
		mTheme = mResources.newTheme();
		@@ -731,12 +735,18 @@ class ContextImpl extends Context {

		@UnsupportedAppUsage
		private File getPreferencesDir() {
		synchronized (mSync) {
		if (mPreferencesDir == null) {
		mPreferencesDir = new File(getDataDir(), "shared_prefs");
		File localPreferencesDir = mPreferencesDir;
		if (localPreferencesDir == null) {
		synchronized (mDirsLock) {
		localPreferencesDir = mPreferencesDir;
		if (localPreferencesDir == null) {
		localPreferencesDir = new File(getDataDir(), "shared_prefs");
		ensurePrivateDirExists(localPreferencesDir);
		mPreferencesDir = localPreferencesDir;
		}
		}
		return ensurePrivateDirExists(mPreferencesDir);
		}
		return localPreferencesDir;
		}

		@Override
		@@ -778,16 +788,16 @@ class ContextImpl extends Context {
		/**
		* Common-path handling of app data dir creation
		*/
		private static File ensurePrivateDirExists(File file) {
		return ensurePrivateDirExists(file, 0771, -1, null);
		private static void ensurePrivateDirExists(File file) {
		ensurePrivateDirExists(file, 0771, -1, null);
		}

		private static File ensurePrivateCacheDirExists(File file, String xattr) {
		private static void ensurePrivateCacheDirExists(File file, String xattr) {
		final int gid = UserHandle.getCacheAppGid(Process.myUid());
		return ensurePrivateDirExists(file, 02771, gid, xattr);
		ensurePrivateDirExists(file, 02771, gid, xattr);
		}

		private static File ensurePrivateDirExists(File file, int mode, int gid, String xattr) {
		private static void ensurePrivateDirExists(File file, int mode, int gid, String xattr) {
		if (!file.exists()) {
		final String path = file.getAbsolutePath();
		try {
		@@ -815,17 +825,22 @@ class ContextImpl extends Context {
		}
		}
		}
		return file;
		}

		@Override
		public File getFilesDir() {
		synchronized (mSync) {
		if (mFilesDir == null) {
		mFilesDir = new File(getDataDir(), "files");
		File localFilesDir = mFilesDir;
		if (localFilesDir == null) {
		localFilesDir = mFilesDir;
		synchronized (mDirsLock) {
		if (localFilesDir == null) {
		localFilesDir = new File(getDataDir(), "files");
		ensurePrivateDirExists(localFilesDir);
		mFilesDir = localFilesDir;
		}
		}
		return ensurePrivateDirExists(mFilesDir);
		}
		return localFilesDir;
		}

		@Override
		@@ -835,26 +850,38 @@ class ContextImpl extends Context {
		final Path absoluteNormalizedCratePath = cratesRootPath.resolve(crateId)
		.toAbsolutePath().normalize();

		synchronized (mSync) {
		if (mCratesDir == null) {
		mCratesDir = cratesRootPath.toFile();
		File localCratesDir = mCratesDir;
		if (localCratesDir == null) {
		synchronized (mDirsLock) {
		localCratesDir = mCratesDir;
		if (localCratesDir == null) {
		localCratesDir = cratesRootPath.toFile();
		ensurePrivateDirExists(localCratesDir);
		mCratesDir = localCratesDir;
		}
		}
		ensurePrivateDirExists(mCratesDir);
		}

		File cratedDir = absoluteNormalizedCratePath.toFile();
		return ensurePrivateDirExists(cratedDir);
		File crateDir = absoluteNormalizedCratePath.toFile();
		ensurePrivateDirExists(crateDir);
		return crateDir;
		}

		@Override
		public File getNoBackupFilesDir() {
		synchronized (mSync) {
		if (mNoBackupFilesDir == null) {
		mNoBackupFilesDir = new File(getDataDir(), "no_backup");
		File localNoBackupFilesDir = mNoBackupFilesDir;
		if (localNoBackupFilesDir == null) {
		synchronized (mDirsLock) {
		localNoBackupFilesDir = mNoBackupFilesDir;
		if (localNoBackupFilesDir == null) {
		localNoBackupFilesDir = new File(getDataDir(), "no_backup");
		ensurePrivateDirExists(localNoBackupFilesDir);
		mNoBackupFilesDir = localNoBackupFilesDir;
		}
		return ensurePrivateDirExists(mNoBackupFilesDir);
		}
		}
		return localNoBackupFilesDir;
		}

		@Override
		public File getExternalFilesDir(String type) {
		@@ -865,14 +892,25 @@ class ContextImpl extends Context {

		@Override
		public File[] getExternalFilesDirs(String type) {
		synchronized (mSync) {
		File[] dirs = Environment.buildExternalStorageAppFilesDirs(getPackageName());
		File[] localExternalFilesDirs = mExternalFilesDirs;
		if (localExternalFilesDirs == null) {
		synchronized (mDirsLock) {
		localExternalFilesDirs = mExternalFilesDirs;
		if (localExternalFilesDirs == null) {
		localExternalFilesDirs =
		Environment.buildExternalStorageAppFilesDirs(getPackageName());
		if (type != null) {
		dirs = Environment.buildPaths(dirs, type);
		localExternalFilesDirs =
		Environment.buildPaths(localExternalFilesDirs, type);
		}
		localExternalFilesDirs = ensureExternalDirsExistOrFilter(
		localExternalFilesDirs, true /* tryCreateInProcess */);
		mExternalFilesDirs = localExternalFilesDirs;
		}
		return ensureExternalDirsExistOrFilter(dirs, true /* tryCreateInProcess */);
		}
		}
		return localExternalFilesDirs;
		}

		@Override
		public File getObbDir() {
		@@ -883,30 +921,51 @@ class ContextImpl extends Context {

		@Override
		public File[] getObbDirs() {
		synchronized (mSync) {
		File[] dirs = Environment.buildExternalStorageAppObbDirs(getPackageName());
		return ensureExternalDirsExistOrFilter(dirs, true /* tryCreateInProcess */);
		File[] localObbDirs = mObbDirs;
		if (mObbDirs == null) {
		synchronized (mDirsLock) {
		localObbDirs = mObbDirs;
		if (localObbDirs == null) {
		localObbDirs = Environment.buildExternalStorageAppObbDirs(getPackageName());
		localObbDirs = ensureExternalDirsExistOrFilter(
		localObbDirs, true /* tryCreateInProcess */);
		mObbDirs = localObbDirs;
		}
		}
		}
		return localObbDirs;
		}

		@Override
		public File getCacheDir() {
		synchronized (mSync) {
		if (mCacheDir == null) {
		mCacheDir = new File(getDataDir(), "cache");
		File localCacheDir = mCacheDir;
		if (localCacheDir == null) {
		synchronized (mDirsLock) {
		localCacheDir = mCacheDir;
		if (localCacheDir == null) {
		localCacheDir = new File(getDataDir(), "cache");
		ensurePrivateCacheDirExists(localCacheDir, XATTR_INODE_CACHE);
		mCacheDir = localCacheDir;
		}
		return ensurePrivateCacheDirExists(mCacheDir, XATTR_INODE_CACHE);
		}
		}
		return localCacheDir;
		}

		@Override
		public File getCodeCacheDir() {
		synchronized (mSync) {
		if (mCodeCacheDir == null) {
		mCodeCacheDir = getCodeCacheDirBeforeBind(getDataDir());
		File localCodeCacheDir = mCodeCacheDir;
		if (localCodeCacheDir == null) {
		synchronized (mDirsLock) {
		localCodeCacheDir = mCodeCacheDir;
		if (localCodeCacheDir == null) {
		localCodeCacheDir = getCodeCacheDirBeforeBind(getDataDir());
		ensurePrivateCacheDirExists(localCodeCacheDir, XATTR_INODE_CODE_CACHE);
		mCodeCacheDir = localCodeCacheDir;
		}
		}
		return ensurePrivateCacheDirExists(mCodeCacheDir, XATTR_INODE_CODE_CACHE);
		}
		return localCodeCacheDir;
		}

		/**
		@@ -927,22 +986,38 @@ class ContextImpl extends Context {

		@Override
		public File[] getExternalCacheDirs() {
		synchronized (mSync) {
		File[] dirs = Environment.buildExternalStorageAppCacheDirs(getPackageName());
		// We don't try to create cache directories in-process, because they need special
		// setup for accurate quota tracking. This ensures the cache dirs are always
		// created through StorageManagerService.
		return ensureExternalDirsExistOrFilter(dirs, false /* tryCreateInProcess */);
		File[] localExternalCacheDirs = mExternalCacheDirs;
		if (localExternalCacheDirs == null) {
		synchronized (mDirsLock) {
		localExternalCacheDirs = mExternalCacheDirs;
		if (localExternalCacheDirs == null) {
		localExternalCacheDirs =
		Environment.buildExternalStorageAppCacheDirs(getPackageName());
		localExternalCacheDirs = ensureExternalDirsExistOrFilter(
		localExternalCacheDirs, false /* tryCreateInProcess */);
		mExternalCacheDirs = localExternalCacheDirs;
		}
		}
		}
		return localExternalCacheDirs;
		}

		@Override
		public File[] getExternalMediaDirs() {
		synchronized (mSync) {
		File[] dirs = Environment.buildExternalStorageAppMediaDirs(getPackageName());
		return ensureExternalDirsExistOrFilter(dirs, true /* tryCreateInProcess */);
		File[] localExternalMediaDirs = mExternalMediaDirs;
		if (localExternalMediaDirs == null) {
		synchronized (mDirsLock) {
		localExternalMediaDirs = mExternalMediaDirs;
		if (localExternalMediaDirs == null) {
		localExternalMediaDirs = Environment.buildExternalStorageAppMediaDirs(getPackageName());
		localExternalMediaDirs = ensureExternalDirsExistOrFilter(
		localExternalMediaDirs, true /* tryCreateInProcess */);
		mExternalMediaDirs = localExternalMediaDirs;
		}
		}
		}
		return localExternalMediaDirs;
		}

		/**
		* @hide
		@@ -1040,16 +1115,22 @@ class ContextImpl extends Context {
		}

		private File getDatabasesDir() {
		synchronized (mSync) {
		if (mDatabasesDir == null) {
		File localDatabasesDir = mDatabasesDir;
		if (localDatabasesDir == null) {
		synchronized (mDirsLock) {
		localDatabasesDir = mDatabasesDir;
		if (localDatabasesDir == null) {
		if ("android".equals(getPackageName())) {
		mDatabasesDir = new File("/data/system");
		localDatabasesDir = new File("/data/system");
		} else {
		mDatabasesDir = new File(getDataDir(), "databases");
		localDatabasesDir = new File(getDataDir(), "databases");
		}
		ensurePrivateDirExists(localDatabasesDir);
		mDatabasesDir = localDatabasesDir;
		}
		}
		return ensurePrivateDirExists(mDatabasesDir);
		}
		return localDatabasesDir;
		}

		@Override