Merge "Revert "Remove a misleading "flush" function.""

3 files changed, 60 insertions, 0 deletions

diff --git a/core/java/android/bluetooth/BluetoothOutputStream.java b/core/java/android/bluetooth/BluetoothOutputStream.java
index a0aa2dee9d34..dfec4e102fd4 100644
--- a/core/java/android/bluetooth/BluetoothOutputStream.java
+++ b/core/java/android/bluetooth/BluetoothOutputStream.java
@@ -75,4 +75,16 @@ import java.io.OutputStream;
         }
         mSocket.write(b, offset, count);
     }
+
+    /**
+     * Wait until the data in sending queue is emptied. A polling version
+     * for flush implementation. Use it to ensure the writing data afterwards will
+     * be packed in the new RFCOMM frame.
+     *
+     * @throws IOException if an i/o error occurs.
+     * @since Android 4.2.3
+     */
+    public void flush() throws IOException {
+        mSocket.flush();
+    }
 }
diff --git a/core/java/android/bluetooth/BluetoothSocket.java b/core/java/android/bluetooth/BluetoothSocket.java
index 760166bfcc5d..a6e3153d6af7 100644
--- a/core/java/android/bluetooth/BluetoothSocket.java
+++ b/core/java/android/bluetooth/BluetoothSocket.java
@@ -515,6 +515,20 @@ public final class BluetoothSocket implements Closeable {
         return mSocketIS.available();
     }
 
+    /**
+     * Wait until the data in sending queue is emptied. A polling version
+     * for flush implementation. Used to ensure the writing data afterwards will
+     * be packed in new RFCOMM frame.
+     *
+     * @throws IOException if an i/o error occurs.
+     */
+    @UnsupportedAppUsage
+    /*package*/ void flush() throws IOException {
+        if (mSocketOS == null) throw new IOException("flush is called on null OutputStream");
+        if (VDBG) Log.d(TAG, "flush: " + mSocketOS);
+        mSocketOS.flush();
+    }
+
     /*package*/ int read(byte[] b, int offset, int length) throws IOException {
         int ret = 0;
         if (VDBG) Log.d(TAG, "read in:  " + mSocketIS + " len: " + length);
diff --git a/core/java/android/net/LocalSocketImpl.java b/core/java/android/net/LocalSocketImpl.java
index b066a15106af..fe7632c25445 100644
--- a/core/java/android/net/LocalSocketImpl.java
+++ b/core/java/android/net/LocalSocketImpl.java
@@ -157,6 +157,40 @@ class LocalSocketImpl
                 write_native(b, myFd);
             }
         }
+
+        /**
+         * Wait until the data in sending queue is emptied. A polling version
+         * for flush implementation.
+         * @throws IOException
+         *             if an i/o error occurs.
+         */
+        @Override
+        public void flush() throws IOException {
+            FileDescriptor myFd = fd;
+            if (myFd == null) throw new IOException("socket closed");
+
+            // Loop until the output buffer is empty.
+            Int32Ref pending = new Int32Ref(0);
+            while (true) {
+                try {
+                    // See linux/net/unix/af_unix.c
+                    Os.ioctlInt(myFd, OsConstants.TIOCOUTQ, pending);
+                } catch (ErrnoException e) {
+                    throw e.rethrowAsIOException();
+                }
+
+                if (pending.value <= 0) {
+                    // The output buffer is empty.
+                    break;
+                }
+
+                try {
+                    Thread.sleep(10);
+                } catch (InterruptedException ie) {
+                    break;
+                }
+            }
+        }
     }
 
     private native int read_native(FileDescriptor fd) throws IOException;