From 0c0275675f58e82e21a66fffd6657c52947fa189 Mon Sep 17 00:00:00 2001
From: Kai Morich <mail@kai-morich.de>
Date: Thu, 30 May 2024 18:57:39 +0200
Subject: [PATCH] SerialInputOutputManager.writeAsync(): handle
 SerialTimeoutException

---
 .../hoho/android/usbserial/DeviceTest.java    |  9 +++++++++
 .../util/SerialInputOutputManager.java        | 19 ++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java b/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java
index 2827342..8e43c64 100644
--- a/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java
+++ b/usbSerialForAndroid/src/androidTest/java/com/hoho/android/usbserial/DeviceTest.java
@@ -1525,6 +1525,15 @@ public class DeviceTest {
         data = telnet.read(2);
         assertEquals(2, data.length);
         usb.ioManager.setReadTimeout(200);
+
+        // with internal SerialTimeoutException
+        TestBuffer tbuf = new TestBuffer(usb.writeBufferSize + 2*usb.writePacketSize);
+        usb.ioManager.setWriteTimeout(20); // tbuf len >= 128, needs 133msec @ 9600 baud
+        usb.setParameters(9600, 8, 1, UsbSerialPort.PARITY_NONE);
+        telnet.setParameters(9600, 8, 1, UsbSerialPort.PARITY_NONE);
+        usb.ioManager.writeAsync(tbuf.buf);
+        while(!tbuf.testRead(telnet.read(-1)))
+            ;
     }
 
     @Test
diff --git a/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/util/SerialInputOutputManager.java b/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/util/SerialInputOutputManager.java
index 2d9b7b0..f6ee3ca 100644
--- a/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/util/SerialInputOutputManager.java
+++ b/usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/util/SerialInputOutputManager.java
@@ -9,6 +9,7 @@ package com.hoho.android.usbserial.util;
 import android.os.Process;
 import android.util.Log;
 
+import com.hoho.android.usbserial.driver.SerialTimeoutException;
 import com.hoho.android.usbserial.driver.UsbSerialPort;
 
 import java.io.IOException;
@@ -254,7 +255,23 @@ public class SerialInputOutputManager implements Runnable {
             if (DEBUG) {
                 Log.d(TAG, "Writing data len=" + len);
             }
-            mSerialPort.write(buffer, mWriteTimeout);
+            try {
+                mSerialPort.write(buffer, mWriteTimeout);
+            } catch (SerialTimeoutException ex) {
+                synchronized (mWriteBufferLock) {
+                    byte[] buffer2 = null;
+                    int len2 = mWriteBuffer.position();
+                    if (len2 > 0) {
+                        buffer2 = new byte[len2];
+                        mWriteBuffer.rewind();
+                        mWriteBuffer.get(buffer2, 0, len2);
+                        mWriteBuffer.clear();
+                    }
+                    mWriteBuffer.put(buffer, ex.bytesTransferred, buffer.length - ex.bytesTransferred);
+                    if (buffer2 != null)
+                        mWriteBuffer.put(buffer2);
+                }
+            }
         }
     }