From f4c37bb2b6fa7c627acd80282304db4626f59941 Mon Sep 17 00:00:00 2001
From: giulcioffi <g.cioffi@arduino.cc>
Date: Tue, 5 Jan 2021 10:25:32 +0100
Subject: [PATCH 1/2] Retry send up to 5 times, then close socket

---
 src/WiFiClient.cpp | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/src/WiFiClient.cpp b/src/WiFiClient.cpp
index bfc21ec7..2d75cdc0 100644
--- a/src/WiFiClient.cpp
+++ b/src/WiFiClient.cpp
@@ -207,19 +207,29 @@ size_t WiFiClient::write(const uint8_t *buf, size_t size) {
   if (size==0)
   {
 	  setWriteError();
-      return 0;
+    return 0;
   }
 
-  size_t written = ServerDrv::sendData(_sock, buf, size);
-  if (!written)
-  {
-	  setWriteError();
-      return 0;
+  bool success = false;
+  size_t written = 0;
+  for (int i=0; i<5; i++) {
+    written = ServerDrv::sendData(_sock, buf, size);
+    if (written) {
+      success = true;
+      break;
+    }
   }
-  if (!ServerDrv::checkDataSent(_sock))
-  {
-	  setWriteError();
-      return 0;
+  if (success) {
+    if (!ServerDrv::checkDataSent(_sock))
+    {
+      setWriteError();
+        return 0;
+    }
+  } else {
+    // close socket
+    ServerDrv::stopClient(_sock);
+    setWriteError();
+    return 0;
   }
 
   return written;

From c0f37d0937ed94c5c12ec45ba7a103521067e8fe Mon Sep 17 00:00:00 2001
From: giulcioffi <g.cioffi@arduino.cc>
Date: Tue, 5 Jan 2021 13:00:50 +0100
Subject: [PATCH 2/2] Add retry function and call it by default + add
 setRetry(bool) to let user disable retry

---
 src/WiFiClient.cpp | 54 +++++++++++++++++++++++++++++++---------------
 src/WiFiClient.h   |  3 +++
 2 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/src/WiFiClient.cpp b/src/WiFiClient.cpp
index 2d75cdc0..b8ec61dd 100644
--- a/src/WiFiClient.cpp
+++ b/src/WiFiClient.cpp
@@ -35,10 +35,10 @@ extern "C" {
 
 uint16_t WiFiClient::_srcport = 1024;
 
-WiFiClient::WiFiClient() : _sock(NO_SOCKET_AVAIL) {
+WiFiClient::WiFiClient() : _sock(NO_SOCKET_AVAIL), _retrySend(true) {
 }
 
-WiFiClient::WiFiClient(uint8_t sock) : _sock(sock) {
+WiFiClient::WiFiClient(uint8_t sock) : _sock(sock), _retrySend(true) {
 }
 
 int WiFiClient::connect(const char* host, uint16_t port) {
@@ -210,31 +210,47 @@ size_t WiFiClient::write(const uint8_t *buf, size_t size) {
     return 0;
   }
 
-  bool success = false;
-  size_t written = 0;
-  for (int i=0; i<5; i++) {
-    written = ServerDrv::sendData(_sock, buf, size);
-    if (written) {
-      success = true;
-      break;
-    }
+  size_t written = ServerDrv::sendData(_sock, buf, size);
+  if (!written && _retrySend) {
+    written = retry(buf, size, true);
   }
-  if (success) {
-    if (!ServerDrv::checkDataSent(_sock))
-    {
-      setWriteError();
-        return 0;
-    }
-  } else {
+  if(!written){
     // close socket
     ServerDrv::stopClient(_sock);
     setWriteError();
     return 0;
   }
 
+  if (!ServerDrv::checkDataSent(_sock))
+  {
+    setWriteError();
+    return 0;
+  }
+
   return written;
 }
 
+size_t WiFiClient::retry(const uint8_t *buf, size_t size, bool write) {
+  size_t rec_bytes = 0;
+
+  if (write) {
+
+    //RETRY WRITE
+    for (int i=0; i<5; i++) {
+      rec_bytes = ServerDrv::sendData(_sock, buf, size);
+      if (rec_bytes) {
+        break;
+      }
+    }
+    return rec_bytes;
+
+  } else {
+    //RETRY READ
+    // To be implemented, if needed
+  }
+
+}
+
 int WiFiClient::available() {
   if (_sock != 255)
   {
@@ -266,6 +282,10 @@ int WiFiClient::peek() {
   return WiFiSocketBuffer.peek(_sock);
 }
 
+void WiFiClient::setRetry(bool retry) {
+  _retrySend = retry;
+}
+
 void WiFiClient::flush() {
   // TODO: a real check to ensure transmission has been completed
 }
diff --git a/src/WiFiClient.h b/src/WiFiClient.h
index 8fcb47a4..a6f43e2b 100644
--- a/src/WiFiClient.h
+++ b/src/WiFiClient.h
@@ -40,10 +40,12 @@ class WiFiClient : public Client {
   virtual int connectBearSSL(const char *host, uint16_t port);
   virtual size_t write(uint8_t);
   virtual size_t write(const uint8_t *buf, size_t size);
+  virtual size_t retry(const uint8_t *buf, size_t size, bool write);
   virtual int available();
   virtual int read();
   virtual int read(uint8_t *buf, size_t size);
   virtual int peek();
+  virtual void setRetry(bool retry);
   virtual void flush();
   virtual void stop();
   virtual uint8_t connected();
@@ -61,6 +63,7 @@ class WiFiClient : public Client {
   static uint16_t _srcport;
   uint8_t _sock;   //not used
   uint16_t  _socket;
+  bool _retrySend;
 };
 
 #endif