update flush()

Author: d-a-v

libraries/ESP8266WiFi/src/WiFiClient.cpp

@@ -285,18 +285,21 @@ size_t WiFiClient::peekBytes(uint8_t *buffer, size_t length) {
     return _client->peekBytes((char *)buffer, count);
 }
 
-void WiFiClient::flush()
+bool WiFiClient::flush(int maxWaitMs)
 {
     if (_client)
-        _client->wait_until_sent();
+        return !_client || _client->wait_until_sent(maxWaitMs);
+    return true;
 }
 
-void WiFiClient::stop()
+bool WiFiClient::stop(int maxWaitMs)
 {
     if (!_client)
-        return;
+        return true;
 
-    _client->close();
+    bool ok = _client->wait_until_sent(maxWaitMs);
+    ok &= _client->close() == ERR_OK;
+    return ok;
 }
 
 uint8_t WiFiClient::connected()

libraries/ESP8266WiFi/src/WiFiClient.h

@@ -28,7 +28,12 @@
 #include "IPAddress.h"
 #include "include/slist.h"
 
-#define WIFICLIENT_MAX_PACKET_SIZE 1460
+#ifndef TCP_MSS
+#define TCP_MSS 1460 // lwip1.4
+#endif
+
+#define WIFICLIENT_MAX_PACKET_SIZE TCP_MSS
+#define WIFICLIENT_MAX_FLUSH_WAIT_MS 100
 
 #define TCP_DEFAULT_KEEPALIVE_IDLE_SEC          7200 // 2 hours
 #define TCP_DEFAULT_KEEPALIVE_INTERVAL_SEC      75   // 75 sec
@@ -67,8 +72,10 @@ class WiFiClient : public Client, public SList<WiFiClient> {
   size_t peekBytes(char *buffer, size_t length) {
     return peekBytes((uint8_t *) buffer, length);
   }
-  virtual void flush();
-  virtual void stop();
+  bool flush(int maxWaitMs);
+  bool stop(int maxWaitMs);
+  virtual void flush() { flush(WIFICLIENT_MAX_FLUSH_WAIT_MS); }
+  virtual void stop() { stop(WIFICLIENT_MAX_FLUSH_WAIT_MS); }
   virtual uint8_t connected();
   virtual operator bool();
 

libraries/ESP8266WiFi/src/include/ClientContext.h

@@ -296,20 +296,30 @@ class ClientContext
         _rx_buf_offset = 0;
     }
 
-    void wait_until_sent()
+    bool wait_until_sent(int max_wait_ms = WIFICLIENT_MAX_FLUSH_WAIT_MS)
     {
-        // fix option 1 in
-        // https://github.com/esp8266/Arduino/pull/3967#pullrequestreview-83451496
-        // TODO: option 2
+        if (!_pcb)
+            return;
+        tcp_output(_pcb);
 
-        #define WAIT_TRIES_MS 10	// at most 10ms
+        // https://github.com/esp8266/Arduino/pull/3967#pullrequestreview-83451496
+        // option 1 done
+        // option 2 / _write_some() not necessary since _datasource is always nullptr here
 
-        int tries = 1+ WAIT_TRIES_MS;
+        max_wait_ms++;
 
-        while (state() == ESTABLISHED && tcp_sndbuf(_pcb) != TCP_SND_BUF && --tries) {
-            //_write_some();
+        // wait for peer's acks flushing lwIP's output buffer
+        while (state() == ESTABLISHED && tcp_sndbuf(_pcb) != TCP_SND_BUF && --max_wait_ms)
             delay(1); // esp_ schedule+yield
+
+        #ifdef DEBUGV
+        if (max_wait_ms == 0) {
+            // wait until sent: timeout
+            DEBUGV(":wustmo\n");
         }
+        #endif
+
+        return max_wait_ms > 0;
     }
 
     uint8_t state() const