Fix UDP send to not temporarily use connect()

Author: jwatte

hardware/esp8266com/esp8266/libraries/ESP8266WiFi/src/WiFiUdp.cpp

@@ -132,14 +132,13 @@ int WiFiUDP::beginPacket(const char *host, uint16_t port)
 
 int WiFiUDP::beginPacket(IPAddress ip, uint16_t port)
 {
-    ip_addr_t addr;
-    addr.addr = ip;
-
     if (!_ctx) {
         _ctx = new UdpContext;
         _ctx->ref();
     }
-    return (_ctx->connect(addr, port)) ? 1 : 0;
+    begunIp_ = ip;
+    begunPort_= port;
+    return 1;
 }
 
 int WiFiUDP::beginPacketMulticast(IPAddress multicastAddress, uint16_t port, 
@@ -167,8 +166,9 @@ int WiFiUDP::endPacket()
     if (!_ctx)
         return 0;
 
-    _ctx->send();
-    _ctx->disconnect();
+    ip_addr_t addr;
+    addr.addr = begunIp_;
+    _ctx->send(&addr, begunPort_);
     return 1;
 }
 

hardware/esp8266com/esp8266/libraries/ESP8266WiFi/src/WiFiUdp.h

@@ -31,6 +31,8 @@ class UdpContext;
 class WiFiUDP : public UDP {
 private:
   UdpContext* _ctx;
+  IPAddress begunIp_;
+  uint16_t begunPort_;
 
 public:
   WiFiUDP();  // Constructor

hardware/esp8266com/esp8266/libraries/ESP8266WiFi/src/include/UdpContext.h

@@ -281,7 +281,7 @@ class UdpContext
 
     void _reserve(size_t size)
     {
-        const size_t pbuf_unit_size = 1024;
+        const size_t pbuf_unit_size = 512;
         if (!_tx_buf_head)
         {
             _tx_buf_head = pbuf_alloc(PBUF_TRANSPORT, pbuf_unit_size, PBUF_RAM);