Fail WiFiClient::write if send buffer is full and a recv is blocking …

…m2m_wifi_handle_events

src/WiFiClient.cpp

@@ -129,14 +129,13 @@ size_t WiFiClient::write(const uint8_t *buf, size_t size)
 
 	while ((err = send(_socket, (void *)buf, size, 0)) < 0) {
 		// Exit on fatal error, retry if buffer not ready.
-		if (err != SOCK_ERR_BUFFER_FULL) {
+		// or can't wait for send event because a recv is pending
+		if (err != SOCK_ERR_BUFFER_FULL || socketBufferSendWait(_socket) == 0) {
 			setWriteError();
 			m2m_periph_gpio_set_val(M2M_PERIPH_GPIO16, 1);
 			m2m_periph_gpio_set_val(M2M_PERIPH_GPIO5, 1);
 			return 0;
 		}
-
-		socketBufferSendWait(_socket);
 	}
 
 	// Network led OFF (rev A then rev B).

src/socket/include/socket_buffer.h

@@ -77,7 +77,7 @@ sint16 socketBufferDataAvailable(SOCKET sock);
 void socketBufferSetupBuffer(SOCKET sock);
 sint8 socketBufferBindWait(SOCKET sock);
 sint8 socketBufferConnectWait(SOCKET sock);
-void socketBufferSendWait(SOCKET sock);
+sint8 socketBufferSendWait(SOCKET sock);
 void socketBufferReadUdpHeader(SOCKET sock, uint16_t* rcvSize, uint16_t* rcvPort, uint32_t* rcvIP);
 uint8 socketBufferPeek(SOCKET sock);
 sint16 socketBufferRead(SOCKET sock, uint8 *buf, uint16 len);

src/socket/source/socket_buffer.c

@@ -140,13 +140,25 @@ sint8 socketBufferConnectWait(SOCKET sock)
 	return (gastrSocketBuffer[sock].flag & SOCKET_BUFFER_FLAG_CONNECTED) != 0;
 }
 
-void socketBufferSendWait(SOCKET sock)
+sint8 socketBufferSendWait(SOCKET sock)
 {
+	SOCKET s;
+
+	// check if any sockets are full, if so fail because m2m_wifi_handle_events
+	// won't be able to run
+	for (s = 0; s < MAX_SOCKET; s++) {
+		if (socketBufferIsFull(s)) {
+			return 0;
+		}
+	}
+
 	gastrSocketBuffer[sock].flag = SOCKET_BUFFER_FLAG_SENDING;
 
 	while (gastrSocketBuffer[sock].flag & SOCKET_BUFFER_FLAG_SENDING) {
 		m2m_wifi_handle_events(NULL);
 	}
+
+	return 1;
 }
 
 void socketBufferReadUdpHeader(SOCKET sock, uint16_t* rcvSize, uint16_t* rcvPort, uint32_t* rcvIP)