From 73bacdd32c66016b2e1fe5f9eee9840363da867c Mon Sep 17 00:00:00 2001
From: Ivan Grokhotkov <igrokhotkov@gmail.com>
Date: Wed, 7 Jan 2015 01:57:41 +0300
Subject: [PATCH] Automatically call yield() in WiFiClient::available if called
 more than once

---
 .../esp8266/cores/esp8266/core_esp8266_main.cpp     |  8 ++++++++
 .../libraries/ESP8266WiFi/src/WiFiClient.cpp        | 13 +++++++++++--
 .../esp8266/libraries/ESP8266WiFi/src/WiFiClient.h  |  2 ++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/hardware/arduino/esp8266/cores/esp8266/core_esp8266_main.cpp b/hardware/arduino/esp8266/cores/esp8266/core_esp8266_main.cpp
index d4f50e431..55d60fa60 100644
--- a/hardware/arduino/esp8266/cores/esp8266/core_esp8266_main.cpp
+++ b/hardware/arduino/esp8266/cores/esp8266/core_esp8266_main.cpp
@@ -49,6 +49,13 @@ extern void (*__init_array_end)(void);
 static cont_t g_cont;
 static os_event_t g_loop_queue[LOOP_QUEUE_SIZE];
 
+static uint32_t g_micros_at_task_start;
+
+extern "C" uint32_t esp_micros_at_task_start()
+{
+    return g_micros_at_task_start;
+}
+
 extern "C" void abort()
 {
     while(1){}
@@ -86,6 +93,7 @@ static void loop_wrapper()
 
 static void loop_task(os_event_t *events)
 {
+    g_micros_at_task_start = system_get_time();
     cont_run(&g_cont, &loop_wrapper);
     if (cont_check(&g_cont) != 0)
     {
diff --git a/hardware/arduino/esp8266/libraries/ESP8266WiFi/src/WiFiClient.cpp b/hardware/arduino/esp8266/libraries/ESP8266WiFi/src/WiFiClient.cpp
index 9ea2d7728..63acbccfd 100644
--- a/hardware/arduino/esp8266/libraries/ESP8266WiFi/src/WiFiClient.cpp
+++ b/hardware/arduino/esp8266/libraries/ESP8266WiFi/src/WiFiClient.cpp
@@ -46,7 +46,8 @@ extern "C"
  static int g_localPort = MIN_LOCAL_PORT;
 
 ICACHE_FLASH_ATTR WiFiClient::WiFiClient() 
-: _client(0) 
+: _client(0)
+, _lastPollTime(0)
 {
 }
 
@@ -153,12 +154,20 @@ size_t ICACHE_FLASH_ATTR WiFiClient::write(const uint8_t *buf, size_t size)
     return _client->write(reinterpret_cast<const char*>(buf), size);
 }
 
+extern "C" uint32_t esp_micros_at_task_start();
+
 int ICACHE_FLASH_ATTR WiFiClient::available()
 {
     if (!_client)
         return 0;
 
-    return _client->getSize();
+    if (_lastPollTime > esp_micros_at_task_start())
+        yield();
+
+    _lastPollTime = micros();
+
+    int result = _client->getSize();
+    return result;
 }
 
 int ICACHE_FLASH_ATTR WiFiClient::read() 
diff --git a/hardware/arduino/esp8266/libraries/ESP8266WiFi/src/WiFiClient.h b/hardware/arduino/esp8266/libraries/ESP8266WiFi/src/WiFiClient.h
index ecc31f3bc..8994e710a 100644
--- a/hardware/arduino/esp8266/libraries/ESP8266WiFi/src/WiFiClient.h
+++ b/hardware/arduino/esp8266/libraries/ESP8266WiFi/src/WiFiClient.h
@@ -66,6 +66,8 @@ private:
   void _err(int8_t err);
 
   ClientContext* _client;
+  uint32_t _lastPollTime;
+  
 };
 
 #endif