From 7d3621dae45e5657651997e768d37ffb0b525024 Mon Sep 17 00:00:00 2001
From: Veijo Pesonen <veijo.pesonen@arm.com>
Date: Tue, 18 Dec 2018 12:33:22 +0200
Subject: [PATCH] ESP8266: reduces SIGIO signaled to the upper layers

---
 .../wifi/esp8266-driver/ESP8266Interface.cpp  | 28 +++++++++++++------
 .../wifi/esp8266-driver/ESP8266Interface.h    |  2 ++
 2 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/components/wifi/esp8266-driver/ESP8266Interface.cpp b/components/wifi/esp8266-driver/ESP8266Interface.cpp
index eea53d71a4..48644a40c8 100644
--- a/components/wifi/esp8266-driver/ESP8266Interface.cpp
+++ b/components/wifi/esp8266-driver/ESP8266Interface.cpp
@@ -28,7 +28,6 @@
 #include "platform/Callback.h"
 #include "platform/mbed_debug.h"
 #include "platform/mbed_wait_api.h"
-#include "Kernel.h"
 
 #ifndef MBED_CONF_ESP8266_DEBUG
 #define MBED_CONF_ESP8266_DEBUG false
@@ -495,6 +494,10 @@ int ESP8266Interface::socket_close(void *handle)
         err = NSAPI_ERROR_DEVICE_ERROR;
     }
 
+    _cbs[socket->id].callback = NULL;
+    _cbs[socket->id].data = NULL;
+    _cbs[socket->id].deferred = false;
+
     socket->connected = false;
     _sock_i[socket->id].open = false;
     _sock_i[socket->id].sport = 0;
@@ -573,15 +576,12 @@ int ESP8266Interface::socket_send(void *handle, const void *data, unsigned size)
         return socket->proto == NSAPI_TCP ? 0 : NSAPI_ERROR_UNSUPPORTED;
     }
 
-    unsigned long int sendStartTime = rtos::Kernel::get_ms_count();
-    do {
-        status = _esp.send(socket->id, data, size);
-    } while ((sendStartTime - rtos::Kernel::get_ms_count() < 50)
-            && (status != NSAPI_ERROR_OK));
+    status = _esp.send(socket->id, data, size);
 
-    if (status == NSAPI_ERROR_WOULD_BLOCK && socket->proto == NSAPI_TCP) {
-        tr_debug("ESP8266Interface::socket_send(): enqueuing the event call");
-        _global_event_queue->call_in(100, callback(this, &ESP8266Interface::event));
+    if (status == NSAPI_ERROR_WOULD_BLOCK && !_cbs[socket->id].deferred && socket->proto == NSAPI_TCP) {
+        tr_debug("Postponing SIGIO from the device");
+        _cbs[socket->id].deferred = true;
+        _global_event_queue->call_in(50, callback(this, &ESP8266Interface::event_deferred));
     } else if (status == NSAPI_ERROR_WOULD_BLOCK && socket->proto == NSAPI_UDP) {
         status = NSAPI_ERROR_DEVICE_ERROR;
     }
@@ -731,6 +731,16 @@ void ESP8266Interface::event()
     }
 }
 
+void ESP8266Interface::event_deferred()
+{
+    for (int i = 0; i < ESP8266_SOCKET_COUNT; i++) {
+        if (_cbs[i].deferred && _cbs[i].callback) {
+            _cbs[i].deferred = false;
+            _cbs[i].callback(_cbs[i].data);
+        }
+    }
+}
+
 void ESP8266Interface::attach(Callback<void(nsapi_event_t, intptr_t)> status_cb)
 {
     _conn_stat_cb = status_cb;
diff --git a/components/wifi/esp8266-driver/ESP8266Interface.h b/components/wifi/esp8266-driver/ESP8266Interface.h
index f123cf27cd..580d358158 100644
--- a/components/wifi/esp8266-driver/ESP8266Interface.h
+++ b/components/wifi/esp8266-driver/ESP8266Interface.h
@@ -373,8 +373,10 @@ private:
     struct {
         void (*callback)(void *);
         void *data;
+        bool deferred;
     } _cbs[ESP8266_SOCKET_COUNT];
     void event();
+    void event_deferred();
 
     // Connection state reporting to application
     nsapi_connection_status_t _conn_stat;