From 37dbf4d8ec8e9281c19dab077e215634ee4e857c Mon Sep 17 00:00:00 2001
From: Blaz Kristan <blaz@kristan-sp.si>
Date: Sat, 18 Dec 2021 10:25:58 +0100
Subject: [PATCH] Prevent memory exceptions using WS.

---
 wled00/const.h |  4 ++--
 wled00/ws.cpp  | 13 +++++++++----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/wled00/const.h b/wled00/const.h
index 51c3d496a..902521ae5 100644
--- a/wled00/const.h
+++ b/wled00/const.h
@@ -302,9 +302,9 @@
 #endif
 
 #ifdef WLED_USE_DYNAMIC_JSON
-  #define MIN_HEAP_SIZE JSON_BUFFER_SIZE+512
+  #define MIN_HEAP_SIZE (JSON_BUFFER_SIZE+512)
 #else
-  #define MIN_HEAP_SIZE 4096
+  #define MIN_HEAP_SIZE (MAX_LED_MEMORY+2048)
 #endif
 
 // Maximum size of node map (list of other WLED instances)
diff --git a/wled00/ws.cpp b/wled00/ws.cpp
index 0cb9d5392..1d4e524f1 100644
--- a/wled00/ws.cpp
+++ b/wled00/ws.cpp
@@ -117,8 +117,10 @@ void sendDataWs(AsyncWebSocketClient * client)
     serializeInfo(info);
     DEBUG_PRINTF("JSON buffer size: %u for WS request.\n", doc.memoryUsage());
     size_t len = measureJson(doc);
-    buffer = ws.makeBuffer(len);
-    if (!buffer) {
+    size_t heap1 = ESP.getFreeHeap();
+    buffer = ws.makeBuffer(len); // will not allocate correct memory sometimes
+    size_t heap2 = ESP.getFreeHeap();
+    if (!buffer || heap1-heap2<len) {
       releaseJSONBufferLock();
       return; //out of memory
     }
@@ -139,10 +141,13 @@ void handleWs()
 {
   if (millis() - wsLastLiveTime > WS_LIVE_INTERVAL)
   {
+    #ifdef ESP8266
+    ws.cleanupClients(2);
+    #else
     ws.cleanupClients();
+    #endif
     bool success = true;
-    if (wsLiveClientId)
-      success = serveLiveLeds(nullptr, wsLiveClientId);
+    if (wsLiveClientId) success = serveLiveLeds(nullptr, wsLiveClientId);
     wsLastLiveTime = millis();
     if (!success) wsLastLiveTime -= 20; //try again in 20ms if failed due to non-empty WS queue
   }