From b94ea923b0b095a5c985cbf8ad45a5ccef3cda94 Mon Sep 17 00:00:00 2001
From: david gauchard <gauchard@laas.fr>
Date: Wed, 26 Jun 2019 15:18:07 +0200
Subject: [PATCH] scheduled function: replacing new by malloc needs to
 initialize complex members (#6233)

* scheduled function: replacing new by malloc needs to initialize complex members

Functional was not initialized because of malloc() instead of new.
First assignment calls destructor on initial value which was not constructed (->frozen,wdt).
---
 cores/esp8266/Schedule.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/cores/esp8266/Schedule.cpp b/cores/esp8266/Schedule.cpp
index 33c3b16e3..f8d7b6791 100644
--- a/cores/esp8266/Schedule.cpp
+++ b/cores/esp8266/Schedule.cpp
@@ -41,14 +41,18 @@ static scheduled_fn_t* get_fn_unsafe ()
     {
         result = sUnused;
         sUnused = sUnused->mNext;
-        result->mNext = nullptr;
     }
     // if no unused items, and count not too high, allocate a new one
     else if (sCount < SCHEDULED_FN_MAX_COUNT)
     {
+        // calling malloc instead of new to avoid exception raising while in ISR
+        // construct complex members in place (never raises exceptions)
         result = (scheduled_fn_t*)malloc(sizeof(scheduled_fn_t));
         if (result)
+        {
+            new (&result->mFunc) decltype(result->mFunc)();
             ++sCount;
+        }
     }
     return result;
 }
@@ -70,6 +74,7 @@ bool schedule_function (const std::function<void(void)>& fn)
         return false;
 
     item->mFunc = fn;
+    item->mNext = nullptr;
 
     if (sFirst)
         sLast->mNext = item;