[BREAKING] polledTimeout: new remaining() returns time units until (next) expiration

cores/esp8266/PolledTimeout.h

@@ -145,7 +145,6 @@ class timeoutTemplate
   using timeType = typename TimePolicyT::timeType;
   static_assert(std::is_unsigned<timeType>::value == true, "timeType must be unsigned");
 
-  static constexpr timeType alwaysExpired   = 0;
   static constexpr timeType neverExpires    = std::numeric_limits<timeType>::max();
   static constexpr timeType rangeCompensate = TimePolicyT::rangeCompensate; //debug
 
@@ -157,10 +156,10 @@ class timeoutTemplate
   IRAM_ATTR // fast
   bool expired()
   {
-    YieldPolicyT::execute(); //in case of DoNothing: gets optimized away
-    if(PeriodicT)           //in case of false: gets optimized away
-      return expiredRetrigger();
-    return expiredOneShot();
+    bool hasExpired = PeriodicT ? expiredRetrigger() : expiredOneShot();
+    if (!hasExpired) //in case of DoNothing: gets optimized away
+      YieldPolicyT::execute();
+    return hasExpired;
   }
 
   IRAM_ATTR // fast
@@ -176,7 +175,7 @@ class timeoutTemplate
 
   bool canWait () const
   {
-    return _timeout != alwaysExpired;
+    return _timeout != 0;
   }
 
   // Resets, will trigger after this new timeout.
@@ -185,7 +184,7 @@ class timeoutTemplate
   {
     reset();
     _timeout = TimePolicyT::toTimeTypeUnit(newUserTimeout);
-    _neverExpires = (newUserTimeout < 0) || (newUserTimeout > timeMax());
+    _neverExpires = newUserTimeout > timeMax();
   }
 
   // Resets, will trigger after the timeout previously set.
@@ -214,15 +213,31 @@ class timeoutTemplate
 
   void resetToNeverExpires ()
   {
-    _timeout = alwaysExpired + 1; // because canWait() has precedence
+    _timeout = 1; // because canWait() has precedence
     _neverExpires = true;
   }
 
+  void stop()
+  {
+    resetToNeverExpires();
+  }
+
   timeType getTimeout() const
   {
     return TimePolicyT::toUserUnit(_timeout);
   }
 
+  IRAM_ATTR // fast
+  timeType remaining() const
+  {
+    if (_neverExpires)
+      return timeMax();
+    timeType current = TimePolicyT::time();
+    if (checkExpired(current))
+      return TimePolicyT::toUserUnit(0);
+    return TimePolicyT::toUserUnit(_timeout - (current - _start));
+  }
+
   static constexpr timeType timeMax()
   {
     return TimePolicyT::timeMax;
@@ -234,7 +249,7 @@ class timeoutTemplate
   bool checkExpired(const timeType internalUnit) const
   {
     // canWait() is not checked here
-    // returns "can expire" and "time expired"
+    // returns "can expire" and "time has expired"
     return (!_neverExpires) && ((internalUnit - _start) >= _timeout);
   }
 
@@ -249,7 +264,7 @@ class timeoutTemplate
     timeType current = TimePolicyT::time();
     if(checkExpired(current))
     {
-      unsigned long n = (current - _start) / _timeout; //how many _timeouts periods have elapsed, will usually be 1 (current - _start >= _timeout)
+      timeType n = (current - _start) / _timeout; //how many _timeouts periods have elapsed, will usually be 1 (current - _start >= _timeout)
       _start += n  * _timeout;
       return true;
     }

cores/esp8266/Stream.h

@@ -168,7 +168,7 @@ class Stream: public Print {
 
         // transfers already buffered / immediately available data (no timeout)
         // returns number of transfered bytes
-        size_t sendAvailable (Print* to) { return sendGeneric(to, -1, -1, oneShotMs::alwaysExpired); }
+        size_t sendAvailable (Print* to) { return sendGeneric(to, -1, -1, 0); }
         size_t sendAvailable (Print& to) { return sendAvailable(&to); }
 
         // transfers data until timeout