use a scheduled function for settimeofday_cb (#6600)

* use a scheduled function for settimeofday_cb

* per review

* use a generic and clear name for trivial functional variable type name used for callbacks

Author: d-a-v

cores/esp8266/coredecls.h

@@ -17,14 +17,21 @@ extern bool timeshift64_is_set;
 void esp_yield();
 void esp_schedule();
 void tune_timeshift64 (uint64_t now_us);
-void settimeofday_cb (void (*cb)(void));
 void disable_extra4k_at_link_time (void) __attribute__((noinline));
 
 uint32_t sqrt32 (uint32_t n);
 uint32_t crc32 (const void* data, size_t length, uint32_t crc = 0xffffffff);
 
 #ifdef __cplusplus
 }
+
+#include <functional>
+
+using TrivialCB = std::function<void()>;
+
+void settimeofday_cb (TrivialCB&& cb);
+void settimeofday_cb (const TrivialCB& cb);
+
 #endif
 
 #endif // __COREDECLS_H

cores/esp8266/sntp-lwip2.cpp

@@ -42,16 +42,22 @@
 #include <osapi.h>
 #include <os_type.h>
 #include "coredecls.h"
+#include "Schedule.h"
 
-extern "C" {
+static TrivialCB _settimeofday_cb;
 
-static void (*_settimeofday_cb)(void) = NULL;
+void settimeofday_cb (TrivialCB&& cb)
+{
+    _settimeofday_cb = std::move(cb);
+}
 
-void settimeofday_cb (void (*cb)(void))
+void settimeofday_cb (const TrivialCB& cb)
 {
     _settimeofday_cb = cb;
 }
 
+extern "C" {
+
 #if LWIP_VERSION_MAJOR == 1
 
 #include <pgmspace.h>
@@ -478,7 +484,7 @@ int settimeofday(const struct timeval* tv, const struct timezone* tz)
         sntp_set_system_time(tv->tv_sec);
 
         if (_settimeofday_cb)
-            _settimeofday_cb();
+            schedule_function(_settimeofday_cb);
     }
     return 0;
 }

libraries/esp8266/examples/NTP-TZ-DST/NTP-TZ-DST.ino

@@ -152,6 +152,10 @@ void printTm(const char* what, const tm* tm) {
 void time_is_set_scheduled() {
   // everything is allowed in this function
 
+  if (time_machine_days == 0) {
+    time_machine_running = !time_machine_running;
+  }
+
   // time machine demo
   if (time_machine_running) {
     if (time_machine_days == 0)
@@ -178,19 +182,6 @@ void time_is_set_scheduled() {
   }
 }
 
-void time_is_set_callback() {
-  // As in an ISR,
-  // it is not allowed to call "heavy" core API
-  // like yield()/delay()/print()/network/...
-  // If this is needed, use a scheduled function.
-
-  // This scheduled function is used for the demo, it is normaly unneeded
-  schedule_function(time_is_set_scheduled);
-  if (time_machine_days == 0) {
-    time_machine_running = !time_machine_running;
-  }
-}
-
 void setup() {
   Serial.begin(115200);
   Serial.println("\nStarting...\n");
@@ -204,7 +195,7 @@ void setup() {
 
   // install callback - called when settimeofday is called (by SNTP or us)
   // once enabled (by DHCP), SNTP is updated every hour
-  settimeofday_cb(time_is_set_callback);
+  settimeofday_cb(time_is_set_scheduled);
 
   // NTP servers may be overriden by your DHCP server for a more local one
   // (see below)