add locks to PeriodicTask

src/PeriodicTask.cpp

@@ -1,23 +1,25 @@
 #include "PeriodicTask.h"
 #include "Periodic.h"
 
-PeriodicTask::PeriodicTask(uint32_t initialPeriod) : period(initialPeriod)
-{
-}
+PeriodicTask::PeriodicTask(uint32_t initialPeriod) : period(initialPeriod) {}
 
 /// call this from loop
 void PeriodicTask::loop()
 {
-    uint32_t now = millis();
-    if (period && (now - lastMsec) >= period)
     {
+        meshtastic::LockGuard lg(&lock);
+        uint32_t now = millis();
+        if (!period || (now - lastMsec) < period) {
+            return;
+        }
         lastMsec = now;
-        doTask();
     }
+    // Release the lock in case the task wants to change the period.
+    doTask();
 }
 
 void Periodic::doTask()
 {
     uint32_t p = callback();
     setPeriod(p);
-}
+}