SystemLayerImplSelect: consistently use #if/#elif for DISPATCH vs LIBEV

- as discussed in #22043 - also add conditional definition for `ev_io_modify()` required for older libev versions (taken from current libev source, blown up to multiline by clang-format)
project-chip · Aug 29, 2022 · 5d66185 · 5d66185
1 parent 6a0d64c
commit 5d66185
Showing 1 changed file with 21 additions and 9 deletions.
diff --git a/src/system/SystemLayerImplSelect.cpp b/src/system/SystemLayerImplSelect.cpp
@@ -35,6 +35,17 @@
 #define PTHREAD_NULL 0
 #endif // CHIP_SYSTEM_CONFIG_POSIX_LOCKING && !defined(PTHREAD_NULL)
 
+#if CHIP_SYSTEM_CONFIG_USE_LIBEV
+// older libev do not yet have ev_io_modify
+#ifndef ev_io_modify
+#define ev_io_modify(ev, events_)                                                                                                  \
+    do                                                                                                                             \
+    {                                                                                                                              \
+        (ev)->events = ((ev)->events & EV__IOFDSET) | (events_);                                                                   \
+    } while (0)
+#endif // ev_io_modify
+#endif // CHIP_SYSTEM_CONFIG_USE_LIBEV
+
 namespace chip {
 namespace System {
 
@@ -169,8 +180,7 @@ CHIP_ERROR LayerImplSelect::StartTimer(Clock::Timeout delay, TimerCompleteCallba
         dispatch_resume(timerSource);
         return CHIP_NO_ERROR;
     }
-#endif // CHIP_SYSTEM_CONFIG_USE_DISPATCH
-#if CHIP_SYSTEM_CONFIG_USE_LIBEV
+#elif CHIP_SYSTEM_CONFIG_USE_LIBEV
     if (mLibEvLoopP == nullptr)
     {
         chipDie();
@@ -189,7 +199,7 @@ CHIP_ERROR LayerImplSelect::StartTimer(Clock::Timeout delay, TimerCompleteCallba
         Signal();
     }
     return CHIP_NO_ERROR;
-#endif // !CHIP_SYSTEM_CONFIG_USE_LIBEV
+#endif // CHIP_SYSTEM_CONFIG_USE_DISPATCH/LIBEV
 }
 
 void LayerImplSelect::CancelTimer(TimerCompleteCallback onComplete, void * appState)
@@ -230,11 +240,12 @@ CHIP_ERROR LayerImplSelect::ScheduleWork(TimerCompleteCallback onComplete, void
         });
         return CHIP_NO_ERROR;
     }
-#endif // CHIP_SYSTEM_CONFIG_USE_DISPATCH
-#if CHIP_SYSTEM_CONFIG_USE_LIBEV
+#elif CHIP_SYSTEM_CONFIG_USE_LIBEV
     // just a timer with no delay
     return StartTimer(Clock::Timeout(0), onComplete, appState);
-#else
+#endif // CHIP_SYSTEM_CONFIG_USE_DISPATCH/LIBEV
+#if !CHIP_SYSTEM_CONFIG_USE_LIBEV
+    // Note: DISPATCH needs this code as a fallback, LIBEV does not
     CancelTimer(onComplete, appState);
 
     TimerList::Node * timer = mTimerPool.Create(*this, SystemClock().GetMonotonicTimestamp(), onComplete, appState);
@@ -587,14 +598,14 @@ void LayerImplSelect::HandleEvents()
 }
 
 #if CHIP_SYSTEM_CONFIG_USE_DISPATCH
+
 void LayerImplSelect::HandleTimerComplete(TimerList::Node * timer)
 {
     mTimerList.Remove(timer);
     mTimerPool.Invoke(timer);
 }
-#endif
+#elif CHIP_SYSTEM_CONFIG_USE_LIBEV
 
-#if CHIP_SYSTEM_CONFIG_USE_LIBEV
 void LayerImplSelect::HandleLibEvTimer(EV_P_ struct ev_timer * t, int revents)
 {
     TimerList::Node * timer = static_cast<TimerList::Node *>(t->data);
@@ -625,7 +636,8 @@ void LayerImplSelect::HandleLibEvIoWatcher(EV_P_ struct ev_io * i, int revents)
         }
     }
 }
-#endif // CHIP_SYSTEM_CONFIG_USE_LIBEV
+
+#endif // CHIP_SYSTEM_CONFIG_USE_DISPATCH/LIBEV
 
 void LayerImplSelect::SocketWatch::Clear()
 {