- change pollfibre to try nonblocking poll before blocking

- clerical updates in BaseProcessor

src/libfibre/Poller.cc

@@ -66,12 +66,16 @@ inline void BasePoller::pollLoop(T& This, bool pollerFibre) {
 }
 
 inline int PollerThread::blockingPoll() {
+  int evcnt;
+  for (;;) {
 #if __FreeBSD__
-  int evcnt =  kevent(pollFD, nullptr, 0, events, maxPoll, nullptr); // blocking
+    evcnt =  kevent(pollFD, nullptr, 0, events, maxPoll, nullptr); // blocking
 #else // __linux__ below
-  int evcnt =  epoll_wait(pollFD, events, maxPoll, -1);              // blocking
+    evcnt =  epoll_wait(pollFD, events, maxPoll, -1);              // blocking
 #endif
-  if (evcnt < 0) { GENASSERT1(errno == EINTR, errno); } // gracefully handle EINTR
+    if (evcnt > 0) break;
+    if (evcnt < 0) { GENASSERT1(errno == EINTR, errno); } // gracefully handle EINTR
+  }
   if (paused) pauseSem.P();
   return evcnt;
 }
@@ -116,14 +120,18 @@ void Poller::stop() {
 }
 
 inline int Poller::blockingPoll() {
-  _lfEventEngine->blockPollFD(pollFD);
+  int evcnt;
+  for (;;) {
 #if __FreeBSD__
-  static const timespec ts = Time::zero();
-  int evcnt = kevent(pollFD, nullptr, 0, events, maxPoll, &ts);
+    static const timespec ts = Time::zero();
+    evcnt = kevent(pollFD, nullptr, 0, events, maxPoll, &ts);
 #else // __linux__ below
-  int evcnt =  epoll_wait(pollFD, events, maxPoll, 0);
+    evcnt =  epoll_wait(pollFD, events, maxPoll, 0);
 #endif
-  if (evcnt < 0) { GENASSERT1(errno == EINTR, errno); } // gracefully handle EINTR
+    if (evcnt > 0) break;
+    if (evcnt < 0) { GENASSERT1(errno == EINTR, errno); } // gracefully handle EINTR
+    _lfEventEngine->blockPollFD(pollFD);
+  }
   if (paused) pauseSem.P();
   return evcnt;
 }

src/runtime/BaseProcessor.cc

@@ -44,11 +44,13 @@ bool BaseProcessor::findWork() {
 #endif
   for (size_t spin = 0; spin < spinMax; spin += 1) {
     if (StackContext::idleYield(_friend<BaseProcessor>())) return true;
+    if (terminate) return true;
+    Pause();
   }
   return false;
 }
 
-inline bool BaseProcessor::tryDequeue(StackContext*& s) {
+inline bool BaseProcessor::tryLocal(StackContext*& s) {
 #if TESTING_WORK_STEALING
   s = readyQueue.dequeueSafe();
 #else
@@ -100,7 +102,7 @@ inline bool BaseProcessor::tryBorrow(StackContext*& s) {
 
 StackContext* BaseProcessor::schedule(_friend<StackContext>) {
   StackContext* nextStack;
-  if (tryDequeue(nextStack)) return nextStack;
+  if (tryLocal(nextStack)) return nextStack;
   if (terminate) return idleStack;
 #if TESTING_POLLER_FIBRES
   if (tryBorrow(nextStack)) return nextStack;

src/runtime/BaseProcessor.h

@@ -192,7 +192,7 @@ typedef IntrusiveList<BaseProcessor,0,1> ProcessorList;
 #endif
 
 class BaseProcessor : public ProcessorList::Link, public VirtualProcessor {
-  inline bool tryDequeue(StackContext*& s);
+  inline bool tryLocal(StackContext*& s);
   inline bool tryStage(StackContext*& s);
   inline bool trySteal(StackContext*& s);
   inline bool tryBorrow(StackContext*& s);