Fix kqueue handling of no timeout

runtime/bin/eventhandler_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/eventhandler.h"
 
 #include <errno.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <string.h>
@@ skipping 326 matching lines @@
 
 
 void EventHandlerImplementation::EventHandlerEntry(uword args) {
   static const intptr_t kMaxEvents = 16;
   struct kevent events[kMaxEvents];
   EventHandlerImplementation* handler =
       reinterpret_cast<EventHandlerImplementation*>(args);
   ASSERT(handler != NULL);
   while (1) {
     intptr_t millis = handler->GetTimeout();
+    // NULL pointer timespec for infinite timeout.
+    ASSERT(kInfinityTimeout < 0);
+    struct timespec* timeout = NULL;
     struct timespec ts;
-    int64_t secs = 0;
-    int64_t nanos = 0;
-    if (millis > 0) {
-      secs = millis / 1000;
-      nanos = (millis - (secs * 1000)) * 1000000;
+    if (millis >= 0) {
+      ts.tv_sec = millis / 1000;
+      ts.tv_nsec = (millis - (ts.tv_sec * 1000)) * 1000000;
+      timeout = &ts;
     }
-    ts.tv_sec = secs;
-    ts.tv_nsec = nanos;
     intptr_t result = TEMP_FAILURE_RETRY(kevent(handler->kqueue_fd_,
                                                 NULL,
                                                 0,
                                                 events,
                                                 kMaxEvents,
-                                                &ts));
+                                                timeout));
     if (result == -1) {
       perror("kevent failed");
       FATAL("kevent failed\n");
     } else {
       handler->HandleTimeout();
       handler->HandleEvents(events, result);
     }
   }
 }
 
@@ skipping 18 matching lines @@
 void* EventHandlerImplementation::GetHashmapKeyFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return reinterpret_cast<void*>(fd + 1);
 }
 
 
 uint32_t EventHandlerImplementation::GetHashmapHashFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return dart::Utils::WordHash(fd + 1);
 }