Don't make timerfd non-blocking and add errno to error-mesage.

runtime/bin/eventhandler_linux.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 "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "bin/eventhandler.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 116 matching lines @@
   struct epoll_event event;
   event.events = EPOLLIN;
   event.data.ptr = NULL;
   int status = TEMP_FAILURE_RETRY(epoll_ctl(epoll_fd_,
                                             EPOLL_CTL_ADD,
                                             interrupt_fds_[0],
                                             &event));
   if (status == -1) {
     FATAL("Failed adding interrupt fd to epoll instance");
   }
-  timer_fd_ = TEMP_FAILURE_RETRY(timerfd_create(CLOCK_REALTIME,
-                                                TFD_NONBLOCK | TFD_CLOEXEC));
+  timer_fd_ = TEMP_FAILURE_RETRY(timerfd_create(CLOCK_REALTIME, TFD_CLOEXEC));
   if (epoll_fd_ == -1) {
     FATAL("Failed creating timerfd file descriptor");
   }
   // Register the timer_fd_ with the epoll instance.
   event.events = EPOLLIN;
   event.data.fd = timer_fd_;
   status = TEMP_FAILURE_RETRY(epoll_ctl(epoll_fd_,
                                         EPOLL_CTL_ADD,
                                         timer_fd_,
                                         &event));
   if (status == -1) {
-    FATAL("Failed adding timerfd fd to epoll instance");
+    FATAL2(
+        "Failed adding timerfd fd(%i) to epoll instance: %i", timer_fd_, errno);
   }
 }
 
 
 EventHandlerImplementation::~EventHandlerImplementation() {
   TEMP_FAILURE_RETRY(close(epoll_fd_));
   TEMP_FAILURE_RETRY(close(timer_fd_));
   TEMP_FAILURE_RETRY(close(interrupt_fds_[0]));
   TEMP_FAILURE_RETRY(close(interrupt_fds_[1]));
 }
@@ skipping 282 matching lines @@
 
 uint32_t EventHandlerImplementation::GetHashmapHashFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return dart::Utils::WordHash(fd + 1);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)