Replace use of pipe2 with pipe,fcntl

pipe2 is not supported on macos platform

Author: hchataing

model/setup/async_manager.cc

@@ -19,14 +19,14 @@
 #include <algorithm>
 #include <atomic>
 #include <condition_variable>
+#include <fcntl.h>
 #include <mutex>
+#include <sys/select.h>
 #include <thread>
 #include <unistd.h>
 #include <vector>
 
-#include "fcntl.h"
 #include "log.h"
-#include "sys/select.h"
 
 #ifndef TEMP_FAILURE_RETRY
 /* Used to retry syscalls that can return EINTR. */
@@ -167,13 +167,23 @@ class AsyncManager::AsyncFdWatcher {
     }
     // set up the communication channel
     int pipe_fds[2];
-    if (pipe2(pipe_fds, O_NONBLOCK)) {
+    if (pipe(pipe_fds)) {
       ERROR(
           "{}: Unable to establish a communication channel to the reading "
           "thread",
           __func__);
       return -1;
     }
+    // configure the fds as non blocking.
+    if (fcntl(pipe_fds[0], F_SETFL, O_NONBLOCK) ||
+        fcntl(pipe_fds[1], F_SETFL, O_NONBLOCK)) {
+      ERROR(
+          "{}: Unable to configure the communication channel to the reading "
+          "thread",
+          __func__);
+      return -1;
+    }
+
     notification_listen_fd_ = pipe_fds[0];
     notification_write_fd_ = pipe_fds[1];