Reland "Open MessagePumpLibevent's pipe with O_CLOEXEC"

base/files/file_util_posix.cc

Index: base/files/file_util_posix.cc
diff --git a/base/files/file_util_posix.cc b/base/files/file_util_posix.cc
index 42de9316f1c9b02aa803feb8113c6a03d958e5c7..a8db2599c642ff920e87533f0bcb6566a7253168 100644
--- a/base/files/file_util_posix.cc
+++ b/base/files/file_util_posix.cc
@@ -351,6 +351,29 @@ bool CopyDirectory(const FilePath& from_path,
 }
 #endif  // !defined(OS_NACL_NONSFI)
 
+bool CreateLocalNonBlockingPipe(int fds[2]) {
+#if defined(OS_LINUX)
+  return pipe2(fds, O_CLOEXEC | O_NONBLOCK) == 0;
+#else
+  int raw_fds[2];
+  if (pipe(raw_fds) != 0)
+    return false;
+  ScopedFD fd_out(raw_fds[0]);
+  ScopedFD fd_in(raw_fds[1]);
+  if (!SetCloseOnExec(fd_out.get()))
+    return false;
+  if (!SetCloseOnExec(fd_in.get()))
+    return false;
+  if (!SetNonBlocking(fd_out.get()))
+    return false;
+  if (!SetNonBlocking(fd_in.get()))
+    return false;
+  fds[0] = fd_out.release();
+  fds[1] = fd_in.release();
+  return true;
+#endif
+}
+
 bool SetNonBlocking(int fd) {
   const int flags = fcntl(fd, F_GETFL);
   if (flags == -1)
@@ -362,6 +385,21 @@ bool SetNonBlocking(int fd) {
   return true;
 }
 
+bool SetCloseOnExec(int fd) {
+#if defined(OS_NACL_NONSFI)
+  const int flags = 0;
+#else
+  const int flags = fcntl(fd, F_GETFD);
+  if (flags == -1)
+    return false;
+  if (flags & FD_CLOEXEC)
+    return true;
+#endif  // defined(OS_NACL_NONSFI)
+  if (HANDLE_EINTR(fcntl(fd, F_SETFD, flags | FD_CLOEXEC)) == -1)
+    return false;
+  return true;
+}
+
 bool PathExists(const FilePath& path) {
   ThreadRestrictions::AssertIOAllowed();
 #if defined(OS_ANDROID)