Linux sandbox: add a new low-level broker process mechanism.

base/posix/unix_domain_socket.cc

Index: base/posix/unix_domain_socket.cc
diff --git a/base/posix/unix_domain_socket.cc b/base/posix/unix_domain_socket.cc
index 730657dfcdbc4c5f6c87b31f5a659a2ce32abd5a..5bfcef17fef97a10160cbdf2ef988ac7b8ff8957 100644
--- a/base/posix/unix_domain_socket.cc
+++ b/base/posix/unix_domain_socket.cc
@@ -43,7 +43,14 @@ bool UnixDomainSocket::SendMsg(int fd,
     msg.msg_controllen = cmsg->cmsg_len;
   }
 
-  const ssize_t r = HANDLE_EINTR(sendmsg(fd, &msg, 0));
+  // When available, take advantage of MSG_NOSIGNAL to avoid
+  // a SIGPIPE if the other end breaks the connection.
+#if defined(MSG_NOSIGNAL)
+  const int flags = MSG_NOSIGNAL;
+#else
+  const int flags = 0;
+#endif
+  const ssize_t r = HANDLE_EINTR(sendmsg(fd, &msg, flags));
   const bool ret = static_cast<ssize_t>(length) == r;
   delete[] control_buffer;
   return ret;