45     int rc = fcntl(fd, F_SETFL, flags | O_NONBLOCK);  in Open()  local
46     if (rc < 0) {  in Open()
64     int rc = poll(&pfd, 1, timeout_ms);  in WaitForEvent()  local
65     if (rc != 1) {  in WaitForEvent()
83     auto rc = read(metrics_fd_, msg, sizeof(msg));  in HandleEvent()  local
84     if (rc < 0) {  in HandleEvent()
87     size_t msg_len = rc;  in HandleEvent()
90         return Error() << "message too small: " << rc;  in HandleEvent()
99                 return Error() << "message too small: " << rc;  in HandleEvent()
105                 return Error() << "message too small: " << rc;  in HandleEvent()
128     rc = write(metrics_fd_, &resp, sizeof(resp));  in HandleEvent()
129     if (rc < 0) {  in HandleEvent()
133     if (rc != (int)sizeof(resp)) {  in HandleEvent()
134         return Error() << "unexpected number of bytes sent event: " << rc;  in HandleEvent()