From 2258b7bcc265b5fe9bfa79ddd079f57e61557da7 Mon Sep 17 00:00:00 2001 From: Jay Satiro Date: Thu, 5 Mar 2020 23:35:32 -0500 Subject: multi: skip EINTR check on wakeup socket if it was closed - Don't check errno on wakeup socket if sread returned 0 since sread doesn't set errno in that case. This is a follow-up to cf7760a from several days ago which fixed Curl_multi_wait to stop busy looping sread on the non-blocking wakeup socket if it was closed (ie sread returns 0). Due to a logic error it was still possible to busy loop in that case if errno == EINTR. Closes https://github.com/curl/curl/pull/5047 --- lib/multi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/multi.c b/lib/multi.c index cef2805c8..e10e75293 100644 --- a/lib/multi.c +++ b/lib/multi.c @@ -1194,14 +1194,16 @@ static CURLMcode Curl_multi_wait(struct Curl_multi *multi, if(use_wakeup && multi->wakeup_pair[0] != CURL_SOCKET_BAD) { if(ufds[curlfds + extra_nfds].revents & POLLIN) { char buf[64]; + ssize_t nread; while(1) { /* the reading socket is non-blocking, try to read data from it until it receives an error (except EINTR). In normal cases it will get EAGAIN or EWOULDBLOCK when there is no more data, breaking the loop. */ - if(sread(multi->wakeup_pair[0], buf, sizeof(buf)) <= 0) { + nread = sread(multi->wakeup_pair[0], buf, sizeof(buf)); + if(nread <= 0) { #ifndef USE_WINSOCK - if(EINTR == SOCKERRNO) + if(nread < 0 && EINTR == SOCKERRNO) continue; #endif break; -- cgit v1.2.1