From 6524068ff3252f1373807f1ebfde21408cef624e Mon Sep 17 00:00:00 2001 From: Bram Moolenaar Date: Sun, 10 Feb 2019 22:23:26 +0100 Subject: patch 8.1.0889: MS-Windows: a channel write may hang Problem: MS-Windows: a channel write may hang. Solution: Check for WriteFile() not writing anything. (Yasuhiro Matsumoto, closes #3920) --- src/channel.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'src/channel.c') diff --git a/src/channel.c b/src/channel.c index 34a1fc3e0..d728c77d9 100644 --- a/src/channel.c +++ b/src/channel.c @@ -91,9 +91,10 @@ fd_write(sock_T fd, char *buf, size_t len) size = MAX_NAMED_PIPE_SIZE; else size = (DWORD)todo; - // If the pipe overflows while the job does not read the data, WriteFile - // will block forever. This abandons the write. + // If the pipe overflows while the job does not read the data, + // WriteFile() will block forever. This abandons the write. memset(&ov, 0, sizeof(ov)); + nwrite = 0; if (!WriteFile(h, buf + done, size, &nwrite, &ov)) { DWORD err = GetLastError(); @@ -104,6 +105,10 @@ fd_write(sock_T fd, char *buf, size_t len) return -1; FlushFileBuffers(h); } + else if (nwrite == 0) + // WriteFile() returns TRUE but did not write anything. This causes + // a hang, so bail out. + break; todo -= nwrite; done += nwrite; } -- cgit v1.2.1