[libvirt] [PATCH v4 15/23] utils: Write a maximum of MAX_PIPE_WRITE_BYTES into a pipe

To avoid blocking on a write on a pipe that the receiving process does not read from, write only MAX_PIPE_WRITE_BYTES into the pipe so that we can serve other pipes as well. Signed-off-by: Stefan Berger <stefanb(a)linux.ibm.com&gt; --- src/util/vircommand.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/util/vircommand.c b/src/util/vircommand.c index 49347a9800..3ac51c77a8 100644 --- a/src/util/vircommand.c +++ b/src/util/vircommand.c @@ -86,6 +86,8 @@ struct _virCommandSendBuffer { size_t buflen; off_t offset; }; +/* max. number of bytes we write to pipe to avoid blocking on it */ +#define MAX_PIPE_WRITE_BYTES 1024 struct _virCommand { int has_error; /* ENOMEM on allocation failure, -1 for anything else. */ @@ -2251,7 +2253,7 @@ virCommandProcessIO(virCommandPtr cmd) int done; done = write(cmd->inpipe, cmd->inbuf + inoff, - inlen - inoff); + MIN(inlen - inoff, MAX_PIPE_WRITE_BYTES)); if (done < 0) { if (errno == EPIPE) { VIR_DEBUG("child closed stdin early, ignoring EPIPE " -- 2.20.1