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authorMarc-André Lureau2022-10-06 13:36:52 +0200
committerMarc-André Lureau2022-10-12 17:22:00 +0200
commitc1f798091319c74cd9a90f36af604c782e7ee7bd (patch)
tree62b386f2c9ed9f8f9a22e29c190dc26f7d0df773 /util
parentwin32: set threads name (diff)
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osdep: make readv_writev() work with partial read/write
With a pipe or other reasons, read/write may return less than the requested bytes. This happens with the test-io-channel-command test on Windows. glib spawn code uses a binary pipe of 4096 bytes, and the first read returns that much (although more are requested), for some unclear reason... Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Message-Id: <20221006113657.2656108-2-marcandre.lureau@redhat.com>
Diffstat (limited to 'util')
-rw-r--r--util/osdep.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/util/osdep.c b/util/osdep.c
index 60fcbbaebe..746d5f7d71 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -538,18 +538,22 @@ int socket_init(void)
#ifndef CONFIG_IOVEC
-/* helper function for iov_send_recv() */
static ssize_t
readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
{
unsigned i = 0;
ssize_t ret = 0;
+ ssize_t off = 0;
while (i < iov_cnt) {
ssize_t r = do_write
- ? write(fd, iov[i].iov_base, iov[i].iov_len)
- : read(fd, iov[i].iov_base, iov[i].iov_len);
+ ? write(fd, iov[i].iov_base + off, iov[i].iov_len - off)
+ : read(fd, iov[i].iov_base + off, iov[i].iov_len - off);
if (r > 0) {
ret += r;
+ off += r;
+ if (off < iov[i].iov_len) {
+ continue;
+ }
} else if (!r) {
break;
} else if (errno == EINTR) {
@@ -562,6 +566,7 @@ readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
}
break;
}
+ off = 0;
i++;
}
return ret;