-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
+/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+#include <errno.h>
+#include <limits.h>
#include <poll.h>
+#include <stdio.h>
+#include <time.h>
#include <unistd.h>
#include "io-util.h"
+#include "time-util.h"
int flush_fd(int fd) {
struct pollfd pollfd = {
.fd = fd,
.events = POLLIN,
};
+ int count = 0;
+
+ /* Read from the specified file descriptor, until POLLIN is not set anymore, throwing away everything
+ * read. Note that some file descriptors (notable IP sockets) will trigger POLLIN even when no data can be read
+ * (due to IP packet checksum mismatches), hence this function is only safe to be non-blocking if the fd used
+ * was set to non-blocking too. */
for (;;) {
char buf[LINE_MAX];
return -errno;
} else if (r == 0)
- return 0;
+ return count;
l = read(fd, buf, sizeof(buf));
if (l < 0) {
continue;
if (errno == EAGAIN)
- return 0;
+ return count;
return -errno;
} else if (l == 0)
- return 0;
+ return count;
+
+ count += (int) l;
}
}
assert(fd >= 0);
assert(buf);
- if (nbytes > (size_t) SSIZE_MAX)
+ if (_unlikely_(nbytes > (size_t) SSIZE_MAX))
return -EINVAL;
do {
r = ppoll(&pollfd, 1, t == USEC_INFINITY ? NULL : timespec_store(&ts, t), NULL);
if (r < 0)
return -errno;
-
if (r == 0)
return 0;
} else if (n > 0)
q += n;
else
- q ++;
+ q++;
}
if (q > w) {