libreplace: poll based on select

1 files changed, 133 insertions, 0 deletions

diff --git a/lib/replace/poll.c b/lib/replace/poll.c
new file mode 100644
index 0000000000..e41548dd39
--- /dev/null
+++ b/lib/replace/poll.c
@@ -0,0 +1,133 @@
+/*
+   Unix SMB/CIFS implementation.
+   poll.c - poll wrapper
+
+   This file is based on code from libssh (LGPLv2.1+ at the time it
+   was downloaded), thus the following copyrights:
+
+   Copyright (c) 2009-2010 by Andreas Schneider <mail@cynapses.org>
+   Copyright (c) 2003-2009 by Aris Adamantiadis
+   Copyright (c) 2009 Aleksandar Kanchev
+   Copyright (C) Volker Lendecke 2011
+
+     ** NOTE! The following LGPL license applies to the replace
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+
+   This library 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 3 of the License, or (at your option) any later version.
+
+   This library 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 this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "replace.h"
+#include "system/select.h"
+
+
+int rep_poll(struct pollfd *fds, nfds_t nfds, int timeout)
+{
+	fd_set rfds, wfds, efds;
+	struct timeval tv, *ptv;
+	int max_fd;
+	int rc;
+	nfds_t i;
+
+	if (fds == NULL) {
+		errno = EFAULT;
+		return -1;
+	}
+
+	FD_ZERO(&rfds);
+	FD_ZERO(&wfds);
+	FD_ZERO(&efds);
+
+	rc = 0;
+	max_fd = 0;
+
+	/* compute fd_sets and find largest descriptor */
+	for (i = 0; i < nfds; i++) {
+		if ((fds[i].fd < 0) || (fds[i].fd >= FD_SETSIZE)) {
+			fds[i].revents = POLLNVAL;
+			continue;
+		}
+
+		if (fds[i].events & (POLLIN | POLLRDNORM)) {
+			FD_SET(fds[i].fd, &rfds);
+		}
+		if (fds[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND)) {
+			FD_SET(fds[i].fd, &wfds);
+		}
+		if (fds[i].events & (POLLPRI | POLLRDBAND)) {
+			FD_SET(fds[i].fd, &efds);
+		}
+		if (fds[i].fd > max_fd &&
+		    (fds[i].events & (POLLIN | POLLOUT | POLLPRI |
+				      POLLRDNORM | POLLRDBAND |
+				      POLLWRNORM | POLLWRBAND))) {
+			max_fd = fds[i].fd;
+		}
+	}
+
+	if (timeout < 0) {
+		ptv = NULL;
+	} else {
+		ptv = &tv;
+		if (timeout == 0) {
+			tv.tv_sec = 0;
+			tv.tv_usec = 0;
+		} else {
+			tv.tv_sec = timeout / 1000;
+			tv.tv_usec = (timeout % 1000) * 1000;
+		}
+	}
+
+	rc = select(max_fd + 1, &rfds, &wfds, &efds, ptv);
+	if (rc < 0) {
+		return -1;
+	}
+
+	for (rc = 0, i = 0; i < nfds; i++) {
+		if ((fds[i].fd < 0) || (fds[i].fd >= FD_SETSIZE)) {
+			continue;
+		}
+
+		fds[i].revents = 0;
+
+		if (FD_ISSET(fds[i].fd, &rfds)) {
+			int err = errno;
+			int available = 0;
+			int ret;
+
+			/* support for POLLHUP */
+			ret = ioctl(fds[i].fd, FIONREAD, &available);
+			if ((ret == -1) || (available == 0)) {
+				fds[i].revents |= POLLHUP;
+			} else {
+				fds[i].revents |= fds[i].events
+					& (POLLIN | POLLRDNORM);
+			}
+
+			errno = err;
+		}
+		if (FD_ISSET(fds[i].fd, &wfds)) {
+			fds[i].revents |= fds[i].events
+				& (POLLOUT | POLLWRNORM | POLLWRBAND);
+		}
+		if (FD_ISSET(fds[i].fd, &efds)) {
+			fds[i].revents |= fds[i].events
+				& (POLLPRI | POLLRDBAND);
+		}
+		if (fds[i].revents & ~POLLHUP) {
+			rc++;
+		}
+	}
+	return rc;
+}