Imported Upstream version 16.11

Change-Id: I1944c65ddc88a9ad70f8c0eb6731552b84fbcb77
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>

1 files changed, 299 insertions, 0 deletions

diff --git a/lib/librte_vhost/fd_man.c b/lib/librte_vhost/fd_man.c
new file mode 100644
index 00000000..2d3eeb7d
--- /dev/null
+++ b/lib/librte_vhost/fd_man.c
@@ -0,0 +1,299 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <sys/select.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <rte_common.h>
+#include <rte_log.h>
+
+#include "fd_man.h"
+
+/**
+ * Returns the index in the fdset for a given fd.
+ * If fd is -1, it means to search for a free entry.
+ * @return
+ *   index for the fd, or -1 if fd isn't in the fdset.
+ */
+static int
+fdset_find_fd(struct fdset *pfdset, int fd)
+{
+	int i;
+
+	if (pfdset == NULL)
+		return -1;
+
+	for (i = 0; i < MAX_FDS && pfdset->fd[i].fd != fd; i++)
+		;
+
+	return i ==  MAX_FDS ? -1 : i;
+}
+
+static int
+fdset_find_free_slot(struct fdset *pfdset)
+{
+	return fdset_find_fd(pfdset, -1);
+}
+
+static int
+fdset_add_fd(struct fdset  *pfdset, int idx, int fd,
+	fd_cb rcb, fd_cb wcb, void *dat)
+{
+	struct fdentry *pfdentry;
+
+	if (pfdset == NULL || idx >= MAX_FDS || fd >= FD_SETSIZE)
+		return -1;
+
+	pfdentry = &pfdset->fd[idx];
+	pfdentry->fd = fd;
+	pfdentry->rcb = rcb;
+	pfdentry->wcb = wcb;
+	pfdentry->dat = dat;
+
+	return 0;
+}
+
+/**
+ * Fill the read/write fd_set with the fds in the fdset.
+ * @return
+ *  the maximum fds filled in the read/write fd_set.
+ */
+static int
+fdset_fill(fd_set *rfset, fd_set *wfset, struct fdset *pfdset)
+{
+	struct fdentry *pfdentry;
+	int i, maxfds = -1;
+	int num = MAX_FDS;
+
+	if (pfdset == NULL)
+		return -1;
+
+	for (i = 0; i < num; i++) {
+		pfdentry = &pfdset->fd[i];
+		if (pfdentry->fd != -1) {
+			int added = 0;
+			if (pfdentry->rcb && rfset) {
+				FD_SET(pfdentry->fd, rfset);
+				added = 1;
+			}
+			if (pfdentry->wcb && wfset) {
+				FD_SET(pfdentry->fd, wfset);
+				added = 1;
+			}
+			if (added)
+				maxfds = pfdentry->fd < maxfds ?
+					maxfds : pfdentry->fd;
+		}
+	}
+	return maxfds;
+}
+
+void
+fdset_init(struct fdset *pfdset)
+{
+	int i;
+
+	if (pfdset == NULL)
+		return;
+
+	for (i = 0; i < MAX_FDS; i++) {
+		pfdset->fd[i].fd = -1;
+		pfdset->fd[i].dat = NULL;
+	}
+	pfdset->num = 0;
+}
+
+/**
+ * Register the fd in the fdset with read/write handler and context.
+ */
+int
+fdset_add(struct fdset *pfdset, int fd, fd_cb rcb, fd_cb wcb, void *dat)
+{
+	int i;
+
+	if (pfdset == NULL || fd == -1)
+		return -1;
+
+	pthread_mutex_lock(&pfdset->fd_mutex);
+
+	/* Find a free slot in the list. */
+	i = fdset_find_free_slot(pfdset);
+	if (i == -1 || fdset_add_fd(pfdset, i, fd, rcb, wcb, dat) < 0) {
+		pthread_mutex_unlock(&pfdset->fd_mutex);
+		return -2;
+	}
+
+	pfdset->num++;
+
+	pthread_mutex_unlock(&pfdset->fd_mutex);
+
+	return 0;
+}
+
+/**
+ *  Unregister the fd from the fdset.
+ *  Returns context of a given fd or NULL.
+ */
+void *
+fdset_del(struct fdset *pfdset, int fd)
+{
+	int i;
+	void *dat = NULL;
+
+	if (pfdset == NULL || fd == -1)
+		return NULL;
+
+	do {
+		pthread_mutex_lock(&pfdset->fd_mutex);
+
+		i = fdset_find_fd(pfdset, fd);
+		if (i != -1 && pfdset->fd[i].busy == 0) {
+			/* busy indicates r/wcb is executing! */
+			dat = pfdset->fd[i].dat;
+			pfdset->fd[i].fd = -1;
+			pfdset->fd[i].rcb = pfdset->fd[i].wcb = NULL;
+			pfdset->fd[i].dat = NULL;
+			pfdset->num--;
+			i = -1;
+		}
+		pthread_mutex_unlock(&pfdset->fd_mutex);
+	} while (i != -1);
+
+	return dat;
+}
+
+/**
+ *  Unregister the fd at the specified slot from the fdset.
+ */
+static void
+fdset_del_slot(struct fdset *pfdset, int index)
+{
+	if (pfdset == NULL || index < 0 || index >= MAX_FDS)
+		return;
+
+	pthread_mutex_lock(&pfdset->fd_mutex);
+
+	pfdset->fd[index].fd = -1;
+	pfdset->fd[index].rcb = pfdset->fd[index].wcb = NULL;
+	pfdset->fd[index].dat = NULL;
+	pfdset->num--;
+
+	pthread_mutex_unlock(&pfdset->fd_mutex);
+}
+
+/**
+ * This functions runs in infinite blocking loop until there is no fd in
+ * pfdset. It calls corresponding r/w handler if there is event on the fd.
+ *
+ * Before the callback is called, we set the flag to busy status; If other
+ * thread(now rte_vhost_driver_unregister) calls fdset_del concurrently, it
+ * will wait until the flag is reset to zero(which indicates the callback is
+ * finished), then it could free the context after fdset_del.
+ */
+void
+fdset_event_dispatch(struct fdset *pfdset)
+{
+	fd_set rfds, wfds;
+	int i, maxfds;
+	struct fdentry *pfdentry;
+	int num = MAX_FDS;
+	fd_cb rcb, wcb;
+	void *dat;
+	int fd;
+	int remove1, remove2;
+	int ret;
+
+	if (pfdset == NULL)
+		return;
+
+	while (1) {
+		struct timeval tv;
+		tv.tv_sec = 1;
+		tv.tv_usec = 0;
+		FD_ZERO(&rfds);
+		FD_ZERO(&wfds);
+		pthread_mutex_lock(&pfdset->fd_mutex);
+
+		maxfds = fdset_fill(&rfds, &wfds, pfdset);
+
+		pthread_mutex_unlock(&pfdset->fd_mutex);
+
+		/*
+		 * When select is blocked, other threads might unregister
+		 * listenfds from and register new listenfds into fdset.
+		 * When select returns, the entries for listenfds in the fdset
+		 * might have been updated. It is ok if there is unwanted call
+		 * for new listenfds.
+		 */
+		ret = select(maxfds + 1, &rfds, &wfds, NULL, &tv);
+		if (ret <= 0)
+			continue;
+
+		for (i = 0; i < num; i++) {
+			remove1 = remove2 = 0;
+			pthread_mutex_lock(&pfdset->fd_mutex);
+			pfdentry = &pfdset->fd[i];
+			fd = pfdentry->fd;
+			rcb = pfdentry->rcb;
+			wcb = pfdentry->wcb;
+			dat = pfdentry->dat;
+			pfdentry->busy = 1;
+			pthread_mutex_unlock(&pfdset->fd_mutex);
+			if (fd >= 0 && FD_ISSET(fd, &rfds) && rcb)
+				rcb(fd, dat, &remove1);
+			if (fd >= 0 && FD_ISSET(fd, &wfds) && wcb)
+				wcb(fd, dat, &remove2);
+			pfdentry->busy = 0;
+			/*
+			 * fdset_del needs to check busy flag.
+			 * We don't allow fdset_del to be called in callback
+			 * directly.
+			 */
+			/*
+			 * When we are to clean up the fd from fdset,
+			 * because the fd is closed in the cb,
+			 * the old fd val could be reused by when creates new
+			 * listen fd in another thread, we couldn't call
+			 * fd_set_del.
+			 */
+			if (remove1 || remove2)
+				fdset_del_slot(pfdset, i);
+		}
+	}
+}