1 files changed, 300 insertions, 0 deletions
diff --git a/src/spdk/lib/rte_vhost/fd_man.c b/src/spdk/lib/rte_vhost/fd_man.c
new file mode 100644
index 000000000..2ceacc9ab
--- /dev/null
+++ b/src/spdk/lib/rte_vhost/fd_man.c
@@ -0,0 +1,300 @@
+/*-
+ *   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/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <rte_common.h>
+#include <rte_log.h>
+
+#include "fd_man.h"
+
+#define FDPOLLERR (POLLERR | POLLHUP | POLLNVAL)
+
+static int
+get_last_valid_idx(struct fdset *pfdset, int last_valid_idx)
+{
+	int i;
+
+	for (i = last_valid_idx; i >= 0 && pfdset->fd[i].fd == -1; i--)
+		;
+
+	return i;
+}
+
+static void
+fdset_move(struct fdset *pfdset, int dst, int src)
+{
+	pfdset->fd[dst]    = pfdset->fd[src];
+	pfdset->rwfds[dst] = pfdset->rwfds[src];
+}
+
+static void
+fdset_shrink_nolock(struct fdset *pfdset)
+{
+	int i;
+	int last_valid_idx = get_last_valid_idx(pfdset, pfdset->num - 1);
+
+	for (i = 0; i < last_valid_idx; i++) {
+		if (pfdset->fd[i].fd != -1)
+			continue;
+
+		fdset_move(pfdset, i, last_valid_idx);
+		last_valid_idx = get_last_valid_idx(pfdset, last_valid_idx - 1);
+	}
+	pfdset->num = last_valid_idx + 1;
+}
+
+/*
+ * Find deleted fd entries and remove them
+ */
+static void
+fdset_shrink(struct fdset *pfdset)
+{
+	pthread_mutex_lock(&pfdset->fd_mutex);
+	fdset_shrink_nolock(pfdset);
+	pthread_mutex_unlock(&pfdset->fd_mutex);
+}
+
+/**
+ * Returns the index in the fdset for a given fd.
+ * @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;
+
+	for (i = 0; i < pfdset->num && pfdset->fd[i].fd != fd; i++)
+		;
+
+	return i == pfdset->num ? -1 : i;
+}
+
+static void
+fdset_add_fd(struct fdset *pfdset, int idx, int fd,
+	fd_cb rcb, fd_cb wcb, void *dat)
+{
+	struct fdentry *pfdentry = &pfdset->fd[idx];
+	struct pollfd *pfd = &pfdset->rwfds[idx];
+
+	pfdentry->fd  = fd;
+	pfdentry->rcb = rcb;
+	pfdentry->wcb = wcb;
+	pfdentry->dat = dat;
+
+	pfd->fd = fd;
+	pfd->events  = rcb ? POLLIN : 0;
+	pfd->events |= wcb ? POLLOUT : 0;
+	pfd->revents = 0;
+}
+
+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);
+	i = pfdset->num < MAX_FDS ? pfdset->num++ : -1;
+	if (i == -1) {
+		fdset_shrink_nolock(pfdset);
+		i = pfdset->num < MAX_FDS ? pfdset->num++ : -1;
+		if (i == -1) {
+			pthread_mutex_unlock(&pfdset->fd_mutex);
+			return -2;
+		}
+	}
+
+	fdset_add_fd(pfdset, i, fd, rcb, wcb, dat);
+	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;
+			i = -1;
+		}
+		pthread_mutex_unlock(&pfdset->fd_mutex);
+	} while (i != -1);
+
+	return dat;
+}
+
+
+/**
+ * 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(void *arg)
+{
+	int i;
+	struct pollfd *pfd;
+	struct fdentry *pfdentry;
+	fd_cb rcb, wcb;
+	void *dat;
+	int fd, numfds;
+	int remove1, remove2;
+	int need_shrink;
+	struct fdset *pfdset = arg;
+
+	if (pfdset == NULL)
+		return NULL;
+
+	while (1) {
+
+		/*
+		 * When poll is blocked, other threads might unregister
+		 * listenfds from and register new listenfds into fdset.
+		 * When poll returns, the entries for listenfds in the fdset
+		 * might have been updated. It is ok if there is unwanted call
+		 * for new listenfds.
+		 */
+		pthread_mutex_lock(&pfdset->fd_mutex);
+		numfds = pfdset->num;
+		pthread_mutex_unlock(&pfdset->fd_mutex);
+
+		poll(pfdset->rwfds, numfds, 1000 /* millisecs */);
+
+		need_shrink = 0;
+		for (i = 0; i < numfds; i++) {
+			pthread_mutex_lock(&pfdset->fd_mutex);
+
+			pfdentry = &pfdset->fd[i];
+			fd = pfdentry->fd;
+			pfd = &pfdset->rwfds[i];
+
+			if (fd < 0) {
+				need_shrink = 1;
+				pthread_mutex_unlock(&pfdset->fd_mutex);
+				continue;
+			}
+
+			if (!pfd->revents) {
+				pthread_mutex_unlock(&pfdset->fd_mutex);
+				continue;
+			}
+
+			remove1 = remove2 = 0;
+
+			rcb = pfdentry->rcb;
+			wcb = pfdentry->wcb;
+			dat = pfdentry->dat;
+			pfdentry->busy = 1;
+
+			pthread_mutex_unlock(&pfdset->fd_mutex);
+
+			if (rcb && pfd->revents & (POLLIN | FDPOLLERR))
+				rcb(fd, dat, &remove1);
+			if (wcb && pfd->revents & (POLLOUT | FDPOLLERR))
+				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) {
+				pfdentry->fd = -1;
+				need_shrink = 1;
+			}
+		}
+
+		if (need_shrink)
+			fdset_shrink(pfdset);
+	}
+
+	return NULL;
+}