--- /dev/null
+/*-
+ * 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 void
+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)
+ return;
+
+ pfdentry = &pfdset->fd[idx];
+ pfdentry->fd = fd;
+ pfdentry->rcb = rcb;
+ pfdentry->wcb = wcb;
+ pfdentry->dat = dat;
+}
+
+/**
+ * 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->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) {
+ pthread_mutex_unlock(&pfdset->fd_mutex);
+ return -2;
+ }
+
+ fdset_add_fd(pfdset, i, fd, rcb, wcb, dat);
+ pfdset->num++;
+
+ pthread_mutex_unlock(&pfdset->fd_mutex);
+
+ return 0;
+}
+
+/**
+ * Unregister the fd from the fdset.
+ */
+void
+fdset_del(struct fdset *pfdset, int fd)
+{
+ int i;
+
+ if (pfdset == NULL || fd == -1)
+ return;
+
+ 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! */
+ pfdset->fd[i].fd = -1;
+ pfdset->fd[i].rcb = pfdset->fd[i].wcb = NULL;
+ pfdset->num--;
+ i = -1;
+ }
+ pthread_mutex_unlock(&pfdset->fd_mutex);
+ } while (i != -1);
+}
+
+/**
+ * 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->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);
+ }
+ }
+}
Code Review / deb_dpdk.git / blobdiff