[dpdk-dev] [PATCH 1/4] vhost: move fdset functions from fd_man.c to fd_man.h

[Zhiyong Yang]

The patch moves fdset related funcitons from fd_man.c to fd_man.h in
order to reuse these funcitons from the perspective of PMDs.

Signed-off-by: Zhiyong Yang <zhiyong.yang at intel.com>
---
 lib/librte_vhost/Makefile |   3 +-
 lib/librte_vhost/fd_man.c | 274 ----------------------------------------------
 lib/librte_vhost/fd_man.h | 258 +++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 253 insertions(+), 282 deletions(-)
 delete mode 100644 lib/librte_vhost/fd_man.c

diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile
index 5d6c6abae..e201df79c 100644
--- a/lib/librte_vhost/Makefile
+++ b/lib/librte_vhost/Makefile
@@ -21,10 +21,11 @@ endif
 LDLIBS += -lrte_eal -lrte_mempool -lrte_mbuf -lrte_ethdev -lrte_net
 
 # all source are stored in SRCS-y
-SRCS-$(CONFIG_RTE_LIBRTE_VHOST) := fd_man.c iotlb.c socket.c vhost.c \
+SRCS-$(CONFIG_RTE_LIBRTE_VHOST) := iotlb.c socket.c vhost.c \
 					vhost_user.c virtio_net.c
 
 # install includes
 SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_vhost.h
+SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += fd_man.h
 
 include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/lib/librte_vhost/fd_man.c b/lib/librte_vhost/fd_man.c
deleted file mode 100644
index 181711c2a..000000000
--- a/lib/librte_vhost/fd_man.c
+++ /dev/null
@@ -1,274 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2010-2014 Intel Corporation
- */
-
-#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;
-	int val;
-
-	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);
-
-		val = poll(pfdset->rwfds, numfds, 1000 /* millisecs */);
-		if (val < 0)
-			continue;
-
-		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;
-}
diff --git a/lib/librte_vhost/fd_man.h b/lib/librte_vhost/fd_man.h
index 3a9276c3c..b1c628251 100644
--- a/lib/librte_vhost/fd_man.h
+++ b/lib/librte_vhost/fd_man.h
@@ -4,11 +4,11 @@
 
 #ifndef _FD_MAN_H_
 #define _FD_MAN_H_
-#include <stdint.h>
-#include <pthread.h>
 #include <poll.h>
+#include <stdio.h>
 
 #define MAX_FDS 1024
+#define FDPOLLERR (POLLERR | POLLHUP | POLLNVAL)
 
 typedef void (*fd_cb)(int fd, void *dat, int *remove);
 
@@ -27,14 +27,258 @@ struct fdset {
 	int num;	/* current fd number of this fdset */
 };
 
+static inline int
+get_last_valid_idx(struct fdset *pfdset, int last_valid_idx)
+{
+	int i;
 
-void fdset_init(struct fdset *pfdset);
+	for (i = last_valid_idx; i >= 0 && pfdset->fd[i].fd == -1; i--)
+		;
 
-int fdset_add(struct fdset *pfdset, int fd,
-	fd_cb rcb, fd_cb wcb, void *dat);
+	return i;
+}
 
-void *fdset_del(struct fdset *pfdset, int fd);
+static inline void
+fdset_move(struct fdset *pfdset, int dst, int src)
+{
+	pfdset->fd[dst]    = pfdset->fd[src];
+	pfdset->rwfds[dst] = pfdset->rwfds[src];
+}
 
-void *fdset_event_dispatch(void *arg);
+static inline 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 inline 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 inline 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 inline 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;
+}
+
+static inline 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.
+ */
+static inline 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.
+ */
+static inline 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.
+ */
+static inline 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;
+	int val;
+
+	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);
+
+		val = poll(pfdset->rwfds, numfds, 1000 /* millisecs */);
+		if (val < 0)
+			continue;
+
+		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;
+}
 
 #endif
-- 
2.13.3