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poll-loop: Port to Windows.

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Use WaitForMultipleObjects for polling on windows.  This works on all kinds
of objects, e.g. sockets, files, especially ioctl calls to the kernel.
poll_fd_wait_event() is used if events need to be passed to pollfds.  latch
is signaled with event, to be waited/polled by WaitForMultipleObjects() as
well.  Changed array of fds to hmap to check for duplicate fds.

Signed-off-by: Linda Sun <lsun@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
This commit is contained in:
Linda Sun
2014-01-09 16:26:12 -08:00
committed by Ben Pfaff
parent d103f479c6
commit 4ca828d713
9 changed files with 231 additions and 42 deletions
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137
lib/poll-loop.c
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@@ -1,5 +1,5 @@
/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
* Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -30,18 +30,24 @@
#include "socket-util.h"
#include "timeval.h"
#include "vlog.h"
#include "hmap.h"
#include "hash.h"
VLOG_DEFINE_THIS_MODULE(poll_loop);
COVERAGE_DEFINE(poll_fd_wait);
COVERAGE_DEFINE(poll_zero_timeout);
struct poll_node {
struct hmap_node hmap_node;
struct pollfd pollfd; /* Events to pass to time_poll(). */
HANDLE wevent; /* Events for WaitForMultipleObjects(). */
const char *where; /* Where poll_node was created. */
};
struct poll_loop {
/* All active poll waiters. */
struct pollfd *pollfds; /* Events to pass to poll(). */
const char **where; /* Where each pollfd was created. */
size_t n_waiters; /* Number of elems in 'where' and 'pollfds'. */
size_t allocated_waiters; /* Allocated elems in 'where' and 'pollfds'. */
struct hmap poll_nodes;
/* Time at which to wake up the next call to poll_block(), LLONG_MIN to
* wake up immediately, or LLONG_MAX to wait forever. */
@@ -51,35 +57,68 @@ struct poll_loop {
static struct poll_loop *poll_loop(void);
/* Registers 'fd' as waiting for the specified 'events' (which should be POLLIN
* or POLLOUT or POLLIN | POLLOUT). The following call to poll_block() will
* wake up when 'fd' becomes ready for one or more of the requested events.
/* Look up the node with same fd and wevent. */
static struct poll_node *
find_poll_node(struct poll_loop *loop, int fd, uint32_t wevent)
{
struct poll_node *node;
HMAP_FOR_EACH_WITH_HASH (node, hmap_node, hash_2words(fd, wevent),
&loop->poll_nodes) {
if (node->pollfd.fd == fd && node->wevent == wevent) {
return node;
}
}
return NULL;
}
/* On Unix based systems:
*
* The event registration is one-shot: only the following call to poll_block()
* is affected. The event will need to be re-registered after poll_block() is
* called if it is to persist.
* Registers 'fd' as waiting for the specified 'events' (which should be
* POLLIN or POLLOUT or POLLIN | POLLOUT). The following call to
* poll_block() will wake up when 'fd' becomes ready for one or more of the
* requested events. the 'fd's are given to poll() function later.
*
* On Windows system:
*
* Register 'wevent' handle for the specified 'events'. These wevents are
* given to the handleMultipleObjects() to be polled. The event
* registration is one-shot: only the following call to poll_block() is
* affected. The event will need to be re-registered after poll_block() is
* called if it is to persist.
*
* ('where' is used in debug logging. Commonly one would use poll_fd_wait() to
* automatically provide the caller's source file and line number for
* 'where'.) */
void
poll_fd_wait_at(int fd, short int events, const char *where)
poll_fd_wait_at(int fd, HANDLE wevent, short int events, const char *where)
{
struct poll_loop *loop = poll_loop();
struct poll_node *node;
COVERAGE_INC(poll_fd_wait);
if (loop->n_waiters >= loop->allocated_waiters) {
loop->where = x2nrealloc(loop->where, &loop->allocated_waiters,
sizeof *loop->where);
loop->pollfds = xrealloc(loop->pollfds,
(loop->allocated_waiters
* sizeof *loop->pollfds));
}
loop->where[loop->n_waiters] = where;
loop->pollfds[loop->n_waiters].fd = fd;
loop->pollfds[loop->n_waiters].events = events;
loop->n_waiters++;
#ifdef _WIN32
/* Null event cannot be polled. */
if (wevent == 0) {
VLOG_ERR("No event to wait fd %d", fd);
return;
}
#endif
/* Check for duplicate. If found, "or" the event. */
node = find_poll_node(loop, fd, wevent);
if (node) {
node->pollfd.events |= events;
} else {
node = xzalloc(sizeof *node);
hmap_insert(&loop->poll_nodes, &node->hmap_node,
hash_2words(fd, wevent));
node->pollfd.fd = fd;
node->pollfd.events = events;
node->wevent = wevent;
node->where = where;
}
}
/* Causes the following call to poll_block() to block for no more than 'msec'
@@ -208,6 +247,17 @@ log_wakeup(const char *where, const struct pollfd *pollfd, int timeout)
ds_destroy(&s);
}
static void
free_poll_nodes(struct poll_loop *loop)
{
struct poll_node *node, *next;
HMAP_FOR_EACH_SAFE (node, next, hmap_node, &loop->poll_nodes) {
hmap_remove(&loop->poll_nodes, &node->hmap_node);
free(node);
}
}
/* Blocks until one or more of the events registered with poll_fd_wait()
* occurs, or until the minimum duration registered with poll_timer_wait()
* elapses, or not at all if poll_immediate_wake() has been called. */
@@ -215,8 +265,12 @@ void
poll_block(void)
{
struct poll_loop *loop = poll_loop();
struct poll_node *node;
struct pollfd *pollfds;
HANDLE *wevents = NULL;
int elapsed;
int retval;
int i;
/* Register fatal signal events before actually doing any real work for
* poll_block. */
@@ -227,7 +281,23 @@ poll_block(void)
}
timewarp_wait();
retval = time_poll(loop->pollfds, loop->n_waiters,
pollfds = xmalloc(hmap_count(&loop->poll_nodes) * sizeof *pollfds);
#ifdef _WIN32
wevents = xmalloc(hmap_count(&loop->poll_nodes) * sizeof *wevents);
#endif
/* Populate with all the fds and events. */
i = 0;
HMAP_FOR_EACH (node, hmap_node, &loop->poll_nodes) {
pollfds[i] = node->pollfd;
#ifdef _WIN32
wevents[i] = node->wevent;
#endif
i++;
}
retval = time_poll(pollfds, hmap_count(&loop->poll_nodes), wevents,
loop->timeout_when, &elapsed);
if (retval < 0) {
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
@@ -235,18 +305,20 @@ poll_block(void)
} else if (!retval) {
log_wakeup(loop->timeout_where, NULL, elapsed);
} else if (get_cpu_usage() > 50 || VLOG_IS_DBG_ENABLED()) {
size_t i;
for (i = 0; i < loop->n_waiters; i++) {
if (loop->pollfds[i].revents) {
log_wakeup(loop->where[i], &loop->pollfds[i], 0);
i = 0;
HMAP_FOR_EACH (node, hmap_node, &loop->poll_nodes) {
if (pollfds[i].revents) {
log_wakeup(node->where, &pollfds[i], 0);
}
i++;
}
}
free_poll_nodes(loop);
loop->timeout_when = LLONG_MAX;
loop->timeout_where = NULL;
loop->n_waiters = 0;
free(pollfds);
free(wevents);
/* Handle any pending signals before doing anything else. */
fatal_signal_run();
@@ -259,8 +331,8 @@ free_poll_loop(void *loop_)
{
struct poll_loop *loop = loop_;
free(loop->pollfds);
free(loop->where);
free_poll_nodes(loop);
hmap_destroy(&loop->poll_nodes);
free(loop);
}
@@ -279,6 +351,7 @@ poll_loop(void)
loop = pthread_getspecific(key);
if (!loop) {
loop = xzalloc(sizeof *loop);
hmap_init(&loop->poll_nodes);
xpthread_setspecific(key, loop);
}
return loop;