/*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 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.
#include "dynamic-string.h"
#include "fatal-signal.h"
#include "list.h"
+#include "ovs-thread.h"
+#include "seq.h"
#include "socket-util.h"
#include "timeval.h"
#include "vlog.h"
-
-#undef poll_fd_wait
-#undef poll_timer_wait
-#undef poll_timer_wait_until
-#undef poll_immediate_wake
+#include "hmap.h"
+#include "hash.h"
VLOG_DEFINE_THIS_MODULE(poll_loop);
COVERAGE_DEFINE(poll_fd_wait);
COVERAGE_DEFINE(poll_zero_timeout);
-/* An event that will wake the following call to poll_block(). */
-struct poll_waiter {
- /* Set when the waiter is created. */
- struct list node; /* Element in global waiters list. */
- int fd; /* File descriptor. */
- short int events; /* Events to wait for (POLLIN, POLLOUT). */
- const char *where; /* Where the waiter was created. */
-
- /* Set only when poll_block() is called. */
- struct pollfd *pollfd; /* Pointer to element of the pollfds array. */
+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. */
};
-/* All active poll waiters. */
-static struct list waiters = LIST_INITIALIZER(&waiters);
+struct poll_loop {
+ /* All active poll waiters. */
+ struct hmap poll_nodes;
-/* Time at which to wake up the next call to poll_block(), in milliseconds as
- * returned by time_msec(), LLONG_MIN to wake up immediately, or LLONG_MAX to
- * wait forever. */
-static long long int timeout_when = LLONG_MAX;
+ /* Time at which to wake up the next call to poll_block(), LLONG_MIN to
+ * wake up immediately, or LLONG_MAX to wait forever. */
+ long long int timeout_when; /* In msecs as returned by time_msec(). */
+ const char *timeout_where; /* Where 'timeout_when' was set. */
+};
-/* Location where waiter created. */
-static const char *timeout_where;
+static struct poll_loop *poll_loop(void);
-static struct poll_waiter *new_waiter(int fd, short int events,
- const char *where);
+/* 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;
-/* 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.
+ 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:
*
- * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h
- * for more information. */
-struct poll_waiter *
-poll_fd_wait(int fd, short int events, const char *where)
+ * 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, HANDLE wevent, short int events, const char *where)
{
+ struct poll_loop *loop = poll_loop();
+ struct poll_node *node;
+
COVERAGE_INC(poll_fd_wait);
- return new_waiter(fd, events, where);
+
+#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'
* is affected. The timer will need to be re-registered after poll_block() is
* called if it is to persist.
*
- * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h
- * for more information. */
+ * ('where' is used in debug logging. Commonly one would use poll_timer_wait()
+ * to automatically provide the caller's source file and line number for
+ * 'where'.) */
void
-poll_timer_wait(long long int msec, const char *where)
+poll_timer_wait_at(long long int msec, const char *where)
{
long long int now = time_msec();
long long int when;
when = LLONG_MAX;
}
- poll_timer_wait_until(when, where);
+ poll_timer_wait_until_at(when, where);
}
/* Causes the following call to poll_block() to wake up when the current time,
* is affected. The timer will need to be re-registered after poll_block() is
* called if it is to persist.
*
- * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h
- * for more information. */
+ * ('where' is used in debug logging. Commonly one would use
+ * poll_timer_wait_until() to automatically provide the caller's source file
+ * and line number for 'where'.) */
void
-poll_timer_wait_until(long long int when, const char *where)
+poll_timer_wait_until_at(long long int when, const char *where)
{
- if (when < timeout_when) {
- timeout_when = when;
- timeout_where = where;
+ struct poll_loop *loop = poll_loop();
+ if (when < loop->timeout_when) {
+ loop->timeout_when = when;
+ loop->timeout_where = where;
}
}
/* Causes the following call to poll_block() to wake up immediately, without
* blocking.
*
- * Ordinarily the 'where' argument is supplied automatically; see poll-loop.h
- * for more information. */
+ * ('where' is used in debug logging. Commonly one would use
+ * poll_immediate_wake() to automatically provide the caller's source file and
+ * line number for 'where'.) */
void
-poll_immediate_wake(const char *where)
+poll_immediate_wake_at(const char *where)
{
- poll_timer_wait(0, where);
+ poll_timer_wait_at(0, where);
}
/* Logs, if appropriate, that the poll loop was awakened by an event
static void
log_wakeup(const char *where, const struct pollfd *pollfd, int timeout)
{
- static struct vlog_rate_limit trace_rl = VLOG_RATE_LIMIT_INIT(1, 1);
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 10);
enum vlog_level level;
int cpu_usage;
cpu_usage = get_cpu_usage();
if (VLOG_IS_DBG_ENABLED()) {
level = VLL_DBG;
- } else if (cpu_usage > 50 && !VLOG_DROP_WARN(&rl)) {
- level = VLL_WARN;
+ } else if (cpu_usage > 50 && !VLOG_DROP_INFO(&rl)) {
+ level = VLL_INFO;
} else {
return;
}
}
if (cpu_usage >= 0) {
ds_put_format(&s, " (%d%% CPU usage)", cpu_usage);
-
- if (!vlog_should_drop(THIS_MODULE, level, &trace_rl)) {
- ds_put_char(&s, '\n');
- format_backtraces(&s, 2);
- }
}
VLOG(level, "%s", ds_cstr(&s));
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. */
void
poll_block(void)
{
- static struct pollfd *pollfds;
- static size_t max_pollfds;
-
- struct poll_waiter *pw, *next;
- int n_waiters, n_pollfds;
+ 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. */
fatal_signal_wait();
- n_waiters = list_size(&waiters);
- if (max_pollfds < n_waiters) {
- max_pollfds = n_waiters;
- pollfds = xrealloc(pollfds, max_pollfds * sizeof *pollfds);
+ if (loop->timeout_when == LLONG_MIN) {
+ COVERAGE_INC(poll_zero_timeout);
}
- n_pollfds = 0;
- LIST_FOR_EACH (pw, node, &waiters) {
- pw->pollfd = &pollfds[n_pollfds];
- pollfds[n_pollfds].fd = pw->fd;
- pollfds[n_pollfds].events = pw->events;
- pollfds[n_pollfds].revents = 0;
- n_pollfds++;
- }
+ timewarp_wait();
+ pollfds = xmalloc(hmap_count(&loop->poll_nodes) * sizeof *pollfds);
- if (timeout_when == LLONG_MIN) {
- COVERAGE_INC(poll_zero_timeout);
+#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, n_pollfds, timeout_when, &elapsed);
+
+ 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);
- VLOG_ERR_RL(&rl, "poll: %s", strerror(-retval));
+ VLOG_ERR_RL(&rl, "poll: %s", ovs_strerror(-retval));
} else if (!retval) {
- log_wakeup(timeout_where, NULL, elapsed);
- }
-
- LIST_FOR_EACH_SAFE (pw, next, node, &waiters) {
- if (pw->pollfd->revents) {
- log_wakeup(pw->where, pw->pollfd, 0);
+ log_wakeup(loop->timeout_where, NULL, elapsed);
+ } else if (get_cpu_usage() > 50 || VLOG_IS_DBG_ENABLED()) {
+ i = 0;
+ HMAP_FOR_EACH (node, hmap_node, &loop->poll_nodes) {
+ if (pollfds[i].revents) {
+ log_wakeup(node->where, &pollfds[i], 0);
+ }
+ i++;
}
- poll_cancel(pw);
}
- timeout_when = LLONG_MAX;
- timeout_where = NULL;
+ free_poll_nodes(loop);
+ loop->timeout_when = LLONG_MAX;
+ loop->timeout_where = NULL;
+ free(pollfds);
+ free(wevents);
/* Handle any pending signals before doing anything else. */
fatal_signal_run();
-}
-/* Cancels the file descriptor event registered with poll_fd_wait() using 'pw',
- * the struct poll_waiter returned by that function.
- *
- * An event registered with poll_fd_wait() may be canceled from its time of
- * registration until the next call to poll_block(). At that point, the event
- * is automatically canceled by the system and its poll_waiter is freed. */
-void
-poll_cancel(struct poll_waiter *pw)
-{
- if (pw) {
- list_remove(&pw->node);
- free(pw);
- }
+ seq_woke();
}
\f
-/* Creates and returns a new poll_waiter for 'fd' and 'events'. */
-static struct poll_waiter *
-new_waiter(int fd, short int events, const char *where)
+static void
+free_poll_loop(void *loop_)
+{
+ struct poll_loop *loop = loop_;
+
+ free_poll_nodes(loop);
+ hmap_destroy(&loop->poll_nodes);
+ free(loop);
+}
+
+static struct poll_loop *
+poll_loop(void)
{
- struct poll_waiter *waiter = xzalloc(sizeof *waiter);
- ovs_assert(fd >= 0);
- waiter->fd = fd;
- waiter->events = events;
- waiter->where = where;
- list_push_back(&waiters, &waiter->node);
- return waiter;
+ static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
+ static pthread_key_t key;
+ struct poll_loop *loop;
+
+ if (ovsthread_once_start(&once)) {
+ xpthread_key_create(&key, free_poll_loop);
+ ovsthread_once_done(&once);
+ }
+
+ loop = pthread_getspecific(key);
+ if (!loop) {
+ loop = xzalloc(sizeof *loop);
+ hmap_init(&loop->poll_nodes);
+ xpthread_setspecific(key, loop);
+ }
+ return loop;
}
+