/*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 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 <config.h>
#include "poll-loop.h"
-#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <poll.h>
/* 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. */
};
/* All active poll waiters. */
-static struct list waiters = LIST_INITIALIZER(&waiters);
-
-/* Number of elements in the waiters list. */
-static size_t n_waiters;
+static struct poll_waiter *waiters;
+static struct pollfd *pollfds;
+static size_t n_waiters, allocated_waiters;
-/* Max time to wait in next call to poll_block(), in milliseconds, or -1 to
+/* 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 int timeout = -1;
+static long long int timeout_when = LLONG_MAX;
/* Location where waiter created. */
static const char *timeout_where;
-static struct poll_waiter *new_waiter(int fd, short int events,
- const char *where);
+static void new_waiter(int fd, short int events, const char *where);
/* Registers 'fd' as waiting for the specified 'events' (which should be POLLIN
* or POLLOUT or POLLIN | POLLOUT). The following call to poll_block() will
*
* Ordinarily the 'where' argument is supplied automatically; see poll-loop.h
* for more information. */
-struct poll_waiter *
+void
poll_fd_wait(int fd, short int events, const char *where)
{
COVERAGE_INC(poll_fd_wait);
- return new_waiter(fd, events, where);
-}
-
-/* The caller must ensure that 'msec' is not negative. */
-static void
-poll_timer_wait__(int msec, const char *where)
-{
- if (timeout < 0 || msec < timeout) {
- timeout = msec;
- timeout_where = where;
- }
+ new_waiter(fd, events, where);
}
/* Causes the following call to poll_block() to block for no more than 'msec'
void
poll_timer_wait(long long int msec, const char *where)
{
- poll_timer_wait__((msec < 0 ? 0
- : msec > INT_MAX ? INT_MAX
- : msec),
- where);
+ long long int now = time_msec();
+ long long int when;
+
+ if (msec <= 0) {
+ /* Wake up immediately. */
+ when = LLONG_MIN;
+ } else if ((unsigned long long int) now + msec <= LLONG_MAX) {
+ /* Normal case. */
+ when = now + msec;
+ } else {
+ /* now + msec would overflow. */
+ when = LLONG_MAX;
+ }
+
+ poll_timer_wait_until(when, where);
}
/* Causes the following call to poll_block() to wake up when the current time,
- * as returned by time_msec(), reaches 'msec' or later. If 'msec' is earlier
+ * as returned by time_msec(), reaches 'when' or later. If 'when' is earlier
* than the current time, the following call to poll_block() will not block at
* all.
*
* Ordinarily the 'where' argument is supplied automatically; see poll-loop.h
* for more information. */
void
-poll_timer_wait_until(long long int msec, const char *where)
+poll_timer_wait_until(long long int when, const char *where)
{
- long long int now = time_msec();
- poll_timer_wait__((msec <= now ? 0
- : msec < now + INT_MAX ? msec - now
- : INT_MAX),
- where);
+ if (when < timeout_when) {
+ timeout_when = when;
+ timeout_where = where;
+ }
}
/* Causes the following call to poll_block() to wake up immediately, without
* arguments have two possible interpretations:
*
* - If 'pollfd' is nonnull then it should be the "struct pollfd" that caused
- * the wakeup. In this case, 'timeout' is ignored.
+ * the wakeup. 'timeout' is ignored.
*
- * - If 'pollfd' is nonnull then 'timeout' is the number of milliseconds
- * after which the poll loop woke up.
+ * - If 'pollfd' is NULL then 'timeout' is the number of milliseconds after
+ * which the poll loop woke up.
*/
static void
log_wakeup(const char *where, const struct pollfd *pollfd, int timeout)
{
- static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(120, 120);
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 10);
enum vlog_level level;
int cpu_usage;
struct ds s;
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;
}
void
poll_block(void)
{
- static struct pollfd *pollfds;
- static size_t max_pollfds;
-
- struct poll_waiter *pw, *next;
- int n_pollfds;
+ int elapsed;
int retval;
/* Register fatal signal events before actually doing any real work for
* poll_block. */
fatal_signal_wait();
- if (max_pollfds < n_waiters) {
- max_pollfds = n_waiters;
- pollfds = xrealloc(pollfds, max_pollfds * sizeof *pollfds);
- }
-
- 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++;
- }
-
- if (!timeout) {
+ if (timeout_when == LLONG_MIN) {
COVERAGE_INC(poll_zero_timeout);
}
- retval = time_poll(pollfds, n_pollfds, timeout);
+ retval = time_poll(pollfds, n_waiters, 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, timeout);
- }
-
- LIST_FOR_EACH_SAFE (pw, next, node, &waiters) {
- if (pw->pollfd->revents) {
- log_wakeup(pw->where, pw->pollfd, 0);
+ log_wakeup(timeout_where, NULL, elapsed);
+ } else if (get_cpu_usage() > 50 || VLOG_IS_DBG_ENABLED()) {
+ size_t i;
+
+ for (i = 0; i < n_waiters; i++) {
+ if (pollfds[i].revents) {
+ log_wakeup(waiters[i].where, &pollfds[i], 0);
+ }
}
- poll_cancel(pw);
}
- timeout = -1;
+ timeout_when = LLONG_MAX;
timeout_where = NULL;
+ n_waiters = 0;
/* 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);
- n_waiters--;
- }
-}
\f
-/* Creates and returns a new poll_waiter for 'fd' and 'events'. */
-static struct poll_waiter *
+/* Creates a new poll_waiter for 'fd' and 'events', recording 'where' as the
+ * location where the event was registered. */
+static void
new_waiter(int fd, short int events, const char *where)
{
- struct poll_waiter *waiter = xzalloc(sizeof *waiter);
- assert(fd >= 0);
- waiter->fd = fd;
- waiter->events = events;
- waiter->where = where;
- list_push_back(&waiters, &waiter->node);
+ if (n_waiters >= allocated_waiters) {
+ waiters = x2nrealloc(waiters, &allocated_waiters, sizeof *waiters);
+ pollfds = xrealloc(pollfds, allocated_waiters * sizeof *pollfds);
+ }
+
+ waiters[n_waiters].where = where;
+ pollfds[n_waiters].fd = fd;
+ pollfds[n_waiters].events = events;
n_waiters++;
- return waiter;
}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff