/*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
+ * 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>
#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
-
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. */
+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'. */
- /* Set only when poll_block() is called. */
- struct pollfd *pollfd; /* Pointer to element of the pollfds array. */
+ /* 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. */
};
-/* All active poll waiters. */
-static struct list waiters = LIST_INITIALIZER(&waiters);
-
-/* 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;
-
-/* Location where waiter created. */
-static const char *timeout_where;
-
-static struct poll_waiter *new_waiter(int fd, short int events,
- const char *where);
+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
* is affected. The event 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. */
-struct poll_waiter *
-poll_fd_wait(int fd, short int events, const char *where)
+ * ('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)
{
+ struct poll_loop *loop = poll_loop();
+
COVERAGE_INC(poll_fd_wait);
- return new_waiter(fd, events, where);
+ 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++;
}
/* 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);
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();
int elapsed;
int retval;
* 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);
- }
-
- 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_when == LLONG_MIN) {
+ if (loop->timeout_when == LLONG_MIN) {
COVERAGE_INC(poll_zero_timeout);
}
- retval = time_poll(pollfds, n_pollfds, timeout_when, &elapsed);
+
+ timewarp_wait();
+ retval = time_poll(loop->pollfds, loop->n_waiters,
+ 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);
- }
+ log_wakeup(loop->timeout_where, NULL, elapsed);
+ } else if (get_cpu_usage() > 50 || VLOG_IS_DBG_ENABLED()) {
+ size_t i;
- LIST_FOR_EACH_SAFE (pw, next, node, &waiters) {
- if (pw->pollfd->revents) {
- log_wakeup(pw->where, pw->pollfd, 0);
+ for (i = 0; i < loop->n_waiters; i++) {
+ if (loop->pollfds[i].revents) {
+ log_wakeup(loop->where[i], &loop->pollfds[i], 0);
+ }
}
- poll_cancel(pw);
}
- timeout_when = LLONG_MAX;
- timeout_where = NULL;
+ loop->timeout_when = LLONG_MAX;
+ loop->timeout_where = NULL;
+ loop->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);
- }
+ 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(loop->pollfds);
+ free(loop->where);
+ free(loop);
+}
+
+static struct poll_loop *
+poll_loop(void)
{
- 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);
- 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);
+ xpthread_setspecific(key, loop);
+ }
+ return loop;
}
+
projects / cascardo / ovs.git / blobdiff