#include "dynamic-string.h"
#include "fatal-signal.h"
#include "list.h"
+#include "ovs-thread.h"
#include "socket-util.h"
#include "timeval.h"
#include "vlog.h"
COVERAGE_DEFINE(poll_fd_wait);
COVERAGE_DEFINE(poll_zero_timeout);
-/* An event that will wake the following call to poll_block(). */
-struct poll_waiter {
- const char *where; /* Where the waiter was created. */
-};
-
-/* All active poll waiters. */
-static struct poll_waiter *waiters;
-static struct pollfd *pollfds;
-static size_t n_waiters, allocated_waiters;
+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'. */
-/* 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;
+ /* 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. */
+};
-static void 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
void
poll_fd_wait(int fd, short int events, const char *where)
{
+ struct poll_loop *loop = poll_loop();
+
COVERAGE_INC(poll_fd_wait);
- 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'
void
poll_timer_wait_until(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;
}
}
void
poll_block(void)
{
+ struct poll_loop *loop = poll_loop();
int elapsed;
int retval;
* poll_block. */
fatal_signal_wait();
- if (timeout_when == LLONG_MIN) {
+ if (loop->timeout_when == LLONG_MIN) {
COVERAGE_INC(poll_zero_timeout);
}
- retval = time_poll(pollfds, n_waiters, timeout_when, &elapsed);
+
+ 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", 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;
- for (i = 0; i < n_waiters; i++) {
- if (pollfds[i].revents) {
- log_wakeup(waiters[i].where, &pollfds[i], 0);
+ for (i = 0; i < loop->n_waiters; i++) {
+ if (loop->pollfds[i].revents) {
+ log_wakeup(loop->where[i], &loop->pollfds[i], 0);
}
}
}
- timeout_when = LLONG_MAX;
- timeout_where = NULL;
- n_waiters = 0;
+ loop->timeout_when = LLONG_MAX;
+ loop->timeout_where = NULL;
+ loop->n_waiters = 0;
/* Handle any pending signals before doing anything else. */
fatal_signal_run();
}
\f
-/* 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)
+free_poll_loop(void *loop_)
{
- if (n_waiters >= allocated_waiters) {
- waiters = x2nrealloc(waiters, &allocated_waiters, sizeof *waiters);
- pollfds = xrealloc(pollfds, allocated_waiters * sizeof *pollfds);
+ struct poll_loop *loop = loop_;
+
+ free(loop->pollfds);
+ free(loop->where);
+ free(loop);
+}
+
+static struct poll_loop *
+poll_loop(void)
+{
+ 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);
}
- waiters[n_waiters].where = where;
- pollfds[n_waiters].fd = fd;
- pollfds[n_waiters].events = events;
- n_waiters++;
+ loop = pthread_getspecific(key);
+ if (!loop) {
+ loop = xzalloc(sizeof *loop);
+ pthread_setspecific(key, loop);
+ }
+ return loop;
}
+
/*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 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.
/* High-level wrapper around the "poll" system call.
*
- * Intended usage is for the program's main loop to go about its business
+ * The intended usage is for each thread's main loop to go about its business
* servicing whatever events it needs to. Then, when it runs out of immediate
* tasks, it calls each subordinate module's "wait" function, which in turn
* calls one (or more) of the functions poll_fd_wait(), poll_immediate_wake(),
* and poll_timer_wait() to register to be awakened when the appropriate event
* occurs. Then the main loop calls poll_block(), which blocks until one of
- * the registered events happens. */
-
+ * the registered events happens.
+ *
+ *
+ * Thread-safety
+ * =============
+ *
+ * The poll set is per-thread, so all functions in this module are thread-safe.
+ */
#ifndef POLL_LOOP_H
#define POLL_LOOP_H 1
projects / cascardo / ovs.git / commitdiff