/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include "poll-loop.h"
#include <assert.h>
#include <errno.h>
+#include <inttypes.h>
#include <poll.h>
#include <stdlib.h>
#include <string.h>
#include "backtrace.h"
#include "coverage.h"
#include "dynamic-string.h"
+#include "fatal-signal.h"
#include "list.h"
#include "timeval.h"
-
-#define THIS_MODULE VLM_poll_loop
#include "vlog.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). */
- poll_fd_func *function; /* Callback function, if any, or null. */
- void *aux; /* Argument to callback function. */
struct backtrace *backtrace; /* Optionally, event that created waiter. */
/* Set only when poll_block() is called. */
- struct pollfd *pollfd; /* Pointer to element of the pollfds array
- (null if added from a callback). */
+ struct pollfd *pollfd; /* Pointer to element of the pollfds array. */
};
/* All active poll waiters. */
/* Backtrace of 'timeout''s registration, if debugging is enabled. */
static struct backtrace timeout_backtrace;
-/* Callback currently running, to allow verifying that poll_cancel() is not
- * being called on a running callback. */
-#ifndef NDEBUG
-static struct poll_waiter *running_cb;
-#endif
-
static struct poll_waiter *new_waiter(int fd, short int events);
/* Registers 'fd' as waiting for the specified 'events' (which should be POLLIN
return new_waiter(fd, events);
}
+/* The caller must ensure that 'msec' is not negative. */
+static void
+poll_timer_wait__(int msec)
+{
+ if (timeout < 0 || msec < timeout) {
+ timeout = msec;
+ if (VLOG_IS_DBG_ENABLED()) {
+ backtrace_capture(&timeout_backtrace);
+ }
+ }
+}
+
/* Causes the following call to poll_block() to block for no more than 'msec'
* milliseconds. If 'msec' is nonpositive, the following call to poll_block()
* will not block at all.
* is affected. The timer will need to be re-registered after poll_block() is
* called if it is to persist. */
void
-poll_timer_wait(int msec)
+poll_timer_wait(long long int msec)
{
- if (timeout < 0 || msec < timeout) {
- timeout = MAX(0, msec);
- if (VLOG_IS_DBG_ENABLED()) {
- backtrace_capture(&timeout_backtrace);
- }
- }
+ poll_timer_wait__(msec < 0 ? 0
+ : msec > INT_MAX ? INT_MAX
+ : msec);
+}
+
+/* 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
+ * than the current time, the following call to poll_block() will not block at
+ * all.
+ *
+ * The timer registration is one-shot: only the following call to poll_block()
+ * is affected. The timer will need to be re-registered after poll_block() is
+ * called if it is to persist. */
+void
+poll_timer_wait_until(long long int msec)
+{
+ long long int now = time_msec();
+ poll_timer_wait__(msec <= now ? 0
+ : msec < now + INT_MAX ? msec - now
+ : INT_MAX);
}
/* Causes the following call to poll_block() to wake up immediately, without
ds_put_char(&ds, ':');
for (i = 0; i < backtrace->n_frames; i++) {
- ds_put_format(&ds, " 0x%x", backtrace->frames[i]);
+ ds_put_format(&ds, " 0x%"PRIxPTR, backtrace->frames[i]);
}
}
VLOG_DBG("%s", ds_cstr(&ds));
/* 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.
- *
- * Also executes any autonomous subroutines registered with poll_fd_callback(),
- * if their file descriptors have become ready. */
+ * 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;
- struct list *node;
+ struct poll_waiter *pw, *next;
int n_pollfds;
int retval;
- assert(!running_cb);
+ /* 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, struct poll_waiter, node, &waiters) {
+ LIST_FOR_EACH (pw, node, &waiters) {
pw->pollfd = &pollfds[n_pollfds];
pollfds[n_pollfds].fd = pw->fd;
pollfds[n_pollfds].events = pw->events;
log_wakeup(&timeout_backtrace, "%d-ms timeout", timeout);
}
- for (node = waiters.next; node != &waiters; ) {
- pw = CONTAINER_OF(node, struct poll_waiter, node);
- if (!pw->pollfd || !pw->pollfd->revents) {
- if (pw->function) {
- node = node->next;
- continue;
- }
- } else {
- if (VLOG_IS_DBG_ENABLED()) {
- log_wakeup(pw->backtrace, "%s%s%s%s%s on fd %d",
- pw->pollfd->revents & POLLIN ? "[POLLIN]" : "",
- pw->pollfd->revents & POLLOUT ? "[POLLOUT]" : "",
- pw->pollfd->revents & POLLERR ? "[POLLERR]" : "",
- pw->pollfd->revents & POLLHUP ? "[POLLHUP]" : "",
- pw->pollfd->revents & POLLNVAL ? "[POLLNVAL]" : "",
- pw->fd);
- }
-
- if (pw->function) {
-#ifndef NDEBUG
- running_cb = pw;
-#endif
- pw->function(pw->fd, pw->pollfd->revents, pw->aux);
-#ifndef NDEBUG
- running_cb = NULL;
-#endif
- }
+ LIST_FOR_EACH_SAFE (pw, next, node, &waiters) {
+ if (pw->pollfd->revents && VLOG_IS_DBG_ENABLED()) {
+ log_wakeup(pw->backtrace, "%s%s%s%s%s on fd %d",
+ pw->pollfd->revents & POLLIN ? "[POLLIN]" : "",
+ pw->pollfd->revents & POLLOUT ? "[POLLOUT]" : "",
+ pw->pollfd->revents & POLLERR ? "[POLLERR]" : "",
+ pw->pollfd->revents & POLLHUP ? "[POLLHUP]" : "",
+ pw->pollfd->revents & POLLNVAL ? "[POLLNVAL]" : "",
+ pw->fd);
}
- node = node->next;
poll_cancel(pw);
}
timeout = -1;
timeout_backtrace.n_frames = 0;
-}
-/* Registers 'function' to be called with argument 'aux' by poll_block() when
- * 'fd' becomes ready for one of the events in 'events', which should be POLLIN
- * or POLLOUT or POLLIN | POLLOUT.
- *
- * The callback registration persists until the event actually occurs. At that
- * point, it is automatically de-registered. The callback function must
- * re-register the event by calling poll_fd_callback() again within the
- * callback, if it wants to be called back again later. */
-struct poll_waiter *
-poll_fd_callback(int fd, short int events, poll_fd_func *function, void *aux)
-{
- struct poll_waiter *pw = new_waiter(fd, events);
- pw->function = function;
- pw->aux = aux;
- return pw;
+ /* Handle any pending signals before doing anything else. */
+ fatal_signal_run();
}
-/* Cancels the file descriptor event registered with poll_fd_wait() or
- * poll_fd_callback(). 'pw' must be the struct poll_waiter returned by one of
- * those functions.
+/* 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.
- *
- * An event registered with poll_fd_callback() may be canceled from its time of
- * registration until its callback is actually called. At that point, the
- * event is automatically canceled by the system and its poll_waiter is
- * freed. */
+ * is automatically canceled by the system and its poll_waiter is freed. */
void
poll_cancel(struct poll_waiter *pw)
{
if (pw) {
- assert(pw != running_cb);
list_remove(&pw->node);
free(pw->backtrace);
free(pw);
git://git.onelab.eu / sliver-openvswitch.git / blobdiff