|
Packit |
eace71 |
/*
|
|
Packit |
eace71 |
* iSCSI timeout & deferred work handling
|
|
Packit |
eace71 |
*
|
|
Packit |
eace71 |
* Copyright (C) 2004 Dmitry Yusupov, Alex Aizman
|
|
Packit |
eace71 |
* Copyright (C) 2014 Red Hat Inc.
|
|
Packit |
eace71 |
* maintained by open-iscsi@googlegroups.com
|
|
Packit |
eace71 |
*
|
|
Packit |
eace71 |
* This program is free software; you can redistribute it and/or modify
|
|
Packit |
eace71 |
* it under the terms of the GNU General Public License as published
|
|
Packit |
eace71 |
* by the Free Software Foundation; either version 2 of the License, or
|
|
Packit |
eace71 |
* (at your option) any later version.
|
|
Packit |
eace71 |
*
|
|
Packit |
eace71 |
* This program is distributed in the hope that it will be useful, but
|
|
Packit |
eace71 |
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
Packit |
eace71 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Packit |
eace71 |
* General Public License for more details.
|
|
Packit |
eace71 |
*
|
|
Packit |
eace71 |
* See the file COPYING included with this distribution for more details.
|
|
Packit |
eace71 |
*/
|
|
Packit |
eace71 |
#include <inttypes.h>
|
|
Packit |
eace71 |
#include <time.h>
|
|
Packit |
eace71 |
#include <sys/signalfd.h>
|
|
Packit |
eace71 |
#include <assert.h>
|
|
Packit |
eace71 |
#include <unistd.h>
|
|
Packit |
eace71 |
#include "actor.h"
|
|
Packit |
eace71 |
#include "log.h"
|
|
Packit |
eace71 |
#include "list.h"
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
static LIST_HEAD(pend_list);
|
|
Packit |
eace71 |
static LIST_HEAD(ready_list);
|
|
Packit |
eace71 |
static volatile int poll_in_progress;
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
static uint64_t
|
|
Packit |
eace71 |
actor_time_left(actor_t *thread, uint64_t current_time)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
if (current_time > thread->ttschedule)
|
|
Packit |
eace71 |
return 0;
|
|
Packit |
eace71 |
else
|
|
Packit |
eace71 |
return (thread->ttschedule - current_time);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
#define time_after(a,b) \
|
|
Packit |
eace71 |
((int64_t)(b) - (int64_t)(a) < 0)
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
void
|
|
Packit |
eace71 |
actor_init(actor_t *thread, void (*callback)(void *), void *data)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
INIT_LIST_HEAD(&thread->list);
|
|
Packit |
eace71 |
thread->state = ACTOR_NOTSCHEDULED;
|
|
Packit |
eace71 |
thread->callback = callback;
|
|
Packit |
eace71 |
thread->data = data;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
void
|
|
Packit |
eace71 |
actor_delete(actor_t *thread)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
log_debug(7, "thread %08lx delete: state %d", (long)thread,
|
|
Packit |
eace71 |
thread->state);
|
|
Packit |
eace71 |
switch(thread->state) {
|
|
Packit |
eace71 |
case ACTOR_WAITING:
|
|
Packit |
eace71 |
/* TODO: remove/reset alarm if we were 1st entry in pend_list */
|
|
Packit |
eace71 |
/* priority: low */
|
|
Packit |
eace71 |
/* fallthrough */
|
|
Packit |
eace71 |
case ACTOR_SCHEDULED:
|
|
Packit |
eace71 |
log_debug(1, "deleting a scheduled/waiting thread!");
|
|
Packit |
eace71 |
list_del_init(&thread->list);
|
|
Packit |
eace71 |
if (list_empty(&pend_list)) {
|
|
Packit |
eace71 |
log_debug(7, "nothing left on pend_list, deactivating alarm");
|
|
Packit |
eace71 |
alarm(0);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
break;
|
|
Packit |
eace71 |
default:
|
|
Packit |
eace71 |
break;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
thread->state = ACTOR_NOTSCHEDULED;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
/*
|
|
Packit |
eace71 |
* Inserts actor on pend list and sets alarm if new item is
|
|
Packit |
eace71 |
* sooner than previous entries.
|
|
Packit |
eace71 |
*/
|
|
Packit |
eace71 |
static void
|
|
Packit |
eace71 |
actor_insert_on_pend_list(actor_t *thread, uint32_t delay_secs)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
struct actor *orig_head;
|
|
Packit |
eace71 |
struct actor *new_head;
|
|
Packit |
eace71 |
struct actor *next_thread;
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
orig_head = list_first_entry_or_null(&pend_list,
|
|
Packit |
eace71 |
struct actor, list);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
/* insert new entry in sort order */
|
|
Packit |
eace71 |
list_for_each_entry(next_thread, &pend_list, list) {
|
|
Packit |
eace71 |
if (time_after(next_thread->ttschedule, thread->ttschedule)) {
|
|
Packit |
eace71 |
log_debug(7, "next thread %p due %lld", next_thread,
|
|
Packit |
eace71 |
(long long)next_thread->ttschedule);
|
|
Packit |
eace71 |
log_debug(7, "new thread %p is before (%lld), inserting", thread,
|
|
Packit |
eace71 |
(long long)thread->ttschedule);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
/* insert new thread before the next thread */
|
|
Packit |
eace71 |
__list_add(&thread->list, next_thread->list.prev, &next_thread->list);
|
|
Packit |
eace71 |
goto inserted;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
if (orig_head) {
|
|
Packit |
eace71 |
log_debug(7, "last thread %p due %lld", next_thread,
|
|
Packit |
eace71 |
(long long)next_thread->ttschedule);
|
|
Packit |
eace71 |
log_debug(7, "new thread %p is after (%lld), inserting at tail", thread,
|
|
Packit |
eace71 |
(long long)thread->ttschedule);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
else
|
|
Packit |
eace71 |
log_debug(7, "new thread %p due %lld is first item on pend_list", thread,
|
|
Packit |
eace71 |
(long long)thread->ttschedule);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
/* Not before any existing entries */
|
|
Packit |
eace71 |
list_add_tail(&thread->list, &pend_list);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
inserted:
|
|
Packit |
eace71 |
new_head = list_first_entry(&pend_list, struct actor, list);
|
|
Packit |
eace71 |
if (orig_head != new_head) {
|
|
Packit |
eace71 |
int result = alarm(delay_secs);
|
|
Packit |
eace71 |
log_debug(7, "new alarm set for %d seconds, old alarm %d",
|
|
Packit |
eace71 |
delay_secs, result);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
static void
|
|
Packit |
eace71 |
actor_schedule_private(actor_t *thread, uint32_t delay_secs, int head)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
time_t current_time;
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
struct timespec tv;
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
if (clock_gettime(CLOCK_MONOTONIC_COARSE, &tv)) {
|
|
Packit |
eace71 |
log_error("clock_getime failed, can't schedule!");
|
|
Packit |
eace71 |
return;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
current_time = tv.tv_sec;
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
log_debug(7, "thread %p schedule: delay %u state %d",
|
|
Packit |
eace71 |
thread, delay_secs, thread->state);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
switch(thread->state) {
|
|
Packit |
eace71 |
case ACTOR_WAITING:
|
|
Packit |
eace71 |
log_error("rescheduling a waiting thread!");
|
|
Packit |
eace71 |
list_del(&thread->list);
|
|
Packit |
eace71 |
/* fall-through */
|
|
Packit |
eace71 |
case ACTOR_NOTSCHEDULED:
|
|
Packit |
eace71 |
INIT_LIST_HEAD(&thread->list);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
if (delay_secs == 0) {
|
|
Packit |
eace71 |
thread->state = ACTOR_SCHEDULED;
|
|
Packit |
eace71 |
if (head)
|
|
Packit |
eace71 |
list_add(&thread->list, &ready_list);
|
|
Packit |
eace71 |
else
|
|
Packit |
eace71 |
list_add_tail(&thread->list, &ready_list);
|
|
Packit |
eace71 |
} else {
|
|
Packit |
eace71 |
thread->state = ACTOR_WAITING;
|
|
Packit |
eace71 |
thread->ttschedule = current_time + delay_secs;
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
actor_insert_on_pend_list(thread, delay_secs);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
break;
|
|
Packit |
eace71 |
case ACTOR_SCHEDULED:
|
|
Packit |
eace71 |
// don't do anything
|
|
Packit |
eace71 |
break;
|
|
Packit |
eace71 |
case ACTOR_INVALID:
|
|
Packit |
eace71 |
log_error("BUG: Trying to schedule a thread that has not been "
|
|
Packit |
eace71 |
"setup. Ignoring sched.");
|
|
Packit |
eace71 |
break;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
void
|
|
Packit |
eace71 |
actor_schedule_head(actor_t *thread)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
actor_schedule_private(thread, 0, 1);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
void
|
|
Packit |
eace71 |
actor_schedule(actor_t *thread)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
actor_schedule_private(thread, 0, 0);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
void
|
|
Packit |
eace71 |
actor_timer(actor_t *thread, uint32_t timeout_secs, void (*callback)(void *),
|
|
Packit |
eace71 |
void *data)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
actor_init(thread, callback, data);
|
|
Packit |
eace71 |
actor_schedule_private(thread, timeout_secs, 0);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
void
|
|
Packit |
eace71 |
actor_timer_mod(actor_t *thread, uint32_t new_timeout_secs, void *data)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
actor_delete(thread);
|
|
Packit |
eace71 |
thread->data = data;
|
|
Packit |
eace71 |
actor_schedule_private(thread, new_timeout_secs, 0);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
/*
|
|
Packit |
eace71 |
* Execute all items that have expired.
|
|
Packit |
eace71 |
*
|
|
Packit |
eace71 |
* Set an alarm if items remain. Caller must catch SIGALRM and
|
|
Packit |
eace71 |
* then re-invoke this function.
|
|
Packit |
eace71 |
*/
|
|
Packit |
eace71 |
void
|
|
Packit |
eace71 |
actor_poll(void)
|
|
Packit |
eace71 |
{
|
|
Packit |
eace71 |
struct actor *thread, *tmp;
|
|
Packit |
eace71 |
uint64_t current_time;
|
|
Packit |
eace71 |
struct timespec tv;
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
if (poll_in_progress) {
|
|
Packit |
eace71 |
log_error("recursive actor_poll() is not allowed");
|
|
Packit |
eace71 |
return;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
if (clock_gettime(CLOCK_MONOTONIC_COARSE, &tv)) {
|
|
Packit |
eace71 |
log_error("clock_gettime failed, can't schedule!");
|
|
Packit |
eace71 |
return;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
current_time = tv.tv_sec;
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
/*
|
|
Packit |
eace71 |
* Move items that are ripe from pend_list to ready_list.
|
|
Packit |
eace71 |
* Actors are in sorted order of ascending run time, so
|
|
Packit |
eace71 |
* stop at the first unripe entry.
|
|
Packit |
eace71 |
*/
|
|
Packit |
eace71 |
log_debug(7, "current time %" PRIu64, current_time);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
list_for_each_entry_safe(thread, tmp, &pend_list, list) {
|
|
Packit |
eace71 |
uint64_t time_left = actor_time_left(thread, current_time);
|
|
Packit |
eace71 |
if (time_left) {
|
|
Packit |
eace71 |
log_debug(7, "thread %08lx due %" PRIu64 ", wait %" PRIu64 " more",
|
|
Packit |
eace71 |
(long)thread, thread->ttschedule, time_left);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
alarm(time_left);
|
|
Packit |
eace71 |
break;
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
/* This entry can be run now */
|
|
Packit |
eace71 |
list_del_init(&thread->list);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
log_debug(2, "thread %08lx was scheduled for "
|
|
Packit |
eace71 |
"%" PRIu64 ", curtime %" PRIu64 " q_forw %p "
|
|
Packit |
eace71 |
"&pend_list %p",
|
|
Packit |
eace71 |
(long)thread, thread->ttschedule,
|
|
Packit |
eace71 |
current_time, pend_list.next, &pend_list);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
list_add_tail(&thread->list, &ready_list);
|
|
Packit |
eace71 |
assert(thread->state == ACTOR_WAITING);
|
|
Packit |
eace71 |
thread->state = ACTOR_SCHEDULED;
|
|
Packit |
eace71 |
log_debug(7, "thread %08lx now in ready_list",
|
|
Packit |
eace71 |
(long)thread);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
/* Disable alarm if nothing else pending */
|
|
Packit |
eace71 |
if (list_empty(&pend_list)) {
|
|
Packit |
eace71 |
log_debug(7, "nothing on pend_list, deactivating alarm");
|
|
Packit |
eace71 |
alarm(0);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
poll_in_progress = 1;
|
|
Packit |
eace71 |
while (!list_empty(&ready_list)) {
|
|
Packit |
eace71 |
thread = list_first_entry(&ready_list, struct actor, list);
|
|
Packit |
eace71 |
list_del_init(&thread->list);
|
|
Packit |
eace71 |
|
|
Packit |
eace71 |
if (thread->state != ACTOR_SCHEDULED)
|
|
Packit |
eace71 |
log_error("ready_list: thread state corrupted! "
|
|
Packit |
eace71 |
"Thread with state %d in actor list.",
|
|
Packit |
eace71 |
thread->state);
|
|
Packit |
eace71 |
thread->state = ACTOR_NOTSCHEDULED;
|
|
Packit |
eace71 |
log_debug(7, "exec thread %08lx callback", (long)thread);
|
|
Packit |
eace71 |
thread->callback(thread->data);
|
|
Packit |
eace71 |
log_debug(7, "thread %08lx done", (long)thread);
|
|
Packit |
eace71 |
}
|
|
Packit |
eace71 |
poll_in_progress = 0;
|
|
Packit |
eace71 |
}
|