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qemu/qemu-timer.c

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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "sysemu/sysemu.h"
#include "monitor/monitor.h"
#include "ui/console.h"
#include "hw/hw.h"
#include "qemu/timer.h"
#ifdef CONFIG_POSIX
#include <pthread.h>
#endif
#ifdef CONFIG_PPOLL
#include <poll.h>
#endif
#ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
#include <sys/prctl.h>
#endif
/***********************************************************/
/* timers */
typedef struct QEMUClock {
QLIST_HEAD(, QEMUTimerList) timerlists;
NotifierList reset_notifiers;
int64_t last;
QEMUClockType type;
bool enabled;
} QEMUClock;
QEMUTimerListGroup main_loop_tlg;
QEMUClock qemu_clocks[QEMU_CLOCK_MAX];
/* A QEMUTimerList is a list of timers attached to a clock. More
* than one QEMUTimerList can be attached to each clock, for instance
* used by different AioContexts / threads. Each clock also has
* a list of the QEMUTimerLists associated with it, in order that
* reenabling the clock can call all the notifiers.
*/
struct QEMUTimerList {
QEMUClock *clock;
QEMUTimer *active_timers;
QLIST_ENTRY(QEMUTimerList) list;
QEMUTimerListNotifyCB *notify_cb;
void *notify_opaque;
};
/**
* qemu_clock_ptr:
* @type: type of clock
*
* Translate a clock type into a pointer to QEMUClock object.
*
* Returns: a pointer to the QEMUClock object
*/
static inline QEMUClock *qemu_clock_ptr(QEMUClockType type)
{
return &qemu_clocks[type];
}
static bool timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
{
return timer_head && (timer_head->expire_time <= current_time);
}
QEMUTimerList *timerlist_new(QEMUClockType type,
QEMUTimerListNotifyCB *cb,
void *opaque)
{
QEMUTimerList *timer_list;
QEMUClock *clock = qemu_clock_ptr(type);
timer_list = g_malloc0(sizeof(QEMUTimerList));
timer_list->clock = clock;
timer_list->notify_cb = cb;
timer_list->notify_opaque = opaque;
QLIST_INSERT_HEAD(&clock->timerlists, timer_list, list);
return timer_list;
}
void timerlist_free(QEMUTimerList *timer_list)
{
assert(!timerlist_has_timers(timer_list));
if (timer_list->clock) {
QLIST_REMOVE(timer_list, list);
}
g_free(timer_list);
}
static void qemu_clock_init(QEMUClockType type)
{
QEMUClock *clock = qemu_clock_ptr(type);
clock->type = type;
clock->enabled = true;
clock->last = INT64_MIN;
QLIST_INIT(&clock->timerlists);
notifier_list_init(&clock->reset_notifiers);
main_loop_tlg.tl[type] = timerlist_new(type, NULL, NULL);
}
bool qemu_clock_use_for_deadline(QEMUClockType type)
{
return !(use_icount && (type == QEMU_CLOCK_VIRTUAL));
}
void qemu_clock_notify(QEMUClockType type)
{
QEMUTimerList *timer_list;
QEMUClock *clock = qemu_clock_ptr(type);
QLIST_FOREACH(timer_list, &clock->timerlists, list) {
timerlist_notify(timer_list);
}
}
void qemu_clock_enable(QEMUClockType type, bool enabled)
{
QEMUClock *clock = qemu_clock_ptr(type);
bool old = clock->enabled;
clock->enabled = enabled;
if (enabled && !old) {
qemu_clock_notify(type);
}
}
bool timerlist_has_timers(QEMUTimerList *timer_list)
{
return !!timer_list->active_timers;
}
bool qemu_clock_has_timers(QEMUClockType type)
{
return timerlist_has_timers(
main_loop_tlg.tl[type]);
}
bool timerlist_expired(QEMUTimerList *timer_list)
{
return (timer_list->active_timers &&
timer_list->active_timers->expire_time <
qemu_clock_get_ns(timer_list->clock->type));
}
bool qemu_clock_expired(QEMUClockType type)
{
return timerlist_expired(
main_loop_tlg.tl[type]);
}
/*
* As above, but return -1 for no deadline, and do not cap to 2^32
* as we know the result is always positive.
*/
int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
{
int64_t delta;
if (!timer_list->clock->enabled || !timer_list->active_timers) {
return -1;
}
delta = timer_list->active_timers->expire_time -
qemu_clock_get_ns(timer_list->clock->type);
if (delta <= 0) {
return 0;
}
return delta;
}
/* Calculate the soonest deadline across all timerlists attached
* to the clock. This is used for the icount timeout so we
* ignore whether or not the clock should be used in deadline
* calculations.
*/
int64_t qemu_clock_deadline_ns_all(QEMUClockType type)
{
int64_t deadline = -1;
QEMUTimerList *timer_list;
QEMUClock *clock = qemu_clock_ptr(type);
QLIST_FOREACH(timer_list, &clock->timerlists, list) {
deadline = qemu_soonest_timeout(deadline,
timerlist_deadline_ns(timer_list));
}
return deadline;
}
QEMUClockType timerlist_get_clock(QEMUTimerList *timer_list)
{
return timer_list->clock->type;
}
QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClockType type)
{
return main_loop_tlg.tl[type];
}
void timerlist_notify(QEMUTimerList *timer_list)
{
if (timer_list->notify_cb) {
timer_list->notify_cb(timer_list->notify_opaque);
} else {
qemu_notify_event();
}
}
/* Transition function to convert a nanosecond timeout to ms
* This is used where a system does not support ppoll
*/
int qemu_timeout_ns_to_ms(int64_t ns)
{
int64_t ms;
if (ns < 0) {
return -1;
}
if (!ns) {
return 0;
}
/* Always round up, because it's better to wait too long than to wait too
* little and effectively busy-wait
*/
ms = (ns + SCALE_MS - 1) / SCALE_MS;
/* To avoid overflow problems, limit this to 2^31, i.e. approx 25 days */
if (ms > (int64_t) INT32_MAX) {
ms = INT32_MAX;
}
return (int) ms;
}
/* qemu implementation of g_poll which uses a nanosecond timeout but is
* otherwise identical to g_poll
*/
int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout)
{
#ifdef CONFIG_PPOLL
if (timeout < 0) {
return ppoll((struct pollfd *)fds, nfds, NULL, NULL);
} else {
struct timespec ts;
ts.tv_sec = timeout / 1000000000LL;
ts.tv_nsec = timeout % 1000000000LL;
return ppoll((struct pollfd *)fds, nfds, &ts, NULL);
}
#else
return g_poll(fds, nfds, qemu_timeout_ns_to_ms(timeout));
#endif
}
void timer_init(QEMUTimer *ts,
QEMUTimerList *timer_list, int scale,
QEMUTimerCB *cb, void *opaque)
{
ts->timer_list = timer_list;
ts->cb = cb;
ts->opaque = opaque;
ts->scale = scale;
}
void timer_free(QEMUTimer *ts)
{
g_free(ts);
}
/* stop a timer, but do not dealloc it */
void timer_del(QEMUTimer *ts)
{
QEMUTimer **pt, *t;
/* NOTE: this code must be signal safe because
timer_expired() can be called from a signal. */
pt = &ts->timer_list->active_timers;
for(;;) {
t = *pt;
if (!t)
break;
if (t == ts) {
*pt = t->next;
break;
}
pt = &t->next;
}
}
/* modify the current timer so that it will be fired when current_time
>= expire_time. The corresponding callback will be called. */
void timer_mod_ns(QEMUTimer *ts, int64_t expire_time)
{
QEMUTimer **pt, *t;
timer_del(ts);
/* add the timer in the sorted list */
/* NOTE: this code must be signal safe because
timer_expired() can be called from a signal. */
pt = &ts->timer_list->active_timers;
for(;;) {
t = *pt;
if (!timer_expired_ns(t, expire_time)) {
break;
}
pt = &t->next;
}
ts->expire_time = expire_time;
ts->next = *pt;
*pt = ts;
/* Rearm if necessary */
if (pt == &ts->timer_list->active_timers) {
/* Interrupt execution to force deadline recalculation. */
qemu_clock_warp(ts->timer_list->clock->type);
timerlist_notify(ts->timer_list);
}
}
void timer_mod(QEMUTimer *ts, int64_t expire_time)
{
timer_mod_ns(ts, expire_time * ts->scale);
}
bool timer_pending(QEMUTimer *ts)
{
QEMUTimer *t;
for (t = ts->timer_list->active_timers; t != NULL; t = t->next) {
if (t == ts) {
return true;
}
}
return false;
}
bool timer_expired(QEMUTimer *timer_head, int64_t current_time)
{
return timer_expired_ns(timer_head, current_time * timer_head->scale);
}
bool timerlist_run_timers(QEMUTimerList *timer_list)
{
QEMUTimer *ts;
int64_t current_time;
bool progress = false;
if (!timer_list->clock->enabled) {
return progress;
}
current_time = qemu_clock_get_ns(timer_list->clock->type);
for(;;) {
ts = timer_list->active_timers;
if (!timer_expired_ns(ts, current_time)) {
break;
}
/* remove timer from the list before calling the callback */
timer_list->active_timers = ts->next;
ts->next = NULL;
/* run the callback (the timer list can be modified) */
ts->cb(ts->opaque);
progress = true;
}
return progress;
}
bool qemu_clock_run_timers(QEMUClockType type)
{
return timerlist_run_timers(main_loop_tlg.tl[type]);
}
void timerlistgroup_init(QEMUTimerListGroup *tlg,
QEMUTimerListNotifyCB *cb, void *opaque)
{
QEMUClockType type;
for (type = 0; type < QEMU_CLOCK_MAX; type++) {
tlg->tl[type] = timerlist_new(type, cb, opaque);
}
}
void timerlistgroup_deinit(QEMUTimerListGroup *tlg)
{
QEMUClockType type;
for (type = 0; type < QEMU_CLOCK_MAX; type++) {
timerlist_free(tlg->tl[type]);
}
}
bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg)
{
QEMUClockType type;
bool progress = false;
for (type = 0; type < QEMU_CLOCK_MAX; type++) {
progress |= timerlist_run_timers(tlg->tl[type]);
}
return progress;
}
int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg)
{
int64_t deadline = -1;
QEMUClockType type;
for (type = 0; type < QEMU_CLOCK_MAX; type++) {
if (qemu_clock_use_for_deadline(tlg->tl[type]->clock->type)) {
deadline = qemu_soonest_timeout(deadline,
timerlist_deadline_ns(
tlg->tl[type]));
}
}
return deadline;
}
int64_t qemu_clock_get_ns(QEMUClockType type)
{
int64_t now, last;
QEMUClock *clock = qemu_clock_ptr(type);
switch (type) {
case QEMU_CLOCK_REALTIME:
return get_clock();
default:
case QEMU_CLOCK_VIRTUAL:
if (use_icount) {
return cpu_get_icount();
} else {
return cpu_get_clock();
}
case QEMU_CLOCK_HOST:
now = get_clock_realtime();
last = clock->last;
clock->last = now;
if (now < last) {
notifier_list_notify(&clock->reset_notifiers, &now);
}
return now;
}
}
void qemu_clock_register_reset_notifier(QEMUClockType type,
Notifier *notifier)
{
QEMUClock *clock = qemu_clock_ptr(type);
notifier_list_add(&clock->reset_notifiers, notifier);
}
void qemu_clock_unregister_reset_notifier(QEMUClockType type,
Notifier *notifier)
{
notifier_remove(notifier);
}
void init_clocks(void)
{
QEMUClockType type;
for (type = 0; type < QEMU_CLOCK_MAX; type++) {
qemu_clock_init(type);
}
#ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK
prctl(PR_SET_TIMERSLACK, 1, 0, 0, 0);
#endif
}
uint64_t timer_expire_time_ns(QEMUTimer *ts)
{
return timer_pending(ts) ? ts->expire_time : -1;
}
bool qemu_clock_run_all_timers(void)
{
bool progress = false;
QEMUClockType type;
for (type = 0; type < QEMU_CLOCK_MAX; type++) {
progress |= qemu_clock_run_timers(type);
}
return progress;
}
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