--- /dev/null
+/*
+ * 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 "qemu/main-loop.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 {
+ /* We rely on BQL to protect the timerlists */
+ QLIST_HEAD(, QEMUTimerList) timerlists;
+
+ NotifierList reset_notifiers;
+ int64_t last;
+
+ QEMUClockType type;
+ bool enabled;
+} QEMUClock;
+
+QEMUTimerListGroup main_loop_tlg;
+static 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;
+ QemuMutex active_timers_lock;
+ QEMUTimer *active_timers;
+ QLIST_ENTRY(QEMUTimerList) list;
+ QEMUTimerListNotifyCB *notify_cb;
+ void *notify_opaque;
+
+ /* lightweight method to mark the end of timerlist's running */
+ QemuEvent timers_done_ev;
+};
+
+/**
+ * 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));
+ qemu_event_init(&timer_list->timers_done_ev, true);
+ timer_list->clock = clock;
+ timer_list->notify_cb = cb;
+ timer_list->notify_opaque = opaque;
+ qemu_mutex_init(&timer_list->active_timers_lock);
+ 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);
+ }
+ qemu_mutex_destroy(&timer_list->active_timers_lock);
+ g_free(timer_list);
+}
+
+static void qemu_clock_init(QEMUClockType type)
+{
+ QEMUClock *clock = qemu_clock_ptr(type);
+
+ /* Assert that the clock of type TYPE has not been initialized yet. */
+ assert(main_loop_tlg.tl[type] == NULL);
+
+ 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);
+ }
+}
+
+/* Disabling the clock will wait for related timerlists to stop
+ * executing qemu_run_timers. Thus, this functions should not
+ * be used from the callback of a timer that is based on @clock.
+ * Doing so would cause a deadlock.
+ *
+ * Caller should hold BQL.
+ */
+void qemu_clock_enable(QEMUClockType type, bool enabled)
+{
+ QEMUClock *clock = qemu_clock_ptr(type);
+ QEMUTimerList *tl;
+ bool old = clock->enabled;
+ clock->enabled = enabled;
+ if (enabled && !old) {
+ qemu_clock_notify(type);
+ } else if (!enabled && old) {
+ QLIST_FOREACH(tl, &clock->timerlists, list) {
+ qemu_event_wait(&tl->timers_done_ev);
+ }
+ }
+}
+
+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)
+{
+ int64_t expire_time;
+
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+ if (!timer_list->active_timers) {
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+ return false;
+ }
+ expire_time = timer_list->active_timers->expire_time;
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+
+ return 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;
+ int64_t expire_time;
+
+ if (!timer_list->clock->enabled) {
+ return -1;
+ }
+
+ /* The active timers list may be modified before the caller uses our return
+ * value but ->notify_cb() is called when the deadline changes. Therefore
+ * the caller should notice the change and there is no race condition.
+ */
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+ if (!timer_list->active_timers) {
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+ return -1;
+ }
+ expire_time = timer_list->active_timers->expire_time;
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+
+ delta = 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;
+ int64_t tvsec = timeout / 1000000000LL;
+ /* Avoid possibly overflowing and specifying a negative number of
+ * seconds, which would turn a very long timeout into a busy-wait.
+ */
+ if (tvsec > (int64_t)INT32_MAX) {
+ tvsec = INT32_MAX;
+ }
+ ts.tv_sec = tvsec;
+ 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_tl(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;
+ ts->expire_time = -1;
+}
+
+void timer_deinit(QEMUTimer *ts)
+{
+ assert(ts->expire_time == -1);
+ ts->timer_list = NULL;
+}
+
+void timer_free(QEMUTimer *ts)
+{
+ g_free(ts);
+}
+
+static void timer_del_locked(QEMUTimerList *timer_list, QEMUTimer *ts)
+{
+ QEMUTimer **pt, *t;
+
+ ts->expire_time = -1;
+ pt = &timer_list->active_timers;
+ for(;;) {
+ t = *pt;
+ if (!t)
+ break;
+ if (t == ts) {
+ *pt = t->next;
+ break;
+ }
+ pt = &t->next;
+ }
+}
+
+static bool timer_mod_ns_locked(QEMUTimerList *timer_list,
+ QEMUTimer *ts, int64_t expire_time)
+{
+ QEMUTimer **pt, *t;
+
+ /* add the timer in the sorted list */
+ pt = &timer_list->active_timers;
+ for (;;) {
+ t = *pt;
+ if (!timer_expired_ns(t, expire_time)) {
+ break;
+ }
+ pt = &t->next;
+ }
+ ts->expire_time = MAX(expire_time, 0);
+ ts->next = *pt;
+ *pt = ts;
+
+ return pt == &timer_list->active_timers;
+}
+
+static void timerlist_rearm(QEMUTimerList *timer_list)
+{
+ /* Interrupt execution to force deadline recalculation. */
+ qemu_clock_warp(timer_list->clock->type);
+ timerlist_notify(timer_list);
+}
+
+/* stop a timer, but do not dealloc it */
+void timer_del(QEMUTimer *ts)
+{
+ QEMUTimerList *timer_list = ts->timer_list;
+
+ if (timer_list) {
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+ timer_del_locked(timer_list, ts);
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+ }
+}
+
+/* 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)
+{
+ QEMUTimerList *timer_list = ts->timer_list;
+ bool rearm;
+
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+ timer_del_locked(timer_list, ts);
+ rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+
+ if (rearm) {
+ timerlist_rearm(timer_list);
+ }
+}
+
+/* modify the current timer so that it will be fired when current_time
+ >= expire_time or the current deadline, whichever comes earlier.
+ The corresponding callback will be called. */
+void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time)
+{
+ QEMUTimerList *timer_list = ts->timer_list;
+ bool rearm;
+
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+ if (ts->expire_time == -1 || ts->expire_time > expire_time) {
+ if (ts->expire_time != -1) {
+ timer_del_locked(timer_list, ts);
+ }
+ rearm = timer_mod_ns_locked(timer_list, ts, expire_time);
+ } else {
+ rearm = false;
+ }
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+
+ if (rearm) {
+ timerlist_rearm(timer_list);
+ }
+}
+
+void timer_mod(QEMUTimer *ts, int64_t expire_time)
+{
+ timer_mod_ns(ts, expire_time * ts->scale);
+}
+
+void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time)
+{
+ timer_mod_anticipate_ns(ts, expire_time * ts->scale);
+}
+
+bool timer_pending(QEMUTimer *ts)
+{
+ return ts->expire_time >= 0;
+}
+
+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;
+ QEMUTimerCB *cb;
+ void *opaque;
+
+ qemu_event_reset(&timer_list->timers_done_ev);
+ if (!timer_list->clock->enabled) {
+ goto out;
+ }
+
+ current_time = qemu_clock_get_ns(timer_list->clock->type);
+ for(;;) {
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+ ts = timer_list->active_timers;
+ if (!timer_expired_ns(ts, current_time)) {
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+ break;
+ }
+
+ /* remove timer from the list before calling the callback */
+ timer_list->active_timers = ts->next;
+ ts->next = NULL;
+ ts->expire_time = -1;
+ cb = ts->cb;
+ opaque = ts->opaque;
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+
+ /* run the callback (the timer list can be modified) */
+ cb(opaque);
+ progress = true;
+ }
+
+out:
+ qemu_event_set(&timer_list->timers_done_ev);
+ 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 || now > (last + get_max_clock_jump())) {
+ notifier_list_notify(&clock->reset_notifiers, &now);
+ }
+ return now;
+ case QEMU_CLOCK_VIRTUAL_RT:
+ return cpu_get_clock();
+ }
+}
+
+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;
+}
Code Review / kvmfornfv.git / blobdiff