[Qemu-devel] [RFC] [PATCHv6 15/16] aio / timers: Remove alarm timers

[Alex Bligh <alex@alex.org.uk>]

Remove alarm timers from qemu-timers.c now we use g_poll / ppoll
instead.

Signed-off-by: Alex Bligh <alex@alex.org.uk>
---
 include/qemu/timer.h |    2 -
 main-loop.c          |    4 -
 qemu-timer.c         |  500 +-------------------------------------------------
 vl.c                 |    4 +-
 4 files changed, 4 insertions(+), 506 deletions(-)

diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index b6e5efd..8d6a050 100644
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -142,9 +142,7 @@ static inline uint64_t timer_expire_time_ns(QEMUTimer *ts)
 
 bool qemu_run_timers(QEMUClock *clock);
 bool qemu_run_all_timers(void);
-void configure_alarms(char const *opt);
 void init_clocks(void);
-int init_timer_alarm(void);
 
 int64_t cpu_get_ticks(void);
 void cpu_enable_ticks(void);
diff --git a/main-loop.c b/main-loop.c
index 43dfcd7..754d276 100644
--- a/main-loop.c
+++ b/main-loop.c
@@ -131,10 +131,6 @@ int qemu_init_main_loop(void)
     GSource *src;
 
     init_clocks();
-    if (init_timer_alarm() < 0) {
-        fprintf(stderr, "could not initialize alarm timer\n");
-        exit(1);
-    }
 
     ret = qemu_signal_init();
     if (ret) {
diff --git a/qemu-timer.c b/qemu-timer.c
index a7ef047..e820e63 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -33,10 +33,6 @@
 #include <pthread.h>
 #endif
 
-#ifdef _WIN32
-#include <mmsystem.h>
-#endif
-
 #ifdef CONFIG_PPOLL
 #include <poll.h>
 #endif
@@ -86,174 +82,11 @@ struct QEMUTimer {
     int scale;
 };
 
-struct qemu_alarm_timer {
-    char const *name;
-    int (*start)(struct qemu_alarm_timer *t);
-    void (*stop)(struct qemu_alarm_timer *t);
-    void (*rearm)(struct qemu_alarm_timer *t, int64_t nearest_delta_ns);
-#if defined(__linux__)
-    timer_t timer;
-    int fd;
-#elif defined(_WIN32)
-    HANDLE timer;
-#endif
-    bool expired;
-    bool pending;
-};
-
-static struct qemu_alarm_timer *alarm_timer;
-
 static bool qemu_timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
 {
     return timer_head && (timer_head->expire_time <= current_time);
 }
 
-static int64_t qemu_next_alarm_deadline(void)
-{
-    int64_t delta = INT64_MAX;
-    int64_t rtdelta;
-    int64_t hdelta;
-
-    if (!use_icount && vm_clock->enabled &&
-        vm_clock->default_timerlist->active_timers) {
-        delta = vm_clock->default_timerlist->active_timers->expire_time -
-            qemu_get_clock_ns(vm_clock);
-    }
-    if (host_clock->enabled &&
-        host_clock->default_timerlist->active_timers) {
-        hdelta = host_clock->default_timerlist->active_timers->expire_time -
-            qemu_get_clock_ns(host_clock);
-        if (hdelta < delta) {
-            delta = hdelta;
-        }
-    }
-    if (rt_clock->enabled &&
-        rt_clock->default_timerlist->active_timers) {
-        rtdelta = (rt_clock->default_timerlist->active_timers->expire_time -
-                   qemu_get_clock_ns(rt_clock));
-        if (rtdelta < delta) {
-            delta = rtdelta;
-        }
-    }
-
-    return delta;
-}
-
-static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
-{
-    int64_t nearest_delta_ns = qemu_next_alarm_deadline();
-    if (nearest_delta_ns < INT64_MAX) {
-        t->rearm(t, nearest_delta_ns);
-    }
-}
-
-/* TODO: MIN_TIMER_REARM_NS should be optimized */
-#define MIN_TIMER_REARM_NS 250000
-
-#ifdef _WIN32
-
-static int mm_start_timer(struct qemu_alarm_timer *t);
-static void mm_stop_timer(struct qemu_alarm_timer *t);
-static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
-
-static int win32_start_timer(struct qemu_alarm_timer *t);
-static void win32_stop_timer(struct qemu_alarm_timer *t);
-static void win32_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
-
-#else
-
-static int unix_start_timer(struct qemu_alarm_timer *t);
-static void unix_stop_timer(struct qemu_alarm_timer *t);
-static void unix_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
-
-#ifdef __linux__
-
-static int dynticks_start_timer(struct qemu_alarm_timer *t);
-static void dynticks_stop_timer(struct qemu_alarm_timer *t);
-static void dynticks_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
-
-#endif /* __linux__ */
-
-#endif /* _WIN32 */
-
-static struct qemu_alarm_timer alarm_timers[] = {
-#ifndef _WIN32
-#ifdef __linux__
-    {"dynticks", dynticks_start_timer,
-     dynticks_stop_timer, dynticks_rearm_timer},
-#endif
-    {"unix", unix_start_timer, unix_stop_timer, unix_rearm_timer},
-#else
-    {"mmtimer", mm_start_timer, mm_stop_timer, mm_rearm_timer},
-    {"dynticks", win32_start_timer, win32_stop_timer, win32_rearm_timer},
-#endif
-    {NULL, }
-};
-
-static void show_available_alarms(void)
-{
-    int i;
-
-    printf("Available alarm timers, in order of precedence:\n");
-    for (i = 0; alarm_timers[i].name; i++)
-        printf("%s\n", alarm_timers[i].name);
-}
-
-void configure_alarms(char const *opt)
-{
-    int i;
-    int cur = 0;
-    int count = ARRAY_SIZE(alarm_timers) - 1;
-    char *arg;
-    char *name;
-    struct qemu_alarm_timer tmp;
-
-    if (is_help_option(opt)) {
-        show_available_alarms();
-        exit(0);
-    }
-
-    arg = g_strdup(opt);
-
-    /* Reorder the array */
-    name = strtok(arg, ",");
-    while (name) {
-        for (i = 0; i < count && alarm_timers[i].name; i++) {
-            if (!strcmp(alarm_timers[i].name, name))
-                break;
-        }
-
-        if (i == count) {
-            fprintf(stderr, "Unknown clock %s\n", name);
-            goto next;
-        }
-
-        if (i < cur)
-            /* Ignore */
-            goto next;
-
-	/* Swap */
-        tmp = alarm_timers[i];
-        alarm_timers[i] = alarm_timers[cur];
-        alarm_timers[cur] = tmp;
-
-        cur++;
-next:
-        name = strtok(NULL, ",");
-    }
-
-    g_free(arg);
-
-    if (cur) {
-        /* Disable remaining timers */
-        for (i = cur; i < count; i++)
-            alarm_timers[i].name = NULL;
-    } else {
-        show_available_alarms();
-        exit(1);
-    }
-}
-
 static QEMUTimerList *timerlist_new_from_clock(QEMUClock *clock)
 {
     QEMUTimerList *tl;
@@ -318,7 +151,6 @@ void qemu_clock_enable(QEMUClock *clock, bool enabled)
     clock->enabled = enabled;
     if (enabled && !old) {
         qemu_clock_notify(clock);
-        qemu_rearm_alarm_timer(alarm_timer);
     }
 }
 
@@ -549,9 +381,6 @@ void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
 
     /* Rearm if necessary  */
     if (pt == &ts->tl->active_timers) {
-        if (!alarm_timer->pending) {
-            qemu_rearm_alarm_timer(alarm_timer);
-        }
         /* Interrupt execution to force deadline recalculation.  */
         qemu_clock_warp(ts->tl->clock);
         timerlist_notify(ts->tl);
@@ -710,338 +539,11 @@ uint64_t qemu_timer_expire_time_ns(QEMUTimer *ts)
 bool qemu_run_all_timers(void)
 {
     bool progress = false;
-    alarm_timer->pending = false;
-
-    /* vm time timers */
     QEMUClockType type;
+
     for (type = 0; type < QEMU_CLOCK_MAX; type++) {
         progress |= qemu_run_timers(qemu_get_clock(type));
     }
 
-    /* rearm timer, if not periodic */
-    if (alarm_timer->expired) {
-        alarm_timer->expired = false;
-        qemu_rearm_alarm_timer(alarm_timer);
-    }
-
     return progress;
 }
-
-#ifdef _WIN32
-static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
-#else
-static void host_alarm_handler(int host_signum)
-#endif
-{
-    struct qemu_alarm_timer *t = alarm_timer;
-    if (!t)
-	return;
-
-    t->expired = true;
-    t->pending = true;
-    qemu_notify_event();
-}
-
-#if defined(__linux__)
-
-#include "qemu/compatfd.h"
-
-static int dynticks_start_timer(struct qemu_alarm_timer *t)
-{
-    struct sigevent ev;
-    timer_t host_timer;
-    struct sigaction act;
-
-    sigfillset(&act.sa_mask);
-    act.sa_flags = 0;
-    act.sa_handler = host_alarm_handler;
-
-    sigaction(SIGALRM, &act, NULL);
-
-    /* 
-     * Initialize ev struct to 0 to avoid valgrind complaining
-     * about uninitialized data in timer_create call
-     */
-    memset(&ev, 0, sizeof(ev));
-    ev.sigev_value.sival_int = 0;
-    ev.sigev_notify = SIGEV_SIGNAL;
-#ifdef CONFIG_SIGEV_THREAD_ID
-    if (qemu_signalfd_available()) {
-        ev.sigev_notify = SIGEV_THREAD_ID;
-        ev._sigev_un._tid = qemu_get_thread_id();
-    }
-#endif /* CONFIG_SIGEV_THREAD_ID */
-    ev.sigev_signo = SIGALRM;
-
-    if (timer_create(CLOCK_REALTIME, &ev, &host_timer)) {
-        perror("timer_create");
-        return -1;
-    }
-
-    t->timer = host_timer;
-
-    return 0;
-}
-
-static void dynticks_stop_timer(struct qemu_alarm_timer *t)
-{
-    timer_t host_timer = t->timer;
-
-    timer_delete(host_timer);
-}
-
-static void dynticks_rearm_timer(struct qemu_alarm_timer *t,
-                                 int64_t nearest_delta_ns)
-{
-    timer_t host_timer = t->timer;
-    struct itimerspec timeout;
-    int64_t current_ns;
-
-    if (nearest_delta_ns < MIN_TIMER_REARM_NS)
-        nearest_delta_ns = MIN_TIMER_REARM_NS;
-
-    /* check whether a timer is already running */
-    if (timer_gettime(host_timer, &timeout)) {
-        perror("gettime");
-        fprintf(stderr, "Internal timer error: aborting\n");
-        exit(1);
-    }
-    current_ns = timeout.it_value.tv_sec * 1000000000LL + timeout.it_value.tv_nsec;
-    if (current_ns && current_ns <= nearest_delta_ns)
-        return;
-
-    timeout.it_interval.tv_sec = 0;
-    timeout.it_interval.tv_nsec = 0; /* 0 for one-shot timer */
-    timeout.it_value.tv_sec =  nearest_delta_ns / 1000000000;
-    timeout.it_value.tv_nsec = nearest_delta_ns % 1000000000;
-    if (timer_settime(host_timer, 0 /* RELATIVE */, &timeout, NULL)) {
-        perror("settime");
-        fprintf(stderr, "Internal timer error: aborting\n");
-        exit(1);
-    }
-}
-
-#endif /* defined(__linux__) */
-
-#if !defined(_WIN32)
-
-static int unix_start_timer(struct qemu_alarm_timer *t)
-{
-    struct sigaction act;
-
-    /* timer signal */
-    sigfillset(&act.sa_mask);
-    act.sa_flags = 0;
-    act.sa_handler = host_alarm_handler;
-
-    sigaction(SIGALRM, &act, NULL);
-    return 0;
-}
-
-static void unix_rearm_timer(struct qemu_alarm_timer *t,
-                             int64_t nearest_delta_ns)
-{
-    struct itimerval itv;
-    int err;
-
-    if (nearest_delta_ns < MIN_TIMER_REARM_NS)
-        nearest_delta_ns = MIN_TIMER_REARM_NS;
-
-    itv.it_interval.tv_sec = 0;
-    itv.it_interval.tv_usec = 0; /* 0 for one-shot timer */
-    itv.it_value.tv_sec =  nearest_delta_ns / 1000000000;
-    itv.it_value.tv_usec = (nearest_delta_ns % 1000000000) / 1000;
-    err = setitimer(ITIMER_REAL, &itv, NULL);
-    if (err) {
-        perror("setitimer");
-        fprintf(stderr, "Internal timer error: aborting\n");
-        exit(1);
-    }
-}
-
-static void unix_stop_timer(struct qemu_alarm_timer *t)
-{
-    struct itimerval itv;
-
-    memset(&itv, 0, sizeof(itv));
-    setitimer(ITIMER_REAL, &itv, NULL);
-}
-
-#endif /* !defined(_WIN32) */
-
-
-#ifdef _WIN32
-
-static MMRESULT mm_timer;
-static TIMECAPS mm_tc;
-
-static void CALLBACK mm_alarm_handler(UINT uTimerID, UINT uMsg,
-                                      DWORD_PTR dwUser, DWORD_PTR dw1,
-                                      DWORD_PTR dw2)
-{
-    struct qemu_alarm_timer *t = alarm_timer;
-    if (!t) {
-        return;
-    }
-    t->expired = true;
-    t->pending = true;
-    qemu_notify_event();
-}
-
-static int mm_start_timer(struct qemu_alarm_timer *t)
-{
-    timeGetDevCaps(&mm_tc, sizeof(mm_tc));
-    return 0;
-}
-
-static void mm_stop_timer(struct qemu_alarm_timer *t)
-{
-    if (mm_timer) {
-        timeKillEvent(mm_timer);
-    }
-}
-
-static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta)
-{
-    int64_t nearest_delta_ms = delta / 1000000;
-    if (nearest_delta_ms < mm_tc.wPeriodMin) {
-        nearest_delta_ms = mm_tc.wPeriodMin;
-    } else if (nearest_delta_ms > mm_tc.wPeriodMax) {
-        nearest_delta_ms = mm_tc.wPeriodMax;
-    }
-
-    if (mm_timer) {
-        timeKillEvent(mm_timer);
-    }
-    mm_timer = timeSetEvent((UINT)nearest_delta_ms,
-                            mm_tc.wPeriodMin,
-                            mm_alarm_handler,
-                            (DWORD_PTR)t,
-                            TIME_ONESHOT | TIME_CALLBACK_FUNCTION);
-
-    if (!mm_timer) {
-        fprintf(stderr, "Failed to re-arm win32 alarm timer\n");
-        timeEndPeriod(mm_tc.wPeriodMin);
-        exit(1);
-    }
-}
-
-static int win32_start_timer(struct qemu_alarm_timer *t)
-{
-    HANDLE hTimer;
-    BOOLEAN success;
-
-    /* If you call ChangeTimerQueueTimer on a one-shot timer (its period
-       is zero) that has already expired, the timer is not updated.  Since
-       creating a new timer is relatively expensive, set a bogus one-hour
-       interval in the dynticks case.  */
-    success = CreateTimerQueueTimer(&hTimer,
-                          NULL,
-                          host_alarm_handler,
-                          t,
-                          1,
-                          3600000,
-                          WT_EXECUTEINTIMERTHREAD);
-
-    if (!success) {
-        fprintf(stderr, "Failed to initialize win32 alarm timer: %ld\n",
-                GetLastError());
-        return -1;
-    }
-
-    t->timer = hTimer;
-    return 0;
-}
-
-static void win32_stop_timer(struct qemu_alarm_timer *t)
-{
-    HANDLE hTimer = t->timer;
-
-    if (hTimer) {
-        DeleteTimerQueueTimer(NULL, hTimer, NULL);
-    }
-}
-
-static void win32_rearm_timer(struct qemu_alarm_timer *t,
-                              int64_t nearest_delta_ns)
-{
-    HANDLE hTimer = t->timer;
-    int64_t nearest_delta_ms;
-    BOOLEAN success;
-
-    nearest_delta_ms = nearest_delta_ns / 1000000;
-    if (nearest_delta_ms < 1) {
-        nearest_delta_ms = 1;
-    }
-    /* ULONG_MAX can be 32 bit */
-    if (nearest_delta_ms > ULONG_MAX) {
-        nearest_delta_ms = ULONG_MAX;
-    }
-    success = ChangeTimerQueueTimer(NULL,
-                                    hTimer,
-                                    (unsigned long) nearest_delta_ms,
-                                    3600000);
-
-    if (!success) {
-        fprintf(stderr, "Failed to rearm win32 alarm timer: %ld\n",
-                GetLastError());
-        exit(-1);
-    }
-
-}
-
-#endif /* _WIN32 */
-
-static void quit_timers(void)
-{
-    struct qemu_alarm_timer *t = alarm_timer;
-    alarm_timer = NULL;
-    t->stop(t);
-}
-
-#ifdef CONFIG_POSIX
-static void reinit_timers(void)
-{
-    struct qemu_alarm_timer *t = alarm_timer;
-    t->stop(t);
-    if (t->start(t)) {
-        fprintf(stderr, "Internal timer error: aborting\n");
-        exit(1);
-    }
-    qemu_rearm_alarm_timer(t);
-}
-#endif /* CONFIG_POSIX */
-
-int init_timer_alarm(void)
-{
-    struct qemu_alarm_timer *t = NULL;
-    int i, err = -1;
-
-    if (alarm_timer) {
-        return 0;
-    }
-
-    for (i = 0; alarm_timers[i].name; i++) {
-        t = &alarm_timers[i];
-
-        err = t->start(t);
-        if (!err)
-            break;
-    }
-
-    if (err) {
-        err = -ENOENT;
-        goto fail;
-    }
-
-    atexit(quit_timers);
-#ifdef CONFIG_POSIX
-    pthread_atfork(NULL, NULL, reinit_timers);
-#endif
-    alarm_timer = t;
-    return 0;
-
-fail:
-    return err;
-}
-
diff --git a/vl.c b/vl.c
index f422a1c..4c68668 100644
--- a/vl.c
+++ b/vl.c
@@ -3714,7 +3714,9 @@ int main(int argc, char **argv, char **envp)
                 old_param = 1;
                 break;
             case QEMU_OPTION_clock:
-                configure_alarms(optarg);
+                /* Clock options no longer exist.  Keep this option for
+                 * backward compatibility.
+                 */
                 break;
             case QEMU_OPTION_startdate:
                 configure_rtc_date_offset(optarg, 1);
-- 
1.7.9.5