[Qemu-devel] [RFC v2 2/5] timer: pick out timer list info from QemuClock

[Liu Ping Fan]

In qemu-wide, we will have three clocksource, they are present
by rt_clock/vm_clock/host_clock. On the other hand, we want to
run timers on the different backend threads by binding AioContext
with its own three timer lists.
So clean up the QemuClock struct to use it as the clock source.

Signed-off-by: Liu Ping Fan <address@hidden>
---
 qemu-timer.c | 106 ++++++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 68 insertions(+), 38 deletions(-)

diff --git a/qemu-timer.c b/qemu-timer.c
index 9500d12..5a42035 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -30,6 +30,7 @@
 
 #include "qemu/timer.h"
 #include "qemu/thread.h"
+#include "qemu/tls.h"
 #ifdef CONFIG_POSIX
 #include <pthread.h>
 #endif
@@ -44,11 +45,16 @@
 #define QEMU_CLOCK_REALTIME 0
 #define QEMU_CLOCK_VIRTUAL  1
 #define QEMU_CLOCK_HOST     2
+#define QEMU_CLOCK_MAXCNT 3
 
-struct QEMUClock {
+typedef struct TimerList {
     QEMUTimer *active_timers;
     QemuMutex active_timers_lock;
+} TimerList;
+
+static TimerList timer_list[QEMU_CLOCK_MAXCNT];
 
+struct QEMUClock {
     NotifierList reset_notifiers;
     int64_t last;
 
@@ -58,7 +64,7 @@ struct QEMUClock {
 
 struct QEMUTimer {
     int64_t expire_time;       /* in nanoseconds */
-    QEMUClock *clock;
+    TimerList *list;
     QEMUTimerCB *cb;
     void *opaque;
     QEMUTimer *next;
@@ -86,6 +92,13 @@ struct qemu_alarm_timer {
 
 static struct qemu_alarm_timer *alarm_timer;
 
+static TimerList *clock_to_timerlist(QEMUClock *clock)
+{
+    int type = clock->type;
+
+    return  &timer_list[type];
+}
+
 static bool qemu_timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
 {
     return timer_head && (timer_head->expire_time <= current_time);
@@ -95,17 +108,19 @@ static int64_t qemu_next_clock_deadline(QEMUClock *clock, 
int64_t delta)
 {
     int64_t expire_time, next;
     bool has_timer = false;
+    TimerList *tlist;
 
     if (!clock->enabled) {
         return delta;
     }
 
-    qemu_mutex_lock(&clock->active_timers_lock);
-    if (clock->active_timers) {
+    tlist = clock_to_timerlist(clock);
+    qemu_mutex_lock(&tlist->active_timers_lock);
+    if (tlist->active_timers) {
         has_timer = true;
-        expire_time = clock->active_timers->expire_time;
+        expire_time = tlist->active_timers->expire_time;
     }
-    qemu_mutex_unlock(&clock->active_timers_lock);
+    qemu_mutex_unlock(&tlist->active_timers_lock);
     if (!has_timer) {
         return delta;
     }
@@ -244,16 +259,25 @@ QEMUClock *rt_clock;
 QEMUClock *vm_clock;
 QEMUClock *host_clock;
 
+static void timer_list_init(TimerList *tlist)
+{
+    qemu_mutex_init(&tlist->active_timers_lock);
+    tlist->active_timers = NULL;
+}
+
 static QEMUClock *qemu_new_clock(int type)
 {
     QEMUClock *clock;
+    TimerList *tlist;
 
     clock = g_malloc0(sizeof(QEMUClock));
     clock->type = type;
     clock->enabled = true;
     clock->last = INT64_MIN;
     notifier_list_init(&clock->reset_notifiers);
-    qemu_mutex_init(&clock->active_timers_lock);
+    tlist = clock_to_timerlist(clock);
+    timer_list_init(tlist);
+
     return clock;
 }
 
@@ -269,10 +293,11 @@ void qemu_clock_enable(QEMUClock *clock, bool enabled)
 int64_t qemu_clock_has_timers(QEMUClock *clock)
 {
     bool has_timers;
+    TimerList *tlist = clock_to_timerlist(clock);
 
-    qemu_mutex_lock(&clock->active_timers_lock);
-    has_timers = !!clock->active_timers;
-    qemu_mutex_unlock(&clock->active_timers_lock);
+    qemu_mutex_lock(&tlist->active_timers_lock);
+    has_timers = !!tlist->active_timers;
+    qemu_mutex_unlock(&tlist->active_timers_lock);
     return has_timers;
 }
 
@@ -280,11 +305,12 @@ int64_t qemu_clock_expired(QEMUClock *clock)
 {
     bool has_timers;
     int64_t expire_time;
+    TimerList *tlist = clock_to_timerlist(clock);
 
-    qemu_mutex_lock(&clock->active_timers_lock);
-    has_timers = clock->active_timers;
-    expire_time = clock->active_timers->expire_time;
-    qemu_mutex_unlock(&clock->active_timers_lock);
+    qemu_mutex_lock(&tlist->active_timers_lock);
+    has_timers = tlist->active_timers;
+    expire_time = tlist->active_timers->expire_time;
+    qemu_mutex_unlock(&tlist->active_timers_lock);
 
     return has_timers && expire_time < qemu_get_clock_ns(clock);
 }
@@ -295,11 +321,12 @@ int64_t qemu_clock_deadline(QEMUClock *clock)
     int64_t delta = INT32_MAX;
     bool has_timers;
     int64_t expire_time;
+    TimerList *tlist = clock_to_timerlist(clock);
 
-    qemu_mutex_lock(&clock->active_timers_lock);
-    has_timers = clock->active_timers;
-    expire_time = clock->active_timers->expire_time;
-    qemu_mutex_unlock(&clock->active_timers_lock);
+    qemu_mutex_lock(&tlist->active_timers_lock);
+    has_timers = tlist->active_timers;
+    expire_time = tlist->active_timers->expire_time;
+    qemu_mutex_unlock(&tlist->active_timers_lock);
 
     if (has_timers) {
         delta = expire_time - qemu_get_clock_ns(clock);
@@ -316,7 +343,7 @@ QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
     QEMUTimer *ts;
 
     ts = g_malloc0(sizeof(QEMUTimer));
-    ts->clock = clock;
+    ts->list = clock_to_timerlist(clock);
     ts->cb = cb;
     ts->opaque = opaque;
     ts->scale = scale;
@@ -331,11 +358,11 @@ void qemu_free_timer(QEMUTimer *ts)
 /* stop a timer, but do not dealloc it */
 void qemu_del_timer(QEMUTimer *ts)
 {
-    QEMUClock *clock = ts->clock;
+    TimerList *tlist = ts->list;
     QEMUTimer **pt, *t;
 
-    qemu_mutex_lock(&clock->active_timers_lock);
-    pt = &ts->clock->active_timers;
+    qemu_mutex_lock(&tlist->active_timers_lock);
+    pt = &tlist->active_timers;
     for(;;) {
         t = *pt;
         if (!t)
@@ -346,21 +373,21 @@ void qemu_del_timer(QEMUTimer *ts)
         }
         pt = &t->next;
     }
-    qemu_mutex_unlock(&clock->active_timers_lock);
+    qemu_mutex_unlock(&tlist->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 qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
 {
-    QEMUClock *clock = ts->clock;
+    TimerList *tlist = ts->list;
     QEMUTimer **pt, *t;
 
     qemu_del_timer(ts);
 
     /* add the timer in the sorted list */
-    qemu_mutex_lock(&clock->active_timers_lock);
-    pt = &clock->active_timers;
+    qemu_mutex_lock(&tlist->active_timers_lock);
+    pt = &tlist->active_timers;
     for(;;) {
         t = *pt;
         if (!qemu_timer_expired_ns(t, expire_time)) {
@@ -371,10 +398,10 @@ void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
     ts->expire_time = expire_time;
     ts->next = *pt;
     *pt = ts;
-    qemu_mutex_unlock(&clock->active_timers_lock);
+    qemu_mutex_unlock(&tlist->active_timers_lock);
 
     /* Rearm if necessary  */
-    if (pt == &ts->clock->active_timers) {
+    if (pt == &tlist->active_timers) {
         qemu_mutex_lock(&alarm_timer->timer_modified_lock);
         alarm_timer->timer_modified = true;
         qemu_mutex_unlock(&alarm_timer->timer_modified_lock);
@@ -390,15 +417,15 @@ void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)
 bool qemu_timer_pending(QEMUTimer *ts)
 {
     QEMUTimer *t;
-    QEMUClock *clock = ts->clock;
+    TimerList *tlist = ts->list;
 
-    qemu_mutex_lock(&clock->active_timers_lock);
-    for (t = ts->clock->active_timers; t != NULL; t = t->next) {
+    qemu_mutex_lock(&tlist->active_timers_lock);
+    for (t = tlist->active_timers; t != NULL; t = t->next) {
         if (t == ts) {
             break;
         }
     }
-    qemu_mutex_unlock(&clock->active_timers_lock);
+    qemu_mutex_unlock(&tlist->active_timers_lock);
     return t;
 }
 
@@ -411,22 +438,25 @@ void qemu_run_timers(QEMUClock *clock)
 {
     QEMUTimer *ts;
     int64_t current_time;
-   
+    TimerList *tlist;
+
     if (!clock->enabled)
         return;
 
     current_time = qemu_get_clock_ns(clock);
+    tlist = clock_to_timerlist(clock);
+
     for(;;) {
-        qemu_mutex_lock(&clock->active_timers_lock);
-        ts = clock->active_timers;
+        qemu_mutex_lock(&tlist->active_timers_lock);
+        ts = tlist->active_timers;
         if (!qemu_timer_expired_ns(ts, current_time)) {
-            qemu_mutex_unlock(&clock->active_timers_lock);
+            qemu_mutex_unlock(&tlist->active_timers_lock);
             break;
         }
         /* remove timer from the list before calling the callback */
-        clock->active_timers = ts->next;
+        tlist->active_timers = ts->next;
         ts->next = NULL;
-        qemu_mutex_unlock(&clock->active_timers_lock);
+        qemu_mutex_unlock(&tlist->active_timers_lock);
 
         /* run the callback (the timer list can be modified) */
         ts->cb(ts->opaque);
-- 
1.8.1.4