[Qemu-devel] [PATCH 18/19] introduce qemu_clock_enable

[Paolo Bonzini]

By adding the possibility to turn on/off a clock, yet another
incestuous relationship between timers and CPUs can be disentangled.

This also needs qemu_run_timers to accept a QEMUClock, and nicely
simplifies host_alarm_handler.

Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
 vl.c |   32 +++++++++++++++++++++-----------
 1 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/vl.c b/vl.c
index 204b6a0..17ad374 100644
--- a/vl.c
+++ b/vl.c
@@ -569,6 +569,7 @@ void cpu_disable_ticks(void)
 
 struct QEMUClock {
     int type;
+    int enabled;
     /* XXX: add frequency */
 };
 
@@ -799,9 +800,15 @@ static QEMUClock *qemu_new_clock(int type)
     QEMUClock *clock;
     clock = qemu_mallocz(sizeof(QEMUClock));
     clock->type = type;
+    clock->enabled = 1;
     return clock;
 }
 
+static void qemu_clock_enable(QEMUClock *clock, int enabled)
+{
+    clock->enabled = enabled;
+}
+
 QEMUTimer *qemu_new_timer(QEMUClock *clock, QEMUTimerCB *cb, void *opaque)
 {
     QEMUTimer *ts;
@@ -890,10 +897,16 @@ int qemu_timer_expired(QEMUTimer *timer_head, int64_t 
current_time)
     return (timer_head->expire_time <= current_time);
 }
 
-static void qemu_run_timers(QEMUTimer **ptimer_head, int64_t current_time)
+static void qemu_run_timers(QEMUClock *clock)
 {
-    QEMUTimer *ts;
+    QEMUTimer **ptimer_head, *ts;
+    int64_t current_time;
+   
+    if (!clock->enabled)
+        return;
 
+    current_time = qemu_get_clock (clock);
+    ptimer_head = &active_timers[clock->type];
     for(;;) {
         ts = *ptimer_head;
         if (!ts || ts->expire_time > current_time)
@@ -1032,17 +1045,11 @@ static void qemu_timer_bh(void *opaque)
 
     /* vm time timers */
     if (vm_running) {
-        if (!cur_cpu || likely(!(cur_cpu->singlestep_enabled & SSTEP_NOTIMER)))
-            qemu_run_timers(&active_timers[QEMU_CLOCK_VIRTUAL],
-                            qemu_get_clock(vm_clock));
+        qemu_run_timers(vm_clock);
     }
 
-    /* real time timers */
-    qemu_run_timers(&active_timers[QEMU_CLOCK_REALTIME],
-                    qemu_get_clock(rt_clock));
-
-    qemu_run_timers(&active_timers[QEMU_CLOCK_HOST],
-                    qemu_get_clock(host_clock));
+    qemu_run_timers(rt_clock);
+    qemu_run_timers(host_clock);
 }
 
 #ifdef _WIN32
@@ -3907,6 +3914,9 @@ static bool tcg_cpu_exec(void)
     for (; next_cpu != NULL; next_cpu = next_cpu->next_cpu) {
         CPUState *env = cur_cpu = next_cpu;
 
+        qemu_clock_enable(vm_clock, 
+                          (cur_cpu->singlestep_enabled & SSTEP_NOTIMER) != 0);
+
         if (!vm_running)
             return false;
         if (qemu_alarm_pending())
-- 
1.6.5.2