xnu-2050.48.11.tar.gz

[apple/xnu.git] / osfmk / kern / clock.c

diff --git a/osfmk/kern/clock.c b/osfmk/kern/clock.c
index e9c487ad64f211dea31495f1d384e08e05144965..771a0dbef4fc75a1cda1602d89427a61656480f4 100644 (file)
--- a/osfmk/kern/clock.c
+++ b/osfmk/kern/clock.c
@@ -126,6 +126,9 @@ static thread_call_data_t   calend_wakecall;
 
 extern void    IOKitResetTime(void);
 
+void _clock_delay_until_deadline(uint64_t              interval,
+                                                                uint64_t               deadline);
+
 static uint64_t                clock_boottime;                         /* Seconds boottime epoch */
 
 #define TIME_ADD(rsecs, secs, rfrac, frac, unit)       \
@@ -773,6 +776,15 @@ mach_wait_until_continue(
        /*NOTREACHED*/
 }
 
+/*
+ * mach_wait_until_trap: Suspend execution of calling thread until the specified time has passed
+ *
+ * Parameters:    args->deadline          Amount of time to wait
+ *
+ * Returns:        0                      Success
+ *                !0                      Not success           
+ *
+ */
 kern_return_t
 mach_wait_until_trap(
        struct mach_wait_until_trap_args        *args)
@@ -796,27 +808,44 @@ clock_delay_until(
        if (now >= deadline)
                return;
 
-       if (    (deadline - now) < (8 * sched_cswtime)  ||
+       _clock_delay_until_deadline(deadline - now, deadline);
+}
+
+/*
+ * Preserve the original precise interval that the client
+ * requested for comparison to the spin threshold.
+ */
+void
+_clock_delay_until_deadline(
+       uint64_t                interval,
+       uint64_t                deadline)
+{
+
+       if (interval == 0)
+               return;
+
+       if (    ml_delay_should_spin(interval)  ||
                        get_preemption_level() != 0                             ||
-                       ml_get_interrupts_enabled() == FALSE    )
-               machine_delay_until(deadline);
-       else {
-               assert_wait_deadline((event_t)clock_delay_until, THREAD_UNINT, deadline - sched_cswtime);
+                       ml_get_interrupts_enabled() == FALSE    ) {
+               machine_delay_until(interval, deadline);
+       } else {
+               assert_wait_deadline((event_t)clock_delay_until, THREAD_UNINT, deadline);
 
                thread_block(THREAD_CONTINUE_NULL);
        }
 }
 
+
 void
 delay_for_interval(
        uint32_t                interval,
        uint32_t                scale_factor)
 {
-       uint64_t                end;
+       uint64_t                abstime;
 
-       clock_interval_to_deadline(interval, scale_factor, &end);
+       clock_interval_to_absolutetime_interval(interval, scale_factor, &abstime);
 
-       clock_delay_until(end);
+       _clock_delay_until_deadline(abstime, mach_absolute_time() + abstime);
 }
 
 void