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authorSverker Eriksson <[email protected]>2012-07-05 17:55:46 +0200
committerSverker Eriksson <[email protected]>2012-07-05 18:46:18 +0200
commit413c99d6721b9a28d13bb98cfd278e707cc0722a (patch)
tree022d4aafdbd0ba0c30088d081ca8987e44a5c5ef
parent866cf9343b289d94c144600af1765e6754cfb593 (diff)
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erts: Fixate timer wheel resultion at compile time if possible
-rw-r--r--erts/emulator/beam/time.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index 932d157cd8..e8cd4a3a02 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -105,7 +105,14 @@ static ErlTimer *tiw_min_ptr;
/* END tiw_lock protected variables */
/* Actual interval time chosen by sys_init_time() */
-static int itime; /* Constant after init */
+
+#if SYS_CLOCK_RESOLUTION == 1
+# define TIW_ITIME 1
+# define TIW_ITIME_IS_CONSTANT
+#else
+static int tiw_itime; /* Constant after init */
+# define TIW_ITIME tiw_itime
+#endif
erts_smp_atomic32_t do_time; /* set at clock interrupt */
static ERTS_INLINE erts_short_time_t do_time_read(void)
@@ -123,7 +130,7 @@ static ERTS_INLINE void do_time_init(void)
erts_smp_atomic32_init_nob(&do_time, 0);
}
-/* get the time (in units of itime) to the next timeout,
+/* get the time (in units of TIW_ITIME) to the next timeout,
or -1 if there are no timeouts */
static erts_short_time_t next_time_internal(void) /* PRE: tiw_lock taken by caller */
@@ -305,11 +312,18 @@ erts_timer_wheel_memory_size(void)
void
erts_init_time(void)
{
- int i;
+ int i, itime;
/* system dependent init; must be done before do_time_init()
if timer thread is enabled */
itime = erts_init_time_sup();
+#ifdef TIW_ITIME_IS_CONSTANT
+ if (itime != TIW_ITIME) {
+ erl_exit(ERTS_ABORT_EXIT, "timer resolution mismatch %d != %d", itime, TIW_ITIME);
+ }
+#else
+ tiw_itime = itime;
+#endif
erts_smp_mtx_init(&tiw_lock, "timer_wheel");
@@ -340,7 +354,7 @@ insert_timer(ErlTimer* p, Uint t)
*
* (x + y - 1)/y is precisely the "number of bins" formula.
*/
- ticks = (t + itime - 1) / itime;
+ ticks = (t + (TIW_ITIME - 1)) / TIW_ITIME;
/*
* Ticks must be a Uint64, or the addition may overflow here,
@@ -455,7 +469,7 @@ erts_time_left(ErlTimer *p)
erts_smp_mtx_unlock(&tiw_lock);
- return (Uint) left * itime;
+ return (Uint) left * TIW_ITIME;
}
#ifdef DEBUG