From 413c99d6721b9a28d13bb98cfd278e707cc0722a Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Thu, 5 Jul 2012 17:55:46 +0200 Subject: erts: Fixate timer wheel resultion at compile time if possible --- erts/emulator/beam/time.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) (limited to 'erts/emulator/beam') 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 -- cgit v1.2.3