From d07319f790eb38c867bd04a23de674e2393825ff Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Sun, 22 Mar 2015 20:20:28 +0100 Subject: Better support for poor os monotonic sources --- .../sys/common/erl_os_monotonic_time_extender.c | 88 ++++++++++++++++++++++ .../sys/common/erl_os_monotonic_time_extender.h | 65 ++++++++++++++++ 2 files changed, 153 insertions(+) create mode 100644 erts/emulator/sys/common/erl_os_monotonic_time_extender.c create mode 100644 erts/emulator/sys/common/erl_os_monotonic_time_extender.h (limited to 'erts/emulator/sys/common') diff --git a/erts/emulator/sys/common/erl_os_monotonic_time_extender.c b/erts/emulator/sys/common/erl_os_monotonic_time_extender.c new file mode 100644 index 0000000000..f3633b7267 --- /dev/null +++ b/erts/emulator/sys/common/erl_os_monotonic_time_extender.c @@ -0,0 +1,88 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2015. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif +#include "erl_os_monotonic_time_extender.h" + +#ifdef USE_THREADS + +static void *os_monotonic_time_extender(void *vstatep) +{ + ErtsOsMonotonicTimeExtendState *state = (ErtsOsMonotonicTimeExtendState *) vstatep; + long sleep_time = state->check_interval*1000; + Uint32 (*raw_os_mtime)(void) = state->raw_os_monotonic_time; + Uint32 last_msb = 0; + + while (1) { + Uint32 msb = (*raw_os_mtime)() & (((Uint32) 1) << 31); + + if (msb != last_msb) { + int ix = ((int) (last_msb >> 31)) & 1; + Uint32 xtnd = (Uint32) erts_atomic32_read_nob(&state->extend[ix]); + erts_atomic32_set_nob(&state->extend[ix], (erts_aint32_t) (xtnd + 1)); + last_msb = msb; + } + erts_milli_sleep(sleep_time); + } + + erl_exit(ERTS_ABORT_EXIT, "os_monotonic_time_extender thread terminating"); + return NULL; +} + +static erts_tid_t os_monotonic_extender_tid; +#endif + +void +erts_init_os_monotonic_time_extender(ErtsOsMonotonicTimeExtendState *statep, + Uint32 (*raw_os_monotonic_time)(void), + int check_seconds) +{ +#ifdef USE_THREADS + statep->raw_os_monotonic_time = raw_os_monotonic_time; + erts_atomic32_init_nob(&statep->extend[0], (erts_aint32_t) 0); + erts_atomic32_init_nob(&statep->extend[1], (erts_aint32_t) 0); + statep->check_interval = check_seconds; + +#else + statep->extend[0] = (Uint32) 0; + statep->extend[1] = (Uint32) 0; + statep->last_msb = (ErtsMonotonicTime) 0; +#endif +} + +void +erts_late_init_os_monotonic_time_extender(ErtsOsMonotonicTimeExtendState *statep) +{ +#ifdef USE_THREADS + erts_thr_opts_t thr_opts = ERTS_THR_OPTS_DEFAULT_INITER; + thr_opts.detached = 1; + thr_opts.suggested_stack_size = 4; + +#if 0 + thr_opts.name = "os_monotonic_time_extender"; +#endif + + erts_thr_create(&os_monotonic_extender_tid, + os_monotonic_time_extender, + (void*) statep, + &thr_opts); +#endif +} diff --git a/erts/emulator/sys/common/erl_os_monotonic_time_extender.h b/erts/emulator/sys/common/erl_os_monotonic_time_extender.h new file mode 100644 index 0000000000..0f9e7c86ae --- /dev/null +++ b/erts/emulator/sys/common/erl_os_monotonic_time_extender.h @@ -0,0 +1,65 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2015. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + */ + +#ifndef ERL_OS_MONOTONIC_TIME_EXTENDER_H__ +#define ERL_OS_MONOTONIC_TIME_EXTENDER_H__ + +#include "sys.h" +#include "erl_threads.h" + +typedef struct { +#ifdef USE_THREADS + Uint32 (*raw_os_monotonic_time)(void); + erts_atomic32_t extend[2]; + int check_interval; +#else + Uint32 extend[2]; + ErtsMonotonicTime last_msb; +#endif +} ErtsOsMonotonicTimeExtendState; + +#ifdef USE_THREADS +# define ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(S, RT) ((void) 1) +# define ERTS_EXTEND_OS_MONOTONIC_TIME(S, RT) \ + ((((ErtsMonotonicTime) \ + erts_atomic32_read_nob(&((S)->extend[((int) ((RT) >> 31)) & 1]))) \ + << 32) \ + + (RT)) +#else +# define ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(S, RT) \ + do { \ + Uint32 msb__ = (RT) & (((Uint32) 1) << 31); \ + if (msb__ != (S)->last_msb) { \ + int ix__ = ((int) ((S)->last_msb >> 31)) & 1; \ + (S)->extend[ix__]++; \ + (S)->last_msb = msb; \ + } \ + } while (0) +# define ERTS_EXTEND_OS_MONOTONIC_TIME(S, RT) \ + ((((ErtsMonotonicTime) (S)->extend[((int) ((RT) >> 31)) & 1]) << 32) + (RT)) +#endif + +void +erts_init_os_monotonic_time_extender(ErtsOsMonotonicTimeExtendState *statep, + Uint32 (*raw_os_monotonic_time)(void), + int check_seconds); +void +erts_late_init_os_monotonic_time_extender(ErtsOsMonotonicTimeExtendState *statep); + +#endif -- cgit v1.2.3