Introduce a new time API

The old time API is based on erlang:now/0. The major issue with
erlang:now/0 is that it was intended to be used for so many
unrelated things. This tied these unrelated operations together
and unnecessarily caused performance, scalability as well as
accuracy, and precision issues for operations that do not need
to have such issues. The new API spreads different functionality
over multiple functions in order to improve on this.

The new API consists of a number of new BIFs:
- erlang:convert_time_unit/3
- erlang:monotonic_time/0
- erlang:monotonic_time/1
- erlang:system_time/0
- erlang:system_time/1
- erlang:time_offset/0
- erlang:time_offset/1
- erlang:timestamp/0
- erlang:unique_integer/0
- erlang:unique_integer/1
- os:system_time/0
- os:system_time/1

and a number of extensions of existing BIFs:
- erlang:monitor(time_offset, clock_service)
- erlang:system_flag(time_offset, finalize)
- erlang:system_info(os_monotonic_time_source)
- erlang:system_info(time_offset)
- erlang:system_info(time_warp_mode)
- erlang:system_info(time_correction)
- erlang:system_info(start_time)

See the "Time and Time Correction in Erlang" chapter of the
ERTS User's Guide for more information.

1 files changed, 80 insertions, 27 deletions

diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index c29d4b3777..7e64623686 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -21,6 +21,25 @@
 #define __SYS_H__
 
 
+#if defined(DEBUG) || defined(ERTS_ENABLE_LOCK_CHECK)
+#  undef ERTS_CAN_INLINE
+#  define ERTS_CAN_INLINE 0
+#  undef ERTS_INLINE
+#  define ERTS_INLINE
+#endif
+
+#if ERTS_CAN_INLINE
+#define ERTS_GLB_INLINE static ERTS_INLINE
+#else
+#define ERTS_GLB_INLINE
+#endif
+
+#if ERTS_CAN_INLINE || defined(ERTS_DO_INCL_GLB_INLINE_FUNC_DEF) 
+#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 1
+#else
+#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 0
+#endif
+
 #if defined(VALGRIND) && !defined(NO_FPE_SIGNALS)
 #  define NO_FPE_SIGNALS
 #endif
@@ -132,24 +151,8 @@ typedef ERTS_SYS_FD_TYPE ErtsSysFdType;
 #  endif
 #endif
 
-#if defined(DEBUG) || defined(ERTS_ENABLE_LOCK_CHECK)
-#  undef ERTS_CAN_INLINE
-#  define ERTS_CAN_INLINE 0
-#  undef ERTS_INLINE
-#  define ERTS_INLINE
-#endif
-
-#if ERTS_CAN_INLINE
-#define ERTS_GLB_INLINE static ERTS_INLINE
-#else
-#define ERTS_GLB_INLINE
-#endif
-
-#if ERTS_CAN_INLINE || defined(ERTS_DO_INCL_GLB_INLINE_FUNC_DEF) 
-#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 1
-#else
-#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 0
-#endif
+#define ERTS_MK_VSN_INT(Major, Minor, Build) \
+    ((((Major) & 0x3ff) << 20) | (((Minor) & 0x3ff) << 10) | ((Build) & 0x3ff))
 
 #ifndef ERTS_EXIT_AFTER_DUMP
 #  define ERTS_EXIT_AFTER_DUMP exit
@@ -359,17 +362,45 @@ typedef Sint SWord;
 typedef UWord BeamInstr;
 
 #ifndef HAVE_INT64
-#if SIZEOF_LONG == 8
-#define HAVE_INT64 1
+#  if SIZEOF_LONG == 8
+#    define HAVE_INT64 1
 typedef unsigned long Uint64;
 typedef long          Sint64;
-#elif SIZEOF_LONG_LONG == 8
-#define HAVE_INT64 1
+#    ifdef ULONG_MAX
+#      define ERTS_UINT64_MAX ULONG_MAX
+#    endif
+#    ifdef LONG_MAX
+#      define ERTS_SINT64_MAX LONG_MAX
+#    endif
+#    ifdef LONG_MIN
+#      define ERTS_SINT64_MIN LONG_MIN
+#    endif
+#  elif SIZEOF_LONG_LONG == 8
+#    define HAVE_INT64 1
 typedef unsigned long long Uint64;
 typedef long long          Sint64;
-#else
-#define HAVE_INT64 0
+#    ifdef ULLONG_MAX
+#      define ERTS_UINT64_MAX ULLONG_MAX
+#    endif
+#    ifdef LLONG_MAX
+#      define ERTS_SINT64_MAX LLONG_MAX
+#    endif
+#    ifdef LLONG_MIN
+#      define ERTS_SINT64_MIN LLONG_MIN
+#    endif
+#  else
+#    error "No 64-bit integer type found"
+#  endif
+#endif
+
+#ifndef ERTS_UINT64_MAX
+#  define ERTS_UINT64_MAX (~((Uint64) 0))
 #endif
+#ifndef ERTS_SINT64_MAX
+#  define ERTS_SINT64_MAX ((Sint64) ((((Uint64) 1) << 63)-1))
+#endif
+#ifndef ERTS_SINT64_MIN
+#  define ERTS_SINT64_MIN (-1*(((Sint64) 1) << 63))
 #endif
 
 #if SIZEOF_LONG == 4
@@ -646,10 +677,31 @@ extern char *erts_default_arg0;
 
 extern char os_type[];
 
-extern int sys_init_time(void);
+typedef enum {
+    ERTS_NO_TIME_WARP_MODE,
+    ERTS_SINGLE_TIME_WARP_MODE,
+    ERTS_MULTI_TIME_WARP_MODE
+} ErtsTimeWarpMode;
+
+typedef struct {
+    int have_os_monotonic;
+    ErtsMonotonicTime os_monotonic_time_unit;
+    ErtsMonotonicTime sys_clock_resolution;
+    struct {
+	Uint64 resolution;
+	char *func;
+	char *clock_id;
+	int locked_use;
+    } os_monotonic_info;
+} ErtsSysInitTimeResult;
+
+#define ERTS_SYS_INIT_TIME_RESULT_INITER \
+    {0, (ErtsMonotonicTime) -1, (ErtsMonotonicTime) 1}
+
+extern void sys_init_time(ErtsSysInitTimeResult *);
 extern void erts_deliver_time(void);
 extern void erts_time_remaining(SysTimeval *);
-extern int erts_init_time_sup(void);
+extern int erts_init_time_sup(int, ErtsTimeWarpMode);
 extern void erts_sys_init_float(void);
 extern void erts_thread_init_float(void);
 extern void erts_thread_disable_fpe(void);
@@ -700,7 +752,7 @@ extern char *erts_sys_ddll_error(int code);
 
 void erts_sys_schedule_interrupt(int set);
 #ifdef ERTS_SMP
-void erts_sys_schedule_interrupt_timed(int set, erts_short_time_t msec);
+void erts_sys_schedule_interrupt_timed(int, ErtsMonotonicTime);
 void erts_sys_main_thread(void);
 #endif
 
@@ -739,6 +791,7 @@ int univ_to_local(
 int local_to_univ(Sint *year, Sint *month, Sint *day, 
 		  Sint *hour, Sint *minute, Sint *second, int isdst);
 void get_now(Uint*, Uint*, Uint*);
+ErtsMonotonicTime erts_get_monotonic_time(void);
 void get_sys_now(Uint*, Uint*, Uint*);
 void set_break_quit(void (*)(void), void (*)(void));