Merge branch 'rickard/time_api/OTP-11997'

* rickard/time_api/OTP-11997:
  Better OS system time implementation
  Documentation adjustments
  Fix zero timout timers
  erts_sys_hrtime() for lcnt
  Better support for poor os monotonic sources

Conflicts:
	erts/preloaded/ebin/erlang.beam

2 files changed, 164 insertions, 35 deletions

diff --git a/erts/emulator/sys/win32/erl_win_sys.h b/erts/emulator/sys/win32/erl_win_sys.h
index 33aa88ab5f..9aeb460720 100644
--- a/erts/emulator/sys/win32/erl_win_sys.h
+++ b/erts/emulator/sys/win32/erl_win_sys.h
@@ -172,13 +172,19 @@ typedef long long          Sint64;
 #  endif
 
 typedef long long ErtsMonotonicTime;
+typedef long long ErtsSysHrTime;
 #else
 typedef ULONGLONG Uint64;
 typedef LONGLONG  Sint64;
 
 typedef LONGLONG ErtsMonotonicTime;
+typedef LONGLONG ErtsSysHrTime;
 #endif
 
+typedef ErtsMonotonicTime ErtsSystemTime;
+
+ErtsSystemTime erts_os_system_time(void);
+
 #define ERTS_MONOTONIC_TIME_MIN (((ErtsMonotonicTime) 1) << 63)
 #define ERTS_MONOTONIC_TIME_MAX (~ERTS_MONOTONIC_TIME_MIN)
 
@@ -187,6 +193,7 @@ typedef LONGLONG ErtsMonotonicTime;
 
 struct erts_sys_time_read_only_data__ {
     ErtsMonotonicTime (*os_monotonic_time)(void);
+    ErtsSysHrTime (*sys_hrtime)(void);
 };
 
 typedef struct {
@@ -201,6 +208,7 @@ typedef struct {
 extern ErtsSysTimeData__ erts_sys_time_data__;
 
 ERTS_GLB_INLINE ErtsMonotonicTime erts_os_monotonic_time(void);
+ERTS_GLB_INLINE ErtsSysHrTime erts_sys_hrtime(void);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
@@ -210,6 +218,12 @@ erts_os_monotonic_time(void)
     return (*erts_sys_time_data__.r.o.os_monotonic_time)();
 }
 
+ERTS_GLB_INLINE ErtsSysHrTime
+erts_sys_hrtime(void)
+{
+    return (*erts_sys_time_data__.r.o.sys_hrtime)();
+}
+
 #endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
 
 extern void sys_gettimeofday(SysTimeval *tv);
diff --git a/erts/emulator/sys/win32/sys_time.c b/erts/emulator/sys/win32/sys_time.c
index 3a10125c81..da9c4d2e29 100644
--- a/erts/emulator/sys/win32/sys_time.c
+++ b/erts/emulator/sys/win32/sys_time.c
@@ -25,6 +25,8 @@
 #endif
 #include "sys.h"
 #include "assert.h"
+#include "erl_os_monotonic_time_extender.h"
+#include "erl_time.h"
 
 #define LL_LITERAL(X) ERTS_I64_LITERAL(X)
 
@@ -71,6 +73,8 @@ static int days_in_month[2][13] = {
     {0,31,28,31,30,31,30,31,31,30,31,30,31},
     {0,31,29,31,30,31,30,31,31,30,31,30,31}};
 
+#define ERTS_GET_TICK_COUNT_TIME_UNIT_SHIFT 10
+
 /*
  * erts_os_monotonic_time()
  */
@@ -78,6 +82,12 @@ static int days_in_month[2][13] = {
 struct sys_time_internal_state_read_only__ {
     ULONGLONG (WINAPI *pGetTickCount64)(void);
     BOOL (WINAPI *pQueryPerformanceCounter)(LARGE_INTEGER *);
+    Sint32 pcf;
+    int using_get_tick_count_time_unit;
+};
+
+struct sys_time_internal_state_read_mostly__ {
+    ErtsOsMonotonicTimeExtendState os_mtime_xtnd;
 };
 
 struct sys_time_internal_state_write_freq__ {
@@ -94,6 +104,12 @@ __declspec(align(ASSUMED_CACHE_LINE_SIZE)) struct {
 		     * ASSUMED_CACHE_LINE_SIZE];
     } r;
     union {
+	struct sys_time_internal_state_read_mostly__ m;
+	char align__[(((sizeof(struct sys_time_internal_state_read_mostly__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } wr;
+    union {
 	struct sys_time_internal_state_write_freq__ f;
 	char align__[(((sizeof(struct sys_time_internal_state_write_freq__) - 1)
 		       / ASSUMED_CACHE_LINE_SIZE) + 1)
@@ -114,29 +130,63 @@ os_monotonic_time_qpc(void)
     return (ErtsMonotonicTime) pc.QuadPart;
 }
 
+static Uint32
+get_tick_count(void)
+{
+    return (Uint32) GetTickCount();
+}
+
 static ErtsMonotonicTime
 os_monotonic_time_gtc32(void) 
 {
-    ULONGLONG res, ticks;
+    Uint32 ticks = (Uint32) GetTickCount();
+    ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+				      tick_count);
+    return ERTS_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+					 ticks) << 10;
+}
 
-    erts_smp_mtx_lock(&internal_state.w.f.mtime_mtx);
+static ErtsMonotonicTime
+os_monotonic_time_gtc64(void) 
+{
+    ULONGLONG ticks = (*internal_state.r.o.pGetTickCount64)();
+    return (ErtsMonotonicTime) ticks << 10;
+}
 
-    ticks = (ULONGLONG) (GetTickCount() & 0x7FFFFFFF);
-    if (ticks < internal_state.w.f.last_tick_count)
-	internal_state.w.f.wrap += (ULONGLONG) LL_LITERAL(1) << 31;
-    internal_state.w.f.last_tick_count = ticks;
-    res = ticks + internal_state.w.f.wrap;
+static ErtsSysHrTime
+sys_hrtime_qpc(void)
+{
+    LARGE_INTEGER pc;
 
-    erts_smp_mtx_unlock(&internal_state.w.f.mtime_mtx);
+    if (!(*internal_state.r.o.pQueryPerformanceCounter)(&pc))
+	erl_exit(ERTS_ABORT_EXIT, "QueryPerformanceCounter() failed\n");
 
-    return (ErtsMonotonicTime) res*1000;
+    ASSERT(pc.QuadPart > 0);
+
+    return (ErtsSysHrTime) erts_time_unit_conversion((Uint64) pc.QuadPart,
+						     internal_state.r.o.pcf,
+						     (Uint32) 1000*1000*1000);
 }
 
-static ErtsMonotonicTime
-os_monotonic_time_gtc64(void) 
+static ErtsSysHrTime
+sys_hrtime_gtc32(void)
 {
-    ULONGLONG ticks = (*internal_state.r.o.pGetTickCount64)();
-    return (ErtsMonotonicTime) ticks*1000;
+    ErtsSysHrTime time;
+    Uint32 ticks = (Uint32) GetTickCount();
+    ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+				      tick_count);
+    time = (ErtsSysHrTime) ERTS_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+							 ticks);
+    time *= (ErtsSysHrTime) (1000 * 1000);
+    return time;
+}
+
+static ErtsSysHrTime
+sys_hrtime_gtc64(void)
+{
+    ErtsSysHrTime time = (*internal_state.r.o.pGetTickCount64)();
+    time *= (ErtsSysHrTime) (1000*1000);
+    return time;
 }
 
 /*
@@ -147,11 +197,12 @@ void
 sys_init_time(ErtsSysInitTimeResult *init_resp)
 {
     ErtsMonotonicTime (*os_mtime_func)(void);
+    ErtsSysHrTime (*sys_hrtime_func)(void) = NULL;
     ErtsMonotonicTime time_unit;
     char kernel_dll_name[] = "kernel32";
     HMODULE module;
 
-    init_resp->os_monotonic_info.clock_id = NULL;
+    init_resp->os_monotonic_time_info.clock_id = NULL;
 
     module = GetModuleHandle(kernel_dll_name);
     if (!module) {
@@ -161,11 +212,20 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 	internal_state.w.f.wrap = 0;
 	internal_state.w.f.last_tick_count = 0;
 
-	init_resp->os_monotonic_info.func = "GetTickCount";
-	init_resp->os_monotonic_info.locked_use = 1;
-	init_resp->os_monotonic_info.resolution = 1000;
-	time_unit = (ErtsMonotonicTime) 1000*1000;
+	init_resp->os_monotonic_time_info.func = "GetTickCount";
+	init_resp->os_monotonic_time_info.locked_use = 1;
+	/* 10-16 ms resolution according to MicroSoft documentation */
+	init_resp->os_monotonic_time_info.resolution = 100; /* 10 ms */
+	time_unit = (ErtsMonotonicTime) 1000;
+	time_unit <<= ERTS_GET_TICK_COUNT_TIME_UNIT_SHIFT;
+	internal_state.r.o.using_get_tick_count_time_unit = 1;
 	os_mtime_func = os_monotonic_time_gtc32;
+	init_resp->os_monotonic_time_info.extended = 1;
+	erts_init_os_monotonic_time_extender(&internal_state.wr.m.os_mtime_xtnd,
+					     get_tick_count,
+					     60*60*24*7); /* Check once a week */
+	if (!sys_hrtime_func)
+	    sys_hrtime_func = sys_hrtime_gtc32;
     }
     else {
 	int major, minor, build;
@@ -182,11 +242,16 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 	    if (!internal_state.r.o.pGetTickCount64)
 		goto get_tick_count;
 
-	    init_resp->os_monotonic_info.func = "GetTickCount64";
-	    init_resp->os_monotonic_info.locked_use = 0;
-	    init_resp->os_monotonic_info.resolution = 1000;
-	    time_unit = (ErtsMonotonicTime) 1000*1000;
+	    init_resp->os_monotonic_time_info.func = "GetTickCount64";
+	    init_resp->os_monotonic_time_info.locked_use = 0;
+	    /* 10-16 ms resolution according to MicroSoft documentation */
+	    init_resp->os_monotonic_time_info.resolution = 100; /* 10 ms */
+	    time_unit = (ErtsMonotonicTime) 1000;
+	    time_unit <<= ERTS_GET_TICK_COUNT_TIME_UNIT_SHIFT;
+	    internal_state.r.o.using_get_tick_count_time_unit = 1;
 	    os_mtime_func = os_monotonic_time_gtc64;
+	    if (!sys_hrtime_func)
+		sys_hrtime_func = sys_hrtime_gtc64;
 	}
 	else { /* Vista or newer... */
 
@@ -199,40 +264,59 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 		goto get_tick_count64;
 	    if (!(*QPF)(&pf))
 		goto get_tick_count64;
-	    /*
-	     * We only use QueryPerformanceCounter() if
-	     * its frequency is equal to, or larger than
-	     * GHz in order to ensure that the user wont
-	     * be able to observe faulty order between
-	     * values retrieved on different threads.
-	     */
-	    if (pf.QuadPart < (LONGLONG) 1000*1000*1000)
-		goto get_tick_count64;
+
 	    internal_state.r.o.pQueryPerformanceCounter
 		= ((BOOL (WINAPI *)(LARGE_INTEGER *))
 		   GetProcAddress(module, "QueryPerformanceCounter"));
 	    if (!internal_state.r.o.pQueryPerformanceCounter)
 		goto get_tick_count64;
 
-	    init_resp->os_monotonic_info.func = "QueryPerformanceCounter";
-	    init_resp->os_monotonic_info.locked_use = 0;
+	    if (pf.QuadPart < (((LONGLONG) 1) << 32)) {
+		internal_state.r.o.pcf = (Uint32) pf.QuadPart;
+		sys_hrtime_func = sys_hrtime_qpc;
+	    }
+	    
+	    /*
+	     * We only use QueryPerformanceCounter() for
+	     * os-monotonic-time if its frequency is equal
+	     * to, or larger than GHz in order to ensure
+	     * that the user wont be able to observe faulty
+	     * order between values retrieved on different threads.
+	     */
+	    if (pf.QuadPart < (LONGLONG) 1000*1000*1000)
+		goto get_tick_count64;
+
+	    init_resp->os_monotonic_time_info.func = "QueryPerformanceCounter";
+	    init_resp->os_monotonic_time_info.locked_use = 0;
 	    time_unit = (ErtsMonotonicTime) pf.QuadPart;
-	    init_resp->os_monotonic_info.resolution = time_unit;
+	    internal_state.r.o.using_get_tick_count_time_unit = 0;
+	    init_resp->os_monotonic_time_info.resolution = time_unit;
 	    os_mtime_func = os_monotonic_time_qpc;
 	}
     }
 
     erts_sys_time_data__.r.o.os_monotonic_time = os_mtime_func;
     init_resp->os_monotonic_time_unit = time_unit;
-    init_resp->have_os_monotonic = 1;
+    init_resp->have_os_monotonic_time = 1;
     init_resp->sys_clock_resolution = 1;
 
+    init_resp->os_system_time_info.func = "GetSystemTime";    
+    init_resp->os_system_time_info.clock_id = NULL;
+    init_resp->os_system_time_info.resolution = 100;
+    init_resp->os_system_time_info.locked_use = 0;
+
     if(GetTimeZoneInformation(&static_tzi) && 
        static_tzi.StandardDate.wMonth != 0 &&
        static_tzi.DaylightDate.wMonth != 0) {
 	have_static_tzi = 1;
     }
+}
 
+void
+erts_late_sys_init_time(void)
+{
+    if (erts_sys_time_data__.r.o.os_monotonic_time == os_monotonic_time_gtc32)
+	erts_late_init_os_monotonic_time_extender(&internal_state.wr.m.os_mtime_xtnd);
 }
 
 /* Returns a switchtimes for DST as UTC filetimes given data from a 
@@ -513,6 +597,37 @@ sys_gettimeofday(SysTimeval *tv)
 			 EPOCH_JULIAN_DIFF);
 }
 
+ErtsSystemTime
+erts_os_system_time(void)
+{
+    SYSTEMTIME t;
+    FILETIME ft;
+    ULARGE_INTEGER ull;
+    ErtsSystemTime stime;
+
+    GetSystemTime(&t);
+    SystemTimeToFileTime(&t, &ft);
+    FILETIME_TO_ULI(ull,ft);
+
+    /* now in 100 ns units */
+
+    stime = (ErtsSystemTime) ull.QuadPart;
+    stime -= (((ErtsSystemTime) EPOCH_JULIAN_DIFF)
+	      * ((ErtsSystemTime) (10*1000*1000)));
+    stime /= (ErtsSystemTime) (10*1000);
+
+    if (internal_state.r.o.using_get_tick_count_time_unit) {
+	stime <<= ERTS_GET_TICK_COUNT_TIME_UNIT_SHIFT;
+	return stime;
+    }
+
+    return ((ErtsSystemTime)
+	    erts_time_unit_conversion(stime,
+				      (Uint32) 1000,
+				      (Uint32) ERTS_MONOTONIC_TIME_UNIT));
+}
+
+
 clock_t 
 sys_times(SysTimes *buffer) {
     clock_t kernel_ticks = (GetTickCount() /