oysteikt/heimdal
0
0
Fork 0
Code Issues5 Pull Requests Releases Activity

roken: gettimeofday using GetSystemTimePreciseAsFileTime

Browse Source 
GetSystemTimeAsFileTime() has 16ms precision.

GetSystemTimePreciseAsFileTime() has <1ns precision but is only available
on Windows 8 or later.

This change dynamically loads GetSystemTimePreciseAsFileTime() if it is
available.

Change-Id: Ib9c616c01948384e6b256ac9b6023f1e39673613
This commit is contained in:
Jeffrey Altman
2018-09-18 22:06:23 -04:00
committed by Jeffrey Altman
parent 07b3e6fd74
commit 1feff82129
1 changed files with 18 additions and 2 deletions

20
lib/roken/gettimeofday.c

@@ -37,6 +37,10 @@
#ifdef _WIN32 #ifdef _WIN32
typedef BOOL (WINAPI *LPFN_GETSYSTEMTIME) (LPFILETIME);
static LPFN_GETSYSTEMTIME lpGetSystemTime = NULL;
ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
gettimeofday (struct timeval *tp, void *ignore) gettimeofday (struct timeval *tp, void *ignore)
{ {
@@ -44,7 +48,20 @@ gettimeofday (struct timeval *tp, void *ignore)
ULARGE_INTEGER li; ULARGE_INTEGER li;
ULONGLONG ull; ULONGLONG ull;
GetSystemTimeAsFileTime(&ft); if (lpGetSystemTime == NULL) {
HANDLE h1;
LPFN_GETSYSTEMTIME fn;
h1 = GetModuleHandle(TEXT("kernel32.dll")); /* no refcount increase */
fn = (LPFN_GETSYSTEMTIME)GetProcAddress(h1,
"GetSystemTimePreciseAsFileTime");
if (fn == NULL)
fn = (LPFN_GETSYSTEMTIME)GetProcAddress(h1,
"GetSystemTimeAsFileTime");
lpGetSystemTime = fn;
}
lpGetSystemTime(&ft);
li.LowPart = ft.dwLowDateTime; li.LowPart = ft.dwLowDateTime;
li.HighPart = ft.dwHighDateTime; li.HighPart = ft.dwHighDateTime;
ull = li.QuadPart; ull = li.QuadPart;
@@ -57,7 +74,6 @@ gettimeofday (struct timeval *tp, void *ignore)
return 0; return 0;
} }
#else #else
/* /*