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Use higher resolution timestamps on Windows.

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The resolution of the GetTickCount function is limited to the resolution
of the system timer, which is typically in the range of 10 to 16
milliseconds. This is unsufficient for measuring very short time
intervals in the milliseconds range. The QueryPerformanceCounter
function provides much higher resolution timestamps. We already use it
for the half-duplex workaround.
This commit is contained in:
Jef Driesen 2014-03-12 08:45:44 +01:00
parent c9202454bb
commit 886884ab60
1 changed files with 9 additions and 5 deletions
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14
examples/utils.c
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@ -34,7 +34,7 @@ static unsigned char g_lastchar = '\n';
#ifdef _WIN32
#include <windows.h>
static unsigned long g_timestamp;
static LARGE_INTEGER g_timestamp, g_frequency;
#else
#include <sys/time.h>
static struct timeval g_timestamp;
@ -47,9 +47,12 @@ int message (const char* fmt, ...)
if (g_logfile) {
if (g_lastchar == '\n') {
#ifdef _WIN32
unsigned long timestamp = GetTickCount () - g_timestamp;
unsigned long sec = timestamp / 1000L, msec = timestamp % 1000L;
fprintf (g_logfile, "[%li.%03li] ", sec, msec);
LARGE_INTEGER now, timestamp;
QueryPerformanceCounter(&now);
timestamp.QuadPart = now.QuadPart - g_timestamp.QuadPart;
timestamp.QuadPart *= 1000000;
timestamp.QuadPart /= g_frequency.QuadPart;
fprintf (g_logfile, "[%I64i.%06I64i] ", timestamp.QuadPart / 1000000, timestamp.QuadPart % 1000000);
#else
struct timeval now, timestamp;
gettimeofday (&now, NULL);
@ -89,7 +92,8 @@ void message_set_logfile (const char* filename)
if (g_logfile) {
g_lastchar = '\n';
#ifdef _WIN32
g_timestamp = GetTickCount ();
QueryPerformanceFrequency(&g_frequency);
QueryPerformanceCounter(&g_timestamp);
#else
gettimeofday (&g_timestamp, NULL);
#endif