Re: LuaProfiler on Windows
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: LuaProfiler on Windows
- From: Doug Currie <doug.currie@...>
- Date: Fri, 3 Mar 2006 18:57:16 -0500
Friday, March 3, 2006, 3:43:05 PM, Matt Campbell wrote:
> I noticed that LuaProfiler uses the clock() function for timing by
> default. On Windows (at least with Microsoft Visual C++), a clock is
> one millisecond -- much less than on Linux and other Unix systems. Does
> this mean that function timing is significantly more distorted on
> Windows than on Linux, particularly for very fast functions that are
> called many times? If so, what can be done about this? Thanks.
Fun with lua_tcc...
timer = tcc.compile ([[
#include "lua.h"
#include "winapi/windows.h"
int getraw (lua_State *L) {
LARGE_INTEGER t;
QueryPerformanceCounter(&t);
//lua_pushnumber (L, (double )t.QuadPart);
lua_pushnumber (L, (double)t.u.LowPart + ((double )t.u.HighPart * (double )4294967296.0));
return 1;
}
int getfreq (lua_State *L) {
LARGE_INTEGER t;
QueryPerformanceFrequency(&t);
//lua_pushnumber (L, (double )t.QuadPart);
lua_pushnumber (L, (double)t.u.LowPart + ((double )t.u.HighPart * (double )4294967296.0));
return 1;
}
int getsec (lua_State *L) {
static int getsec_init = 0;
static double getsec_freq;
LARGE_INTEGER t;
if (!getsec_init) {
QueryPerformanceFrequency(&t);
getsec_freq = (double)t.u.LowPart + ((double )t.u.HighPart * (double )4294967296.0);
if (getsec_freq == 0) return 0;
getsec_init = 1;
}
QueryPerformanceCounter(&t);
//lua_pushnumber (L, (double )t.QuadPart);
lua_pushnumber (L, (double)(t.u.LowPart + ((double )t.u.HighPart * (double )4294967296.0)) / getsec_freq);
return 1;
}
]], {"getraw", "getfreq", "getsec"}, {"lua51", "kernel32"})
function SmallestDiff (n,m)
local t0 = timer.getsec()
local t1
local mint = 100000
for i = 1 , n do
-- t1 = timer.getsec()
for j = 1, m do t1 = timer.getsec() end
if (t1 - t0) < mint then mint = t1 - t0 end
t0 = t1
end
return mint
end
> =SmallestDiff(10,1)
2.7936475817114e-006
> =SmallestDiff(10,10)
2.3466651327908e-005
> =SmallestDiff(10,100)
0.00023019683430903
>
e