ref: dcf466b34d62b087c003ecc6347a43e247217b65
parent: 42681cb8ee1bab11448ddda478f5791b6b7699e9
author: Sigrid Solveig Haflínudóttir <ftrvxmtrx@gmail.com>
date: Mon Feb 8 04:55:13 EST 2021
replace nsec() with nanosec(): less context switching
--- a/fns.h
+++ b/fns.h
@@ -54,6 +54,7 @@
void fppsgl(void);
void fppdbl(void);
void shutdown(void);
+uvlong nanosec(void);
#pragma varargck argpos dprint 1
#pragma varargck argpos fatal 1
--- a/mkfile
+++ b/mkfile
@@ -35,6 +35,7 @@
mathlib.$O\
menu.$O\
model.$O\
+ nanosec.$O\
net_dgrm.$O\
net_loop.$O\
net_main.$O\
--- /dev/null
+++ b/nanosec.c
@@ -1,0 +1,36 @@
+#include <u.h>
+#include <libc.h>
+#include <tos.h>
+
+/*
+ * nsec() is wallclock and can be adjusted by timesync
+ * so need to use cycles() instead, but fall back to
+ * nsec() in case we can't
+ */
+uvlong
+nanosec(void)
+{+ static uvlong fasthz, xstart;
+ uvlong x, div;
+
+ if(fasthz == ~0ULL)
+ return nsec() - xstart;
+
+ if(fasthz == 0){+ if(_tos->cyclefreq){+ fasthz = _tos->cyclefreq;
+ cycles(&xstart);
+ } else {+ fasthz = ~0ULL;
+ xstart = nsec();
+ }
+ return 0;
+ }
+ cycles(&x);
+ x -= xstart;
+
+ /* this is ugly */
+ for(div = 1000000000ULL; x < 0x1999999999999999ULL && div > 1 ; div /= 10ULL, x *= 10ULL);
+
+ return x / (fasthz / div);
+}
--- a/qk1.c
+++ b/qk1.c
@@ -78,7 +78,7 @@
if(t0 == 0.0)
t0 = time(nil);
- return nsec() / 1000000000.0 - t0;
+ return nanosec() / 1000000000.0 - t0;
}
void
--- a/qw/mkfile
+++ b/qw/mkfile
@@ -38,6 +38,7 @@
md4.$O\
menu.$O\
model.$O\
+ nanosec.$O\
net_chan.$O\
net_udp.$O\
nonintel.$O\
@@ -75,6 +76,7 @@
cvar.$O\
mathlib.$O\
md4.$O\
+ nanosec.$O\
net_chan.$O\
net_udp.$O\
pmove.$O\
--- /dev/null
+++ b/qw/nanosec.c
@@ -1,0 +1,36 @@
+#include <u.h>
+#include <libc.h>
+#include <tos.h>
+
+/*
+ * nsec() is wallclock and can be adjusted by timesync
+ * so need to use cycles() instead, but fall back to
+ * nsec() in case we can't
+ */
+uvlong
+nanosec(void)
+{+ static uvlong fasthz, xstart;
+ uvlong x, div;
+
+ if(fasthz == ~0ULL)
+ return nsec() - xstart;
+
+ if(fasthz == 0){+ if(_tos->cyclefreq){+ fasthz = _tos->cyclefreq;
+ cycles(&xstart);
+ } else {+ fasthz = ~0ULL;
+ xstart = nsec();
+ }
+ return 0;
+ }
+ cycles(&x);
+ x -= xstart;
+
+ /* this is ugly */
+ for(div = 1000000000ULL; x < 0x1999999999999999ULL && div > 1 ; div /= 10ULL, x *= 10ULL);
+
+ return x / (fasthz / div);
+}
--- a/qw/snd.c
+++ b/qw/snd.c
@@ -586,8 +586,8 @@
}
}
if(sndt == 0)
- sndt = nsec() - Te9 / Fpsmax;
- nsamp = (nsec() - sndt) / (Te9 / Srate);
+ sndt = nanosec() - Te9 / Fpsmax;
+ nsamp = (nanosec() - sndt) / (Te9 / Srate);
if(!cls.timedemo)
nsamp = nsamp + 15 & ~15;
if(nsamp > Ssamp)
@@ -600,7 +600,7 @@
fprint(2, "sndwrite: %r\n");
shutsnd();
}
- sndt = nsec();
+ sndt = nanosec();
}
void
--- a/qw/sys.c
+++ b/qw/sys.c
@@ -106,11 +106,7 @@
double
Sys_DoubleTime(void)
{- static long secbase;
-
- if(secbase == 0)
- secbase = time(nil);
- return nsec()/1000000000.0 - secbase;
+ return nanosec()/1000000000.0;
}
void
--- a/qw/sys.h
+++ b/qw/sys.h
@@ -25,5 +25,6 @@
void Sys_SetFPCW(void);
void Sys_Init(void);
void initparm(quakeparms_t *);
+uvlong nanosec(void);
void* emalloc(ulong);
--- a/snd.c
+++ b/snd.c
@@ -561,8 +561,8 @@
}
}
if(sndt == 0)
- sndt = nsec() - Te9 / Fpsmax;
- nsamp = (nsec() - sndt) / (Te9 / Srate);
+ sndt = nanosec() - Te9 / Fpsmax;
+ nsamp = (nanosec() - sndt) / (Te9 / Srate);
if(!cls.timedemo)
nsamp = nsamp + 15 & ~15;
if(nsamp > Ssamp)
@@ -576,7 +576,7 @@
fprint(2, "sndwrite: %r\n");
shutsnd();
}
- sndt = nsec();
+ sndt = nanosec();
}
void