mirror of https://github.com/0intro/conterm
52 lines
878 B
C
52 lines
878 B
C
|
#include <u.h>
|
||
|
|
#include <libc.h>
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* After a fork with fd's copied, both fd's are pointing to
|
||
|
|
* the same Chan structure. Since the offset is kept in the Chan
|
||
|
|
* structure, the seek's and read's in the two processes can
|
||
|
|
* compete at moving the offset around. Hence the unusual loop
|
||
|
|
* in the middle of this routine.
|
||
|
|
*/
|
||
|
|
static long
|
||
|
|
oldtime(long *tp)
|
||
|
|
{
|
||
|
|
char b[20];
|
||
|
|
static int f = -1;
|
||
|
|
int i, retries;
|
||
|
|
long t;
|
||
|
|
|
||
|
|
memset(b, 0, sizeof(b));
|
||
|
|
for(retries = 0; retries < 100; retries++){
|
||
|
|
if(f < 0)
|
||
|
|
f = open("/dev/time", OREAD|OCEXEC);
|
||
|
|
if(f < 0)
|
||
|
|
break;
|
||
|
|
if(seek(f, 0, 0) < 0 || (i = read(f, b, sizeof(b))) < 0){
|
||
|
|
close(f);
|
||
|
|
f = -1;
|
||
|
|
} else {
|
||
|
|
if(i != 0)
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
t = atol(b);
|
||
|
|
if(tp)
|
||
|
|
*tp = t;
|
||
|
|
return t;
|
||
|
|
}
|
||
|
|
|
||
|
|
long
|
||
|
|
time(long *tp)
|
||
|
|
{
|
||
|
|
vlong t;
|
||
|
|
|
||
|
|
t = nsec()/((vlong)1000000000);
|
||
|
|
if(t == 0)
|
||
|
|
t = oldtime(0);
|
||
|
|
if(tp != nil)
|
||
|
|
*tp = t;
|
||
|
|
return t;
|
||
|
|
}
|