ref: f801657f77f3923ec2388c25bdcb036c8019ba89
dir: /port/compat.c/
#include <u.h>
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "libkern/kern.h"
#include "port/error.h"
int
incref(Ref *r)
{
int x;
lock(&r->l);
x = ++r->ref;
unlock(&r->l);
return x;
}
int
decref(Ref *r)
{
int x;
lock(&r->l);
x = --r->ref;
unlock(&r->l);
if(x < 0)
panic("decref, pc=0x%lux", getcallerpc(&r));
return x;
}
/*
* Rather than strncpy, which zeros the rest of the buffer, kstrcpy
* truncates if necessary, always zero terminates, does not zero fill,
* and puts ... at the end of the string if it's too long. Usually used to
* save a string in up->genbuf;
*/
void
kstrcpy(char *s, char *t, int ns)
{
int nt;
nt = strlen(t);
if(nt+1 <= ns){
memmove(s, t, nt+1);
return;
}
/* too long */
if(ns < 4){
/* but very short! */
strncpy(s, t, ns);
return;
}
/* truncate with ... at character boundary (very rare case) */
memmove(s, t, ns-4);
ns -= 4;
s[ns] = '\0';
/* look for first byte of UTF-8 sequence by skipping continuation bytes */
while(ns>0 && (s[--ns]&0xC0)==0x80)
;
strcpy(s+ns, "...");
}
int
emptystr(char *s)
{
if(s == nil)
return 1;
if(s[0] == '\0')
return 1;
return 0;
}
/*
* Atomically replace *p with copy of s
*/
void
kstrdup(char **p, char *s)
{
int n;
char *t, *prev;
n = strlen(s)+1;
/* if it's a user, we can wait for memory; if not, something's very wrong */
if(up){
t = smalloc(n);
setmalloctag(t, getcallerpc(&p));
}else{
t = malloc(n);
if(t == nil)
panic("kstrdup: no memory");
}
memmove(t, s, n);
prev = *p;
*p = t;
free(prev);
}
void
_assert(char *fmt)
{
panic("assert failed: %s", fmt);
}