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/* ISC license. */
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <skalibs/djbunix.h>
#include <s6-rc/s6rc-utils.h>
static inline int modefor (int what)
{
return (what > 1 ? O_RDWR | O_CREAT | O_TRUNC : O_RDONLY) | O_NONBLOCK | O_CLOEXEC ;
}
int s6rc_lock (char const *live, int lwhat, int *llfd, char const *compiled, int cwhat, int *ccfd, int blocking)
{
int lfd = -1, cfd = -1 ;
if (lwhat)
{
int r ;
size_t llen = strlen(live) ;
char lfn[llen + 6] ;
memcpy(lfn, live, llen) ;
memcpy(lfn + llen, "/lock", 6) ;
lfd = open3(lfn, modefor(lwhat), 0644) ;
if (lfd < 0) return 0 ;
r = fd_lock(lfd, lwhat > 1, !blocking) ;
if (!r) errno = EBUSY ;
if (r < 1) goto lerr ;
}
if (cwhat)
{
int r ;
size_t clen = strlen(compiled) ;
char cfn[clen + 6] ;
memcpy(cfn, compiled, clen) ;
memcpy(cfn + clen, "/lock", 6) ;
cfd = open3(cfn, modefor(cwhat), 0644) ;
if (cfd < 0) goto lerr ;
r = fd_lock(cfd, cwhat > 1, !blocking) ;
if (!r) errno = EBUSY ;
if (r < 1) goto cerr ;
*ccfd = cfd ;
}
if (lwhat) *llfd = lfd ;
return 1 ;
cerr:
fd_close(cfd) ;
lerr:
if (lwhat) fd_close(lfd) ;
return 0 ;
}
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