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/* ISC license. */
#include <string.h>
#include <errno.h>
#include <skalibs/djbunix.h>
#include <s6-rc/s6rc-utils.h>
static inline int lockex (int fd, int blocking)
{
return blocking ? lock_ex(fd) : lock_exnb(fd) ;
}
static inline int locksh (int fd, int blocking)
{
return blocking ? lock_sh(fd) : lock_shnb(fd) ;
}
int s6rc_lock (char const *live, int lwhat, int *llfd, char const *compiled, int cwhat, int *ccfd, int blocking)
{
int e = 0 ;
int lfd = -1, cfd = -1 ;
if (lwhat)
{
size_t llen = strlen(live) ;
char lfn[llen + 6] ;
memcpy(lfn, live, llen) ;
memcpy(lfn + llen, "/lock", 6) ;
lfd = open_create(lfn) ;
if (lfd < 0) return 0 ;
if (coe(lfd) < 0) { e = errno ; goto lerr ; }
if ((lwhat > 1 ? lockex(lfd, blocking) : locksh(lfd, blocking)) < 0) { e = errno ; goto lerr ; }
}
if (cwhat)
{
size_t clen = strlen(compiled) ;
char cfn[clen + 6] ;
memcpy(cfn, compiled, clen) ;
memcpy(cfn + clen, "/lock", 6) ;
cfd = open_create(cfn) ;
if (cfd < 0)
if (cwhat > 1 || errno != EROFS) { e = errno ; goto lerr ; }
else cfd = -errno ;
else
{
if (coe(cfd) < 0) { e = errno ; goto cerr ; }
if ((cwhat > 1 ? lockex(cfd, blocking) : locksh(cfd, blocking)) < 0) { e = errno ; goto cerr ; }
}
}
if (lwhat) *llfd = lfd ;
if (cwhat) *ccfd = cfd ;
return 1 ;
cerr:
fd_close(cfd) ;
lerr:
if (lwhat) fd_close(lfd) ;
errno = e ;
return 0 ;
}
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