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#include <sys/file.h>
#define NANO_wait \
if (nsec < 500000000) nsec *= 2;\
else carp("could not acquire lock on: ",home,"/in");\
nano_sleep(0,nsec)
static void open_inout(char *home) {
char *x,*y;
uint32t nsec = 3906249;
int len=str_len(home);
x=alloca(len+6); if (x==0) _exit(1);
y=x+len;
while (len--) x[len] = home[len];
y[0]='/'; y[1]='i'; y[2]='n'; y[3]=0;
infd = open(x, O_WRONLY);
y[1]='o'; y[2]='u'; y[3]='t'; y[4]=0;
outfd = open(x, O_RDONLY);
if (infd<0 || outfd<0) die(1, "could not open ",home,"/[in|out]");
#ifdef HAVE__NR_flock
while (flock(infd, LOCK_EX | LOCK_NB)) { NANO_wait; }
#else
#ifndef INIT_SYSTEM
while (lockf(infd, F_LOCKW, 1)) { NANO_wait; }
#else
{
struct flock fl;
byte_zero(&fl, sizeof(fl));
fl.l_whence=SEEK_CUR;
fl.l_len = 1;
fl.l_type = F_WRLCK;
while (fcntl(infd, F_SETLKW, &fl)) { NANO_wait; }
}
#endif
#endif
}
#undef NANO_wait
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