/*
* dup2 is not thread safe
*/
int dup2(int oldfd, int newfd)
{
struct fd_info *oldfdi, *newfdi;
int ret;
init_preload();
oldfdi = idm_lookup(&idm, oldfd);
if (oldfdi) {
if (oldfdi->state == fd_fork_passive)
fork_passive(oldfd);
else if (oldfdi->state == fd_fork_active)
fork_active(oldfd);
}
newfdi = idm_lookup(&idm, newfd);
if (newfdi) {
/* newfd cannot have been dup'ed directly */
if (atomic_get(&newfdi->refcnt) > 1)
return ERR(EBUSY);
close(newfd);
}
ret = real.dup2(oldfd, newfd);
if (!oldfdi || ret != newfd)
return ret;
newfdi = calloc(1, sizeof *newfdi);
if (!newfdi) {
close(newfd);
return ERR(ENOMEM);
}
pthread_mutex_lock(&mut);
idm_set(&idm, newfd, newfdi);
pthread_mutex_unlock(&mut);
newfdi->fd = oldfdi->fd;
newfdi->type = oldfdi->type;
if (oldfdi->dupfd != -1) {
newfdi->dupfd = oldfdi->dupfd;
oldfdi = idm_lookup(&idm, oldfdi->dupfd);
} else {
newfdi->dupfd = oldfd;
}
atomic_init(&newfdi->refcnt);
atomic_set(&newfdi->refcnt, 1);
atomic_inc(&oldfdi->refcnt);
return newfd;
}
static inline enum fd_type fd_fork_get(int index, int *fd)
{
struct fd_info *fdi;
fdi = idm_lookup(&idm, index);
if (fdi) {
if (fdi->state == fd_fork_passive)
fork_passive(index);
else if (fdi->state == fd_fork_active)
fork_active(index);
*fd = fdi->fd;
return fdi->type;
} else {
*fd = index;
return fd_normal;
}
}
