/* Looks up the user-level 'FD info' for a given file descriptor.
** Returns pointer to the user-level 'FD info' for a given file
** descriptor, or NULL if the FD is not user-level.
** NOTE: The reference count of the 'FD info' is incremented, the
** caller should ensure the reference is dropped when no
** longer needed by calling citp_fdinfo_release_ref().
*/
citp_fdinfo* citp_fdtable_lookup_noprobe(unsigned fd)
{
/* Need to be initialised before we can try and grab the lock at the
** moment. TODO: make this more efficient by using a trylock to grab the
** fdtable lock, and on fail see if we need to initialise it.
*/
if( CI_UNLIKELY(citp.init_level < CITP_INIT_FDTABLE) ) {
if (_citp_do_init_inprogress == 0)
CI_TRY(citp_do_init(CITP_INIT_ALL));
else
CI_TRY(citp_do_init(CITP_INIT_FDTABLE)); /* get what we need */
return NULL;
}
if( fd < citp_fdtable.inited_count ) {
volatile citp_fdinfo_p* p_fdip = &citp_fdtable.table[fd].fdip;
citp_fdinfo_p fdip;
again:
/* Swap in the busy marker. */
fdip = *p_fdip;
if( fdip_is_normal(fdip) ) {
if( fdip_cas_succeed(p_fdip, fdip, fdip_busy) ) {
/* Bump the reference count. */
citp_fdinfo* fdi = fdip_to_fdi(fdip);
citp_fdinfo_ref(fdi);
/* Swap the busy marker out again. */
citp_fdtable_busy_clear(fd, fdip, 0);
return fdi;
}
goto again;
}
/* Not normal! */
else if( fdip_is_busy(fdip) ) {
citp_fdtable_busy_wait(fd, 0);
goto again;
}
}
return NULL;
}
/* This function does some simple tests to ensure that the fdtable makes sense.
* There are many more tests we could do; feel free to add them at your
* leisure!
*/
void
citp_fdtable_assert_valid(void)
{
int i;
if( ! citp_fdtable.table ) return;
CITP_FDTABLE_LOCK_RD();
for( i = 0; i < citp_fdtable.inited_count; i++ ) {
citp_fdinfo_p fdip = citp_fdtable.table[i].fdip;
if( fdip_is_normal(fdip) ) {
citp_fdinfo * fdi = fdip_to_fdi(fdip);
ci_assert(fdi);
ci_assert(fdi->protocol);
if( ( fdi->protocol->type == CITP_TCP_SOCKET ||
fdi->protocol->type == CITP_UDP_SOCKET )
&& fdi_to_socket(fdi)->s )
ci_assert(! (fdi_to_socket(fdi)->s->b.sb_aflags & CI_SB_AFLAG_ORPHAN));
if (!fdi->is_special) {
/* Ensure the "back pointer" makes sense */
ci_assert (fdi->fd == i);
/* Ensure that the reference count is in a vaguely sensible range */
ci_assert ((oo_atomic_read (&fdi->ref_count) > 0) &&
(oo_atomic_read (&fdi->ref_count) < 10000));
/* 10,000 threads is a bit mad, warn if more than 20 */
if (oo_atomic_read (&fdi->ref_count) > 20) {
Log_U (log ("Warning: fd %d's ref-count suspiciously large (%d)\n",
i, oo_atomic_read (&fdi->ref_count)));
}
}
}
}
CITP_FDTABLE_UNLOCK_RD();
}
citp_fdinfo*
citp_fdtable_lookup_fast(citp_lib_context_t* ctx, unsigned fd)
{
/* Note that if we haven't yet initialised this module, then
** [inited_count] will be zero, and the following test will fail. So the
** test for initialisation is done further down...
**
** This is highly performance critial. DO NOT add any code between here
** and the first [return] statement.
*/
citp_fdinfo* fdi;
/* Try to avoid entering lib. */
ctx->thread = NULL;
if( fd < citp_fdtable.inited_count ) {
volatile citp_fdinfo_p* p_fdip = &citp_fdtable.table[fd].fdip;
citp_fdinfo_p fdip;
again:
fdip = *p_fdip;
if( fdip_is_normal(fdip) ) {
citp_enter_lib_if(ctx);
if( citp_fdtable_is_mt_safe() ) {
/* No need to use atomic ops or add a ref to the fdi when MT-safe.
* The definition of "fds_mt_safe" is that the app does not change
* the meaning of a file descriptor in one thread when it is being
* used in another thread.
*/
fdi = fdip_to_fdi(fdip);
if( ! citp_fdinfo_is_consistent(fdi) )
fdi = citp_reprobe_moved(fdi, CI_TRUE, CI_FALSE);
return fdi;
}
else {
/* Swap in the busy marker. */
if( fdip_cas_succeed(p_fdip, fdip, fdip_busy) ) {
fdi = fdip_to_fdi(fdip);
ci_assert(fdi);
ci_assert_gt(oo_atomic_read(&fdi->ref_count), 0);
ci_assert(fdip_is_closing(fdip) || fdip_is_reserved(fdip) ||
fdi->fd == fd);
/* Bump the reference count. */
citp_fdinfo_ref(fdi);
if( ! citp_fdinfo_is_consistent(fdi) )
fdi = citp_reprobe_moved(fdi, CI_FALSE, CI_TRUE);
else {
/* Swap the busy marker out again. */
citp_fdtable_busy_clear(fd, fdip, 0);
}
return fdi;
}
goto again;
}
}
/* Not normal! */
if( fdip_is_passthru(fdip) )
return NULL;
citp_enter_lib_if(ctx);
if( fdip_is_busy(fdip) ) {
citp_fdtable_busy_wait(fd, 0);
goto again;
}
ci_assert(fdip_is_unknown(fdip));
goto probe;
}
if( citp.init_level < CITP_INIT_FDTABLE ) {
if( _citp_do_init_inprogress == 0 )
CI_TRY(citp_do_init(CITP_INIT_ALL));
else
CI_TRY(citp_do_init(CITP_INIT_FDTABLE)); /* get what we need */
}
if( fd >= citp_fdtable.size )
return NULL;
probe:
citp_enter_lib_if(ctx);
fdi = citp_fdtable_probe(fd);
if( fdi && citp_fdtable_is_mt_safe() )
citp_fdinfo_release_ref(fdi, 0);
return fdi;
}
citp_fdinfo *
citp_fdtable_lookup(unsigned fd)
{
/* Note that if we haven't yet initialised this module, then
** [inited_count] will be zero, and the following test will fail. So the
** test for initialisation is done further down...
**
** This is highly performance critial. DO NOT add any code between here
** and the first [return] statement.
*/
citp_fdinfo* fdi;
/* In some cases, we'll lock fdtable. Assert that it is possible: */
ci_assert(oo_per_thread_get()->sig.inside_lib);
if( fd < citp_fdtable.inited_count ) {
volatile citp_fdinfo_p* p_fdip = &citp_fdtable.table[fd].fdip;
citp_fdinfo_p fdip;
again:
/* Swap in the busy marker. */
fdip = *p_fdip;
if( fdip_is_normal(fdip) ) {
if( citp_fdtable_not_mt_safe() ) {
if( fdip_cas_succeed(p_fdip, fdip, fdip_busy) ) {
fdi = fdip_to_fdi(fdip);
ci_assert(fdi);
ci_assert_gt(oo_atomic_read(&fdi->ref_count), 0);
ci_assert(fdip_is_closing(fdip) || fdip_is_reserved(fdip) ||
fdi->fd == fd);
/* Bump the reference count. */
citp_fdinfo_ref(fdi);
if( ! citp_fdinfo_is_consistent(fdi) ) {
/* Something is wrong. Re-probe. */
fdi = citp_reprobe_moved(fdi, CI_FALSE, CI_TRUE);
}
else {
/* Swap the busy marker out again. */
citp_fdtable_busy_clear(fd, fdip, 0);
}
return fdi;
}
goto again;
}
else {
/* No need to use atomic ops when single-threaded. The definition
* of "fds_mt_safe" is that the app does not change the meaning of
* a file descriptor in one thread when it is being used in another
* thread. In that case I'm hoping this should be safe, but at
* time of writing I'm really not confident. (FIXME).
*/
fdi = fdip_to_fdi(fdip);
if( ci_is_multithreaded() )
citp_fdinfo_ref(fdi);
else
++fdi->ref_count.n;
if( ! citp_fdinfo_is_consistent(fdi) )
fdi = citp_reprobe_moved(fdi, CI_FALSE, CI_FALSE);
return fdi;
}
}
/* Not normal! */
if( fdip_is_passthru(fdip) ) return NULL;
if( fdip_is_busy(fdip) ) {
citp_fdtable_busy_wait(fd, 0);
goto again;
}
ci_assert(fdip_is_unknown(fdip));
goto probe;
}
if (citp.init_level < CITP_INIT_FDTABLE) {
if (_citp_do_init_inprogress == 0)
CI_TRY(citp_do_init(CITP_INIT_ALL));
else
CI_TRY(citp_do_init(CITP_INIT_FDTABLE)); /* get what we need */
}
if( fd >= citp_fdtable.size ) return NULL;
probe:
fdi = citp_fdtable_probe(fd);
return fdi;
}
/* Find out what sort of thing [fd] is, and if it is a user-level socket
* then map in the user-level state.
*/
static citp_fdinfo * citp_fdtable_probe_locked(unsigned fd, int print_banner,
int fdip_is_already_busy)
{
citp_fdinfo* fdi = NULL;
struct stat64 st;
ci_ep_info_t info;
if( ! fdip_is_already_busy ) {
volatile citp_fdinfo_p* p_fdip;
citp_fdinfo_p fdip;
/* ?? We're repeating some effort already expended in lookup() here, but
** this keeps it cleaner. May optimise down the line when I understand
** what other code needs to call this.
*/
p_fdip = &citp_fdtable.table[fd].fdip;
again:
fdip = *p_fdip;
if( fdip_is_busy(fdip) ) fdip = citp_fdtable_busy_wait(fd, 1);
if( ! fdip_is_unknown(fdip) && ! fdip_is_normal(fdip) ) goto exit;
if( fdip_cas_fail(p_fdip, fdip, fdip_busy) ) goto again;
if( fdip_is_normal(fdip) ) {
fdi = fdip_to_fdi(fdip);
citp_fdinfo_ref(fdi);
citp_fdtable_busy_clear(fd, fdip, 1);
goto exit;
}
}
if( ci_sys_fstat64(fd, &st) != 0 ) {
/* fstat() failed. Must be a bad (closed) file descriptor, so
** leave this entry as unknown. Return citp_the_closed_fd to avoid the
** caller passing through to an fd that is created asynchronously.
*/
citp_fdtable_busy_clear(fd, fdip_unknown, 1);
fdi = &citp_the_closed_fd;
citp_fdinfo_ref(fdi);
goto exit;
}
/* oo_get_st_rdev() and oo_onloadfs_dev_t() open-and-close fd, so
* fdtable should be locked if strict mode requested. */
if( fdtable_strict() ) { CITP_FDTABLE_ASSERT_LOCKED(1); }
if( st.st_dev == oo_onloadfs_dev_t() ) {
/* Retrieve user-level endpoint info */
if( oo_ep_info(fd, &info) < 0 ) {
Log_V(log("%s: fd=%d type=%d unknown", __FUNCTION__,fd,info.fd_type));
citp_fdtable_busy_clear(fd, fdip_passthru, 1);
goto exit;
}
switch( info.fd_type ) {
case CI_PRIV_TYPE_TCP_EP:
case CI_PRIV_TYPE_UDP_EP:
case CI_PRIV_TYPE_PASSTHROUGH_EP:
case CI_PRIV_TYPE_ALIEN_EP:
#if CI_CFG_USERSPACE_PIPE
case CI_PRIV_TYPE_PIPE_READER:
case CI_PRIV_TYPE_PIPE_WRITER:
#endif
{
citp_fdinfo_p fdip;
Log_V(log("%s: fd=%d %s restore", __FUNCTION__, fd,
info.fd_type == CI_PRIV_TYPE_TCP_EP ? "TCP":
#if CI_CFG_USERSPACE_PIPE
info.fd_type != CI_PRIV_TYPE_UDP_EP ? "PIPE" :
#endif
"UDP"));
fdip = citp_fdtable_probe_restore(fd, &info, print_banner);
if( fdip_is_normal(fdip) )
fdi = fdip_to_fdi(fdip);
else
citp_fdtable_busy_clear(fd, fdip, 1);
goto exit;
}
case CI_PRIV_TYPE_NETIF:
/* This should never happen, because netif fds are close-on-exec.
** But let's leave this code here just in case my reasoning is bad.
*/
Log_U(log("%s: fd=%d NETIF reserved", __FUNCTION__, fd));
citp_fdtable_busy_clear(fd, fdip_reserved, 1);
fdi = &citp_the_reserved_fd;
citp_fdinfo_ref(fdi);
goto exit;
case CI_PRIV_TYPE_NONE:
/* This happens if a thread gets at an onload driver fd that has just
* been created, but not yet specialised. On Linux I think this
* means it will shortly be a new netif internal fd. (fds associated
* with sockets and pipes are never unspecialised).
*/
Log_V(log("%s: fd=%d TYPE_NONE", __FUNCTION__, fd));
citp_fdtable_busy_clear(fd, fdip_passthru, 1);
goto exit;
default:
CI_TEST(0);
break;
}
}
else if( ci_major(st.st_rdev) == ci_major(oo_get_st_rdev(OO_EPOLL_DEV)) ) {
citp_epollb_fdi *epi = CI_ALLOC_OBJ(citp_epollb_fdi);
if( ! epi ) {
Log_E(log("%s: out of memory (epoll_fdi)", __FUNCTION__));
citp_fdtable_busy_clear(fd, fdip_passthru, 1);
goto exit;
}
oo_epollb_ctor(epi);
fdi = &epi->fdinfo;
citp_fdinfo_init(fdi, &citp_epollb_protocol_impl);
citp_fdinfo_ref(fdi);
citp_fdtable_insert(fdi, fd, 1);
goto exit;
}
#ifndef NDEBUG
/* /dev/onload may be netif only; they are closed on fork or exec */
if( ci_major(st.st_rdev) == ci_major(oo_get_st_rdev(OO_STACK_DEV)) )
Log_U(log("%s: %d is /dev/onload", __FUNCTION__, fd));
#endif
/* Not one of ours, so pass-through. */
Log_V(log("%s: fd=%u non-efab", __FUNCTION__, fd));
citp_fdtable_busy_clear(fd, fdip_passthru, 1);
exit:
return fdi;
}
/* Re-probe fdinfo after endpoint was moved to another stack.
* The function assumes that fdinfo was obtained via citp_fdtable_lookup()
* or from citp_fdtable_lookup_fast(). */
citp_fdinfo* citp_reprobe_moved(citp_fdinfo* fdinfo, int from_fast_lookup,
int fdip_is_already_busy)
{
int fd = fdinfo->fd;
citp_fdinfo* new_fdinfo = NULL;
CITP_FDTABLE_LOCK();
if( ! fdip_is_already_busy ) {
volatile citp_fdinfo_p* p_fdip;
citp_fdinfo_p fdip;
p_fdip = &citp_fdtable.table[fd].fdip;
again:
fdip = *p_fdip;
if( fdip_is_busy(fdip) ) fdip = citp_fdtable_busy_wait(fd, 1);
ci_assert( fdip_is_normal(fdip) || fdip_is_passthru(fdip) );
if( fdip_cas_fail(p_fdip, fdip, fdip_busy) ) goto again;
/* Possibly, a parrallel thread have already called
* citp_reprobe_moved() for us. */
if( fdip_is_passthru(fdip) ) {
citp_fdtable_busy_clear(fd, fdip, 1);
if( new_fdinfo != NULL )
citp_fdinfo_ref(new_fdinfo);
goto done;
}
ci_assert( fdip_is_normal(fdip) );
new_fdinfo = fdip_to_fdi(fdip);
if( new_fdinfo != fdinfo) {
citp_fdtable_busy_clear(fd, fdip, 1);
if( new_fdinfo != NULL )
citp_fdinfo_ref(new_fdinfo);
goto done;
}
}
else
ci_assert(fdip_is_busy(citp_fdtable.table[fd].fdip));
/* re-probe new fd */
new_fdinfo = citp_fdtable_probe_locked(fd, CI_TRUE, CI_TRUE);
if( fdinfo->epoll_fd >= 0 ) {
citp_fdinfo* epoll_fdi = citp_epoll_fdi_from_member(fdinfo, 1);
if( epoll_fdi->protocol->type == CITP_EPOLL_FD )
citp_epoll_on_move(epoll_fdi, fdinfo, new_fdinfo, 1);
else
citp_epollb_on_handover(epoll_fdi, fdinfo);
citp_fdinfo_release_ref(epoll_fdi, 1);
}
/* Drop refcount from fdtable */
fdinfo->on_ref_count_zero = FDI_ON_RCZ_MOVED;
citp_fdinfo_release_ref(fdinfo, 1);
done:
/* One refcount from the caller */
if( from_fast_lookup )
citp_fdinfo_release_ref_fast(fdinfo);
else
citp_fdinfo_release_ref(fdinfo, 1);
CITP_FDTABLE_UNLOCK();
if( new_fdinfo == NULL )
return NULL;
if( from_fast_lookup ) {
citp_fdinfo_ref_fast(new_fdinfo);
citp_fdinfo_release_ref(new_fdinfo, 0);
}
return new_fdinfo;
}
int citp_ep_close(unsigned fd)
{
volatile citp_fdinfo_p* p_fdip;
citp_fdinfo_p fdip;
int rc, got_lock;
citp_fdinfo* fdi;
/* Do not touch shared fdtable when in vfork child. */
if( oo_per_thread_get()->in_vfork_child )
return ci_tcp_helper_close_no_trampoline(fd);
/* Interlock against other closes, against the fdtable being extended,
** and against select and poll.
*/
CITP_FDTABLE_LOCK();
got_lock = 1;
__citp_fdtable_extend(fd);
if( fd >= citp_fdtable.inited_count ) {
rc = ci_sys_close(fd);
goto done;
}
p_fdip = &citp_fdtable.table[fd].fdip;
again:
fdip = *p_fdip;
if( fdip_is_busy(fdip) ) fdip = citp_fdtable_busy_wait(fd, 1);
if( fdip_is_closing(fdip) | fdip_is_reserved(fdip) ) {
/* Concurrent close or attempt to close reserved. */
Log_V(ci_log("%s: fd=%d closing=%d reserved=%d", __FUNCTION__, fd,
fdip_is_closing(fdip), fdip_is_reserved(fdip)));
errno = EBADF;
rc = -1;
goto done;
}
#if CI_CFG_FD_CACHING
/* Need to check in case this sucker's cached */
if( fdip_is_unknown(fdip) ) {
fdi = citp_fdtable_probe_locked(fd, CI_FALSE, CI_FALSE);
if( fdi == &citp_the_closed_fd ) {
citp_fdinfo_release_ref(fdi, CI_TRUE);
errno = EBADF;
rc = -1;
goto done;
}
if( fdi )
citp_fdinfo_release_ref(fdi, CI_TRUE);
}
#endif
ci_assert(fdip_is_normal(fdip) | fdip_is_passthru(fdip) |
fdip_is_unknown(fdip));
/* Swap in the "closed" pseudo-fdinfo. This lets any other thread know
** that we're in the middle of closing this fd.
*/
if( fdip_cas_fail(p_fdip, fdip, fdip_closing) )
goto again;
if( fdip_is_normal(fdip) ) {
fdi = fdip_to_fdi(fdip);
CITP_FDTABLE_UNLOCK();
got_lock = 0;
if( fdi->is_special ) {
Log_V(ci_log("%s: fd=%d is_special, returning EBADF", __FUNCTION__, fd));
errno = EBADF;
rc = -1;
fdtable_swap(fd, fdip_closing, fdip, 0);
goto done;
}
Log_V(ci_log("%s: fd=%d u/l socket", __FUNCTION__, fd));
ci_assert_equal(fdi->fd, fd);
ci_assert_equal(fdi->on_ref_count_zero, FDI_ON_RCZ_NONE);
fdi->on_ref_count_zero = FDI_ON_RCZ_CLOSE;
if( fdi->epoll_fd >= 0 ) {
citp_fdinfo* epoll_fdi = citp_epoll_fdi_from_member(fdi, 0);
if( epoll_fdi ) {
if( epoll_fdi->protocol->type == CITP_EPOLL_FD )
citp_epoll_on_close(epoll_fdi, fdi, 0);
citp_fdinfo_release_ref(epoll_fdi, 0);
}
}
citp_fdinfo_release_ref(fdi, 0);
rc = 0;
}
else {
ci_assert(fdip_is_passthru(fdip) ||
fdip_is_unknown(fdip));
if( ! fdtable_strict() ) {
CITP_FDTABLE_UNLOCK();
got_lock = 0;
}
Log_V(ci_log("%s: fd=%d passthru=%d unknown=%d", __FUNCTION__, fd,
fdip_is_passthru(fdip), fdip_is_unknown(fdip)));
fdtable_swap(fd, fdip_closing, fdip_unknown, fdtable_strict());
rc = ci_tcp_helper_close_no_trampoline(fd);
}
done:
if( got_lock ) CITP_FDTABLE_UNLOCK();
FDTABLE_ASSERT_VALID();
return rc;
}
int citp_ep_dup3(unsigned fromfd, unsigned tofd, int flags)
{
volatile citp_fdinfo_p* p_tofdip;
citp_fdinfo_p tofdip;
unsigned max;
Log_V(log("%s(%d, %d)", __FUNCTION__, fromfd, tofd));
/* Must be checked by callers. */
ci_assert(fromfd != tofd);
/* Hack: if [tofd] is the fd we're using for logging, we'd better choose
** a different one!
*/
if( tofd == citp.log_fd ) citp_log_change_fd();
ci_assert(citp.init_level >= CITP_INIT_FDTABLE);
max = CI_MAX(fromfd, tofd);
if( max >= citp_fdtable.inited_count ) {
ci_assert(max < citp_fdtable.size);
CITP_FDTABLE_LOCK();
__citp_fdtable_extend(max);
CITP_FDTABLE_UNLOCK();
}
/* Bug1151: Concurrent threads doing dup2(x,y) and dup2(y,x) can deadlock
** against one another. So we take out a fat lock to prevent concurrent
** dup2()s.
*/
/* Lock tofd. We need to interlock against select and poll etc, so we
** also grab the exclusive lock. Also grab the bug1151 lock.
*/
pthread_mutex_lock(&citp_dup_lock);
CITP_FDTABLE_LOCK();
p_tofdip = &citp_fdtable.table[tofd].fdip;
lock_tofdip_again:
tofdip = *p_tofdip;
if( fdip_is_busy(tofdip) )
tofdip = citp_fdtable_busy_wait(tofd, 1);
if( fdip_is_closing(tofdip) )
tofdip = citp_fdtable_closing_wait(tofd, 1);
if( fdip_is_reserved(tofdip) ) {
/* ?? FIXME: we can't cope with this at the moment */
CITP_FDTABLE_UNLOCK();
Log_U(log("%s(%d, %d): target is reserved", __FUNCTION__, fromfd, tofd));
errno = EBUSY;
tofd = -1;
goto out;
}
if( fdip_cas_fail(p_tofdip, tofdip, fdip_busy) )
goto lock_tofdip_again;
CITP_FDTABLE_UNLOCK();
ci_assert(fdip_is_normal(tofdip) | fdip_is_passthru(tofdip) |
fdip_is_unknown(tofdip));
if( fdip_is_normal(tofdip) ) {
/* We're duping onto a user-level socket. */
citp_fdinfo* tofdi = fdip_to_fdi(tofdip);
if( tofdi->epoll_fd >= 0 ) {
citp_fdinfo* epoll_fdi = citp_epoll_fdi_from_member(tofdi, 0);
if( epoll_fdi ) {
if( epoll_fdi->protocol->type == CITP_EPOLL_FD )
citp_epoll_on_close(epoll_fdi, tofdi, 0);
citp_fdinfo_release_ref(epoll_fdi, 0);
}
}
ci_assert_equal(tofdi->on_ref_count_zero, FDI_ON_RCZ_NONE);
tofdi->on_ref_count_zero = FDI_ON_RCZ_DUP2;
tofdi->on_rcz.dup3_args.fd = fromfd;
tofdi->on_rcz.dup3_args.flags = flags;
citp_fdinfo_release_ref(tofdi, 0);
{
int i = 0;
/* We need to free this fdi. If someone is using it right now,
* we are in trouble. So, we spin for a while and interrupt the
* user. See bug 28123. */
while( tofdi->on_ref_count_zero != FDI_ON_RCZ_DONE ) {
if( ci_is_multithreaded() && i % 10000 == 9999 ) {
pthread_t pth = tofdi->thread_id;
if( pth != pthread_self() && pth != PTHREAD_NULL ) {
pthread_kill(pth, SIGONLOAD);
sleep(1);
}
}
ci_spinloop_pause();
i++;
}
ci_rmb();
}
if( tofdi->on_rcz.dup2_result < 0 ) {
errno = -tofdi->on_rcz.dup2_result;
/* Need to re-insert [tofdi] into the table. */
ci_assert_equal(oo_atomic_read(&tofdi->ref_count), 0);
oo_atomic_set(&tofdi->ref_count, 1);
CI_DEBUG(tofdi->on_ref_count_zero = FDI_ON_RCZ_NONE);
citp_fdtable_busy_clear(tofd, tofdip, 0);
tofd = -1;
}
else {
ci_assert(tofdi->on_rcz.dup2_result == tofd);
citp_fdinfo_get_ops(tofdi)->dtor(tofdi, 0);
citp_fdinfo_free(tofdi);
}
goto out;
}
ci_assert(fdip_is_passthru(tofdip) | fdip_is_unknown(tofdip));
{ /* We're dupping onto an O/S descriptor, or it may be closed. Create a
** dummy [citp_fdinfo], just so we can share code with the case above.
*/
citp_fdinfo fdi;
fdi.fd = tofd;
fdi.on_rcz.dup3_args.fd = fromfd;
fdi.on_rcz.dup3_args.flags = flags;
dup2_complete(&fdi, tofdip, 0);
if( fdi.on_rcz.dup2_result < 0 ) {
errno = -fdi.on_rcz.dup2_result;
citp_fdtable_busy_clear(tofd, tofdip, 0);
tofd = -1;
}
else
ci_assert(fdi.on_rcz.dup2_result == tofd);
}
out:
pthread_mutex_unlock(&citp_dup_lock);
return tofd;
}
static void dup2_complete(citp_fdinfo* prev_tofdi,
citp_fdinfo_p prev_tofdip, int fdt_locked)
{
volatile citp_fdinfo_p *p_fromfdip;
unsigned fromfd = prev_tofdi->on_rcz.dup3_args.fd;
unsigned tofd = prev_tofdi->fd;
citp_fdinfo_p fromfdip;
int rc;
#if CI_LIBC_HAS_dup3 || !defined(NDEBUG)
int flags = prev_tofdi->on_rcz.dup3_args.flags;
#endif
#ifndef NDEBUG
volatile citp_fdinfo_p* p_tofdip;
p_tofdip = &citp_fdtable.table[tofd].fdip;
ci_assert(fdip_is_busy(*p_tofdip));
#endif
citp_fdinfo* fromfdi;
p_fromfdip = &citp_fdtable.table[fromfd].fdip;
lock_fromfdip_again:
fromfdip = *p_fromfdip;
if( fdip_is_busy(fromfdip) )
fromfdip = citp_fdtable_busy_wait(fromfd, fdt_locked);
if( fdip_is_closing(fromfdip) | fdip_is_reserved(fromfdip) ) {
prev_tofdi->on_rcz.dup2_result = -EBADF;
ci_wmb();
prev_tofdi->on_ref_count_zero = FDI_ON_RCZ_DONE;
return;
}
#if CI_CFG_FD_CACHING
/* Need to check in case this sucker's cached */
if( fdip_is_unknown(fromfdip) ) {
if( !fdt_locked ) CITP_FDTABLE_LOCK();
fromfdi = citp_fdtable_probe_locked(fromfd, CI_FALSE, CI_FALSE);
if( !fdt_locked ) CITP_FDTABLE_UNLOCK();
if( fromfdi == &citp_the_closed_fd ) {
prev_tofdi->on_rcz.dup2_result = -EBADF;
ci_wmb();
prev_tofdi->on_ref_count_zero = FDI_ON_RCZ_DONE;
citp_fdinfo_release_ref(fromfdi, CI_TRUE);
return;
}
if( fromfdi )
citp_fdinfo_release_ref(fromfdi, CI_TRUE);
}
#endif
if( fdip_cas_fail(p_fromfdip, fromfdip, fdip_busy) )
goto lock_fromfdip_again;
oo_rwlock_lock_write(&citp_dup2_lock);
#if CI_LIBC_HAS_dup3
rc = ci_sys_dup3(fromfd, tofd, flags);
#else
ci_assert_equal(flags, 0);
rc = ci_sys_dup2(fromfd, tofd);
#endif
oo_rwlock_unlock_write(&citp_dup2_lock);
if( rc < 0 ) {
citp_fdtable_busy_clear(fromfd, fromfdip, fdt_locked);
prev_tofdi->on_rcz.dup2_result = -errno;
ci_wmb();
prev_tofdi->on_ref_count_zero = FDI_ON_RCZ_DONE;
return;
}
ci_assert(fdip_is_normal(fromfdip) | fdip_is_passthru(fromfdip) |
fdip_is_unknown(fromfdip));
if( fdip_is_normal(fromfdip) &&
(((fromfdi = fdip_to_fdi(fromfdip))->protocol->type) == CITP_EPOLL_FD) ) {
citp_fdinfo* newfdi = citp_fdinfo_get_ops(fromfdi)->dup(fromfdi);
if( newfdi ) {
citp_fdinfo_init(newfdi, fdip_to_fdi(fromfdip)->protocol);
citp_fdtable_insert(newfdi, tofd, fdt_locked);
}
else {
/* Out of memory. Can't probe epoll1 fd later on, so fail. */
citp_fdtable_busy_clear(fromfd, fromfdip, fdt_locked);
prev_tofdi->on_rcz.dup2_result = -ENOMEM;
ci_wmb();
prev_tofdi->on_ref_count_zero = FDI_ON_RCZ_DONE;
return;
}
}
else {
/* Mark newfd as unknown. When used, it'll get probed.
*
* We are not just being lazy here: Setting to unknown rather than
* installing a proper fdi (when oldfd is accelerated) is essential to
* vfork()+dup2()+exec() working properly. Reason is that child and
* parent share address space, so child is modifying the parent's
* fdtable. Setting an entry to unknown is safe.
*/
citp_fdtable_busy_clear(tofd, fdip_unknown, fdt_locked);
#if CI_CFG_FD_CACHING
/* Multiple refs to this now, don't allow it to be cached. */
if( fdip_is_normal(fromfdip) )
fdip_to_fdi(fromfdip)->can_cache = 0;
#endif
}
citp_fdtable_busy_clear(fromfd, fromfdip, fdt_locked);
prev_tofdi->on_rcz.dup2_result = tofd;
ci_wmb();
prev_tofdi->on_ref_count_zero = FDI_ON_RCZ_DONE;
}
/*
** Why do these live here? Because they need to hack into the low-level
** dirty nastiness of the fdtable.
*/
int citp_ep_dup(unsigned oldfd, int (*syscall)(int oldfd, long arg),
long arg)
{
/* This implements dup(oldfd) and fcntl(oldfd, F_DUPFD, arg). */
volatile citp_fdinfo_p* p_oldfdip;
citp_fdinfo_p oldfdip;
citp_fdinfo* newfdi = 0;
citp_fdinfo* oldfdi;
int newfd;
Log_V(log("%s(%d)", __FUNCTION__, oldfd));
if(CI_UNLIKELY( citp.init_level < CITP_INIT_FDTABLE ||
oo_per_thread_get()->in_vfork_child ))
/* Lib not initialised, so no U/L state, and therefore system dup()
** will do just fine. */
return syscall(oldfd, arg);
if( oldfd >= citp_fdtable.inited_count ) {
/* NB. We can't just pass through in this case because we need to worry
** about other threads racing with us. So we need to be able to lock
** this fd while we do the dup. */
ci_assert(oldfd < citp_fdtable.size);
CITP_FDTABLE_LOCK();
__citp_fdtable_extend(oldfd);
CITP_FDTABLE_UNLOCK();
}
p_oldfdip = &citp_fdtable.table[oldfd].fdip;
again:
oldfdip = *p_oldfdip;
if( fdip_is_busy(oldfdip) )
oldfdip = citp_fdtable_busy_wait(oldfd, 0);
if( fdip_is_closing(oldfdip) | fdip_is_reserved(oldfdip) ) {
errno = EBADF;
return -1;
}
#if CI_CFG_FD_CACHING
/* Need to check in case this sucker's cached */
if( fdip_is_unknown(oldfdip) ) {
CITP_FDTABLE_LOCK();
oldfdi = citp_fdtable_probe_locked(oldfd, CI_FALSE, CI_FALSE);
CITP_FDTABLE_UNLOCK();
if( oldfdi == &citp_the_closed_fd ) {
citp_fdinfo_release_ref(oldfdi, CI_TRUE);
errno = EBADF;
return -1;
}
if( oldfdi )
citp_fdinfo_release_ref(oldfdi, CI_TRUE);
}
#endif
if( fdip_cas_fail(p_oldfdip, oldfdip, fdip_busy) )
goto again;
#if CI_CFG_FD_CACHING
/* May end up with multiple refs to this, don't allow it to be cached. */
if( fdip_is_normal(oldfdip) )
fdip_to_fdi(oldfdip)->can_cache = 0;
#endif
if( fdip_is_normal(oldfdip) &&
(((oldfdi = fdip_to_fdi(oldfdip))->protocol->type) == CITP_EPOLL_FD) ) {
newfdi = citp_fdinfo_get_ops(oldfdi)->dup(oldfdi);
if( ! newfdi ) {
citp_fdtable_busy_clear(oldfd, oldfdip, 0);
errno = ENOMEM;
return -1;
}
if( fdtable_strict() ) CITP_FDTABLE_LOCK();
newfd = syscall(oldfd, arg);
if( newfd >= 0 )
citp_fdtable_new_fd_set(newfd, fdip_busy, fdtable_strict());
if( fdtable_strict() ) CITP_FDTABLE_UNLOCK();
if( newfd >= 0 ) {
citp_fdtable_insert(newfdi, newfd, 0);
newfdi = 0;
}
}
else {
if( fdtable_strict() ) CITP_FDTABLE_LOCK();
newfd = syscall(oldfd, arg);
if( newfd >= 0 && newfd < citp_fdtable.inited_count ) {
/* Mark newfd as unknown. When used, it'll get probed.
*
* We are not just being lazy here: Setting to unknown rather than
* installing a proper fdi (when oldfd is accelerated) is essential to
* vfork()+dup()+exec() working properly. Reason is that child and
* parent share address space, so child is modifying the parent's
* fdtable. Setting an entry to unknown is safe.
*/
citp_fdtable_new_fd_set(newfd, fdip_unknown, fdtable_strict());
}
if( fdtable_strict() ) CITP_FDTABLE_UNLOCK();
}
citp_fdtable_busy_clear(oldfd, oldfdip, 0);
if( newfdi ) citp_fdinfo_free(newfdi);
return newfd;
}
static void ufd_fmt(int fd, char* buf, int* buf_n, int buf_len)
{
citp_fdinfo_p fdip;
citp_fdinfo* fdi;
char s[30];
if( fd >= citp_fdtable.inited_count ) {
bprintf("unknown");
return;
}
fdip = citp_fdtable.table[fd].fdip;
if( fdip_is_passthru(fdip) ) {
bprintf("passthru");
return;
}
else if( fdip_is_busy(fdip) ) {
bprintf("busy");
return;
}
else if( fdip_is_unknown(fdip) ) {
bprintf("unknown");
return;
}
fdi = fdip_to_fdi(fdip);
#if CI_CFG_FD_CACHING
sprintf(s, "%s%s",
fdi->is_special ? "Special":"",
fdi->can_cache ? "Cancache":"");
#else
sprintf(s, "%s",
fdi->is_special ? "Special":"");
#endif
if( fdi == &citp_the_closed_fd ) {
bprintf("closed_fd[%s]", s);
return;
}
else if( fdi == &citp_the_reserved_fd ) {
bprintf("reserved_fd[%s]", s);
return;
}
if( fdi->protocol == &citp_tcp_protocol_impl ) {
citp_sock_fdi* t = fdi_to_sock_fdi(fdi);
if( citp_fdtable_dump_verbose )
citp_waitable_dump(t->sock.netif, &t->sock.s->b, "");
bprintf("tcp[%s]", s);
}
else if( fdi->protocol == &citp_udp_protocol_impl ) {
citp_sock_fdi* u = fdi_to_sock_fdi(fdi);
if( citp_fdtable_dump_verbose )
citp_waitable_dump(u->sock.netif, &u->sock.s->b, "");
bprintf("udp[%s]", s);
}
#if CI_CFG_USERSPACE_EPOLL
else if( fdi->protocol == &citp_epoll_protocol_impl ) {
bprintf("epoll[%s]", s);
}
#endif
else {
bprintf("bad[%s,%p] *****", s, fdi->protocol);
}
}
