BIF_RETTYPE registered_0(BIF_ALIST_0)
{
int i;
Eterm res;
Uint need;
Eterm* hp;
HashBucket **bucket;
#ifdef ERTS_SMP
ErtsProcLocks proc_locks = ERTS_PROC_LOCK_MAIN;
ERTS_SMP_CHK_HAVE_ONLY_MAIN_PROC_LOCK(BIF_P);
reg_safe_read_lock(BIF_P, &proc_locks);
if (!proc_locks)
erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
#endif
bucket = process_reg.bucket;
/* work out how much heap we need & maybe garb, by scanning through
the registered process table */
need = 0;
for (i = 0; i < process_reg.size; i++) {
HashBucket *b = bucket[i];
while (b != NULL) {
need += 2;
b = b->next;
}
}
if (need == 0) {
reg_read_unlock();
BIF_RET(NIL);
}
hp = HAlloc(BIF_P, need);
/* scan through again and make the list */
res = NIL;
for (i = 0; i < process_reg.size; i++) {
HashBucket *b = bucket[i];
while (b != NULL) {
RegProc *reg = (RegProc *) b;
res = CONS(hp, reg->name, res);
hp += 2;
b = b->next;
}
}
reg_read_unlock();
BIF_RET(res);
}
void register_info(fmtfn_t to, void *to_arg)
{
int lock = !ERTS_IS_CRASH_DUMPING;
if (lock)
reg_read_lock();
hash_info(to, to_arg, &process_reg);
if (lock)
reg_read_unlock();
}
int process_reg_sz(void)
{
int sz;
int lock = !ERTS_IS_CRASH_DUMPING;
if (lock)
reg_read_lock();
sz = hash_table_sz(&process_reg);
if (lock)
reg_read_unlock();
return sz;
}
int process_reg_size(void)
{
int size;
int lock = !ERTS_IS_CRASH_DUMPING;
if (lock)
reg_read_lock();
size = process_reg.size;
if (lock)
reg_read_unlock();
return size;
}
Eterm
erts_whereis_name_to_id(Process *c_p, Eterm name)
{
Eterm res = am_undefined;
HashValue hval;
int ix;
HashBucket* b;
#ifdef ERTS_SMP
ErtsProcLocks c_p_locks = c_p ? ERTS_PROC_LOCK_MAIN : 0;
#ifdef ERTS_ENABLE_LOCK_CHECK
if (c_p) ERTS_SMP_CHK_HAVE_ONLY_MAIN_PROC_LOCK(c_p);
#endif
reg_safe_read_lock(c_p, &c_p_locks);
if (c_p && !c_p_locks)
erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
#endif
hval = REG_HASH(name);
ix = hval % process_reg.size;
b = process_reg.bucket[ix];
/*
* Note: We have inlined the code from hash.c for speed.
*/
while (b) {
RegProc* rp = (RegProc *) b;
if (rp->name == name) {
/*
* SMP NOTE: No need to lock registered entity since it cannot
* be removed without acquiring write reg lock and id on entity
* is read only.
*/
if (rp->p)
res = rp->p->common.id;
else if (rp->pt)
res = rp->pt->common.id;
break;
}
b = b->next;
}
reg_read_unlock();
ASSERT(is_internal_pid(res) || is_internal_port(res) || res==am_undefined);
return res;
}
void
erts_whereis_name(Process *c_p,
ErtsProcLocks c_p_locks,
Eterm name,
Process** proc,
ErtsProcLocks need_locks,
int flags,
Port** port,
int lock_port)
{
RegProc* rp = NULL;
HashValue hval;
int ix;
HashBucket* b;
#ifdef ERTS_SMP
ErtsProcLocks current_c_p_locks;
Port *pending_port = NULL;
if (!c_p)
c_p_locks = 0;
current_c_p_locks = c_p_locks;
restart:
reg_safe_read_lock(c_p, ¤t_c_p_locks);
/* Locked locks:
* - port lock on pending_port if pending_port != NULL
* - read reg lock
* - current_c_p_locks (either c_p_locks or 0) on c_p
*/
#endif
hval = REG_HASH(name);
ix = hval % process_reg.size;
b = process_reg.bucket[ix];
/*
* Note: We have inlined the code from hash.c for speed.
*/
while (b) {
if (((RegProc *) b)->name == name) {
rp = (RegProc *) b;
break;
}
b = b->next;
}
if (proc) {
if (!rp)
*proc = NULL;
else {
#ifdef ERTS_SMP
if (!rp->p)
*proc = NULL;
else {
if (need_locks) {
erts_proc_safelock(c_p,
current_c_p_locks,
c_p_locks,
rp->p,
0,
need_locks);
current_c_p_locks = c_p_locks;
}
if ((flags & ERTS_P2P_FLG_ALLOW_OTHER_X) || is_proc_alive(rp->p))
*proc = rp->p;
else {
if (need_locks)
erts_smp_proc_unlock(rp->p, need_locks);
*proc = NULL;
}
}
#else
if (rp->p
&& ((flags & ERTS_P2P_FLG_ALLOW_OTHER_X) || is_proc_alive(rp->p)))
*proc = rp->p;
else
*proc = NULL;
#endif
if (*proc && (flags & ERTS_P2P_FLG_INC_REFC))
erts_proc_inc_refc(*proc);
}
}
if (port) {
if (!rp || !rp->pt)
*port = NULL;
else {
#ifdef ERTS_SMP
if (lock_port) {
if (pending_port == rp->pt)
pending_port = NULL;
else {
if (pending_port) {
/* Ahh! Registered port changed while reg lock
was unlocked... */
erts_port_release(pending_port);
pending_port = NULL;
}
if (erts_smp_port_trylock(rp->pt) == EBUSY) {
Eterm id = rp->pt->common.id; /* id read only... */
/* Unlock all locks, acquire port lock, and restart... */
if (current_c_p_locks) {
erts_smp_proc_unlock(c_p, current_c_p_locks);
current_c_p_locks = 0;
}
reg_read_unlock();
pending_port = erts_id2port(id);
goto restart;
}
}
ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(rp->pt));
}
#endif
*port = rp->pt;
}
}
#ifdef ERTS_SMP
if (c_p && !current_c_p_locks)
erts_smp_proc_lock(c_p, c_p_locks);
if (pending_port)
erts_port_release(pending_port);
#endif
reg_read_unlock();
}
/*
* Unregister a name
* Return 0 if not registered
* Otherwise returns 1
*
*/
int erts_unregister_name(Process *c_p,
ErtsProcLocks c_p_locks,
Port *c_prt,
Eterm name)
{
int res = 0;
RegProc r, *rp;
Port *port = c_prt;
#ifdef ERTS_SMP
ErtsProcLocks current_c_p_locks;
/*
* SMP note: If 'c_prt != NULL' and 'c_prt->reg->name == name',
* we are *not* allowed to temporarily release the lock
* on c_prt.
*/
if (!c_p)
c_p_locks = 0;
current_c_p_locks = c_p_locks;
restart:
reg_safe_write_lock(c_p, ¤t_c_p_locks);
#endif
r.name = name;
if ((rp = (RegProc*) hash_get(&process_reg, (void*) &r)) != NULL) {
if (rp->pt) {
#ifdef ERTS_SMP
if (port != rp->pt) {
if (port) {
ERTS_SMP_LC_ASSERT(port != c_prt);
erts_smp_port_unlock(port);
port = NULL;
}
if (erts_smp_port_trylock(rp->pt) == EBUSY) {
Eterm id = rp->pt->id; /* id read only... */
/* Unlock all locks, acquire port lock, and restart... */
if (current_c_p_locks) {
erts_smp_proc_unlock(c_p, current_c_p_locks);
current_c_p_locks = 0;
}
reg_read_unlock();
port = erts_id2port(id, NULL, 0);
goto restart;
}
port = rp->pt;
}
#endif
ERTS_SMP_LC_ASSERT(rp->pt == port && erts_lc_is_port_locked(port));
rp->pt->reg = NULL;
if (IS_TRACED_FL(port, F_TRACE_PORTS)) {
trace_port(port, am_unregister, name);
}
} else if (rp->p) {
Process* p = rp->p;
#ifdef ERTS_SMP
erts_proc_safelock(c_p,
current_c_p_locks,
c_p_locks,
rp->p,
0,
ERTS_PROC_LOCK_MAIN);
current_c_p_locks = c_p_locks;
#endif
p->reg = NULL;
#ifdef ERTS_SMP
if (rp->p != c_p)
erts_smp_proc_unlock(rp->p, ERTS_PROC_LOCK_MAIN);
#endif
if (IS_TRACED_FL(p, F_TRACE_PROCS)) {
trace_proc(c_p, p, am_unregister, name);
}
}
hash_erase(&process_reg, (void*) &r);
res = 1;
}
reg_write_unlock();
if (c_prt != port) {
if (port)
erts_smp_port_unlock(port);
if (c_prt)
erts_smp_port_lock(c_prt);
}
#ifdef ERTS_SMP
if (c_p && !current_c_p_locks)
erts_smp_proc_lock(c_p, c_p_locks);
#endif
return res;
}
