static void try_delete_node(void *venp)
{
ErlNode *enp = (ErlNode *) venp;
erts_aint_t refc;
erts_smp_rwmtx_rwlock(&erts_node_table_rwmtx);
/*
* Another thread might have looked up this node after we
* decided to delete it (refc became zero). If so, the other
* thread incremented refc twice. Once for the new reference
* and once for this thread.
*
* If refc reach -1, noone has used the entry since we
* set up the timer. Delete the entry.
*
* If refc reach 0, the entry is currently not in use
* but has been used since we set up the timer. Set up a
* new timer.
*
* If refc > 0, the entry is in use. Keep the entry.
*/
refc = erts_refc_dectest(&enp->refc, -1);
if (refc == -1)
(void) hash_erase(&erts_node_table, (void *) enp);
erts_smp_rwmtx_rwunlock(&erts_node_table_rwmtx);
if (refc == 0)
erts_schedule_delete_node(enp);
}
void
erts_set_this_node(Eterm sysname, Uint creation)
{
erts_smp_mtx_lock(&erts_node_table_mtx);
erts_smp_mtx_lock(&erts_dist_table_mtx);
(void) hash_erase(&erts_dist_table, (void *) erts_this_dist_entry);
erts_this_dist_entry->sysname = sysname;
erts_this_dist_entry->creation = creation;
(void) hash_put(&erts_dist_table, (void *) erts_this_dist_entry);
(void) hash_erase(&erts_node_table, (void *) erts_this_node);
erts_this_node->sysname = sysname;
erts_this_node->creation = creation;
(void) hash_put(&erts_node_table, (void *) erts_this_node);
erts_smp_mtx_unlock(&erts_dist_table_mtx);
erts_smp_mtx_unlock(&erts_node_table_mtx);
}
void
erts_set_this_node(Eterm sysname, Uint creation)
{
erts_smp_rwmtx_rwlock(&erts_node_table_rwmtx);
erts_smp_rwmtx_rwlock(&erts_dist_table_rwmtx);
(void) hash_erase(&erts_dist_table, (void *) erts_this_dist_entry);
erts_this_dist_entry->sysname = sysname;
erts_this_dist_entry->creation = creation;
(void) hash_put(&erts_dist_table, (void *) erts_this_dist_entry);
(void) hash_erase(&erts_node_table, (void *) erts_this_node);
erts_this_node->sysname = sysname;
erts_this_node->creation = creation;
erts_this_node_sysname = erts_this_node_sysname_BUFFER;
erts_snprintf(erts_this_node_sysname, sizeof(erts_this_node_sysname_BUFFER),
"%T", sysname);
(void) hash_put(&erts_node_table, (void *) erts_this_node);
erts_smp_rwmtx_rwunlock(&erts_dist_table_rwmtx);
erts_smp_rwmtx_rwunlock(&erts_node_table_rwmtx);
}
void erts_delete_node(ErlNode *enp)
{
ASSERT(enp != erts_this_node);
if(enp != erts_this_node) {
erts_smp_mtx_lock(&erts_node_table_mtx);
/*
* Another thread might have looked up this node after we
* decided to delete it (refc became zero). If so, the other
* thread incremented refc twice. Once for the new reference
* and once for this thread. Therefore, delete node if refc
* is 0 or -1 after a decrement.
*/
if (erts_refc_dectest(&enp->refc, -1) <= 0)
(void) hash_erase(&erts_node_table, (void *) enp);
erts_smp_mtx_unlock(&erts_node_table_mtx);
}
}
void erts_delete_dist_entry(DistEntry *dep)
{
ASSERT(dep != erts_this_dist_entry);
if(dep != erts_this_dist_entry) {
erts_smp_mtx_lock(&erts_dist_table_mtx);
/*
* Another thread might have looked up this dist entry after
* we decided to delete it (refc became zero). If so, the other
* thread incremented refc twice. Once for the new reference
* and once for this thread. Therefore, delete dist entry if
* refc is 0 or -1 after a decrement.
*/
if (erts_refc_dectest(&dep->refc, -1) <= 0)
(void) hash_erase(&erts_dist_table, (void *) dep);
erts_smp_mtx_unlock(&erts_dist_table_mtx);
}
}
/* Test that we can erase a key from the table */
int test_erase() {
build_hash();
/* The key should no longer be found */
if(!hash_get(hash, (void*)"k1", (void**)&value)) {
printf("Key k1 missing from initial hash.\n");
return 1;
}
/* make sure that unset values actually fail */
hash_erase(hash, (void*)"k1");
value = "";
/* The key should no longer be found */
if(hash_get(hash, (void*)"k1", (void**)&value)) {
printf("Found: '%s'\n", value);
return 1;
}
return 0;
}
/*
* 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;
ErtsProcLocks current_c_p_locks = 0;
#ifdef ERTS_SMP
/*
* 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 (is_non_value(name)) {
/* Unregister current process name */
ASSERT(c_p);
#ifdef ERTS_SMP
if (current_c_p_locks != c_p_locks) {
erts_smp_proc_lock(c_p, c_p_locks);
current_c_p_locks = c_p_locks;
}
#endif
if (c_p->common.u.alive.reg) {
r.name = c_p->common.u.alive.reg->name;
} else {
/* Name got unregistered while main lock was released */
res = 0;
goto done;
}
}
if ((rp = (RegProc*) hash_get(&process_reg, (void*) &r)) != NULL) {
if (rp->pt) {
if (port != rp->pt) {
#ifdef ERTS_SMP
if (port) {
ASSERT(port != c_prt);
erts_port_release(port);
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_write_unlock();
port = erts_id2port(id);
goto restart;
}
#endif
port = rp->pt;
}
ASSERT(rp->pt == port);
ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(port));
rp->pt->common.u.alive.reg = NULL;
if (IS_TRACED_FL(port, F_TRACE_PORTS)) {
if (current_c_p_locks) {
erts_smp_proc_unlock(c_p, current_c_p_locks);
current_c_p_locks = 0;
}
trace_port(port, am_unregister, r.name);
}
} else if (rp->p) {
#ifdef ERTS_SMP
erts_proc_safelock(c_p,
current_c_p_locks,
c_p_locks,
rp->p,
(c_p == rp->p) ? current_c_p_locks : 0,
ERTS_PROC_LOCK_MAIN);
current_c_p_locks = c_p_locks;
#endif
rp->p->common.u.alive.reg = NULL;
if (IS_TRACED_FL(rp->p, F_TRACE_PROCS)) {
trace_proc(rp->p, (c_p == rp->p) ? c_p_locks : ERTS_PROC_LOCK_MAIN,
rp->p, am_unregister, r.name);
}
#ifdef ERTS_SMP
if (rp->p != c_p) {
erts_smp_proc_unlock(rp->p, ERTS_PROC_LOCK_MAIN);
}
#endif
}
hash_erase(&process_reg, (void*) &r);
res = 1;
}
done:
reg_write_unlock();
if (c_prt != port) {
if (port) {
erts_port_release(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;
}
/*
* 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;
}