void*
queue_pop(queue *queue) {
qitem *entry;
void* item;
enif_mutex_lock(queue->lock);
/* Wait for an item to become available. */
while (queue->head == NULL) {
enif_cond_wait(queue->cond, queue->lock);
}
assert(queue->length >= 0 && "Invalid queue size at pop.");
/* Woke up because queue->head != NULL
Remove the entry and return the payload. */
entry = queue->head;
queue->head = entry->next;
entry->next = NULL;
if (queue->head == NULL) {
assert(queue->tail == entry && "Invalid queue state: Bad tail.");
queue->tail = NULL;
}
queue->length -= 1;
enif_mutex_unlock(queue->lock);
item = entry->data;
enif_free(entry);
return item;
}
void* queue_get(queue_t* queue)
{
queue_item_t* item;
enif_mutex_lock(queue->mutex);
// Block until theres something in the queue
while (queue->head == NULL) {
enif_cond_wait(queue->cond, queue->mutex);
}
item = queue->head;
queue->head = queue->head->next;
item->next = NULL;
if (queue->head == NULL) {
queue->tail = NULL;
}
enif_mutex_unlock(queue->mutex);
void* data = item->data;
enif_free(item);
return data;
}
qitem*
queue_pop(queue *queue)
{
qitem *entry;
while (enif_mutex_trylock(queue->lock) != 0)
{
}
while(queue->head == NULL)
enif_cond_wait(queue->cond, queue->lock);
assert(queue->length >= 0 && "Invalid queue size at pop.");
/* Woke up because queue->head != NULL
* Remove the entry and return the payload.
*/
entry = queue->head;
queue->head = entry->next;
entry->next = NULL;
if(queue->head == NULL) {
assert(queue->tail == entry && "Invalid queue state: Bad tail.");
queue->tail = NULL;
}
queue->length--;
enif_mutex_unlock(queue->lock);
return entry;
}
ErlNifPid*
queue_pop(queue_t* queue)
{
qitem_t* item;
ErlNifPid* ret = NULL;
enif_mutex_lock(queue->lock);
while(queue->head == NULL)
{
enif_cond_wait(queue->cond, queue->lock);
}
item = queue->head;
queue->head = item->next;
item->next = NULL;
if(queue->head == NULL)
{
queue->tail = NULL;
}
enif_mutex_unlock(queue->lock);
ret = item->pid;
enif_free(item);
return ret;
}
static struct zdoor_result *
zdoor_cb(struct zdoor_cookie *cookie, char *argp, size_t argp_sz)
{
struct door *d;
struct req *r;
ErlNifEnv *env = enif_alloc_env();
/* we kept the struct door in the biscuit */
d = (struct door *)cookie->zdc_biscuit;
/* this request */
r = req_alloc();
/* take the rlist lock first, then the req lock */
enif_rwlock_rwlock(d->rlock);
enif_mutex_lock(r->lock);
req_insert(d, r);
enif_rwlock_rwunlock(d->rlock);
/* make the request into a binary term to put it into enif_send() */
ErlNifBinary bin;
enif_alloc_binary(argp_sz, &bin);
memcpy(bin.data, argp, argp_sz);
ERL_NIF_TERM binTerm = enif_make_binary(env, &bin);
/* send a message back to the session owner */
enif_send(NULL, &d->owner, env,
enif_make_tuple3(env,
enif_make_atom(env, "zdoor"),
enif_make_resource(env, r),
binTerm));
/* now wait until the request has been replied to */
enif_cond_wait(r->cond, r->lock);
/* convert the reply into a zdoor_result */
/* we have to use naked malloc() since libzdoor will use free() */
struct zdoor_result *res = malloc(sizeof(struct zdoor_result));
res->zdr_size = r->replen;
res->zdr_data = r->rep;
r->rep = NULL;
r->replen = 0;
/* yes, we have to unlock and re-lock to avoid lock inversion here */
enif_mutex_unlock(r->lock);
/* remove and free the struct req */
enif_rwlock_rwlock(d->rlock);
enif_mutex_lock(r->lock);
req_remove(d, r);
enif_rwlock_rwunlock(d->rlock);
req_free(r);
enif_free_env(env);
return res;
}
int wait_pointer(couchfile_modify_request* rq, couchfile_pointer_info *ptr)
{
if(ptr->writerq_resource == NULL)
return 0;
int ret = 0;
btreenif_state *state = rq->globalstate;
enif_mutex_lock(state->writer_cond.mtx);
while(ptr->pointer == 0)
{
enif_cond_wait(state->writer_cond.cond, state->writer_cond.mtx);
if(ptr->pointer == 0 &&
!enif_send(rq->caller_env, &rq->writer, state->check_env, state->atom_heart))
{
//The writer process has died
ret = ERROR_WRITER_DEAD;
break;
}
enif_clear_env(state->check_env);
}
if(ptr->pointer != 0)
{
enif_release_resource(ptr->writerq_resource);
}
enif_mutex_unlock(state->writer_cond.mtx);
ptr->writerq_resource = NULL;
return ret;
}
static ERL_NIF_TERM ErlangCall(ErlNifEnv *env, ERL_NIF_TERM fun, ERL_NIF_TERM args) {
ErlCall *erlCall = CreateCall(fun, args);
enif_mutex_lock(erlCall->mutex);
enif_send(env, &server, erlCall->env, erlCall->msg);
while(!erlCall->complete) {
enif_cond_wait(erlCall->cond, erlCall->mutex);
}
enif_mutex_unlock(erlCall->mutex);
ERL_NIF_TERM result = enif_make_copy(env, erlCall->result);
DestroyCall(erlCall);
return result;
}
void* threaded_sender(void *arg)
{
union { void* vp; struct make_term_info* p; }mti;
mti.vp = arg;
enif_mutex_lock(mti.p->mtx);
while (!mti.p->send_it) {
enif_cond_wait(mti.p->cond, mti.p->mtx);
}
mti.p->send_it = 0;
enif_mutex_unlock(mti.p->mtx);
mti.p->send_res = enif_send(NULL, &mti.p->to_pid, mti.p->dst_env, mti.p->blob);
return NULL;
}
int nif_thread_receive(nif_thread_state* st, nif_thread_message** msg)
{
enif_mutex_lock(st->lock);
while (TAILQ_EMPTY(st->mailbox))
enif_cond_wait(st->cond, st->lock);
*msg = TAILQ_FIRST(st->mailbox);
TAILQ_REMOVE(st->mailbox, TAILQ_FIRST(st->mailbox), next_entry);
enif_mutex_unlock(st->lock);
if ((*msg)->function == NULL)
return 0;
return 1;
}
void *
queue_receive(queue *queue) {
void *item;
enif_mutex_lock(queue->lock);
/* Wait for an item to become available. */
while (queue->message == NULL) {
enif_cond_wait(queue->cond, queue->lock);
}
item = queue->message;
queue->message = NULL;
enif_mutex_unlock(queue->lock);
return item;
}
static void *
salt_worker_loop(void *arg)
{
struct salt_pcb *sc = arg;
struct salt_msg *sm;
struct salt_msg *tmp;
/* XXX initialization of libsodium */
/* XXX send readiness indication to owner */
/* Pick up next batch of work, react promptly to termination requests. */
loop:
enif_mutex_lock(sc->sc_lock);
wait:
if (sc->sc_exit_flag) {
enif_mutex_unlock(sc->sc_lock);
return (NULL);
}
if (sc->sc_req_first == NULL) {
enif_cond_wait(sc->sc_cond, sc->sc_lock);
goto wait;
}
sm = sc->sc_req_first;
sc->sc_req_first = NULL;
sc->sc_req_lastp = &sc->sc_req_first;
sc->sc_req_npend = 0;
enif_mutex_unlock(sc->sc_lock);
/* Handle all requests, release when done. */
next:
salt_handle_req(sc, sm);
tmp = sm->msg_next;
enif_free_env(sm->msg_heap);
enif_free(sm);
if (tmp == NULL)
goto loop;
sm = tmp;
goto next;
}
static int queue_pop_core(queue_ptr queue, void **data, const int wait)
{
node_ptr node = NULL;
*data = NULL;
enif_mutex_lock(queue->lock);
while(1 == wait && 0 == queue->size)
{
enif_cond_wait(queue->cond, queue->lock);
}
if(queue->size > 0)
{
node = queue->first;
// remove from queue, if we are shifting up the last one
// then we are setting the 'first' one to NULL
queue->first = node->next;
--queue->size;
if(0 == queue->size)
{
// queue is empty
queue->last = NULL;
}
}
enif_mutex_unlock(queue->lock);
// if we were able to get one, then we set the result and return
if(NULL != node)
{
*data = node->data;
node_free(node);
return 1;
}
return 0;
}
static void *
cache_bg_thread(void *arg)
{
struct cache *c = (struct cache *)arg;
int i, dud;
while (1) {
enif_mutex_lock(c->ctrl_lock);
/* if we've been told to die, quit this loop and start cleaning up */
if (c->flags & FL_DYING) {
enif_mutex_unlock(c->ctrl_lock);
break;
}
/* sleep until there is work to do */
enif_cond_wait(c->check_cond, c->ctrl_lock);
__sync_add_and_fetch(&(c->wakeups), 1);
dud = 1;
/* we have to let go of ctrl_lock so we can take cache_lock then
ctrl_lock again to get them back in the right order */
enif_mutex_unlock(c->ctrl_lock);
enif_rwlock_rwlock(c->cache_lock);
enif_mutex_lock(c->ctrl_lock);
/* first process the promotion queue before we do any evicting */
for (i = 0; i < N_INCR_BKT; ++i) {
enif_mutex_lock(c->incr_lock[i]);
while (!TAILQ_EMPTY(&(c->incr_head[i]))) {
struct cache_incr_node *n;
n = TAILQ_FIRST(&(c->incr_head[i]));
TAILQ_REMOVE(&(c->incr_head[i]), n, entry);
__sync_sub_and_fetch(&(c->incr_count), 1);
dud = 0;
/* let go of the ctrl_lock here, we don't need it when we aren't looking
at the incr_queue, and this way other threads can use it while we shuffle
queue nodes around */
enif_mutex_unlock(c->incr_lock[i]);
enif_mutex_unlock(c->ctrl_lock);
if (n->node->q == &(c->q1)) {
TAILQ_REMOVE(&(c->q1.head), n->node, entry);
c->q1.size -= n->node->size;
TAILQ_INSERT_HEAD(&(c->q2.head), n->node, entry);
n->node->q = &(c->q2);
c->q2.size += n->node->size;
} else if (n->node->q == &(c->q2)) {
TAILQ_REMOVE(&(c->q2.head), n->node, entry);
TAILQ_INSERT_HEAD(&(c->q2.head), n->node, entry);
}
enif_free(n);
/* take the ctrl_lock back again for the next loop around */
enif_mutex_lock(c->ctrl_lock);
enif_mutex_lock(c->incr_lock[i]);
}
enif_mutex_unlock(c->incr_lock[i]);
}
/* let go of the ctrl_lock here for two reasons:
1. avoid lock inversion, because if we have evictions to do we
will need to take lookup_lock, and we must take lookup_lock
before taking ctrl_lock
2. if we don't need to do evictions, we're done with the structures
that are behind ctrl_lock so we should give it up for others */
enif_mutex_unlock(c->ctrl_lock);
/* do timed evictions -- if anything has expired, nuke it */
{
struct cache_node *n;
if ((n = RB_MIN(expiry_tree, &(c->expiry_head)))) {
struct timespec now;
clock_now(&now);
while (n && n->expiry.tv_sec < now.tv_sec) {
enif_mutex_lock(c->ctrl_lock);
dud = 0;
destroy_cache_node(n);
enif_mutex_unlock(c->ctrl_lock);
n = RB_MIN(expiry_tree, &(c->expiry_head));
}
}
}
/* now check if we need to do ordinary size limit evictions */
if (c->q1.size + c->q2.size > c->max_size) {
enif_rwlock_rwlock(c->lookup_lock);
enif_mutex_lock(c->ctrl_lock);
while ((c->q1.size + c->q2.size > c->max_size) &&
(c->q1.size > c->min_q1_size)) {
struct cache_node *n;
n = TAILQ_LAST(&(c->q1.head), cache_q);
destroy_cache_node(n);
}
while (c->q1.size + c->q2.size > c->max_size) {
struct cache_node *n;
n = TAILQ_LAST(&(c->q2.head), cache_q);
destroy_cache_node(n);
}
dud = 0;
enif_mutex_unlock(c->ctrl_lock);
enif_rwlock_rwunlock(c->lookup_lock);
}
if (dud)
__sync_add_and_fetch(&(c->dud_wakeups), 1);
/* now let go of the cache_lock that we took right back at the start of
this iteration */
enif_rwlock_rwunlock(c->cache_lock);
}
/* first remove us from the atom_tree, so we get no new operations coming in */
enif_rwlock_rwlock(gbl->atom_lock);
RB_REMOVE(atom_tree, &(gbl->atom_head), c->atom_node);
enif_rwlock_rwunlock(gbl->atom_lock);
enif_free(c->atom_node);
/* now take all of our locks, to make sure any pending operations are done */
enif_rwlock_rwlock(c->cache_lock);
enif_rwlock_rwlock(c->lookup_lock);
enif_mutex_lock(c->ctrl_lock);
c->atom_node = NULL;
/* free the actual cache queues */
{
struct cache_node *n, *nextn;
nextn = TAILQ_FIRST(&(c->q1.head));
while ((n = nextn)) {
nextn = TAILQ_NEXT(n, entry);
destroy_cache_node(n);
}
nextn = TAILQ_FIRST(&(c->q2.head));
while ((n = nextn)) {
nextn = TAILQ_NEXT(n, entry);
destroy_cache_node(n);
}
}
for (i = 0; i < N_INCR_BKT; ++i)
enif_mutex_lock(c->incr_lock[i]);
/* free the incr_queue */
for (i = 0; i < N_INCR_BKT; ++i) {
struct cache_incr_node *in, *nextin;
nextin = TAILQ_FIRST(&(c->incr_head[i]));
while ((in = nextin)) {
nextin = TAILQ_NEXT(in, entry);
TAILQ_REMOVE(&(c->incr_head[i]), in, entry);
in->node = 0;
enif_free(in);
}
enif_mutex_unlock(c->incr_lock[i]);
enif_mutex_destroy(c->incr_lock[i]);
}
/* unlock and destroy! */
enif_cond_destroy(c->check_cond);
enif_mutex_unlock(c->ctrl_lock);
enif_mutex_destroy(c->ctrl_lock);
enif_rwlock_rwunlock(c->lookup_lock);
enif_rwlock_destroy(c->lookup_lock);
enif_rwlock_rwunlock(c->cache_lock);
enif_rwlock_destroy(c->cache_lock);
enif_free(c);
return 0;
}
/* the async job thread that handles opening/closing of doors */
void *
job_thread(void *arg)
{
struct zdoor_handle *zhandle;
int cont = 1;
int res;
/* first init the handle */
zhandle = zdoor_handle_init();
enif_mutex_lock(gbl.jlock);
while (cont) {
struct job *j;
while (!gbl.jlist)
enif_cond_wait(gbl.jcond, gbl.jlock);
j = gbl.jlist;
while (j) {
gbl.jlist = j->next;
enif_mutex_unlock(gbl.jlock);
if (j->action == ACT_OPEN) {
enif_rwlock_rwlock(gbl.dlock);
j->door->next = NULL;
if (gbl.dlist != NULL)
j->door->next = gbl.dlist;
gbl.dlist = j->door;
enif_rwlock_rwunlock(gbl.dlock);
res = zdoor_open(zhandle, j->door->zonename, j->door->service, j->door, zdoor_cb);
ErlNifEnv *env = enif_alloc_env();
ERL_NIF_TERM ret = enif_make_atom(env, "ok");
switch (res) {
case ZDOOR_ERROR:
ret = enif_make_atom(env, "error");
break;
case ZDOOR_NOT_GLOBAL_ZONE:
ret = enif_make_atom(env, "not_global");
break;
case ZDOOR_ZONE_NOT_RUNNING:
ret = enif_make_atom(env, "not_running");
break;
case ZDOOR_ZONE_FORBIDDEN:
ret = enif_make_atom(env, "eperm");
break;
case ZDOOR_ARGS_ERROR:
ret = enif_make_atom(env, "badarg");
break;
case ZDOOR_OUT_OF_MEMORY:
ret = enif_make_atom(env, "enomem");
break;
}
enif_send(NULL, &j->owner, env,
enif_make_tuple3(env,
enif_make_atom(env, "zdoor_job"),
enif_make_atom(env, "open"),
ret));
enif_free_env(env);
} else if (j->action == ACT_CLOSE) {
enif_rwlock_rwlock(gbl.dlock);
enif_rwlock_rwlock(j->door->rlock);
if (j->door->rlist) {
enif_rwlock_rwunlock(j->door->rlock);
enif_rwlock_rwunlock(gbl.dlock);
ErlNifEnv *env = enif_alloc_env();
enif_send(NULL, &j->owner, env,
enif_make_tuple3(env,
enif_make_atom(env, "zdoor_job"),
enif_make_atom(env, "close"),
enif_make_atom(env, "busy")));
enif_free_env(env);
} else {
struct door *d = gbl.dlist;
if (d == j->door) {
gbl.dlist = j->door->next;
} else {
for (; d; d = d->next) {
if (d->next == j->door) break;
}
if (d)
d->next = j->door->next;
}
enif_rwlock_rwunlock(gbl.dlock);
zdoor_close(zhandle, j->door->zonename, j->door->service);
door_free(j->door);
ErlNifEnv *env = enif_alloc_env();
enif_send(NULL, &j->owner, env,
enif_make_tuple3(env,
enif_make_atom(env, "zdoor_job"),
enif_make_atom(env, "close"),
enif_make_atom(env, "ok")));
enif_free_env(env);
}
} else if (j->action == ACT_QUIT) {
cont = 0;
}
enif_free(j);
enif_mutex_lock(gbl.jlock);
j = gbl.jlist;
}
}
enif_mutex_unlock(gbl.jlock);
zdoor_handle_destroy(zhandle);
return NULL;
}