void
erts_queue_dist_message(Process *rcvr,
ErtsProcLocks rcvr_locks,
ErtsDistExternal *dist_ext,
Eterm token,
Eterm from)
{
ErtsMessage* mp;
erts_aint_t state;
ERTS_LC_ASSERT(rcvr_locks == erts_proc_lc_my_proc_locks(rcvr));
mp = erts_alloc_message(0, NULL);
mp->data.dist_ext = dist_ext;
ERL_MESSAGE_FROM(mp) = dist_ext->dep->sysname;
ERL_MESSAGE_TERM(mp) = THE_NON_VALUE;
#ifdef USE_VM_PROBES
ERL_MESSAGE_DT_UTAG(mp) = NIL;
if (token == am_have_dt_utag)
ERL_MESSAGE_TOKEN(mp) = NIL;
else
#endif
ERL_MESSAGE_TOKEN(mp) = token;
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ)) {
if (erts_proc_trylock(rcvr, ERTS_PROC_LOCK_MSGQ) == EBUSY) {
ErtsProcLocks need_locks = ERTS_PROC_LOCK_MSGQ;
ErtsProcLocks unlocks =
rcvr_locks & ERTS_PROC_LOCKS_HIGHER_THAN(ERTS_PROC_LOCK_MSGQ);
if (unlocks) {
erts_proc_unlock(rcvr, unlocks);
need_locks |= unlocks;
}
erts_proc_lock(rcvr, need_locks);
}
}
state = erts_atomic32_read_acqb(&rcvr->state);
if (state & ERTS_PSFLG_EXITING) {
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
/* Drop message if receiver is exiting or has a pending exit ... */
erts_cleanup_messages(mp);
}
else {
LINK_MESSAGE(rcvr, mp);
if (rcvr_locks & ERTS_PROC_LOCK_MAIN)
erts_proc_sig_fetch(rcvr);
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
erts_proc_notify_new_message(rcvr, rcvr_locks);
}
}
/* Add messages last in message queue */
static Sint
queue_messages(Process* receiver,
erts_aint32_t *receiver_state,
ErtsProcLocks receiver_locks,
ErtsMessage* first,
ErtsMessage** last,
Uint len,
Eterm from)
{
ErtsTracingEvent* te;
Sint res;
int locked_msgq = 0;
erts_aint32_t state;
ASSERT(is_value(ERL_MESSAGE_TERM(first)));
ASSERT(ERL_MESSAGE_TOKEN(first) == am_undefined ||
ERL_MESSAGE_TOKEN(first) == NIL ||
is_tuple(ERL_MESSAGE_TOKEN(first)));
#ifdef ERTS_ENABLE_LOCK_CHECK
ERTS_LC_ASSERT(erts_proc_lc_my_proc_locks(receiver) < ERTS_PROC_LOCK_MSGQ ||
receiver_locks == erts_proc_lc_my_proc_locks(receiver));
#endif
if (!(receiver_locks & ERTS_PROC_LOCK_MSGQ)) {
if (erts_proc_trylock(receiver, ERTS_PROC_LOCK_MSGQ) == EBUSY) {
ErtsProcLocks need_locks;
if (receiver_state)
state = *receiver_state;
else
state = erts_atomic32_read_nob(&receiver->state);
if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT))
goto exiting;
need_locks = receiver_locks & ERTS_PROC_LOCKS_HIGHER_THAN(ERTS_PROC_LOCK_MSGQ);
if (need_locks) {
erts_proc_unlock(receiver, need_locks);
}
need_locks |= ERTS_PROC_LOCK_MSGQ;
erts_proc_lock(receiver, need_locks);
}
locked_msgq = 1;
}
state = erts_atomic32_read_nob(&receiver->state);
if (state & (ERTS_PSFLG_PENDING_EXIT|ERTS_PSFLG_EXITING)) {
exiting:
/* Drop message if receiver is exiting or has a pending exit... */
if (locked_msgq)
erts_proc_unlock(receiver, ERTS_PROC_LOCK_MSGQ);
erts_cleanup_messages(first);
return 0;
}
res = receiver->msg.len;
if (receiver_locks & ERTS_PROC_LOCK_MAIN) {
/*
* We move 'in queue' to 'private queue' and place
* message at the end of 'private queue' in order
* to ensure that the 'in queue' doesn't contain
* references into the heap. By ensuring this,
* we don't need to include the 'in queue' in
* the root set when garbage collecting.
*/
res += receiver->msg_inq.len;
ERTS_MSGQ_MV_INQ2PRIVQ(receiver);
LINK_MESSAGE_PRIVQ(receiver, first, last, len);
}
else
{
LINK_MESSAGE(receiver, first, last, len);
}
if (IS_TRACED_FL(receiver, F_TRACE_RECEIVE)
&& (te = &erts_receive_tracing[erts_active_bp_ix()],
te->on)) {
ErtsMessage *msg = first;
#ifdef USE_VM_PROBES
if (DTRACE_ENABLED(message_queued)) {
DTRACE_CHARBUF(receiver_name, DTRACE_TERM_BUF_SIZE);
Sint tok_label = 0;
Sint tok_lastcnt = 0;
Sint tok_serial = 0;
Eterm seq_trace_token = ERL_MESSAGE_TOKEN(msg);
dtrace_proc_str(receiver, receiver_name);
if (seq_trace_token != NIL && is_tuple(seq_trace_token)) {
tok_label = signed_val(SEQ_TRACE_T_LABEL(seq_trace_token));
tok_lastcnt = signed_val(SEQ_TRACE_T_LASTCNT(seq_trace_token));
tok_serial = signed_val(SEQ_TRACE_T_SERIAL(seq_trace_token));
}
DTRACE6(message_queued,
receiver_name, size_object(ERL_MESSAGE_TERM(msg)),
receiver->msg.len,
tok_label, tok_lastcnt, tok_serial);
}
#endif
while (msg) {
trace_receive(receiver, from, ERL_MESSAGE_TERM(msg), te);
msg = msg->next;
}
}
if (locked_msgq) {
erts_proc_unlock(receiver, ERTS_PROC_LOCK_MSGQ);
}
erts_proc_notify_new_message(receiver, receiver_locks);
return res;
}
void
erts_queue_dist_message(Process *rcvr,
ErtsProcLocks rcvr_locks,
ErtsDistExternal *dist_ext,
Eterm token,
Eterm from)
{
ErtsMessage* mp;
#ifdef USE_VM_PROBES
Sint tok_label = 0;
Sint tok_lastcnt = 0;
Sint tok_serial = 0;
#endif
erts_aint_t state;
ERTS_LC_ASSERT(rcvr_locks == erts_proc_lc_my_proc_locks(rcvr));
mp = erts_alloc_message(0, NULL);
mp->data.dist_ext = dist_ext;
ERL_MESSAGE_TERM(mp) = THE_NON_VALUE;
#ifdef USE_VM_PROBES
ERL_MESSAGE_DT_UTAG(mp) = NIL;
if (token == am_have_dt_utag)
ERL_MESSAGE_TOKEN(mp) = NIL;
else
#endif
ERL_MESSAGE_TOKEN(mp) = token;
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ)) {
if (erts_proc_trylock(rcvr, ERTS_PROC_LOCK_MSGQ) == EBUSY) {
ErtsProcLocks need_locks = ERTS_PROC_LOCK_MSGQ;
ErtsProcLocks unlocks =
rcvr_locks & ERTS_PROC_LOCKS_HIGHER_THAN(ERTS_PROC_LOCK_MSGQ);
if (unlocks) {
erts_proc_unlock(rcvr, unlocks);
need_locks |= unlocks;
}
erts_proc_lock(rcvr, need_locks);
}
}
state = erts_atomic32_read_acqb(&rcvr->state);
if (state & (ERTS_PSFLG_PENDING_EXIT|ERTS_PSFLG_EXITING)) {
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
/* Drop message if receiver is exiting or has a pending exit ... */
erts_cleanup_messages(mp);
}
else
if (IS_TRACED_FL(rcvr, F_TRACE_RECEIVE)) {
if (from == am_Empty)
from = dist_ext->dep->sysname;
/* Ahh... need to decode it in order to trace it... */
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
if (!erts_decode_dist_message(rcvr, rcvr_locks, mp, 0))
erts_free_message(mp);
else {
Eterm msg = ERL_MESSAGE_TERM(mp);
token = ERL_MESSAGE_TOKEN(mp);
#ifdef USE_VM_PROBES
if (DTRACE_ENABLED(message_queued)) {
DTRACE_CHARBUF(receiver_name, DTRACE_TERM_BUF_SIZE);
dtrace_proc_str(rcvr, receiver_name);
if (have_seqtrace(token)) {
tok_label = signed_val(SEQ_TRACE_T_LABEL(token));
tok_lastcnt = signed_val(SEQ_TRACE_T_LASTCNT(token));
tok_serial = signed_val(SEQ_TRACE_T_SERIAL(token));
}
DTRACE6(message_queued,
receiver_name, size_object(msg), rcvr->msg.len,
tok_label, tok_lastcnt, tok_serial);
}
#endif
erts_queue_message(rcvr, rcvr_locks, mp, msg, from);
}
}
else {
/* Enqueue message on external format */
#ifdef USE_VM_PROBES
if (DTRACE_ENABLED(message_queued)) {
DTRACE_CHARBUF(receiver_name, DTRACE_TERM_BUF_SIZE);
dtrace_proc_str(rcvr, receiver_name);
if (have_seqtrace(token)) {
tok_label = signed_val(SEQ_TRACE_T_LABEL(token));
tok_lastcnt = signed_val(SEQ_TRACE_T_LASTCNT(token));
tok_serial = signed_val(SEQ_TRACE_T_SERIAL(token));
}
/*
* TODO: We don't know the real size of the external message here.
* -1 will appear to a D script as 4294967295.
*/
DTRACE6(message_queued, receiver_name, -1, rcvr->msg.len + 1,
tok_label, tok_lastcnt, tok_serial);
}
#endif
LINK_MESSAGE(rcvr, mp, &mp->next, 1);
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
erts_proc_notify_new_message(rcvr,
rcvr_locks
);
}
}
/* Add a message last in message queue */
static Sint
queue_message(Process *c_p,
Process* receiver,
erts_aint32_t *receiver_state,
ErtsProcLocks *receiver_locks,
ErtsMessage* mp,
Eterm message,
Eterm seq_trace_token
#ifdef USE_VM_PROBES
, Eterm dt_utag
#endif
)
{
Sint res;
int locked_msgq = 0;
erts_aint32_t state;
ERTS_SMP_LC_ASSERT(*receiver_locks == erts_proc_lc_my_proc_locks(receiver));
#ifdef ERTS_SMP
if (!(*receiver_locks & ERTS_PROC_LOCK_MSGQ)) {
if (erts_smp_proc_trylock(receiver, ERTS_PROC_LOCK_MSGQ) == EBUSY) {
ErtsProcLocks need_locks = ERTS_PROC_LOCK_MSGQ;
if (receiver_state)
state = *receiver_state;
else
state = erts_smp_atomic32_read_nob(&receiver->state);
if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT))
goto exiting;
if (*receiver_locks & ERTS_PROC_LOCK_STATUS) {
erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_STATUS);
need_locks |= ERTS_PROC_LOCK_STATUS;
}
erts_smp_proc_lock(receiver, need_locks);
}
locked_msgq = 1;
}
#endif
state = erts_smp_atomic32_read_nob(&receiver->state);
if (state & (ERTS_PSFLG_PENDING_EXIT|ERTS_PSFLG_EXITING)) {
#ifdef ERTS_SMP
exiting:
#endif
/* Drop message if receiver is exiting or has a pending exit... */
if (locked_msgq)
erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_MSGQ);
erts_cleanup_messages(mp);
return 0;
}
ERL_MESSAGE_TERM(mp) = message;
ERL_MESSAGE_TOKEN(mp) = seq_trace_token;
#ifdef USE_VM_PROBES
ERL_MESSAGE_DT_UTAG(mp) = dt_utag;
#endif
res = receiver->msg.len;
#ifdef ERTS_SMP
if (*receiver_locks & ERTS_PROC_LOCK_MAIN) {
/*
* We move 'in queue' to 'private queue' and place
* message at the end of 'private queue' in order
* to ensure that the 'in queue' doesn't contain
* references into the heap. By ensuring this,
* we don't need to include the 'in queue' in
* the root set when garbage collecting.
*/
res += receiver->msg_inq.len;
ERTS_SMP_MSGQ_MV_INQ2PRIVQ(receiver);
LINK_MESSAGE_PRIVQ(receiver, mp);
}
else
#endif
{
LINK_MESSAGE(receiver, mp);
}
#ifdef USE_VM_PROBES
if (DTRACE_ENABLED(message_queued)) {
DTRACE_CHARBUF(receiver_name, DTRACE_TERM_BUF_SIZE);
Sint tok_label = 0;
Sint tok_lastcnt = 0;
Sint tok_serial = 0;
dtrace_proc_str(receiver, receiver_name);
if (seq_trace_token != NIL && is_tuple(seq_trace_token)) {
tok_label = signed_val(SEQ_TRACE_T_LABEL(seq_trace_token));
tok_lastcnt = signed_val(SEQ_TRACE_T_LASTCNT(seq_trace_token));
tok_serial = signed_val(SEQ_TRACE_T_SERIAL(seq_trace_token));
}
DTRACE6(message_queued,
receiver_name, size_object(message), receiver->msg.len,
tok_label, tok_lastcnt, tok_serial);
}
#endif
if (IS_TRACED_FL(receiver, F_TRACE_RECEIVE))
trace_receive(receiver, message);
if (locked_msgq)
erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_MSGQ);
erts_proc_notify_new_message(receiver,
#ifdef ERTS_SMP
*receiver_locks
#else
0
#endif
);
#ifndef ERTS_SMP
ERTS_HOLE_CHECK(receiver);
#endif
return res;
}
void
erts_queue_dist_message(Process *rcvr,
ErtsProcLocks *rcvr_locks,
ErtsDistExternal *dist_ext,
Eterm token)
{
ErlMessage* mp;
#ifdef USE_VM_PROBES
Sint tok_label = 0;
Sint tok_lastcnt = 0;
Sint tok_serial = 0;
#endif
#ifdef ERTS_SMP
erts_aint_t state;
#endif
ERTS_SMP_LC_ASSERT(*rcvr_locks == erts_proc_lc_my_proc_locks(rcvr));
mp = message_alloc();
#ifdef ERTS_SMP
if (!(*rcvr_locks & ERTS_PROC_LOCK_MSGQ)) {
if (erts_smp_proc_trylock(rcvr, ERTS_PROC_LOCK_MSGQ) == EBUSY) {
ErtsProcLocks need_locks = ERTS_PROC_LOCK_MSGQ;
if (*rcvr_locks & ERTS_PROC_LOCK_STATUS) {
erts_smp_proc_unlock(rcvr, ERTS_PROC_LOCK_STATUS);
need_locks |= ERTS_PROC_LOCK_STATUS;
}
erts_smp_proc_lock(rcvr, need_locks);
}
}
state = erts_smp_atomic32_read_acqb(&rcvr->state);
if (state & (ERTS_PSFLG_PENDING_EXIT|ERTS_PSFLG_EXITING)) {
if (!(*rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_smp_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
/* Drop message if receiver is exiting or has a pending exit ... */
if (is_not_nil(token)) {
ErlHeapFragment *heap_frag;
heap_frag = erts_dist_ext_trailer(mp->data.dist_ext);
erts_cleanup_offheap(&heap_frag->off_heap);
}
erts_free_dist_ext_copy(dist_ext);
message_free(mp);
}
else
#endif
if (IS_TRACED_FL(rcvr, F_TRACE_RECEIVE)) {
/* Ahh... need to decode it in order to trace it... */
ErlHeapFragment *mbuf;
Eterm msg;
if (!(*rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_smp_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
message_free(mp);
msg = erts_msg_distext2heap(rcvr, rcvr_locks, &mbuf, &token, dist_ext);
if (is_value(msg))
#ifdef USE_VM_PROBES
if (DTRACE_ENABLED(message_queued)) {
DTRACE_CHARBUF(receiver_name, DTRACE_TERM_BUF_SIZE);
dtrace_proc_str(rcvr, receiver_name);
if (token != NIL && token != am_have_dt_utag) {
tok_label = signed_val(SEQ_TRACE_T_LABEL(token));
tok_lastcnt = signed_val(SEQ_TRACE_T_LASTCNT(token));
tok_serial = signed_val(SEQ_TRACE_T_SERIAL(token));
}
DTRACE6(message_queued,
receiver_name, size_object(msg), rcvr->msg.len,
tok_label, tok_lastcnt, tok_serial);
}
#endif
erts_queue_message(rcvr, rcvr_locks, mbuf, msg, token);
}
else {
/* Enqueue message on external format */
ERL_MESSAGE_TERM(mp) = THE_NON_VALUE;
#ifdef USE_VM_PROBES
ERL_MESSAGE_DT_UTAG(mp) = NIL;
if (token == am_have_dt_utag) {
ERL_MESSAGE_TOKEN(mp) = NIL;
} else {
#endif
ERL_MESSAGE_TOKEN(mp) = token;
#ifdef USE_VM_PROBES
}
#endif
mp->next = NULL;
#ifdef USE_VM_PROBES
if (DTRACE_ENABLED(message_queued)) {
DTRACE_CHARBUF(receiver_name, DTRACE_TERM_BUF_SIZE);
dtrace_proc_str(rcvr, receiver_name);
if (token != NIL && token != am_have_dt_utag) {
tok_label = signed_val(SEQ_TRACE_T_LABEL(token));
tok_lastcnt = signed_val(SEQ_TRACE_T_LASTCNT(token));
tok_serial = signed_val(SEQ_TRACE_T_SERIAL(token));
}
/*
* TODO: We don't know the real size of the external message here.
* -1 will appear to a D script as 4294967295.
*/
DTRACE6(message_queued, receiver_name, -1, rcvr->msg.len + 1,
tok_label, tok_lastcnt, tok_serial);
}
#endif
mp->data.dist_ext = dist_ext;
LINK_MESSAGE(rcvr, mp);
if (!(*rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_smp_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
erts_proc_notify_new_message(rcvr,
#ifdef ERTS_SMP
*rcvr_locks
#else
0
#endif
);
}
}
/* Add messages last in message queue */
static void
queue_messages(Process* receiver,
ErtsProcLocks receiver_locks,
ErtsMessage* first,
ErtsMessage** last,
Uint len)
{
int locked_msgq = 0;
erts_aint32_t state;
#ifdef DEBUG
{
ErtsMessage* fmsg = ERTS_SIG_IS_MSG(first) ? first : first->next;
ASSERT(fmsg);
ASSERT(is_value(ERL_MESSAGE_TERM(fmsg)));
ASSERT(is_value(ERL_MESSAGE_FROM(fmsg)));
ASSERT(ERL_MESSAGE_TOKEN(fmsg) == am_undefined ||
ERL_MESSAGE_TOKEN(fmsg) == NIL ||
is_tuple(ERL_MESSAGE_TOKEN(fmsg)));
}
#endif
ERTS_LC_ASSERT((erts_proc_lc_my_proc_locks(receiver) & ERTS_PROC_LOCK_MSGQ)
== (receiver_locks & ERTS_PROC_LOCK_MSGQ));
if (!(receiver_locks & ERTS_PROC_LOCK_MSGQ)) {
erts_proc_lock(receiver, ERTS_PROC_LOCK_MSGQ);
locked_msgq = 1;
}
state = erts_atomic32_read_nob(&receiver->state);
if (state & ERTS_PSFLG_EXITING) {
/* Drop message if receiver is exiting or has a pending exit... */
if (locked_msgq)
erts_proc_unlock(receiver, ERTS_PROC_LOCK_MSGQ);
if (ERTS_SIG_IS_NON_MSG(first)) {
ErtsSchedulerData* esdp = erts_get_scheduler_data();
ASSERT(esdp);
ASSERT(!esdp->pending_signal.sig);
esdp->pending_signal.sig = (ErtsSignal*) first;
esdp->pending_signal.to = receiver->common.id;
first = first->next;
}
erts_cleanup_messages(first);
return;
}
if (last == &first->next) {
ASSERT(len == 1);
LINK_MESSAGE(receiver, first);
}
else {
erts_enqueue_signals(receiver, first, last, NULL, len, state);
}
if (receiver_locks & ERTS_PROC_LOCK_MAIN)
erts_proc_sig_fetch(receiver);
if (locked_msgq) {
erts_proc_unlock(receiver, ERTS_PROC_LOCK_MSGQ);
}
if (last == &first->next)
erts_proc_notify_new_message(receiver, receiver_locks);
else
erts_proc_notify_new_sig(receiver, state, ERTS_PSFLG_ACTIVE);
}
void
erts_queue_dist_message(Process *rcvr,
ErtsProcLocks rcvr_locks,
ErtsDistExternal *dist_ext,
ErlHeapFragment *hfrag,
Eterm token,
Eterm from)
{
ErtsMessage* mp;
erts_aint_t state;
ERTS_LC_ASSERT(rcvr_locks == erts_proc_lc_my_proc_locks(rcvr));
if (hfrag) {
/* Fragmented message, allocate a message reference */
mp = erts_alloc_message(0, NULL);
mp->data.heap_frag = hfrag;
} else {
/* Un-fragmented message, allocate space for
token and dist_ext in message. */
Uint dist_ext_sz = erts_dist_ext_size(dist_ext) / sizeof(Eterm);
Uint token_sz = size_object(token);
Uint sz = token_sz + dist_ext_sz;
Eterm *hp;
mp = erts_alloc_message(sz, &hp);
mp->data.heap_frag = &mp->hfrag;
mp->hfrag.used_size = token_sz;
erts_make_dist_ext_copy(dist_ext, erts_get_dist_ext(mp->data.heap_frag));
token = copy_struct(token, token_sz, &hp, &mp->data.heap_frag->off_heap);
}
ERL_MESSAGE_FROM(mp) = dist_ext->dep->sysname;
ERL_MESSAGE_TERM(mp) = THE_NON_VALUE;
#ifdef USE_VM_PROBES
ERL_MESSAGE_DT_UTAG(mp) = NIL;
if (token == am_have_dt_utag)
ERL_MESSAGE_TOKEN(mp) = NIL;
else
#endif
ERL_MESSAGE_TOKEN(mp) = token;
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ)) {
if (erts_proc_trylock(rcvr, ERTS_PROC_LOCK_MSGQ) == EBUSY) {
ErtsProcLocks need_locks = ERTS_PROC_LOCK_MSGQ;
ErtsProcLocks unlocks =
rcvr_locks & ERTS_PROC_LOCKS_HIGHER_THAN(ERTS_PROC_LOCK_MSGQ);
if (unlocks) {
erts_proc_unlock(rcvr, unlocks);
need_locks |= unlocks;
}
erts_proc_lock(rcvr, need_locks);
}
}
state = erts_atomic32_read_acqb(&rcvr->state);
if (state & ERTS_PSFLG_EXITING) {
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
/* Drop message if receiver is exiting or has a pending exit ... */
erts_cleanup_messages(mp);
}
else {
LINK_MESSAGE(rcvr, mp);
if (rcvr_locks & ERTS_PROC_LOCK_MAIN)
erts_proc_sig_fetch(rcvr);
if (!(rcvr_locks & ERTS_PROC_LOCK_MSGQ))
erts_proc_unlock(rcvr, ERTS_PROC_LOCK_MSGQ);
erts_proc_notify_new_message(rcvr, rcvr_locks);
}
}
//将消息放入目标进程的消息队列中
static Sint
queue_message(Process *c_p,
Process* receiver,
ErtsProcLocks *receiver_locks,
erts_aint32_t *receiver_state,
ErlHeapFragment* bp,
Eterm message,
Eterm seq_trace_token
#ifdef USE_VM_PROBES
, Eterm dt_utag
#endif
)
{
Sint res;
ErlMessage* mp;
int locked_msgq = 0;
erts_aint_t state;
#ifndef ERTS_SMP
ASSERT(bp != NULL || receiver->mbuf == NULL);
#endif
ERTS_SMP_LC_ASSERT(*receiver_locks == erts_proc_lc_my_proc_locks(receiver));
mp = message_alloc();
if (receiver_state){
state = *receiver_state;
}else{
state = erts_smp_atomic32_read_acqb(&receiver->state);
}
#ifdef ERTS_SMP
//如果目标进程处在退出的状态，直接进入退出清理
if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT)){
goto exiting;
}
//如果当前没有目标Erlang进程的消息队列锁
//尝试获取消息队列的锁
if (!(*receiver_locks & ERTS_PROC_LOCK_MSGQ)) {
if (erts_smp_proc_trylock(receiver, ERTS_PROC_LOCK_MSGQ) == EBUSY) {
ErtsProcLocks need_locks = ERTS_PROC_LOCK_MSGQ;
if (*receiver_locks & ERTS_PROC_LOCK_STATUS) {
erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_STATUS);
need_locks |= ERTS_PROC_LOCK_STATUS;
}
erts_smp_proc_lock(receiver, need_locks);
}
locked_msgq = 1;
state = erts_smp_atomic32_read_nob(&receiver->state);
//获取目标Erlang进程的状态
if (receiver_state){
*receiver_state = state;
}
}
#endif
//Erlang进程处于退出的状态
//直接释放目标进程的锁，和当前消息
if (state & (ERTS_PSFLG_PENDING_EXIT|ERTS_PSFLG_EXITING)) {
#ifdef ERTS_SMP
exiting:
#endif
/* Drop message if receiver is exiting or has a pending exit... */
if (locked_msgq){
erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_MSGQ);
}
if (bp){
free_message_buffer(bp);
}
message_free(mp);
return 0;
}
//从此处可以看出，放入目标进程的消息，只是对当前进程的消息的一个指针应用
//那我们需要找出，message是如何被处理的，何时增加的引用计数
ERL_MESSAGE_TERM(mp) = message;
ERL_MESSAGE_TOKEN(mp) = seq_trace_token;
#ifdef USE_VM_PROBES
ERL_MESSAGE_DT_UTAG(mp) = dt_utag;
#endif
mp->next = NULL;
mp->data.heap_frag = bp;
#ifndef ERTS_SMP
res = receiver->msg.len;
#else
res = receiver->msg_inq.len;
//把消息attach的目标Erlang进程的消息队列或者private
//的消息队列
if (*receiver_locks & ERTS_PROC_LOCK_MAIN) {
/*
* We move 'in queue' to 'private queue' and place
* message at the end of 'private queue' in order
* to ensure that the 'in queue' doesn't contain
* references into the heap. By ensuring this,
* we don't need to include the 'in queue' in
* the root set when garbage collecting.
*/
//这个时候可以操作msg_inq和msg
res += receiver->msg.len;
ERTS_SMP_MSGQ_MV_INQ2PRIVQ(receiver);
LINK_MESSAGE_PRIVQ(receiver, mp);
}
else
#endif
{
//这个时候只操作msg_inq
LINK_MESSAGE(receiver, mp);
}
#ifdef USE_VM_PROBES
if (DTRACE_ENABLED(message_queued)) {
DTRACE_CHARBUF(receiver_name, DTRACE_TERM_BUF_SIZE);
Sint tok_label = 0;
Sint tok_lastcnt = 0;
Sint tok_serial = 0;
dtrace_proc_str(receiver, receiver_name);
if (seq_trace_token != NIL && is_tuple(seq_trace_token)) {
tok_label = signed_val(SEQ_TRACE_T_LABEL(seq_trace_token));
tok_lastcnt = signed_val(SEQ_TRACE_T_LASTCNT(seq_trace_token));
tok_serial = signed_val(SEQ_TRACE_T_SERIAL(seq_trace_token));
}
DTRACE6(message_queued,
receiver_name, size_object(message), receiver->msg.len,
tok_label, tok_lastcnt, tok_serial);
}
#endif
if (IS_TRACED_FL(receiver, F_TRACE_RECEIVE)){
trace_receive(receiver, message);
}
if (locked_msgq){
erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_MSGQ);
}
erts_proc_notify_new_message(receiver,
#ifdef ERTS_SMP
*receiver_locks
#else
0
#endif
);
#ifndef ERTS_SMP
ERTS_HOLE_CHECK(receiver);
#endif
return res;
}
