/* 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; }
/* 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; }
Sint erts_send_message(Process* sender, Process* receiver, ErtsProcLocks *receiver_locks, Eterm message, unsigned flags) { Uint msize; ErlHeapFragment* bp = NULL; Eterm token = NIL; Sint res = 0; #ifdef USE_VM_PROBES DTRACE_CHARBUF(sender_name, 64); DTRACE_CHARBUF(receiver_name, 64); Sint tok_label = 0; Sint tok_lastcnt = 0; Sint tok_serial = 0; #endif BM_STOP_TIMER(system); BM_MESSAGE(message,sender,receiver); BM_START_TIMER(send); #ifdef USE_VM_PROBES *sender_name = *receiver_name = '\0'; if (DTRACE_ENABLED(message_send)) { erts_snprintf(sender_name, sizeof(DTRACE_CHARBUF_NAME(sender_name)), "%T", sender->common.id); erts_snprintf(receiver_name, sizeof(DTRACE_CHARBUF_NAME(receiver_name)), "%T", receiver->common.id); } #endif if (SEQ_TRACE_TOKEN(sender) != NIL && !(flags & ERTS_SND_FLG_NO_SEQ_TRACE)) { Eterm* hp; Eterm stoken = SEQ_TRACE_TOKEN(sender); Uint seq_trace_size = 0; #ifdef USE_VM_PROBES Uint dt_utag_size = 0; Eterm utag = NIL; #endif BM_SWAP_TIMER(send,size); msize = size_object(message); BM_SWAP_TIMER(size,send); #ifdef USE_VM_PROBES if (stoken != am_have_dt_utag) { #endif seq_trace_update_send(sender); seq_trace_output(stoken, message, SEQ_TRACE_SEND, receiver->common.id, sender); seq_trace_size = 6; /* TUPLE5 */ #ifdef USE_VM_PROBES } if (DT_UTAG_FLAGS(sender) & DT_UTAG_SPREADING) { dt_utag_size = size_object(DT_UTAG(sender)); } else if (stoken == am_have_dt_utag ) { stoken = NIL; } #endif bp = new_message_buffer(msize + seq_trace_size #ifdef USE_VM_PROBES + dt_utag_size #endif ); hp = bp->mem; BM_SWAP_TIMER(send,copy); token = copy_struct(stoken, seq_trace_size, &hp, &bp->off_heap); message = copy_struct(message, msize, &hp, &bp->off_heap); #ifdef USE_VM_PROBES if (DT_UTAG_FLAGS(sender) & DT_UTAG_SPREADING) { utag = copy_struct(DT_UTAG(sender), dt_utag_size, &hp, &bp->off_heap); #ifdef DTRACE_TAG_HARDDEBUG erts_fprintf(stderr, "Dtrace -> (%T) Spreading tag (%T) with " "message %T!\r\n",sender->common.id, utag, message); #endif } #endif BM_MESSAGE_COPIED(msize); BM_SWAP_TIMER(copy,send); #ifdef USE_VM_PROBES if (DTRACE_ENABLED(message_send)) { if (stoken != NIL && stoken != am_have_dt_utag) { tok_label = signed_val(SEQ_TRACE_T_LABEL(stoken)); tok_lastcnt = signed_val(SEQ_TRACE_T_LASTCNT(stoken)); tok_serial = signed_val(SEQ_TRACE_T_SERIAL(stoken)); } DTRACE6(message_send, sender_name, receiver_name, msize, tok_label, tok_lastcnt, tok_serial); } #endif res = queue_message(NULL, receiver, receiver_locks, NULL, bp, message, token #ifdef USE_VM_PROBES , utag #endif ); BM_SWAP_TIMER(send,system); } else if (sender == receiver) { /* Drop message if receiver has a pending exit ... */ #ifdef ERTS_SMP ErtsProcLocks need_locks = (~(*receiver_locks) & (ERTS_PROC_LOCK_MSGQ | ERTS_PROC_LOCK_STATUS)); if (need_locks) { *receiver_locks |= need_locks; if (erts_smp_proc_trylock(receiver, need_locks) == EBUSY) { if (need_locks == ERTS_PROC_LOCK_MSGQ) { erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_STATUS); need_locks = ERTS_PROC_LOCK_MSGQ|ERTS_PROC_LOCK_STATUS; } erts_smp_proc_lock(receiver, need_locks); } } if (!ERTS_PROC_PENDING_EXIT(receiver)) #endif { ErlMessage* mp = message_alloc(); DTRACE6(message_send, sender_name, receiver_name, size_object(message), tok_label, tok_lastcnt, tok_serial); mp->data.attached = NULL; ERL_MESSAGE_TERM(mp) = message; ERL_MESSAGE_TOKEN(mp) = NIL; #ifdef USE_VM_PROBES ERL_MESSAGE_DT_UTAG(mp) = NIL; #endif mp->next = NULL; /* * 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. */ ERTS_SMP_MSGQ_MV_INQ2PRIVQ(receiver); LINK_MESSAGE_PRIVQ(receiver, mp); res = receiver->msg.len; if (IS_TRACED_FL(receiver, F_TRACE_RECEIVE)) { trace_receive(receiver, message); } } BM_SWAP_TIMER(send,system); } else { ErlOffHeap *ohp; Eterm *hp; erts_aint32_t state; BM_SWAP_TIMER(send,size); msize = size_object(message); BM_SWAP_TIMER(size,send); hp = erts_alloc_message_heap_state(msize, &bp, &ohp, receiver, receiver_locks, &state); BM_SWAP_TIMER(send,copy); message = copy_struct(message, msize, &hp, ohp); BM_MESSAGE_COPIED(msz); BM_SWAP_TIMER(copy,send); DTRACE6(message_send, sender_name, receiver_name, msize, tok_label, tok_lastcnt, tok_serial); res = queue_message(sender, receiver, receiver_locks, &state, bp, message, token #ifdef USE_VM_PROBES , NIL #endif ); BM_SWAP_TIMER(send,system); } return res; }
/* Add a message last in message queue */ void erts_queue_message(Process* receiver, ErtsProcLocks *receiver_locks, ErlHeapFragment* bp, Eterm message, Eterm seq_trace_token #ifdef USE_VM_PROBES , Eterm dt_utag #endif ) { ErlMessage* mp; #ifdef ERTS_SMP ErtsProcLocks need_locks; #else ASSERT(bp != NULL || receiver->mbuf == NULL); #endif ERTS_SMP_LC_ASSERT(*receiver_locks == erts_proc_lc_my_proc_locks(receiver)); mp = message_alloc(); #ifdef ERTS_SMP need_locks = ~(*receiver_locks) & (ERTS_PROC_LOCK_MSGQ | ERTS_PROC_LOCK_STATUS); if (need_locks) { *receiver_locks |= need_locks; if (erts_smp_proc_trylock(receiver, need_locks) == EBUSY) { if (need_locks == ERTS_PROC_LOCK_MSGQ) { erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_STATUS); need_locks = (ERTS_PROC_LOCK_MSGQ | ERTS_PROC_LOCK_STATUS); } erts_smp_proc_lock(receiver, need_locks); } } if (receiver->is_exiting || ERTS_PROC_PENDING_EXIT(receiver)) { /* Drop message if receiver is exiting or has a pending * exit ... */ if (bp) free_message_buffer(bp); message_free(mp); return; } #endif 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; #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. */ ERTS_SMP_MSGQ_MV_INQ2PRIVQ(receiver); LINK_MESSAGE_PRIVQ(receiver, mp); } else { LINK_MESSAGE(receiver, mp); } #else LINK_MESSAGE(receiver, mp); #endif #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 notify_new_message(receiver); if (IS_TRACED_FL(receiver, F_TRACE_RECEIVE)) { trace_receive(receiver, message); } #ifndef ERTS_SMP ERTS_HOLE_CHECK(receiver); #endif }
//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; }
/* Add a message last in message queue */ void erts_queue_message(Process* receiver, ErtsProcLocks *receiver_locks, ErlHeapFragment* bp, Eterm message, Eterm seq_trace_token) { ErlMessage* mp; #ifdef ERTS_SMP ErtsProcLocks need_locks; #else ASSERT(bp != NULL || receiver->mbuf == NULL); #endif ERTS_SMP_LC_ASSERT(*receiver_locks == erts_proc_lc_my_proc_locks(receiver)); mp = message_alloc(); #ifdef ERTS_SMP need_locks = ~(*receiver_locks) & (ERTS_PROC_LOCK_MSGQ | ERTS_PROC_LOCK_STATUS); if (need_locks) { *receiver_locks |= need_locks; if (erts_smp_proc_trylock(receiver, need_locks) == EBUSY) { if (need_locks == ERTS_PROC_LOCK_MSGQ) { erts_smp_proc_unlock(receiver, ERTS_PROC_LOCK_STATUS); need_locks = (ERTS_PROC_LOCK_MSGQ | ERTS_PROC_LOCK_STATUS); } erts_smp_proc_lock(receiver, need_locks); } } if (receiver->is_exiting || ERTS_PROC_PENDING_EXIT(receiver)) { /* Drop message if receiver is exiting or has a pending * exit ... */ if (bp) free_message_buffer(bp); message_free(mp); return; } #endif ERL_MESSAGE_TERM(mp) = message; ERL_MESSAGE_TOKEN(mp) = seq_trace_token; mp->next = NULL; #ifdef ERTS_SMP if (*receiver_locks & ERTS_PROC_LOCK_MAIN) { mp->data.heap_frag = bp; /* * 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. */ ERTS_SMP_MSGQ_MV_INQ2PRIVQ(receiver); LINK_MESSAGE_PRIVQ(receiver, mp); } else { mp->data.heap_frag = bp; LINK_MESSAGE(receiver, mp); } #else mp->data.heap_frag = bp; LINK_MESSAGE(receiver, mp); #endif notify_new_message(receiver); if (IS_TRACED_FL(receiver, F_TRACE_RECEIVE)) { trace_receive(receiver, message); } #ifndef ERTS_SMP ERTS_HOLE_CHECK(receiver); #endif }