Revert "epmd: Support 32-bit creation values in local node"

This reverts commit bd8f6106d44a58c261920eef72842bb3bc5a4968.

PLUS a little change in epmd_srv.c:750 ("4" -> "replylen")
that was part of e2cf4a8a4b03b9f430ba228276c3b2629159e832
by mistake.

12 files changed, 81 insertions, 105 deletions

diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index d0e2d9afc2..b81056c774 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -1915,7 +1915,7 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm return_term, Eterm *refp,
 	    erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
 	    erts_dsprintf(dsbufp,
 			  "Discarding message %T from %T to %T in an old "
-			  "incarnation (%u) of this node (%u)\n",
+			  "incarnation (%d) of this node (%d)\n",
 			  msg,
 			  p->common.id,
 			  to,
@@ -1959,7 +1959,7 @@ do_send(Process *p, Eterm to, Eterm msg, Eterm return_term, Eterm *refp,
 	erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
 	erts_dsprintf(dsbufp,
 		      "Discarding message %T from %T to %T in an old "
-		      "incarnation (%u) of this node (%u)\n",
+		      "incarnation (%d) of this node (%d)\n",
 		      msg,
 		      p->common.id,
 		      to,
diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c
index 7666f23a4f..522f50287a 100644
--- a/erts/emulator/beam/big.c
+++ b/erts/emulator/beam/big.c
@@ -2176,24 +2176,6 @@ term_to_Uint64(Eterm term, Uint64 *up)
 #endif
 }
 
-int
-term_to_Uint32(Eterm term, Uint32 *up)
-{
-#if ERTS_SIZEOF_ETERM == 4
-    return term_to_Uint(term,up);
-#else
-    if (is_small(term)) {
-	Sint i = signed_val(term);
-	if (i >= 0) {
-            *up = (Uint32) i;
-            return 1;
-        }
-    }
-    *up = BADARG;
-    return 0;
-#endif
-}
-
 
 int term_to_Sint(Eterm term, Sint *sp)
 {
diff --git a/erts/emulator/beam/big.h b/erts/emulator/beam/big.h
index 3fed076419..ad19cce395 100644
--- a/erts/emulator/beam/big.h
+++ b/erts/emulator/beam/big.h
@@ -168,8 +168,6 @@ Eterm erts_uint64_array_to_big(Uint **, int, int, Uint64 *);
 int term_to_Uint64(Eterm, Uint64*);
 int term_to_Sint64(Eterm, Sint64*);
 #endif
-int term_to_Uint32(Eterm, Uint32*);
-
 
 Uint32 big_to_uint32(Eterm b);
 int term_equals_2pow32(Eterm);
diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index 8bbe6450eb..28afae96bd 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -3748,10 +3748,12 @@ int distribution_info(fmtfn_t to, void *arg)	/* Called by break handler */
 BIF_RETTYPE setnode_2(BIF_ALIST_2)
 {
     Process *net_kernel;
-    Uint32 creation;
+    Uint creation;
 
     /* valid creation ? */
-    if(!term_to_Uint32(BIF_ARG_2, &creation))
+    if(!term_to_Uint(BIF_ARG_2, &creation))
+	goto error;
+    if(creation > 3)
 	goto error;
 
     /* valid node name ? */
@@ -3795,7 +3797,7 @@ BIF_RETTYPE setnode_2(BIF_ALIST_2)
     erts_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
     erts_thr_progress_block();
     inc_no_nodes();
-    erts_set_this_node(BIF_ARG_1, creation);
+    erts_set_this_node(BIF_ARG_1, (Uint32) creation);
     erts_is_alive = 1;
     send_nodes_mon_msgs(NULL, am_nodeup, BIF_ARG_1, am_visible, NIL);
     erts_thr_progress_unblock();
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index a7424bbcb8..a32e6de436 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -2797,10 +2797,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
     } else if (BIF_ARG_1 == am_threads) {
 	return am_true;
     } else if (BIF_ARG_1 == am_creation) {
-        Uint hsz = 0;
-        erts_bld_uint(NULL, &hsz, erts_this_node->creation);
-        hp = hsz ? HAlloc(BIF_P, hsz) : NULL;
-        BIF_RET(erts_bld_uint(&hp, NULL, erts_this_node->creation));
+	return make_small(erts_this_node->creation);
     } else if (BIF_ARG_1 == am_break_ignored) {
       extern int ignore_break;
       if (ignore_break) 
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 49dea8919b..5eb9939b73 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -977,7 +977,7 @@ static void print_node(void *venp, void *vpndp)
 	if(pndp->sysname == NIL) {
 	    erts_print(pndp->to, pndp->to_arg, "Name: %T ", enp->sysname);
 	}
-	erts_print(pndp->to, pndp->to_arg, " %u", enp->creation);
+	erts_print(pndp->to, pndp->to_arg, " %d", enp->creation);
 #ifdef DEBUG
 	erts_print(pndp->to, pndp->to_arg, " (refc=%ld)",
 		   erts_refc_read(&enp->refc, 0));
@@ -1020,7 +1020,7 @@ void erts_print_node_info(fmtfn_t to,
 /* ----------------------------------------------------------------------- */
 
 void
-erts_set_this_node(Eterm sysname, Uint32 creation)
+erts_set_this_node(Eterm sysname, Uint creation)
 {
     ERTS_LC_ASSERT(erts_thr_progress_is_blocking());
     ASSERT(2 <= de_refc_read(erts_this_dist_entry, 2));
diff --git a/erts/emulator/beam/erl_node_tables.h b/erts/emulator/beam/erl_node_tables.h
index c434926142..8153699596 100644
--- a/erts/emulator/beam/erl_node_tables.h
+++ b/erts/emulator/beam/erl_node_tables.h
@@ -258,7 +258,7 @@ void erts_set_dist_entry_pending(DistEntry *);
 void erts_set_dist_entry_connected(DistEntry *, Eterm, Uint);
 ErlNode *erts_find_or_insert_node(Eterm, Uint32, Eterm);
 void erts_schedule_delete_node(ErlNode *);
-void erts_set_this_node(Eterm, Uint32);
+void erts_set_this_node(Eterm, Uint);
 Uint erts_node_table_size(void);
 void erts_init_node_tables(int);
 void erts_node_table_info(fmtfn_t, void *);
diff --git a/erts/epmd/epmd.mk b/erts/epmd/epmd.mk
index f6889a7ff1..b1fd04dc04 100644
--- a/erts/epmd/epmd.mk
+++ b/erts/epmd/epmd.mk
@@ -67,5 +67,5 @@ EPMD_NODE_TYPE=110
 # Distribution format 5 contains the new md5 based handshake.
 
 EPMD_DIST_LOW=5
-EPMD_DIST_HIGH=6
+EPMD_DIST_HIGH=5
 
diff --git a/erts/epmd/src/epmd.h b/erts/epmd/src/epmd.h
index 7332294d3d..cffcd4ae7a 100644
--- a/erts/epmd/src/epmd.h
+++ b/erts/epmd/src/epmd.h
@@ -26,7 +26,6 @@
 #define EPMD_ALIVE2_REQ 'x'
 #define EPMD_PORT2_REQ 'z'
 #define EPMD_ALIVE2_RESP 'y'
-#define EPMD_ALIVE2_X_RESP 'v'
 #define EPMD_PORT2_RESP 'w'
 #define EPMD_NAMES_REQ 'n'
 
diff --git a/erts/epmd/src/epmd_int.h b/erts/epmd/src/epmd_int.h
index a5156a142e..ed9bbdb8cd 100644
--- a/erts/epmd/src/epmd_int.h
+++ b/erts/epmd/src/epmd_int.h
@@ -277,12 +277,6 @@ static const struct in6_addr in6addr_loopback =
 #define put_int16(i, s) {((unsigned char*)(s))[0] = ((i) >> 8) & 0xff; \
                         ((unsigned char*)(s))[1] = (i)         & 0xff;}
 
-#define put_int32(i, s) do {((char*)(s))[0] = (char)((i) >> 24) & 0xff;   \
-                            ((char*)(s))[1] = (char)((i) >> 16) & 0xff;   \
-                            ((char*)(s))[2] = (char)((i) >> 8)  & 0xff;   \
-                            ((char*)(s))[3] = (char)(i)         & 0xff;} \
-                        while (0)
-
 #if defined(__GNUC__)
 #  define EPMD_INLINE __inline__
 #elif defined(__WIN32__)
@@ -313,10 +307,10 @@ struct enode {
   int fd;			/* The socket in use */
   unsigned short port;		/* Port number of Erlang node */
   char symname[MAXSYMLEN+1];	/* Name of the Erlang node */
-  unsigned int cr_counter;	/* Used to generate 'creation' numbers */
+  short creation;		/* Started as a random number 1..3 */
   char nodetype;                /* 77 = normal erlang node 72 = hidden (c-node */
   char protocol;                /* 0 = tcp/ipv4 */
-  unsigned short highvsn;       /* 5: creation=1..3, 6: creation=1..(2^32-1)*/
+  unsigned short highvsn;       /* 0 = OTP-R3 erts-4.6.x, 1 = OTP-R4 erts-4.7.x*/
   unsigned short lowvsn;
   int extralen;
   char extra[MAXSYMLEN+1];
diff --git a/erts/epmd/src/epmd_srv.c b/erts/epmd/src/epmd_srv.c
index 633ec71e5f..3c6f1fbdf4 100644
--- a/erts/epmd/src/epmd_srv.c
+++ b/erts/epmd/src/epmd_srv.c
@@ -665,21 +665,6 @@ static int do_accept(EpmdVars *g,int listensock)
     return conn_open(g,msgsock);
 }
 
-static void bump_creation(Node* node)
-{
-    if (++node->cr_counter == 0)
-        node->cr_counter = 1;
-}
-static unsigned int get_creation(Node* node)
-{
-    if (node->highvsn >= 6) {
-        return node->cr_counter;  /* 1..(2^32-1)*/
-    }
-    else {
-        return (node->cr_counter - 1) % 3 + 1;   /* 1..3 */
-    }
-}
-
 /* buf is actually one byte larger than bsize,
    giving place for null termination */
 static void do_request(g, fd, s, buf, bsize)
@@ -721,10 +706,8 @@ static void do_request(g, fd, s, buf, bsize)
 	unsigned char protocol;
 	unsigned short highvsn;
 	unsigned short lowvsn;
-        unsigned int creation;
 	int namelen;
 	int extralen;
-        int replylen;
 	char *name; 
 	char *extra;
 	eport = get_int16(&buf[1]);
@@ -754,22 +737,17 @@ static void do_request(g, fd, s, buf, bsize)
 
 	extra = &buf[11+namelen+2];
 	extra[extralen]='\000';
-        node = node_reg2(g, namelen, name, fd, eport, nodetype, protocol,
-                         highvsn, lowvsn, extralen, extra);
-        creation = node ? get_creation(node) :  99;
-        wbuf[1] = node ? 0 : 1; /* ok | error */
-        if (highvsn >= 6) {
-            wbuf[0] = EPMD_ALIVE2_X_RESP;
-            put_int32(creation, wbuf+2);
-            replylen = 6;
-        }
-        else {
-            wbuf[0] = EPMD_ALIVE2_RESP;
-            put_int16(creation, wbuf+2);
-            replylen = 4;
-        }
+	wbuf[0] = EPMD_ALIVE2_RESP;
+	if ((node = node_reg2(g, namelen, name, fd, eport, nodetype, protocol,
+			      highvsn, lowvsn, extralen, extra)) == NULL) {
+	    wbuf[1] = 1; /* error */
+	    put_int16(99, wbuf+2);
+	} else {
+	    wbuf[1] = 0; /* ok */
+	    put_int16(node->creation, wbuf+2);
+	}
   
-	if (!reply(g, fd, wbuf, replylen))
+	if (!reply(g, fd, wbuf, 4))
 	  {
             node_unreg(g, name);
 	    dbg_tty_printf(g,1,"** failed to send ALIVE2_RESP for \"%s\"",
@@ -1222,8 +1200,8 @@ static int node_unreg(EpmdVars *g,char *name)
   for (; node; prev = &node->next, node = node->next)
     if (is_same_str(node->symname, name))
       {
-	dbg_tty_printf(g,1,"unregistering '%s:%u', port %d",
-		       node->symname, get_creation(node), node->port);
+	dbg_tty_printf(g,1,"unregistering '%s:%d', port %d",
+		       node->symname, node->creation, node->port);
 
 	*prev = node->next;	/* Link out from "reg" list */
 
@@ -1257,8 +1235,8 @@ static int node_unreg_sock(EpmdVars *g,int fd)
   for (; node; prev = &node->next, node = node->next)
     if (node->fd == fd)
       {
-	dbg_tty_printf(g,1,"unregistering '%s:%u', port %d",
-		       node->symname, get_creation(node), node->port);
+	dbg_tty_printf(g,1,"unregistering '%s:%d', port %d",
+		       node->symname, node->creation, node->port);
 
 	*prev = node->next;	/* Link out from "reg" list */
 
@@ -1286,8 +1264,19 @@ static int node_unreg_sock(EpmdVars *g,int fd)
 }
 
 /*
- * Register a new node
+ *  Finding a node slot and a (name,creation) name is a bit tricky.
+ *  We try in order
+ *
+ *  1. If the name was used before and we can reuse that slot but use
+ *     a new "creation" digit in the range 1..3.
+ *
+ *  2. We try to find a new unused slot.
+ *
+ *  3. We try to use an used slot this isn't used any longer.
+ *     FIXME: The criteria for *what* slot to steal should be improved.
+ *     Perhaps use the oldest or something.
  */
+
 static Node *node_reg2(EpmdVars *g,
 		       int namelen,
 		       char* name,
@@ -1357,7 +1346,7 @@ static Node *node_reg2(EpmdVars *g,
       }
 
   /* Try to find the name in the used queue so that we
-     can change "creation" number */
+     can change "creation" number 1..3 */
 
   prev = NULL;
 
@@ -1386,8 +1375,9 @@ static Node *node_reg2(EpmdVars *g,
 
 	g->nodes.unreg_count--;
 
-	/* When reusing we change the "creation" number */
-	bump_creation(node);
+	/* When reusing we change the "creation" number 1..3 */
+
+	node->creation = node->creation % 3 + 1;
 
 	break;
       }
@@ -1414,8 +1404,7 @@ static Node *node_reg2(EpmdVars *g,
 	      exit(1);
 	    }
 
-	  node->cr_counter = current_time(g); /* "random" */
-          bump_creation(node);
+	  node->creation = (current_time(g) % 3) + 1; /* "random" 1-3 */
 	}
     }
 
@@ -1434,11 +1423,11 @@ static Node *node_reg2(EpmdVars *g,
   select_fd_set(g, fd);
 
   if (highvsn == 0) {
-    dbg_tty_printf(g,1,"registering '%s:%u', port %d",
-		   node->symname, get_creation(node), node->port);
+    dbg_tty_printf(g,1,"registering '%s:%d', port %d",
+		   node->symname, node->creation, node->port);
   } else {
-    dbg_tty_printf(g,1,"registering '%s:%u', port %d",
-		   node->symname, get_creation(node), node->port);
+    dbg_tty_printf(g,1,"registering '%s:%d', port %d",
+		   node->symname, node->creation, node->port);
     dbg_tty_printf(g,1,"type %d proto %d highvsn %d lowvsn %d",
 		   nodetype, protocol, highvsn, lowvsn);
   }      
@@ -1572,8 +1561,8 @@ static void print_names(EpmdVars *g)
 
   for (node = g->nodes.reg; node; node = node->next)
     {
-      fprintf(stderr,"*****     active name     \"%s#%u\" at port %d, fd = %d\r\n",
-	      node->symname, get_creation(node), node->port, node->fd);
+      fprintf(stderr,"*****     active name     \"%s#%d\" at port %d, fd = %d\r\n",
+	      node->symname, node->creation, node->port, node->fd);
       count ++;
     }
 
@@ -1583,8 +1572,8 @@ static void print_names(EpmdVars *g)
 
   for (node = g->nodes.unreg; node; node = node->next)
     {
-      fprintf(stderr,"*****     old/unused name \"%s#%u\"\r\n",
-	      node->symname, get_creation(node));
+      fprintf(stderr,"*****     old/unused name \"%s#%d\"\r\n",
+	      node->symname, node->creation);
       count ++;
     }
 
diff --git a/erts/test/erl_print_SUITE.erl b/erts/test/erl_print_SUITE.erl
index 0a5987df88..463d890688 100644
--- a/erts/test/erl_print_SUITE.erl
+++ b/erts/test/erl_print_SUITE.erl
@@ -324,9 +324,6 @@ run_case(Config, TestArgs, Fun) ->
 -define(PORT_EXT,            102).
 -define(PID_EXT,             103).
 -define(NEW_REFERENCE_EXT,   114).
--define(NEW_PID_EXT,         $X).
--define(NEW_PORT_EXT,        $Y).
--define(NEWER_REFERENCE_EXT, $Z).
 
 uint32_be(Uint) when is_integer(Uint), 0 =< Uint, Uint < 1 bsl 32 ->
     [(Uint bsr 24) band 16#ff,
@@ -354,13 +351,13 @@ mk_pid({NodeName, Creation}, Number, Serial) when is_atom(NodeName) ->
     mk_pid({atom_to_list(NodeName), Creation}, Number, Serial);
 mk_pid({NodeName, Creation}, Number, Serial) ->
     case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
-                                              ?NEW_PID_EXT,
+                                              ?PID_EXT,
                                               ?ATOM_EXT,
                                               uint16_be(length(NodeName)),
                                               NodeName,
                                               uint32_be(Number),
                                               uint32_be(Serial),
-                                              uint32_be(Creation)])) of
+                                              uint8(Creation)])) of
         Pid when is_pid(Pid) ->
             Pid;
         {'EXIT', {badarg, _}} ->
@@ -373,12 +370,12 @@ mk_port({NodeName, Creation}, Number) when is_atom(NodeName) ->
     mk_port({atom_to_list(NodeName), Creation}, Number);
 mk_port({NodeName, Creation}, Number) ->
     case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
-                                              ?NEW_PORT_EXT,
+                                              ?PORT_EXT,
                                               ?ATOM_EXT,
                                               uint16_be(length(NodeName)),
                                               NodeName,
                                               uint32_be(Number),
-                                              uint32_be(Creation)])) of
+                                              uint8(Creation)])) of
         Port when is_port(Port) ->
             Port;
         {'EXIT', {badarg, _}} ->
@@ -391,16 +388,33 @@ mk_ref({NodeName, Creation}, Numbers) when is_atom(NodeName),
                                            is_integer(Creation),
                                            is_list(Numbers) ->
     mk_ref({atom_to_list(NodeName), Creation}, Numbers);
+mk_ref({NodeName, Creation}, [Number]) when is_list(NodeName),
+                                            is_integer(Creation),
+                                            is_integer(Number) ->
+    case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
+                                              ?REFERENCE_EXT,
+                                              ?ATOM_EXT,
+                                              uint16_be(length(NodeName)),
+                                              NodeName,
+                                              uint32_be(Number),
+                                              uint8(Creation)])) of
+        Ref when is_reference(Ref) ->
+            Ref;
+        {'EXIT', {badarg, _}} ->
+            exit({badarg, mk_ref, [{NodeName, Creation}, [Number]]});
+        Other ->
+            exit({unexpected_binary_to_term_result, Other})
+    end;
 mk_ref({NodeName, Creation}, Numbers) when is_list(NodeName),
                                            is_integer(Creation),
                                            is_list(Numbers) ->
     case catch binary_to_term(list_to_binary([?VERSION_MAGIC,
-                                              ?NEWER_REFERENCE_EXT,
+                                              ?NEW_REFERENCE_EXT,
                                               uint16_be(length(Numbers)),
                                               ?ATOM_EXT,
                                               uint16_be(length(NodeName)),
                                               NodeName,
-                                              uint32_be(Creation),
+                                              uint8(Creation),
                                               lists:map(fun (N) ->
                                                                 uint32_be(N)
                                                         end,
@@ -415,10 +429,11 @@ mk_ref({NodeName, Creation}, Numbers) when is_list(NodeName),
 
 my_cre() -> erlang:system_info(creation).
 
-oth_cre(N) when N >= 0, N < (1 bsl 32) ->
-    (N rem ((1 bsl 32) - 1)) + 1;
-oth_cre(N) ->
-    exit({invalid_creation, N}).
+oth_cre(0) -> 1;
+oth_cre(1) -> 2;
+oth_cre(2) -> 3;
+oth_cre(3) -> 1;
+oth_cre(N) -> exit({invalid_creation, N}).
 
 str_1_bsl_10000() ->
     "19950631168807583848837421626835850838234968318861924548520089498529438830221946631919961684036194597899331129423209124271556491349413781117593785932096323957855730046793794526765246551266059895520550086918193311542508608460618104685509074866089624888090489894838009253941633257850621568309473902556912388065225096643874441046759871626985453222868538161694315775629640762836880760732228535091641476183956381458969463899410840960536267821064621427333394036525565649530603142680234969400335934316651459297773279665775606172582031407994198179607378245683762280037302885487251900834464581454650557929601414833921615734588139257095379769119277800826957735674444123062018757836325502728323789270710373802866393031428133241401624195671690574061419654342324638801248856147305207431992259611796250130992860241708340807605932320161268492288496255841312844061536738951487114256315111089745514203313820202931640957596464756010405845841566072044962867016515061920631004186422275908670900574606417856951911456055068251250406007519842261898059237118054444788072906395242548339221982707404473162376760846613033778706039803413197133493654622700563169937455508241780972810983291314403571877524768509857276937926433221599399876886660808368837838027643282775172273657572744784112294389733810861607423253291974813120197604178281965697475898164531258434135959862784130128185406283476649088690521047580882615823961985770122407044330583075869039319604603404973156583208672105913300903752823415539745394397715257455290510212310947321610753474825740775273986348298498340756937955646638621874569499279016572103701364433135817214311791398222983845847334440270964182851005072927748364550578634501100852987812389473928699540834346158807043959118985815145779177143619698728131459483783202081474982171858011389071228250905826817436220577475921417653715687725614904582904992461028630081535583308130101987675856234343538955409175623400844887526162643568648833519463720377293240094456246923254350400678027273837755376406726898636241037491410966718557050759098100246789880178271925953381282421954028302759408448955014676668389697996886241636313376393903373455801407636741877711055384225739499110186468219696581651485130494222369947714763069155468217682876200362777257723781365331611196811280792669481887201298643660768551639860534602297871557517947385246369446923087894265948217008051120322365496288169035739121368338393591756418733850510970271613915439590991598154654417336311656936031122249937969999226781732358023111862644575299135758175008199839236284615249881088960232244362173771618086357015468484058622329792853875623486556440536962622018963571028812361567512543338303270029097668650568557157505516727518899194129711337690149916181315171544007728650573189557450920330185304847113818315407324053319038462084036421763703911550639789000742853672196280903477974533320468368795868580237952218629120080742819551317948157624448298518461509704888027274721574688131594750409732115080498190455803416826949787141316063210686391511681774304792596709376".