Merge branch 'sverker/revert-big-creation'

* sverker/revert-big-creation:
  Revert "erts: Make DFLAG_BIG_CREATION mandatory"
  Revert "erts: Remove old encoding of pids, ports and refs"
  Revert "erl_interface: Remove old encoding of pid,port,refs"
  Revert "epmd: Support 32-bit creation values in local node"
  Revert "jinterface: Remove old encoding of pid,port,refs"
  Revert "erl_interface: Support 32-bit creation local cnode"
  Revert "erts: Document new EPMD response ALIVE2_X_RESP"

1 files changed, 57 insertions, 27 deletions

diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index fa8314c115..395ff51ad3 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -51,17 +51,18 @@
 
 #define MAX_STRING_LEN 0xffff
 
-/*
- * MAX value for the creation field in pid, port and reference
- * for the old PID_EXT, PORT_EXT, REFERENCE_EXT and NEW_REFERENCE_EXT.
- * Older nodes (OTP 19-21) will send us these so we must be able to decode them.
- *
- * From OTP 22 DFLAG_BIG_CREATION is mandatory so this node will always
- * encode with new big 32-bit creations using NEW_PID_EXT, NEW_PORT_EXT
- * and NEWER_REFERENCE_EXT.
+/* MAX value for the creation field in pid, port and reference
+   for the local node and for the current external format.
+
+   Larger creation values than this are allowed in external pid, port and refs
+   encoded with NEW_PID_EXT, NEW_PORT_EXT and NEWER_REFERENCE_EXT.
+   The point here is to prepare for future upgrade to 32-bit creation.
+   OTP-19 (erts-8.0) can handle big creation values from other (newer) nodes,
+   but do not use big creation values for the local node yet,
+   as we still may have to communicate with older nodes.
 */
-#define ERTS_MAX_TINY_CREATION (3)
-#define is_tiny_creation(Cre) ((unsigned)(Cre) <= ERTS_MAX_TINY_CREATION)
+#define ERTS_MAX_LOCAL_CREATION (3)
+#define is_valid_creation(Cre) ((unsigned)(Cre) <= ERTS_MAX_LOCAL_CREATION)
 
 #undef ERTS_DEBUG_USE_DIST_SEP
 #ifdef DEBUG
@@ -2383,8 +2384,7 @@ enc_pid(ErtsAtomCacheMap *acmp, Eterm pid, byte* ep, Uint32 dflags)
     Eterm sysname = ((is_internal_pid(pid) && (dflags & DFLAG_INTERNAL_TAGS))
 		      ? INTERNAL_LOCAL_SYSNAME : pid_node_name(pid));
     Uint32 creation = pid_creation(pid);
-
-    *ep++ = NEW_PID_EXT;
+    byte* tagp = ep++;
 
     /* insert  atom here containing host and sysname  */
     ep = enc_atom(acmp, sysname, ep, dflags);
@@ -2396,8 +2396,15 @@ enc_pid(ErtsAtomCacheMap *acmp, Eterm pid, byte* ep, Uint32 dflags)
     ep += 4;
     put_int32(os, ep);
     ep += 4;
-    put_int32(creation, ep);
-    ep += 4;
+    if (creation <= ERTS_MAX_LOCAL_CREATION) {
+        *tagp = PID_EXT;
+        *ep++ = creation;
+    } else {
+        ASSERT(is_external_pid(pid));
+        *tagp = NEW_PID_EXT;
+        put_int32(creation, ep);
+        ep += 4;
+    }
     return ep;
 }
 
@@ -2517,7 +2524,7 @@ dec_pid(ErtsDistExternal *edep, ErtsHeapFactory* factory, byte* ep,
     if (tag == PID_EXT) {
         cre = get_int8(ep);
         ep += 1;
-        if (!is_tiny_creation(cre)) {
+        if (!is_valid_creation(cre)) {
             return NULL;
         }
     } else {
@@ -2778,18 +2785,25 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	    Eterm sysname = (((dflags & DFLAG_INTERNAL_TAGS) && is_internal_ref(obj))
 			     ? INTERNAL_LOCAL_SYSNAME : ref_node_name(obj));
             Uint32 creation = ref_creation(obj);
+            byte* tagp = ep++;
 
 	    ASSERT(dflags & DFLAG_EXTENDED_REFERENCES);
 
 	    erts_magic_ref_save_bin(obj);
 
-            *ep++ = NEWER_REFERENCE_EXT;
 	    i = ref_no_numbers(obj);
 	    put_int16(i, ep);
 	    ep += 2;
 	    ep = enc_atom(acmp, sysname, ep, dflags);
-            put_int32(creation, ep);
-            ep += 4;
+            if (creation <= ERTS_MAX_LOCAL_CREATION) {
+                *tagp = NEW_REFERENCE_EXT;
+                *ep++ = creation;
+            } else {
+                ASSERT(is_external_ref(obj));
+                *tagp = NEWER_REFERENCE_EXT;
+                put_int32(creation, ep);
+                ep += 4;
+            }
 	    ref_num = ref_numbers(obj);
 	    for (j = 0; j < i; j++) {
 		put_int32(ref_num[j], ep);
@@ -2802,14 +2816,21 @@ enc_term_int(TTBEncodeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj, byte* ep,
 	    Eterm sysname = (((dflags & DFLAG_INTERNAL_TAGS) && is_internal_port(obj))
 			     ? INTERNAL_LOCAL_SYSNAME : port_node_name(obj));
             Uint32 creation = port_creation(obj);
+            byte* tagp = ep++;
 
-            *ep++ = NEW_PORT_EXT;
 	    ep = enc_atom(acmp, sysname, ep, dflags);
 	    j = port_number(obj);
 	    put_int32(j, ep);
 	    ep += 4;
-            put_int32(creation, ep);
-            ep += 4;
+            if (creation <= ERTS_MAX_LOCAL_CREATION) {
+                *tagp = PORT_EXT;
+                *ep++ = creation;
+            } else {
+                ASSERT(is_external_port(obj));
+                *tagp = NEW_PORT_EXT;
+                put_int32(creation, ep);
+                ep += 4;
+            }
 	    break;
 	}
 	case LIST_DEF:
@@ -3504,7 +3525,7 @@ dec_term_atom_common:
                 if (tag == PORT_EXT) {
                     cre = get_int8(ep);
                     ep++;
-                    if (!is_tiny_creation(cre)) {
+                    if (!is_valid_creation(cre)) {
                         goto error;
                     }
                 }
@@ -3551,7 +3572,7 @@ dec_term_atom_common:
 
 		cre = get_int8(ep);
 		ep += 1;
-		if (!is_tiny_creation(cre)) {
+		if (!is_valid_creation(cre)) {
 		    goto error;
 		}
 		goto ref_ext_common;
@@ -3565,7 +3586,7 @@ dec_term_atom_common:
 
 		cre = get_int8(ep);
 		ep += 1;
-		if (!is_tiny_creation(cre)) {
+		if (!is_valid_creation(cre)) {
 		    goto error;
 		}
 		r0 = get_int32(ep);
@@ -4263,21 +4284,30 @@ encode_size_struct_int(TTBSizeContext* ctx, ErtsAtomCacheMap *acmp, Eterm obj,
 		result += 1 + 4 + 1 + i;  /* tag,size,sign,digits */
 	    break;
         case EXTERNAL_PID_DEF:
+            if (external_pid_creation(obj) > ERTS_MAX_LOCAL_CREATION)
+                result += 3;
+            /*fall through*/
 	case PID_DEF:
 	    result += (1 + encode_size_struct2(acmp, pid_node_name(obj), dflags) +
-		       4 + 4 + 4);
+		       4 + 4 + 1);
 	    break;
         case EXTERNAL_REF_DEF:
+            if (external_ref_creation(obj) > ERTS_MAX_LOCAL_CREATION)
+                result += 3;
+            /*fall through*/
 	case REF_DEF:
 	    ASSERT(dflags & DFLAG_EXTENDED_REFERENCES);
 	    i = ref_no_numbers(obj);
 	    result += (1 + 2 + encode_size_struct2(acmp, ref_node_name(obj), dflags) +
-		       4 + 4*i);
+		       1 + 4*i);
 	    break;
         case EXTERNAL_PORT_DEF:
+            if (external_port_creation(obj) > ERTS_MAX_LOCAL_CREATION)
+                result += 3;
+            /*fall through*/
         case PORT_DEF:
 	    result += (1 + encode_size_struct2(acmp, port_node_name(obj), dflags) +
-		      4 + 4);
+		      4 + 1);
 	    break;
 	case LIST_DEF: {
 	    int is_str = is_external_string(obj, &m);