Merge branch 'sverker/secret-atom'

7 files changed, 19 insertions, 21 deletions

diff --git a/erts/emulator/beam/atom.c b/erts/emulator/beam/atom.c
index b47739059b..2b5ad097a0 100644
--- a/erts/emulator/beam/atom.c
+++ b/erts/emulator/beam/atom.c
@@ -199,7 +199,7 @@ atom_alloc(Atom* tmpl)
 static void
 atom_free(Atom* obj)
 {
-    erts_free(ERTS_ALC_T_ATOM, (void*) obj);
+    ASSERT(obj->slot.index == atom_val(am_ErtsSecretAtom));
 }
 
 static void latin1_to_utf8(byte* conv_buf, const byte** srcp, int* lenp)
@@ -467,6 +467,9 @@ init_atom_table(void)
 	atom_space -= a.len;
 	atom_tab(ix)->name = (byte*)erl_atom_names[i];
     }
+
+    /* Hide am_ErtsSecretAtom */
+    hash_erase(&erts_atom_table.htable, atom_tab(atom_val(am_ErtsSecretAtom)));
 }
 
 void
diff --git a/erts/emulator/beam/atom.h b/erts/emulator/beam/atom.h
index f3b21e1687..abd3b44993 100644
--- a/erts/emulator/beam/atom.h
+++ b/erts/emulator/beam/atom.h
@@ -133,8 +133,6 @@ int atom_table_sz(void);	/* table size in bytes, excluding stored objects */
 
 Eterm am_atom_put(const char*, int); /* ONLY 7-bit ascii! */
 Eterm erts_atom_put(const byte *name, int len, ErtsAtomEncoding enc, int trunc);
-int atom_erase(byte*, int);
-int atom_static_put(byte*, int);
 void init_atom_table(void);
 void atom_info(fmtfn_t, void *);
 void dump_atoms(fmtfn_t, void *);
diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index 66af05c1f2..b1aeed7889 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -59,6 +59,9 @@ atom nocatch
 atom undefined_function
 atom undefined_lambda
 
+# Secret internal atom that can never be found by string lookup
+# and should never leak out to be seen by the user.
+atom ErtsSecretAtom='3RT$'
 
 # All other atoms.  Try to keep the order alphabetic.
 #
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 3cd395c2c1..8f1faa6719 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -2546,15 +2546,10 @@ load_code(LoaderState* stp)
 
 		if (stp->may_load_nif) {
 		    const int finfo_ix = ci - FUNC_INFO_SZ;
-#ifdef ERTS_DIRTY_SCHEDULERS
-		    enum { MIN_FUNC_SZ = 4 };
-#else
-		    enum { MIN_FUNC_SZ = 3 };
-#endif
-		    if (finfo_ix - last_func_start < MIN_FUNC_SZ && last_func_start) {		   
+		    if (finfo_ix - last_func_start < BEAM_NIF_MIN_FUNC_SZ && last_func_start) {
 			/* Must make room for call_nif op */
-			int pad = MIN_FUNC_SZ - (finfo_ix - last_func_start);
-			ASSERT(pad > 0 && pad < MIN_FUNC_SZ);
+			int pad = BEAM_NIF_MIN_FUNC_SZ - (finfo_ix - last_func_start);
+			ASSERT(pad > 0 && pad < BEAM_NIF_MIN_FUNC_SZ);
 			CodeNeed(pad);
 			sys_memmove(&code[finfo_ix+pad], &code[finfo_ix],
 				    FUNC_INFO_SZ*sizeof(BeamInstr));
diff --git a/erts/emulator/beam/beam_load.h b/erts/emulator/beam/beam_load.h
index d420a4346c..659b9c303f 100644
--- a/erts/emulator/beam/beam_load.h
+++ b/erts/emulator/beam/beam_load.h
@@ -111,6 +111,12 @@ typedef struct beam_code_header {
 
 }BeamCodeHeader;
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+#  define BEAM_NIF_MIN_FUNC_SZ 4
+#else
+#  define BEAM_NIF_MIN_FUNC_SZ 3
+#endif
+
 void erts_release_literal_area(struct ErtsLiteralArea_* literal_area);
 int erts_is_module_native(BeamCodeHeader* code);
 void erts_beam_bif_load_init(void);
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 202f713f67..5499512dd1 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -3341,11 +3341,8 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
 				     mod_atom, f->name, f->arity);
 #endif
 	    }
-#ifdef ERTS_DIRTY_SCHEDULERS
-	    else if (erts_codeinfo_to_code(ci_pp[1]) - erts_codeinfo_to_code(ci_pp[0]) < (4))
-#else
-	    else if (erts_codeinfo_to_code(ci_pp[1]) - erts_codeinfo_to_code(ci_pp[0]) < (3))
-#endif
+	    else if (erts_codeinfo_to_code(ci_pp[1]) - erts_codeinfo_to_code(ci_pp[0])
+                     < BEAM_NIF_MIN_FUNC_SZ)
 	    {
 		ret = load_nif_error(BIF_P,bad_lib,"No explicit call to load_nif"
 				     " in module (%T:%s/%u too small)",
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index a49b242d7c..10e452fa25 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -2163,12 +2163,8 @@ enc_atom(ErtsAtomCacheMap *acmp, Eterm atom, byte *ep, Uint32 dflags)
  * We use this atom as sysname in local pid/port/refs
  * for the ETS compressed format (DFLAG_INTERNAL_TAGS).
  *
- * We used atom '' earlier but that turned out to cause problems
- * for buggy erl_interface/ic usage of c-nodes with empty node names.
- * A long atom reduces risk of nodes actually called this and the length
- * does not matter anyway as it's encoded with atom index (ATOM_INTERNAL_REF2).
  */
-#define INTERNAL_LOCAL_SYSNAME am_await_microstate_accounting_modifications
+#define INTERNAL_LOCAL_SYSNAME am_ErtsSecretAtom
 
 static byte*
 enc_pid(ErtsAtomCacheMap *acmp, Eterm pid, byte* ep, Uint32 dflags)