Implement magic references

Magic references are *intentionally* indistinguishable from ordinary
references for the Erlang software. Magic references do not change
the language, and are intended as a pure runtime internal optimization.

An ordinary reference is typically used as a key in some table. A
magic reference has a direct pointer to a reference counted magic
binary. This makes it possible to implement various things without
having to do lookups in a table, but instead access the data directly.
Besides very fast lookups this can also improve scalability by
removing a potentially contended table. A couple of examples of
planned future usage of magic references are ETS table identifiers,
and BIF timer identifiers.

Besides future optimizations using magic references it should also
be possible to replace the exposed magic binary cludge with magic
references. That is, magic binaries that are exposed as empty
binaries to the Erlang software.

1 files changed, 9 insertions, 3 deletions

diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 0646665b07..b2c307e826 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -111,10 +111,12 @@ const int etp_lock_check = 1;
 #else
 const int etp_lock_check = 0;
 #endif
-#ifdef WORDS_BIGENDIAN
-const int etp_big_endian = 1;
+const int etp_endianness = ERTS_ENDIANNESS;
+const Eterm etp_ref_header = ERTS_REF_THING_HEADER;
+#ifdef ERTS_MAGIC_REF_THING_HEADER
+const Eterm etp_magic_ref_header = ERTS_MAGIC_REF_THING_HEADER;
 #else
-const int etp_big_endian = 0;
+const Eterm etp_magic_ref_header = ERTS_REF_THING_HEADER;
 #endif
 const Eterm etp_the_non_value = THE_NON_VALUE;
 #ifdef ERTS_HOLE_MARKER
@@ -772,6 +774,8 @@ early_init(int *argc, char **argv) /*
     H_MAX_SIZE = H_DEFAULT_MAX_SIZE;
     H_MAX_FLAGS = MAX_HEAP_SIZE_KILL|MAX_HEAP_SIZE_LOG;
 
+    erts_term_init();
+
     erts_initialized = 0;
 
     erts_use_sender_punish = 1;
@@ -1143,6 +1147,8 @@ early_init(int *argc, char **argv) /*
     no_schedulers_online = schdlrs_onln;
 
     erts_no_schedulers = (Uint) no_schedulers;
+#else
+    erts_no_schedulers = 1;
 #endif
 #ifdef ERTS_DIRTY_SCHEDULERS
     erts_no_dirty_cpu_schedulers = no_dirty_cpu_schedulers = dirty_cpu_scheds;