Fragmented young heap generation and off_heap_message_queue option

* The youngest generation of the heap can now consist of multiple
  blocks. Heap fragments and message fragments are added to the
  youngest generation when needed without triggering a GC. After
  a GC the youngest generation is contained in one single block.
* The off_heap_message_queue process flag has been added. When
  enabled all message data in the queue is kept off heap. When
  a message is selected from the queue, the message fragment (or
  heap fragment) containing the actual message is attached to the
  youngest generation. Messages stored off heap is not part of GC.

1 files changed, 5 insertions, 2 deletions

diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 01414f326d..a37cda93ef 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -314,6 +314,7 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
     ErtsProcLocks rp_locks = 0;
     Process* rp;
     Process* c_p;
+    ErtsMessage *mp;
     ErlHeapFragment* frags;
     Eterm receiver = to_pid->pid;
     int flush_me = 0;
@@ -347,7 +348,7 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
     ASSERT(frags == MBUF(&menv->phony_proc));
     if (frags != NULL) {
 	/* Move all offheap's from phony proc to the first fragment.
-	   Quick and dirty, but erts_move_msg_mbuf_to_heap doesn't care. */
+	   Quick and dirty... */
 	ASSERT(!is_offheap(&frags->off_heap));
 	frags->off_heap = MSO(&menv->phony_proc);
 	clear_offheap(&MSO(&menv->phony_proc));
@@ -359,7 +360,9 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
     if (flush_me) {	
 	flush_env(env); /* Needed for ERTS_HOLE_CHECK */ 
     }
-    erts_queue_message(rp, &rp_locks, frags, msg, am_undefined);
+    mp = erts_alloc_message(0, NULL);
+    mp->data.heap_frag = frags;
+    erts_queue_message(rp, &rp_locks, mp, msg, am_undefined);
     if (c_p == rp)
 	rp_locks &= ~ERTS_PROC_LOCK_MAIN;
     if (rp_locks)