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, 9 insertions, 12 deletions

diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
index 3e300f88ea..019aa0f16c 100644
--- a/erts/emulator/beam/erl_alloc.c
+++ b/erts/emulator/beam/erl_alloc.c
@@ -582,7 +582,7 @@ erts_alloc_init(int *argc, char **argv, ErtsAllocInitOpts *eaiop)
     fix_type_sizes[ERTS_ALC_FIX_TYPE_IX(ERTS_ALC_T_DRV_SEL_D_STATE)]
 	= sizeof(ErtsDrvSelectDataState);
     fix_type_sizes[ERTS_ALC_FIX_TYPE_IX(ERTS_ALC_T_MSG_REF)]
-	= sizeof(ErlMessage);
+	= sizeof(ErtsMessageRef);
 #ifdef ERTS_SMP
     fix_type_sizes[ERTS_ALC_FIX_TYPE_IX(ERTS_ALC_T_THR_Q_EL_SL)]
 	= sizeof(ErtsThrQElement_t);
@@ -2916,12 +2916,12 @@ reply_alloc_info(void *vair)
     int global_instances = air->req_sched == sched_id;
     ErtsProcLocks rp_locks;
     Process *rp = air->proc;
-    Eterm ref_copy = NIL, ai_list, msg;
-    Eterm *hp = NULL, *hp_end = NULL, *hp_start = NULL;
+    Eterm ref_copy = NIL, ai_list, msg = NIL;
+    Eterm *hp = NULL, *hp_start = NULL, *hp_end = NULL;
     Eterm **hpp;
     Uint sz, *szp;
     ErlOffHeap *ohp = NULL;
-    ErlHeapFragment *bp = NULL;
+    ErtsMessage *mp = NULL;
     struct erts_mmap_info_struct emis;
     int i;
     Eterm (*info_func)(Allctr_t *,
@@ -3123,20 +3123,17 @@ reply_alloc_info(void *vair)
 	if (hpp)
 	    break;
 
-	hp = erts_alloc_message_heap(sz, &bp, &ohp, rp, &rp_locks);
+	mp = erts_alloc_message_heap(rp, &rp_locks, sz, &hp, &ohp);
 	hp_start = hp;
 	hp_end = hp + sz;
 	szp = NULL;
 	hpp = &hp;
     }
-    if (bp)
-	bp = erts_resize_message_buffer(bp, hp - hp_start, &msg, 1);
-    else {
-	ASSERT(hp);
-	HRelease(rp, hp_end, hp);	    
-    }
 
-    erts_queue_message(rp, &rp_locks, bp, msg, NIL);
+    if (hp != hp_end)
+	erts_shrink_message_heap(&mp, rp, hp_start, hp, hp_end, &msg, 1);
+
+    erts_queue_message(rp, &rp_locks, mp, msg, NIL);
 
     if (air->req_sched == sched_id)
 	rp_locks &= ~ERTS_PROC_LOCK_MAIN;