From 809e70d0c8060f5d96584179b30950344ef51367 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Tue, 13 Sep 2016 17:00:11 +0200 Subject: Fix crash due to heap fragments left after GC Do not decode distribution messages as part of the GC operation. Distribution messages containing maps may generate heap fragments. --- erts/emulator/beam/erl_gc.c | 49 +++++++++++++++++++-------------------------- 1 file changed, 21 insertions(+), 28 deletions(-) diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c index d0d74bbf44..9e0919cc9c 100644 --- a/erts/emulator/beam/erl_gc.c +++ b/erts/emulator/beam/erl_gc.c @@ -531,9 +531,19 @@ young_gen_usage(Process *p) if (p->flags & F_ON_HEAP_MSGQ) { ErtsMessage *mp; - for (mp = p->msg.first; mp; mp = mp->next) + for (mp = p->msg.first; mp; mp = mp->next) { + /* + * We leave not yet decoded distribution messages + * as they are in the queue since it is not + * possible to determine a maximum size until + * actual decoding. However, we use their estimated + * size when calculating need, and by this making + * it more likely that they will fit on the heap + * when actually decoded. + */ if (mp->data.attached) hsz += erts_msg_attached_data_size(mp); + } } aheap = p->abandoned_heap; @@ -2247,37 +2257,22 @@ move_msgq_to_heap(Process *p) if (mp->data.attached) { ErlHeapFragment *bp; - ErtsHeapFactory factory; - - erts_factory_proc_prealloc_init(&factory, p, - erts_msg_attached_data_size(mp)); - - if (is_non_value(ERL_MESSAGE_TERM(mp))) { - if (mp->data.dist_ext) { - ASSERT(mp->data.dist_ext->heap_size >= 0); - if (is_not_nil(ERL_MESSAGE_TOKEN(mp))) { - bp = erts_dist_ext_trailer(mp->data.dist_ext); - ERL_MESSAGE_TOKEN(mp) = copy_struct(ERL_MESSAGE_TOKEN(mp), - bp->used_size, - &factory.hp, - factory.off_heap); - erts_cleanup_offheap(&bp->off_heap); - } - ERL_MESSAGE_TERM(mp) = erts_decode_dist_ext(&factory, - mp->data.dist_ext); - erts_free_dist_ext_copy(mp->data.dist_ext); - mp->data.dist_ext = NULL; - } - } - else { + + /* + * We leave not yet decoded distribution messages + * as they are in the queue since it is not + * possible to determine a maximum size until + * actual decoding... + */ + if (is_value(ERL_MESSAGE_TERM(mp))) { bp = erts_message_to_heap_frag(mp); if (bp->next) - erts_move_multi_frags(&factory.hp, factory.off_heap, bp, + erts_move_multi_frags(&p->htop, &p->off_heap, bp, mp->m, ERL_MESSAGE_REF_ARRAY_SZ, 0); else - copy_one_frag(&factory.hp, factory.off_heap, bp, + copy_one_frag(&p->htop, &p->off_heap, bp, mp->m, ERL_MESSAGE_REF_ARRAY_SZ); if (mp->data.attached != ERTS_MSG_COMBINED_HFRAG) { @@ -2294,8 +2289,6 @@ move_msgq_to_heap(Process *p) mp = new_mp; } } - - erts_factory_close(&factory); } mpp = &(*mpp)->next; -- cgit v1.2.3