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authorBjörn Gustavsson <[email protected]>2017-11-27 12:41:07 +0100
committerGitHub <[email protected]>2017-11-27 12:41:07 +0100
commit0c79be5d1e16308c50656cd7add5502833fba81d (patch)
treea10c4d468c3d6af3613b7b3d7d4ae8932976f996
parenteb2da85bf1f29000cd3c1b2f6dfbfcb5d6aec016 (diff)
parent3105c314beff5c9b226d8e863d32c4329706353c (diff)
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Merge pull request #1644 from bjorng/bjorn/erts/fix-literal-gc/ERL-508
Fix purging of modules with "fake literals" OTP-14791
-rw-r--r--erts/emulator/beam/beam_load.c35
-rw-r--r--erts/emulator/beam/erl_gc.c47
-rw-r--r--erts/emulator/test/code_SUITE.erl60
3 files changed, 124 insertions, 18 deletions
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 23258dbe9c..adf8779f11 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -5665,13 +5665,36 @@ erts_release_literal_area(ErtsLiteralArea* literal_area)
return;
oh = literal_area->off_heap;
-
+
while (oh) {
- Binary* bptr;
- ASSERT(thing_subtag(oh->thing_word) == REFC_BINARY_SUBTAG);
- bptr = ((ProcBin*)oh)->val;
- erts_bin_release(bptr);
- oh = oh->next;
+ switch (thing_subtag(oh->thing_word)) {
+ case REFC_BINARY_SUBTAG:
+ {
+ Binary* bptr = ((ProcBin*)oh)->val;
+ erts_bin_release(bptr);
+ break;
+ }
+ case FUN_SUBTAG:
+ {
+ ErlFunEntry* fe = ((ErlFunThing*)oh)->fe;
+ if (erts_smp_refc_dectest(&fe->refc, 0) == 0) {
+ erts_erase_fun_entry(fe);
+ }
+ break;
+ }
+ case REF_SUBTAG:
+ {
+ ErtsMagicBinary *bptr;
+ ASSERT(is_magic_ref_thing(oh));
+ bptr = ((ErtsMRefThing *) oh)->mb;
+ erts_bin_release((Binary *) bptr);
+ break;
+ }
+ default:
+ ASSERT(is_external_header(oh->thing_word));
+ erts_deref_node_entry(((ExternalThing*)oh)->node);
+ }
+ oh = oh->next;
}
erts_free(ERTS_ALC_T_LITERAL, literal_area);
}
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index 8cb977a7f3..6a87136463 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -1234,8 +1234,8 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
p->old_htop = old_htop;
/*
- * Prepare to sweep binaries. Since all MSOs on the new heap
- * must be come before MSOs on the old heap, find the end of
+ * Prepare to sweep off-heap objects. Since all MSOs on the new
+ * heap must be come before MSOs on the old heap, find the end of
* current MSO list and use that as a starting point.
*/
@@ -1247,25 +1247,50 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
}
/*
- * Sweep through all binaries in the temporary literal area.
+ * Sweep through all off-heap objects in the temporary literal area.
*/
while (oh) {
if (IS_MOVED_BOXED(oh->thing_word)) {
- Binary* bptr;
struct erl_off_heap_header* ptr;
- ptr = (struct erl_off_heap_header*) boxed_val(oh->thing_word);
- ASSERT(thing_subtag(ptr->thing_word) == REFC_BINARY_SUBTAG);
- bptr = ((ProcBin*)ptr)->val;
-
- /*
- * This binary has been copied to the heap.
+ /*
+ * This off-heap object has been copied to the heap.
* We must increment its reference count and
* link it into the MSO list for the process.
*/
- erts_refc_inc(&bptr->intern.refc, 1);
+ ptr = (struct erl_off_heap_header*) boxed_val(oh->thing_word);
+ switch (thing_subtag(ptr->thing_word)) {
+ case REFC_BINARY_SUBTAG:
+ {
+ Binary* bptr = ((ProcBin*)ptr)->val;
+ erts_refc_inc(&bptr->intern.refc, 1);
+ break;
+ }
+ case FUN_SUBTAG:
+ {
+ ErlFunEntry* fe = ((ErlFunThing*)ptr)->fe;
+ erts_refc_inc(&fe->refc, 1);
+ break;
+ }
+ case REF_SUBTAG:
+ {
+ ErtsMagicBinary *bptr;
+ ASSERT(is_magic_ref_thing(ptr));
+ bptr = ((ErtsMRefThing *) ptr)->mb;
+ erts_refc_inc(&bptr->intern.refc, 1);
+ break;
+ }
+ default:
+ {
+ ExternalThing *etp;
+ ASSERT(is_external_header(ptr->thing_word));
+ etp = (ExternalThing *) ptr;
+ erts_smp_refc_inc(&etp->node->refc, 1);
+ break;
+ }
+ }
*prev = ptr;
prev = &ptr->next;
}
diff --git a/erts/emulator/test/code_SUITE.erl b/erts/emulator/test/code_SUITE.erl
index 77321aa50f..dca600bc7b 100644
--- a/erts/emulator/test/code_SUITE.erl
+++ b/erts/emulator/test/code_SUITE.erl
@@ -25,6 +25,7 @@
multi_proc_purge/1, t_check_old_code/1,
external_fun/1,get_chunk/1,module_md5/1,
constant_pools/1,constant_refc_binaries/1,
+ fake_literals/1,
false_dependency/1,coverage/1,fun_confusion/1,
t_copy_literals/1, t_copy_literals_frags/1]).
@@ -38,7 +39,8 @@ all() ->
call_purged_fun_code_reload, call_purged_fun_code_there,
multi_proc_purge, t_check_old_code, external_fun, get_chunk,
module_md5,
- constant_pools, constant_refc_binaries, false_dependency,
+ constant_pools, constant_refc_binaries, fake_literals,
+ false_dependency,
coverage, fun_confusion, t_copy_literals, t_copy_literals_frags].
init_per_suite(Config) ->
@@ -554,6 +556,62 @@ wait_for_memory_deallocations() ->
wait_for_memory_deallocations()
end.
+fake_literals(_Config) ->
+ Mod = fake__literals__module,
+ try
+ do_fake_literals(Mod)
+ after
+ _ = code:purge(Mod),
+ _ = code:delete(Mod),
+ _ = code:purge(Mod),
+ _ = code:delete(Mod)
+ end,
+ ok.
+
+do_fake_literals(Mod) ->
+ Tid = ets:new(test, []),
+ ExtTerms = get_external_terms(),
+ Term0 = {self(),make_ref(),Tid,fun() -> ok end,ExtTerms},
+ Terms = [begin
+ make_literal_module(Mod, Term0),
+ Mod:term()
+ end || _ <- lists:seq(1, 10)],
+ verify_lit_terms(Terms, Term0),
+ true = ets:delete(Tid),
+ ok.
+
+make_literal_module(Mod, Term) ->
+ Exp = [{term,0}],
+ Attr = [],
+ Fs = [{function,term,0,2,
+ [{label,1},
+ {line,[]},
+ {func_info,{atom,Mod},{atom,term},0},
+ {label,2},
+ {move,{literal,Term},{x,0}},
+ return]}],
+ Asm = {Mod,Exp,Attr,Fs,2},
+ {ok,Mod,Beam} = compile:forms(Asm, [from_asm,binary,report]),
+ code:load_binary(Mod, atom_to_list(Mod), Beam).
+
+verify_lit_terms([H|T], Term) ->
+ case H =:= Term of
+ true ->
+ verify_lit_terms(T, Term);
+ false ->
+ error({bad_term,H})
+ end;
+verify_lit_terms([], _) ->
+ ok.
+
+get_external_terms() ->
+ {ok,Node} = test_server:start_node(?FUNCTION_NAME, slave, []),
+ Ref = rpc:call(Node, erlang, make_ref, []),
+ Ports = rpc:call(Node, erlang, ports, []),
+ Pid = rpc:call(Node, erlang, self, []),
+ _ = test_server:stop_node(Node),
+ {Ref,hd(Ports),Pid}.
+
%% OTP-7559: c_p->cp could contain garbage and create a false dependency
%% to a module in a process. (Thanks to Richard Carlsson.)
false_dependency(Config) when is_list(Config) ->