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authorBjörn Gustavsson <[email protected]>2011-04-27 05:24:38 +0200
committerBjörn Gustavsson <[email protected]>2011-05-04 15:20:03 +0200
commit963843aad736997a66db8f8fdec6b3099373b742 (patch)
tree7489f4c8510cf80a254b7f8ff67c3233eb08f5d9
parent73830b087d3a69611c97751156e9f1c61e1ce26a (diff)
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iolist_size/1: Fix truncation of result
iolist_size/1 would silently return a truncated result for iolists whose size exceeded the word size. For example: iolist(lists:duplicate(256, <<0:(1 bsl 24)/unit:8>>)). would return 0 (instead of 4294967296 or 1 bsl 32). Rewrite iolist_size/1 to accumulate the size in a bignum if necessary and result the correct result.
-rw-r--r--erts/emulator/beam/bif.c142
-rw-r--r--erts/emulator/test/binary_SUITE.erl67
2 files changed, 191 insertions, 18 deletions
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 6b1ce823cb..e886792ba7 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -2168,20 +2168,146 @@ BIF_RETTYPE tl_1(BIF_ALIST_1)
/**********************************************************************/
/* return the size of an I/O list */
-BIF_RETTYPE iolist_size_1(BIF_ALIST_1)
+static Eterm
+accumulate(Eterm acc, Uint size)
{
- Sint size = io_list_len(BIF_ARG_1);
+ if (is_non_value(acc)) {
+ /*
+ * There is no pre-existing accumulator. Allocate a
+ * bignum buffer with one extra word to be used if
+ * the bignum grows in the future.
+ */
+ Eterm* hp = (Eterm *) erts_alloc(ERTS_ALC_T_TEMP_TERM,
+ (BIG_UINT_HEAP_SIZE+1) *
+ sizeof(Eterm));
+ return uint_to_big(size, hp);
+ } else {
+ Eterm* big;
+ int need_heap;
- if (size == -1) {
- BIF_ERROR(BIF_P, BADARG);
- } else if (IS_USMALL(0, (Uint) size)) {
- BIF_RET(make_small(size));
+ /*
+ * Add 'size' to 'acc' in place. There is always one
+ * extra word allocated in case the bignum grows by one word.
+ */
+ big = big_val(acc);
+ need_heap = BIG_NEED_SIZE(BIG_SIZE(big));
+ acc = big_plus_small(acc, size, big);
+ if (BIG_NEED_SIZE(big_size(acc)) > need_heap) {
+ /*
+ * The extra word has been consumed. Grow the
+ * allocation by one word.
+ */
+ big = (Eterm *) erts_realloc(ERTS_ALC_T_TEMP_TERM,
+ big_val(acc),
+ (need_heap+1) * sizeof(Eterm));
+ acc = make_big(big);
+ }
+ return acc;
+ }
+}
+
+static Eterm
+consolidate(Process* p, Eterm acc, Uint size)
+{
+ Eterm* hp;
+
+ if (is_non_value(acc)) {
+ return erts_make_integer(size, p);
} else {
- Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
- BIF_RET(uint_to_big(size, hp));
+ Eterm* big;
+ Uint sz;
+ Eterm res;
+
+ acc = accumulate(acc, size);
+ big = big_val(acc);
+ sz = BIG_NEED_SIZE(BIG_SIZE(big));
+ hp = HAlloc(p, sz);
+ res = make_big(hp);
+ while (sz--) {
+ *hp++ = *big++;
+ }
+ erts_free(ERTS_ALC_T_TEMP_TERM, (void *) big_val(acc));
+ return res;
}
}
+BIF_RETTYPE iolist_size_1(BIF_ALIST_1)
+{
+ Eterm obj, hd;
+ Eterm* objp;
+ Uint size = 0;
+ Uint cur_size;
+ Uint new_size;
+ Eterm acc = THE_NON_VALUE;
+ DECLARE_ESTACK(s);
+
+ obj = BIF_ARG_1;
+ goto L_again;
+
+ while (!ESTACK_ISEMPTY(s)) {
+ obj = ESTACK_POP(s);
+ L_again:
+ if (is_list(obj)) {
+ L_iter_list:
+ objp = list_val(obj);
+ hd = CAR(objp);
+ obj = CDR(objp);
+ /* Head */
+ if (is_byte(hd)) {
+ size++;
+ if (size == 0) {
+ acc = accumulate(acc, (Uint) -1);
+ size = 1;
+ }
+ } else if (is_binary(hd) && binary_bitsize(hd) == 0) {
+ cur_size = binary_size(hd);
+ if ((new_size = size + cur_size) >= size) {
+ size = new_size;
+ } else {
+ acc = accumulate(acc, size);
+ size = cur_size;
+ }
+ } else if (is_list(hd)) {
+ ESTACK_PUSH(s, obj);
+ obj = hd;
+ goto L_iter_list;
+ } else if (is_not_nil(hd)) {
+ goto L_type_error;
+ }
+ /* Tail */
+ if (is_list(obj)) {
+ goto L_iter_list;
+ } else if (is_binary(obj) && binary_bitsize(obj) == 0) {
+ cur_size = binary_size(obj);
+ if ((new_size = size + cur_size) >= size) {
+ size = new_size;
+ } else {
+ acc = accumulate(acc, size);
+ size = cur_size;
+ }
+ } else if (is_not_nil(obj)) {
+ goto L_type_error;
+ }
+ } else if (is_binary(obj) && binary_bitsize(obj) == 0) {
+ cur_size = binary_size(obj);
+ if ((new_size = size + cur_size) >= size) {
+ size = new_size;
+ } else {
+ acc = accumulate(acc, size);
+ size = cur_size;
+ }
+ } else if (is_not_nil(obj)) {
+ goto L_type_error;
+ }
+ }
+
+ DESTROY_ESTACK(s);
+ BIF_RET(consolidate(BIF_P, acc, size));
+
+ L_type_error:
+ DESTROY_ESTACK(s);
+ BIF_ERROR(BIF_P, BADARG);
+}
/**********************************************************************/
diff --git a/erts/emulator/test/binary_SUITE.erl b/erts/emulator/test/binary_SUITE.erl
index b7b2aaf89e..401b3c23b6 100644
--- a/erts/emulator/test/binary_SUITE.erl
+++ b/erts/emulator/test/binary_SUITE.erl
@@ -517,18 +517,65 @@ external_size_1(Term, Size0, Limit) when Size0 < Limit ->
external_size_1(_, _, _) -> ok.
t_iolist_size(Config) when is_list(Config) ->
- %% Build a term whose external size only fits in a big num (on 32-bit CPU).
- Bin = iolist_to_binary(lists:seq(0, 254)),
- ?line ok = t_iolist_size_1(Bin, 0, 16#7FFFFFFF),
- ?line ok = t_iolist_size_1(make_unaligned_sub_binary(Bin), 0, 16#7FFFFFFF).
+ ?line Seed = now(),
+ ?line io:format("Seed: ~p", [Seed]),
+ ?line random:seed(Seed),
+ ?line Base = <<0:(1 bsl 20)/unit:8>>,
+ ?line Powers = [1 bsl N || N <- lists:seq(2, 37)],
+ ?line Sizes0 = [[N - random:uniform(N div 2),
+ lists:seq(N-2, N+2),
+ N+N div 2,
+ N + random:uniform(N div 2)] ||
+ N <- Powers],
+ %% Test sizes around 1^32 more thoroughly.
+ FourGigs = 1 bsl 32,
+ ?line Sizes1 = [FourGigs+N || N <- lists:seq(-8, 40)] ++ Sizes0,
+ ?line Sizes2 = lists:flatten(Sizes1),
+ ?line Sizes = lists:usort(Sizes2),
+ io:format("~p sizes:", [length(Sizes)]),
+ io:format("~p\n", [Sizes]),
+ ?line [Sz = iolist_size(build_iolist(Sz, Base)) || Sz <- Sizes],
+ ok.
-t_iolist_size_1(IOList, Size0, Limit) when Size0 < Limit ->
- case iolist_size(IOList) of
- Size when is_integer(Size), Size0 < Size ->
- io:format("~p", [Size]),
- t_iolist_size_1([IOList|IOList], Size, Limit)
+build_iolist(N, Base) when N < 16 ->
+ case random:uniform(3) of
+ 1 ->
+ <<Bin:N/binary,_/binary>> = Base,
+ Bin;
+ _ ->
+ lists:seq(1, N)
end;
-t_iolist_size_1(_, _, _) -> ok.
+build_iolist(N, Base) when N =< byte_size(Base) ->
+ case random:uniform(3) of
+ 1 ->
+ <<Bin:N/binary,_/binary>> = Base,
+ Bin;
+ 2 ->
+ <<Bin:N/binary,_/binary>> = Base,
+ [Bin];
+ 3 ->
+ case N rem 2 of
+ 0 ->
+ L = build_iolist(N div 2, Base),
+ [L,L];
+ 1 ->
+ L = build_iolist(N div 2, Base),
+ [L,L,45]
+ end
+ end;
+build_iolist(N0, Base) ->
+ Small = random:uniform(15),
+ Seq = lists:seq(1, Small),
+ N = N0 - Small,
+ case N rem 2 of
+ 0 ->
+ L = build_iolist(N div 2, Base),
+ [L,L|Seq];
+ 1 ->
+ L = build_iolist(N div 2, Base),
+ [47,L,L|Seq]
+ end.
+
bad_binary_to_term_2(doc) -> "OTP-4053.";
bad_binary_to_term_2(suite) -> [];