diff options
| -rw-r--r-- | erts/emulator/beam/erl_nif.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c index 42a90f706b..d2000aa71e 100644 --- a/erts/emulator/beam/erl_nif.c +++ b/erts/emulator/beam/erl_nif.c @@ -488,6 +488,7 @@ static void cache_env(ErlNifEnv* env) env->hp_end = env->heap_frag->mem + env->heap_frag->alloc_size; } } + void* enif_priv_data(ErlNifEnv* env) { return env->mod_nif->priv_data; @@ -1334,9 +1335,36 @@ Eterm enif_make_binary(ErlNifEnv* env, ErlNifBinary* bin) if (bin->ref_bin != NULL) { Binary* binary = bin->ref_bin; - bin_term = erts_build_proc_bin(&MSO(env->proc), - alloc_heap(env, PROC_BIN_SIZE), - binary); + /* If the binary is smaller than the heap binary limit we'll return a + * heap binary to reduce the number of small refc binaries in the + * system. We can't simply release the refc binary right away however; + * the documentation states that the binary should be considered + * read-only from this point on, which implies that it should still be + * readable. + * + * We could keep it alive until we return by adding it to the temporary + * object list, but that requires an off-heap allocation which is + * potentially quite slow, so we create a dummy ProcBin instead and + * rely on the next minor GC to get rid of it. */ + if (bin->size <= ERL_ONHEAP_BIN_LIMIT) { + ErlHeapBin* hb; + + hb = (ErlHeapBin*)alloc_heap(env, heap_bin_size(bin->size)); + hb->thing_word = header_heap_bin(bin->size); + hb->size = bin->size; + + sys_memcpy(hb->data, bin->data, bin->size); + + erts_build_proc_bin(&MSO(env->proc), + alloc_heap(env, PROC_BIN_SIZE), + binary); + + bin_term = make_binary(hb); + } else { + bin_term = erts_build_proc_bin(&MSO(env->proc), + alloc_heap(env, PROC_BIN_SIZE), + binary); + } /* Our (possibly shared) ownership has been transferred to the term. */ bin->ref_bin = NULL; |