From f77ea1c049c585db93618991eb02d9afbfa7ad21 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 12 Apr 2016 07:14:57 +0200 Subject: Reimplement -on_load() Load the module as old code; swap old and new code if the -on_load function succeeds. That way, a failed update attempt for a module that has an -on_load function will preserve the previous version of the code. --- erts/emulator/beam/erl_nif.c | 62 +++++++++++++++++++++++++------------------- 1 file changed, 36 insertions(+), 26 deletions(-) (limited to 'erts/emulator/beam/erl_nif.c') diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c index 941f44b9ec..dc83a780a2 100644 --- a/erts/emulator/beam/erl_nif.c +++ b/erts/emulator/beam/erl_nif.c @@ -2780,7 +2780,7 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) ErlNifEntry* entry = NULL; ErlNifEnv env; int i, err, encoding; - Module* mod; + Module* module_p; Eterm mod_atom; const Atom* mod_atomp; Eterm f_atom; @@ -2790,6 +2790,8 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) int veto; struct erl_module_nif* lib = NULL; int reload_warning = 0; + struct erl_module_instance* this_mi; + struct erl_module_instance* prev_mi; encoding = erts_get_native_filename_encoding(); if (encoding == ERL_FILENAME_WIN_WCHAR) { @@ -2823,21 +2825,29 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) ASSERT(caller != NULL); mod_atom = caller[0]; ASSERT(is_atom(mod_atom)); - mod=erts_get_module(mod_atom, erts_active_code_ix()); - ASSERT(mod != NULL); + module_p = erts_get_module(mod_atom, erts_active_code_ix()); + ASSERT(module_p != NULL); mod_atomp = atom_tab(atom_val(mod_atom)); init_func = erts_static_nif_get_nif_init((char*)mod_atomp->name, mod_atomp->len); if (init_func != NULL) handle = init_func; - if (!in_area(caller, mod->curr.code_hdr, mod->curr.code_length)) { - ASSERT(in_area(caller, mod->old.code_hdr, mod->old.code_length)); + if (in_area(caller, module_p->old.code_hdr, module_p->old.code_length)) { + if (module_p->old.code_hdr->on_load_function_ptr) { + this_mi = &module_p->old; + prev_mi = &module_p->curr; + } else { + ret = load_nif_error(BIF_P, "old_code", "Calling load_nif from old " + "module '%T' not allowed", mod_atom); + goto error; + } + } else { + this_mi = &module_p->curr; + prev_mi = &module_p->old; + } - ret = load_nif_error(BIF_P, "old_code", "Calling load_nif from old " - "module '%T' not allowed", mod_atom); - } - else if (init_func == NULL && + if (init_func == NULL && (err=erts_sys_ddll_open(lib_name, &handle, &errdesc)) != ERL_DE_NO_ERROR) { const char slogan[] = "Failed to load NIF library"; if (strstr(errdesc.str, lib_name) != NULL) { @@ -2886,7 +2896,7 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) for (i=0; i < entry->num_of_funcs && ret==am_ok; i++) { BeamInstr** code_pp; if (!erts_atom_get(f->name, sys_strlen(f->name), &f_atom, ERTS_ATOM_ENC_LATIN1) - || (code_pp = get_func_pp(mod->curr.code_hdr, f_atom, f->arity))==NULL) { + || (code_pp = get_func_pp(this_mi->code_hdr, f_atom, f->arity))==NULL) { ret = load_nif_error(BIF_P,bad_lib,"Function not found %T:%s/%u", mod_atom, f->name, f->arity); } @@ -2937,9 +2947,9 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) erts_refc_init(&lib->rt_cnt, 0); erts_refc_init(&lib->rt_dtor_cnt, 0); ASSERT(opened_rt_list == NULL); - lib->mod = mod; + lib->mod = module_p; env.mod_nif = lib; - if (mod->curr.nif != NULL) { /*************** Reload ******************/ + if (this_mi->nif != NULL) { /*************** Reload ******************/ /* * Repeated load_nif calls from same Erlang module instance ("reload") * is deprecated and was only ment as a development feature not to @@ -2947,16 +2957,16 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) */ int k, old_incr = 0; ErlNifFunc* old_func; - lib->priv_data = mod->curr.nif->priv_data; + lib->priv_data = this_mi->nif->priv_data; - ASSERT(mod->curr.nif->entry != NULL); + ASSERT(this_mi->nif->entry != NULL); if (entry->reload == NULL) { ret = load_nif_error(BIF_P,reload,"Reload not supported by this NIF library."); goto error; } /* Check that no NIF is removed */ - old_func = mod->curr.nif->entry->funcs; - for (k=0; k < mod->curr.nif->entry->num_of_funcs; k++) { + old_func = this_mi->nif->entry->funcs; + for (k=0; k < this_mi->nif->entry->num_of_funcs; k++) { int incr = 0; ErlNifFunc* f = entry->funcs; for (i=0; i < entry->num_of_funcs; i++) { @@ -2972,7 +2982,7 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) old_func->name, old_func->arity); goto error; } - old_func = next_func(mod->curr.nif->entry, &old_incr, old_func); + old_func = next_func(this_mi->nif->entry, &old_incr, old_func); } erts_pre_nif(&env, BIF_P, lib, NULL); veto = entry->reload(&env, &lib->priv_data, BIF_ARG_2); @@ -2982,24 +2992,24 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) } else { commit_opened_resource_types(lib); - mod->curr.nif->entry = NULL; /* to prevent 'unload' callback */ - erts_unload_nif(mod->curr.nif); + this_mi->nif->entry = NULL; /* to prevent 'unload' callback */ + erts_unload_nif(this_mi->nif); reload_warning = 1; } } else { lib->priv_data = NULL; - if (mod->old.nif != NULL) { /**************** Upgrade ***************/ - void* prev_old_data = mod->old.nif->priv_data; + if (prev_mi->nif != NULL) { /**************** Upgrade ***************/ + void* prev_old_data = prev_mi->nif->priv_data; if (entry->upgrade == NULL) { ret = load_nif_error(BIF_P, upgrade, "Upgrade not supported by this NIF library."); goto error; } - erts_pre_nif(&env, BIF_P, lib, NULL); - veto = entry->upgrade(&env, &lib->priv_data, &mod->old.nif->priv_data, BIF_ARG_2); + erts_pre_nif(&env, BIF_P, lib, NULL); + veto = entry->upgrade(&env, &lib->priv_data, &prev_mi->nif->priv_data, BIF_ARG_2); erts_post_nif(&env); if (veto) { - mod->old.nif->priv_data = prev_old_data; + prev_mi->nif->priv_data = prev_old_data; ret = load_nif_error(BIF_P, upgrade, "Library upgrade-call unsuccessful."); } else @@ -3024,12 +3034,12 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2) int incr = 0; ErlNifFunc* f = entry->funcs; - mod->curr.nif = lib; + this_mi->nif = lib; for (i=0; i < entry->num_of_funcs; i++) { BeamInstr* code_ptr; erts_atom_get(f->name, sys_strlen(f->name), &f_atom, ERTS_ATOM_ENC_LATIN1); - code_ptr = *get_func_pp(mod->curr.code_hdr, f_atom, f->arity); + code_ptr = *get_func_pp(this_mi->code_hdr, f_atom, f->arity); if (code_ptr[1] == 0) { code_ptr[5+0] = (BeamInstr) BeamOp(op_call_nif); -- cgit v1.2.3