From 0f75b2ad2e23107f8112b6dcd4785eeef6cc34aa Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 20 Jun 2024 05:56:58 +0200 Subject: Merging upstream version 2:9.1.0496. Signed-off-by: Daniel Baumann --- src/gc.c | 780 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 780 insertions(+) create mode 100644 src/gc.c (limited to 'src/gc.c') diff --git a/src/gc.c b/src/gc.c new file mode 100644 index 0000000..987ca27 --- /dev/null +++ b/src/gc.c @@ -0,0 +1,780 @@ +/* vi:set ts=8 sts=4 sw=4 noet: + * + * VIM - Vi IMproved by Bram Moolenaar + * + * Do ":help uganda" in Vim to read copying and usage conditions. + * Do ":help credits" in Vim to see a list of people who contributed. + * See README.txt for an overview of the Vim source code. + */ + +/* + * gc.c: Garbage Collection + */ + +#include "vim.h" + +#if defined(FEAT_EVAL) || defined(PROTO) + +/* + * When recursively copying lists and dicts we need to remember which ones we + * have done to avoid endless recursiveness. This unique ID is used for that. + * The last bit is used for previous_funccal, ignored when comparing. + */ +static int current_copyID = 0; + +static int free_unref_items(int copyID); + +/* + * Return the next (unique) copy ID. + * Used for serializing nested structures. + */ + int +get_copyID(void) +{ + current_copyID += COPYID_INC; + return current_copyID; +} + +/* + * Garbage collection for lists and dictionaries. + * + * We use reference counts to be able to free most items right away when they + * are no longer used. But for composite items it's possible that it becomes + * unused while the reference count is > 0: When there is a recursive + * reference. Example: + * :let l = [1, 2, 3] + * :let d = {9: l} + * :let l[1] = d + * + * Since this is quite unusual we handle this with garbage collection: every + * once in a while find out which lists and dicts are not referenced from any + * variable. + * + * Here is a good reference text about garbage collection (refers to Python + * but it applies to all reference-counting mechanisms): + * http://python.ca/nas/python/gc/ + */ + +/* + * Do garbage collection for lists and dicts. + * When "testing" is TRUE this is called from test_garbagecollect_now(). + * Return TRUE if some memory was freed. + */ + int +garbage_collect(int testing) +{ + int copyID; + int abort = FALSE; + buf_T *buf; + win_T *wp; + int did_free = FALSE; + tabpage_T *tp; + + if (!testing) + { + // Only do this once. + want_garbage_collect = FALSE; + may_garbage_collect = FALSE; + garbage_collect_at_exit = FALSE; + } + + // The execution stack can grow big, limit the size. + if (exestack.ga_maxlen - exestack.ga_len > 500) + { + size_t new_len; + char_u *pp; + int n; + + // Keep 150% of the current size, with a minimum of the growth size. + n = exestack.ga_len / 2; + if (n < exestack.ga_growsize) + n = exestack.ga_growsize; + + // Don't make it bigger though. + if (exestack.ga_len + n < exestack.ga_maxlen) + { + new_len = (size_t)exestack.ga_itemsize * (exestack.ga_len + n); + pp = vim_realloc(exestack.ga_data, new_len); + if (pp == NULL) + return FAIL; + exestack.ga_maxlen = exestack.ga_len + n; + exestack.ga_data = pp; + } + } + + // We advance by two because we add one for items referenced through + // previous_funccal. + copyID = get_copyID(); + + /* + * 1. Go through all accessible variables and mark all lists and dicts + * with copyID. + */ + + // Don't free variables in the previous_funccal list unless they are only + // referenced through previous_funccal. This must be first, because if + // the item is referenced elsewhere the funccal must not be freed. + abort = abort || set_ref_in_previous_funccal(copyID); + + // script-local variables + abort = abort || garbage_collect_scriptvars(copyID); + + // buffer-local variables + FOR_ALL_BUFFERS(buf) + abort = abort || set_ref_in_item(&buf->b_bufvar.di_tv, copyID, + NULL, NULL); + + // window-local variables + FOR_ALL_TAB_WINDOWS(tp, wp) + abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID, + NULL, NULL); + // window-local variables in autocmd windows + for (int i = 0; i < AUCMD_WIN_COUNT; ++i) + if (aucmd_win[i].auc_win != NULL) + abort = abort || set_ref_in_item( + &aucmd_win[i].auc_win->w_winvar.di_tv, copyID, NULL, NULL); +#ifdef FEAT_PROP_POPUP + FOR_ALL_POPUPWINS(wp) + abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID, + NULL, NULL); + FOR_ALL_TABPAGES(tp) + FOR_ALL_POPUPWINS_IN_TAB(tp, wp) + abort = abort || set_ref_in_item(&wp->w_winvar.di_tv, copyID, + NULL, NULL); +#endif + + // tabpage-local variables + FOR_ALL_TABPAGES(tp) + abort = abort || set_ref_in_item(&tp->tp_winvar.di_tv, copyID, + NULL, NULL); + // global variables + abort = abort || garbage_collect_globvars(copyID); + + // function-local variables + abort = abort || set_ref_in_call_stack(copyID); + + // named functions (matters for closures) + abort = abort || set_ref_in_functions(copyID); + + // function call arguments, if v:testing is set. + abort = abort || set_ref_in_func_args(copyID); + + // funcstacks keep variables for closures + abort = abort || set_ref_in_funcstacks(copyID); + + // loopvars keep variables for loop blocks + abort = abort || set_ref_in_loopvars(copyID); + + // v: vars + abort = abort || garbage_collect_vimvars(copyID); + + // callbacks in buffers + abort = abort || set_ref_in_buffers(copyID); + + // 'completefunc', 'omnifunc' and 'thesaurusfunc' callbacks + abort = abort || set_ref_in_insexpand_funcs(copyID); + + // 'operatorfunc' callback + abort = abort || set_ref_in_opfunc(copyID); + + // 'tagfunc' callback + abort = abort || set_ref_in_tagfunc(copyID); + + // 'imactivatefunc' and 'imstatusfunc' callbacks + abort = abort || set_ref_in_im_funcs(copyID); + +#ifdef FEAT_LUA + abort = abort || set_ref_in_lua(copyID); +#endif + +#ifdef FEAT_PYTHON + abort = abort || set_ref_in_python(copyID); +#endif + +#ifdef FEAT_PYTHON3 + abort = abort || set_ref_in_python3(copyID); +#endif + +#ifdef FEAT_JOB_CHANNEL + abort = abort || set_ref_in_channel(copyID); + abort = abort || set_ref_in_job(copyID); +#endif +#ifdef FEAT_NETBEANS_INTG + abort = abort || set_ref_in_nb_channel(copyID); +#endif + +#ifdef FEAT_TIMERS + abort = abort || set_ref_in_timer(copyID); +#endif + +#ifdef FEAT_QUICKFIX + abort = abort || set_ref_in_quickfix(copyID); +#endif + +#ifdef FEAT_TERMINAL + abort = abort || set_ref_in_term(copyID); +#endif + +#ifdef FEAT_PROP_POPUP + abort = abort || set_ref_in_popups(copyID); +#endif + + abort = abort || set_ref_in_classes(copyID); + + if (!abort) + { + /* + * 2. Free lists and dictionaries that are not referenced. + */ + did_free = free_unref_items(copyID); + + /* + * 3. Check if any funccal can be freed now. + * This may call us back recursively. + */ + free_unref_funccal(copyID, testing); + } + else if (p_verbose > 0) + { + verb_msg(_("Not enough memory to set references, garbage collection aborted!")); + } + + return did_free; +} + +/* + * Free lists, dictionaries, channels and jobs that are no longer referenced. + */ + static int +free_unref_items(int copyID) +{ + int did_free = FALSE; + + // Let all "free" functions know that we are here. This means no + // dictionaries, lists, channels or jobs are to be freed, because we will + // do that here. + in_free_unref_items = TRUE; + + /* + * PASS 1: free the contents of the items. We don't free the items + * themselves yet, so that it is possible to decrement refcount counters + */ + + // Go through the list of dicts and free items without this copyID. + did_free |= dict_free_nonref(copyID); + + // Go through the list of lists and free items without this copyID. + did_free |= list_free_nonref(copyID); + + // Go through the list of objects and free items without this copyID. + did_free |= object_free_nonref(copyID); + + // Go through the list of classes and free items without this copyID. + did_free |= class_free_nonref(copyID); + +#ifdef FEAT_JOB_CHANNEL + // Go through the list of jobs and free items without the copyID. This + // must happen before doing channels, because jobs refer to channels, but + // the reference from the channel to the job isn't tracked. + did_free |= free_unused_jobs_contents(copyID, COPYID_MASK); + + // Go through the list of channels and free items without the copyID. + did_free |= free_unused_channels_contents(copyID, COPYID_MASK); +#endif + + /* + * PASS 2: free the items themselves. + */ + object_free_items(copyID); + dict_free_items(copyID); + list_free_items(copyID); + +#ifdef FEAT_JOB_CHANNEL + // Go through the list of jobs and free items without the copyID. This + // must happen before doing channels, because jobs refer to channels, but + // the reference from the channel to the job isn't tracked. + free_unused_jobs(copyID, COPYID_MASK); + + // Go through the list of channels and free items without the copyID. + free_unused_channels(copyID, COPYID_MASK); +#endif + + in_free_unref_items = FALSE; + + return did_free; +} + +/* + * Mark all lists and dicts referenced through hashtab "ht" with "copyID". + * "list_stack" is used to add lists to be marked. Can be NULL. + * + * Returns TRUE if setting references failed somehow. + */ + int +set_ref_in_ht(hashtab_T *ht, int copyID, list_stack_T **list_stack) +{ + int todo; + int abort = FALSE; + hashitem_T *hi; + hashtab_T *cur_ht; + ht_stack_T *ht_stack = NULL; + ht_stack_T *tempitem; + + cur_ht = ht; + for (;;) + { + if (!abort) + { + // Mark each item in the hashtab. If the item contains a hashtab + // it is added to ht_stack, if it contains a list it is added to + // list_stack. + todo = (int)cur_ht->ht_used; + FOR_ALL_HASHTAB_ITEMS(cur_ht, hi, todo) + if (!HASHITEM_EMPTY(hi)) + { + --todo; + abort = abort || set_ref_in_item(&HI2DI(hi)->di_tv, copyID, + &ht_stack, list_stack); + } + } + + if (ht_stack == NULL) + break; + + // take an item from the stack + cur_ht = ht_stack->ht; + tempitem = ht_stack; + ht_stack = ht_stack->prev; + free(tempitem); + } + + return abort; +} + +#if defined(FEAT_LUA) || defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \ + || defined(PROTO) +/* + * Mark a dict and its items with "copyID". + * Returns TRUE if setting references failed somehow. + */ + int +set_ref_in_dict(dict_T *d, int copyID) +{ + if (d != NULL && d->dv_copyID != copyID) + { + d->dv_copyID = copyID; + return set_ref_in_ht(&d->dv_hashtab, copyID, NULL); + } + return FALSE; +} +#endif + +/* + * Mark a list and its items with "copyID". + * Returns TRUE if setting references failed somehow. + */ + int +set_ref_in_list(list_T *ll, int copyID) +{ + if (ll != NULL && ll->lv_copyID != copyID) + { + ll->lv_copyID = copyID; + return set_ref_in_list_items(ll, copyID, NULL); + } + return FALSE; +} + +/* + * Mark all lists and dicts referenced through list "l" with "copyID". + * "ht_stack" is used to add hashtabs to be marked. Can be NULL. + * + * Returns TRUE if setting references failed somehow. + */ + int +set_ref_in_list_items(list_T *l, int copyID, ht_stack_T **ht_stack) +{ + listitem_T *li; + int abort = FALSE; + list_T *cur_l; + list_stack_T *list_stack = NULL; + list_stack_T *tempitem; + + cur_l = l; + for (;;) + { + if (!abort && cur_l->lv_first != &range_list_item) + // Mark each item in the list. If the item contains a hashtab + // it is added to ht_stack, if it contains a list it is added to + // list_stack. + for (li = cur_l->lv_first; !abort && li != NULL; li = li->li_next) + abort = abort || set_ref_in_item(&li->li_tv, copyID, + ht_stack, &list_stack); + if (list_stack == NULL) + break; + + // take an item from the stack + cur_l = list_stack->list; + tempitem = list_stack; + list_stack = list_stack->prev; + free(tempitem); + } + + return abort; +} + +/* + * Mark the partial in callback 'cb' with "copyID". + */ + int +set_ref_in_callback(callback_T *cb, int copyID) +{ + typval_T tv; + + if (cb->cb_name == NULL || *cb->cb_name == NUL || cb->cb_partial == NULL) + return FALSE; + + tv.v_type = VAR_PARTIAL; + tv.vval.v_partial = cb->cb_partial; + return set_ref_in_item(&tv, copyID, NULL, NULL); +} + +/* + * Mark the dict "dd" with "copyID". + * Also see set_ref_in_item(). + */ + static int +set_ref_in_item_dict( + dict_T *dd, + int copyID, + ht_stack_T **ht_stack, + list_stack_T **list_stack) +{ + if (dd == NULL || dd->dv_copyID == copyID) + return FALSE; + + // Didn't see this dict yet. + dd->dv_copyID = copyID; + if (ht_stack == NULL) + return set_ref_in_ht(&dd->dv_hashtab, copyID, list_stack); + + ht_stack_T *newitem = ALLOC_ONE(ht_stack_T); + if (newitem == NULL) + return TRUE; + + newitem->ht = &dd->dv_hashtab; + newitem->prev = *ht_stack; + *ht_stack = newitem; + + return FALSE; +} + +/* + * Mark the list "ll" with "copyID". + * Also see set_ref_in_item(). + */ + static int +set_ref_in_item_list( + list_T *ll, + int copyID, + ht_stack_T **ht_stack, + list_stack_T **list_stack) +{ + if (ll == NULL || ll->lv_copyID == copyID) + return FALSE; + + // Didn't see this list yet. + ll->lv_copyID = copyID; + if (list_stack == NULL) + return set_ref_in_list_items(ll, copyID, ht_stack); + + list_stack_T *newitem = ALLOC_ONE(list_stack_T); + if (newitem == NULL) + return TRUE; + + newitem->list = ll; + newitem->prev = *list_stack; + *list_stack = newitem; + + return FALSE; +} + +/* + * Mark the partial "pt" with "copyID". + * Also see set_ref_in_item(). + */ + static int +set_ref_in_item_partial( + partial_T *pt, + int copyID, + ht_stack_T **ht_stack, + list_stack_T **list_stack) +{ + if (pt == NULL || pt->pt_copyID == copyID) + return FALSE; + + // Didn't see this partial yet. + pt->pt_copyID = copyID; + + int abort = set_ref_in_func(pt->pt_name, pt->pt_func, copyID); + + if (pt->pt_dict != NULL) + { + typval_T dtv; + + dtv.v_type = VAR_DICT; + dtv.vval.v_dict = pt->pt_dict; + set_ref_in_item(&dtv, copyID, ht_stack, list_stack); + } + + if (pt->pt_obj != NULL) + { + typval_T objtv; + + objtv.v_type = VAR_OBJECT; + objtv.vval.v_object = pt->pt_obj; + set_ref_in_item(&objtv, copyID, ht_stack, list_stack); + } + + for (int i = 0; i < pt->pt_argc; ++i) + abort = abort || set_ref_in_item(&pt->pt_argv[i], copyID, + ht_stack, list_stack); + // pt_funcstack is handled in set_ref_in_funcstacks() + // pt_loopvars is handled in set_ref_in_loopvars() + + return abort; +} + +#ifdef FEAT_JOB_CHANNEL +/* + * Mark the job "pt" with "copyID". + * Also see set_ref_in_item(). + */ + static int +set_ref_in_item_job( + job_T *job, + int copyID, + ht_stack_T **ht_stack, + list_stack_T **list_stack) +{ + typval_T dtv; + + if (job == NULL || job->jv_copyID == copyID) + return FALSE; + + job->jv_copyID = copyID; + if (job->jv_channel != NULL) + { + dtv.v_type = VAR_CHANNEL; + dtv.vval.v_channel = job->jv_channel; + set_ref_in_item(&dtv, copyID, ht_stack, list_stack); + } + if (job->jv_exit_cb.cb_partial != NULL) + { + dtv.v_type = VAR_PARTIAL; + dtv.vval.v_partial = job->jv_exit_cb.cb_partial; + set_ref_in_item(&dtv, copyID, ht_stack, list_stack); + } + + return FALSE; +} + +/* + * Mark the channel "ch" with "copyID". + * Also see set_ref_in_item(). + */ + static int +set_ref_in_item_channel( + channel_T *ch, + int copyID, + ht_stack_T **ht_stack, + list_stack_T **list_stack) +{ + typval_T dtv; + + if (ch == NULL || ch->ch_copyID == copyID) + return FALSE; + + ch->ch_copyID = copyID; + for (ch_part_T part = PART_SOCK; part < PART_COUNT; ++part) + { + for (jsonq_T *jq = ch->ch_part[part].ch_json_head.jq_next; + jq != NULL; jq = jq->jq_next) + set_ref_in_item(jq->jq_value, copyID, ht_stack, list_stack); + for (cbq_T *cq = ch->ch_part[part].ch_cb_head.cq_next; cq != NULL; + cq = cq->cq_next) + if (cq->cq_callback.cb_partial != NULL) + { + dtv.v_type = VAR_PARTIAL; + dtv.vval.v_partial = cq->cq_callback.cb_partial; + set_ref_in_item(&dtv, copyID, ht_stack, list_stack); + } + if (ch->ch_part[part].ch_callback.cb_partial != NULL) + { + dtv.v_type = VAR_PARTIAL; + dtv.vval.v_partial = ch->ch_part[part].ch_callback.cb_partial; + set_ref_in_item(&dtv, copyID, ht_stack, list_stack); + } + } + if (ch->ch_callback.cb_partial != NULL) + { + dtv.v_type = VAR_PARTIAL; + dtv.vval.v_partial = ch->ch_callback.cb_partial; + set_ref_in_item(&dtv, copyID, ht_stack, list_stack); + } + if (ch->ch_close_cb.cb_partial != NULL) + { + dtv.v_type = VAR_PARTIAL; + dtv.vval.v_partial = ch->ch_close_cb.cb_partial; + set_ref_in_item(&dtv, copyID, ht_stack, list_stack); + } + + return FALSE; +} +#endif + +/* + * Mark the class "cl" with "copyID". + * Also see set_ref_in_item(). + */ + int +set_ref_in_item_class( + class_T *cl, + int copyID, + ht_stack_T **ht_stack, + list_stack_T **list_stack) +{ + int abort = FALSE; + + if (cl == NULL || cl->class_copyID == copyID) + return FALSE; + + cl->class_copyID = copyID; + if (cl->class_members_tv != NULL) + { + // The "class_members_tv" table is allocated only for regular classes + // and not for interfaces. + for (int i = 0; !abort && i < cl->class_class_member_count; ++i) + abort = abort || set_ref_in_item( + &cl->class_members_tv[i], + copyID, ht_stack, list_stack); + } + + for (int i = 0; !abort && i < cl->class_class_function_count; ++i) + abort = abort || set_ref_in_func(NULL, + cl->class_class_functions[i], copyID); + + for (int i = 0; !abort && i < cl->class_obj_method_count; ++i) + abort = abort || set_ref_in_func(NULL, + cl->class_obj_methods[i], copyID); + + return abort; +} + +/* + * Mark the object "cl" with "copyID". + * Also see set_ref_in_item(). + */ + static int +set_ref_in_item_object( + object_T *obj, + int copyID, + ht_stack_T **ht_stack, + list_stack_T **list_stack) +{ + int abort = FALSE; + + if (obj == NULL || obj->obj_copyID == copyID) + return FALSE; + + obj->obj_copyID = copyID; + + // The typval_T array is right after the object_T. + typval_T *mtv = (typval_T *)(obj + 1); + for (int i = 0; !abort + && i < obj->obj_class->class_obj_member_count; ++i) + abort = abort || set_ref_in_item(mtv + i, copyID, + ht_stack, list_stack); + + return abort; +} + +/* + * Mark all lists, dicts and other container types referenced through typval + * "tv" with "copyID". + * "list_stack" is used to add lists to be marked. Can be NULL. + * "ht_stack" is used to add hashtabs to be marked. Can be NULL. + * + * Returns TRUE if setting references failed somehow. + */ + int +set_ref_in_item( + typval_T *tv, + int copyID, + ht_stack_T **ht_stack, + list_stack_T **list_stack) +{ + int abort = FALSE; + + switch (tv->v_type) + { + case VAR_DICT: + return set_ref_in_item_dict(tv->vval.v_dict, copyID, + ht_stack, list_stack); + + case VAR_LIST: + return set_ref_in_item_list(tv->vval.v_list, copyID, + ht_stack, list_stack); + + case VAR_FUNC: + { + abort = set_ref_in_func(tv->vval.v_string, NULL, copyID); + break; + } + + case VAR_PARTIAL: + return set_ref_in_item_partial(tv->vval.v_partial, copyID, + ht_stack, list_stack); + + case VAR_JOB: +#ifdef FEAT_JOB_CHANNEL + return set_ref_in_item_job(tv->vval.v_job, copyID, + ht_stack, list_stack); +#else + break; +#endif + + case VAR_CHANNEL: +#ifdef FEAT_JOB_CHANNEL + return set_ref_in_item_channel(tv->vval.v_channel, copyID, + ht_stack, list_stack); +#else + break; +#endif + + case VAR_CLASS: + return set_ref_in_item_class(tv->vval.v_class, copyID, + ht_stack, list_stack); + + case VAR_OBJECT: + return set_ref_in_item_object(tv->vval.v_object, copyID, + ht_stack, list_stack); + + case VAR_UNKNOWN: + case VAR_ANY: + case VAR_VOID: + case VAR_BOOL: + case VAR_SPECIAL: + case VAR_NUMBER: + case VAR_FLOAT: + case VAR_STRING: + case VAR_BLOB: + case VAR_TYPEALIAS: + case VAR_INSTR: + // Types that do not contain any other item + break; + } + + return abort; +} + +#endif -- cgit v1.2.3