diff options
Diffstat (limited to 'src/H5Cint.c')
| -rw-r--r-- | src/H5Cint.c | 2578 |
1 files changed, 2578 insertions, 0 deletions
diff --git a/src/H5Cint.c b/src/H5Cint.c new file mode 100644 index 0000000..5200ac6 --- /dev/null +++ b/src/H5Cint.c @@ -0,0 +1,2578 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * Copyright by The HDF Group. * + * All rights reserved. * + * * + * This file is part of HDF5. The full HDF5 copyright notice, including * + * terms governing use, modification, and redistribution, is contained in * + * the COPYING file, which can be found at the root of the source code * + * distribution tree, or in https://www.hdfgroup.org/licenses. * + * If you do not have access to either file, you may request a copy from * + * help@hdfgroup.org. * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/*------------------------------------------------------------------------- + * + * Created: H5Centry.c + * May 8 2023 + * Quincey Koziol + * + * Purpose: Routines which operate on cache entries. + * + *------------------------------------------------------------------------- + */ + +/****************/ +/* Module Setup */ +/****************/ + +#include "H5Cmodule.h" /* This source code file is part of the H5C module */ +#define H5F_FRIEND /* suppress error about including H5Fpkg */ + +/***********/ +/* Headers */ +/***********/ +#include "H5private.h" /* Generic Functions */ +#include "H5Cpkg.h" /* Cache */ +#include "H5Eprivate.h" /* Error handling */ +#include "H5Fpkg.h" /* Files */ +#include "H5MFprivate.h" /* File memory management */ + +/****************/ +/* Local Macros */ +/****************/ + +/******************/ +/* Local Typedefs */ +/******************/ + +/********************/ +/* Local Prototypes */ +/********************/ +static herr_t H5C__autoadjust__ageout(H5F_t *f, double hit_rate, enum H5C_resize_status *status_ptr, + size_t *new_max_cache_size_ptr, hbool_t write_permitted); +static herr_t H5C__autoadjust__ageout__cycle_epoch_marker(H5C_t *cache_ptr); +static herr_t H5C__autoadjust__ageout__evict_aged_out_entries(H5F_t *f, hbool_t write_permitted); +static herr_t H5C__autoadjust__ageout__insert_new_marker(H5C_t *cache_ptr); +static herr_t H5C__flush_invalidate_ring(H5F_t *f, H5C_ring_t ring, unsigned flags); +static herr_t H5C__serialize_ring(H5F_t *f, H5C_ring_t ring); + +/*********************/ +/* Package Variables */ +/*********************/ + +/*****************************/ +/* Library Private Variables */ +/*****************************/ + +/*******************/ +/* Local Variables */ +/*******************/ + +/*------------------------------------------------------------------------- + * Function: H5C__auto_adjust_cache_size + * + * Purpose: Obtain the current full cache hit rate, and compare it + * with the hit rate thresholds for modifying cache size. + * If one of the thresholds has been crossed, adjusts the + * size of the cache accordingly. + * + * The function then resets the full cache hit rate + * statistics, and exits. + * + * Return: Non-negative on success/Negative on failure or if there was + * an attempt to flush a protected item. + * + * + * Programmer: John Mainzer, 10/7/04 + * + *------------------------------------------------------------------------- + */ +herr_t +H5C__auto_adjust_cache_size(H5F_t *f, hbool_t write_permitted) +{ + H5C_t *cache_ptr = f->shared->cache; + hbool_t reentrant_call = FALSE; + hbool_t inserted_epoch_marker = FALSE; + size_t new_max_cache_size = 0; + size_t old_max_cache_size = 0; + size_t new_min_clean_size = 0; + size_t old_min_clean_size = 0; + double hit_rate; + enum H5C_resize_status status = in_spec; /* will change if needed */ + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + HDassert(f); + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert(cache_ptr->cache_accesses >= cache_ptr->resize_ctl.epoch_length); + HDassert(0.0 <= cache_ptr->resize_ctl.min_clean_fraction); + HDassert(cache_ptr->resize_ctl.min_clean_fraction <= 100.0); + + /* check to see if cache_ptr->resize_in_progress is TRUE. If it, this + * is a re-entrant call via a client callback called in the resize + * process. To avoid an infinite recursion, set reentrant_call to + * TRUE, and goto done. + */ + if (cache_ptr->resize_in_progress) { + reentrant_call = TRUE; + HGOTO_DONE(SUCCEED) + } /* end if */ + + cache_ptr->resize_in_progress = TRUE; + + if (!cache_ptr->resize_enabled) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Auto cache resize disabled") + + HDassert((cache_ptr->resize_ctl.incr_mode != H5C_incr__off) || + (cache_ptr->resize_ctl.decr_mode != H5C_decr__off)); + + if (H5C_get_cache_hit_rate(cache_ptr, &hit_rate) != SUCCEED) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Can't get hit rate") + + HDassert((0.0 <= hit_rate) && (hit_rate <= 1.0)); + + switch (cache_ptr->resize_ctl.incr_mode) { + case H5C_incr__off: + if (cache_ptr->size_increase_possible) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "size_increase_possible but H5C_incr__off?!?!?") + break; + + case H5C_incr__threshold: + if (hit_rate < cache_ptr->resize_ctl.lower_hr_threshold) { + if (!cache_ptr->size_increase_possible) + status = increase_disabled; + else if (cache_ptr->max_cache_size >= cache_ptr->resize_ctl.max_size) { + HDassert(cache_ptr->max_cache_size == cache_ptr->resize_ctl.max_size); + status = at_max_size; + } + else if (!cache_ptr->cache_full) + status = not_full; + else { + new_max_cache_size = + (size_t)(((double)(cache_ptr->max_cache_size)) * cache_ptr->resize_ctl.increment); + + /* clip to max size if necessary */ + if (new_max_cache_size > cache_ptr->resize_ctl.max_size) + new_max_cache_size = cache_ptr->resize_ctl.max_size; + + /* clip to max increment if necessary */ + if (cache_ptr->resize_ctl.apply_max_increment && + ((cache_ptr->max_cache_size + cache_ptr->resize_ctl.max_increment) < + new_max_cache_size)) + new_max_cache_size = cache_ptr->max_cache_size + cache_ptr->resize_ctl.max_increment; + + status = increase; + } + } + break; + + default: + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unknown incr_mode") + } + + /* If the decr_mode is either age out or age out with threshold, we + * must run the marker maintenance code, whether we run the size + * reduction code or not. We do this in two places -- here we + * insert a new marker if the number of active epoch markers is + * is less than the current epochs before eviction, and after + * the ageout call, we cycle the markers. + * + * However, we can't call the ageout code or cycle the markers + * unless there was a full complement of markers in place on + * entry. The inserted_epoch_marker flag is used to track this. + */ + + if (((cache_ptr->resize_ctl.decr_mode == H5C_decr__age_out) || + (cache_ptr->resize_ctl.decr_mode == H5C_decr__age_out_with_threshold)) && + (cache_ptr->epoch_markers_active < cache_ptr->resize_ctl.epochs_before_eviction)) { + + if (H5C__autoadjust__ageout__insert_new_marker(cache_ptr) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't insert new epoch marker") + + inserted_epoch_marker = TRUE; + } + + /* don't run the cache size decrease code unless the cache size + * increase code is disabled, or the size increase code sees no need + * for action. In either case, status == in_spec at this point. + */ + + if (status == in_spec) { + switch (cache_ptr->resize_ctl.decr_mode) { + case H5C_decr__off: + break; + + case H5C_decr__threshold: + if (hit_rate > cache_ptr->resize_ctl.upper_hr_threshold) { + if (!cache_ptr->size_decrease_possible) + status = decrease_disabled; + else if (cache_ptr->max_cache_size <= cache_ptr->resize_ctl.min_size) { + HDassert(cache_ptr->max_cache_size == cache_ptr->resize_ctl.min_size); + status = at_min_size; + } + else { + new_max_cache_size = + (size_t)(((double)(cache_ptr->max_cache_size)) * cache_ptr->resize_ctl.decrement); + + /* clip to min size if necessary */ + if (new_max_cache_size < cache_ptr->resize_ctl.min_size) + new_max_cache_size = cache_ptr->resize_ctl.min_size; + + /* clip to max decrement if necessary */ + if (cache_ptr->resize_ctl.apply_max_decrement && + ((cache_ptr->resize_ctl.max_decrement + new_max_cache_size) < + cache_ptr->max_cache_size)) + new_max_cache_size = + cache_ptr->max_cache_size - cache_ptr->resize_ctl.max_decrement; + + status = decrease; + } + } + break; + + case H5C_decr__age_out_with_threshold: + case H5C_decr__age_out: + if (!inserted_epoch_marker) { + if (!cache_ptr->size_decrease_possible) + status = decrease_disabled; + else { + if (H5C__autoadjust__ageout(f, hit_rate, &status, &new_max_cache_size, + write_permitted) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "ageout code failed") + } /* end else */ + } /* end if */ + break; + + default: + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unknown incr_mode") + } + } + + /* cycle the epoch markers here if appropriate */ + if (((cache_ptr->resize_ctl.decr_mode == H5C_decr__age_out) || + (cache_ptr->resize_ctl.decr_mode == H5C_decr__age_out_with_threshold)) && + !inserted_epoch_marker) + /* move last epoch marker to the head of the LRU list */ + if (H5C__autoadjust__ageout__cycle_epoch_marker(cache_ptr) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "error cycling epoch marker") + + if ((status == increase) || (status == decrease)) { + old_max_cache_size = cache_ptr->max_cache_size; + old_min_clean_size = cache_ptr->min_clean_size; + + new_min_clean_size = + (size_t)((double)new_max_cache_size * (cache_ptr->resize_ctl.min_clean_fraction)); + + /* new_min_clean_size is of size_t, and thus must be non-negative. + * Hence we have + * + * ( 0 <= new_min_clean_size ). + * + * by definition. + */ + HDassert(new_min_clean_size <= new_max_cache_size); + HDassert(cache_ptr->resize_ctl.min_size <= new_max_cache_size); + HDassert(new_max_cache_size <= cache_ptr->resize_ctl.max_size); + + cache_ptr->max_cache_size = new_max_cache_size; + cache_ptr->min_clean_size = new_min_clean_size; + + if (status == increase) + cache_ptr->cache_full = FALSE; + else if (status == decrease) + cache_ptr->size_decreased = TRUE; + + /* update flash cache size increase fields as appropriate */ + if (cache_ptr->flash_size_increase_possible) { + switch (cache_ptr->resize_ctl.flash_incr_mode) { + case H5C_flash_incr__off: + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, + "flash_size_increase_possible but H5C_flash_incr__off?!") + break; + + case H5C_flash_incr__add_space: + cache_ptr->flash_size_increase_threshold = + (size_t)(((double)(cache_ptr->max_cache_size)) * + (cache_ptr->resize_ctl.flash_threshold)); + break; + + default: /* should be unreachable */ + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Unknown flash_incr_mode?!?!?") + break; + } + } + } + + if (cache_ptr->resize_ctl.rpt_fcn != NULL) + (cache_ptr->resize_ctl.rpt_fcn)(cache_ptr, H5C__CURR_AUTO_RESIZE_RPT_FCN_VER, hit_rate, status, + old_max_cache_size, new_max_cache_size, old_min_clean_size, + new_min_clean_size); + + if (H5C_reset_cache_hit_rate_stats(cache_ptr) < 0) + /* this should be impossible... */ + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5C_reset_cache_hit_rate_stats failed") + +done: + /* Sanity checks */ + HDassert(cache_ptr->resize_in_progress); + if (!reentrant_call) + cache_ptr->resize_in_progress = FALSE; + HDassert((!reentrant_call) || (cache_ptr->resize_in_progress)); + + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__auto_adjust_cache_size() */ + +/*------------------------------------------------------------------------- + * Function: H5C__autoadjust__ageout + * + * Purpose: Implement the ageout automatic cache size decrement + * algorithm. Note that while this code evicts aged out + * entries, the code does not change the maximum cache size. + * Instead, the function simply computes the new value (if + * any change is indicated) and reports this value in + * *new_max_cache_size_ptr. + * + * Return: Non-negative on success/Negative on failure or if there was + * an attempt to flush a protected item. + * + * + * Programmer: John Mainzer, 11/18/04 + * + *------------------------------------------------------------------------- + */ +static herr_t +H5C__autoadjust__ageout(H5F_t *f, double hit_rate, enum H5C_resize_status *status_ptr, + size_t *new_max_cache_size_ptr, hbool_t write_permitted) +{ + H5C_t *cache_ptr = f->shared->cache; + size_t test_size; + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + HDassert(f); + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert((status_ptr) && (*status_ptr == in_spec)); + HDassert((new_max_cache_size_ptr) && (*new_max_cache_size_ptr == 0)); + + /* remove excess epoch markers if any */ + if (cache_ptr->epoch_markers_active > cache_ptr->resize_ctl.epochs_before_eviction) + if (H5C__autoadjust__ageout__remove_excess_markers(cache_ptr) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "can't remove excess epoch markers") + + if ((cache_ptr->resize_ctl.decr_mode == H5C_decr__age_out) || + ((cache_ptr->resize_ctl.decr_mode == H5C_decr__age_out_with_threshold) && + (hit_rate >= cache_ptr->resize_ctl.upper_hr_threshold))) { + + if (cache_ptr->max_cache_size > cache_ptr->resize_ctl.min_size) { + /* evict aged out cache entries if appropriate... */ + if (H5C__autoadjust__ageout__evict_aged_out_entries(f, write_permitted) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "error flushing aged out entries") + + /* ... and then reduce cache size if appropriate */ + if (cache_ptr->index_size < cache_ptr->max_cache_size) { + if (cache_ptr->resize_ctl.apply_empty_reserve) { + test_size = + (size_t)(((double)cache_ptr->index_size) / (1 - cache_ptr->resize_ctl.empty_reserve)); + if (test_size < cache_ptr->max_cache_size) { + *status_ptr = decrease; + *new_max_cache_size_ptr = test_size; + } + } + else { + *status_ptr = decrease; + *new_max_cache_size_ptr = cache_ptr->index_size; + } + + if (*status_ptr == decrease) { + /* clip to min size if necessary */ + if (*new_max_cache_size_ptr < cache_ptr->resize_ctl.min_size) + *new_max_cache_size_ptr = cache_ptr->resize_ctl.min_size; + + /* clip to max decrement if necessary */ + if ((cache_ptr->resize_ctl.apply_max_decrement) && + ((cache_ptr->resize_ctl.max_decrement + *new_max_cache_size_ptr) < + cache_ptr->max_cache_size)) + *new_max_cache_size_ptr = + cache_ptr->max_cache_size - cache_ptr->resize_ctl.max_decrement; + } + } + } + else + *status_ptr = at_min_size; + } + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__autoadjust__ageout() */ + +/*------------------------------------------------------------------------- + * Function: H5C__autoadjust__ageout__cycle_epoch_marker + * + * Purpose: Remove the oldest epoch marker from the LRU list, + * and reinsert it at the head of the LRU list. Also + * remove the epoch marker's index from the head of the + * ring buffer, and re-insert it at the tail of the ring + * buffer. + * + * Return: SUCCEED on success/FAIL on failure. + * + * Programmer: John Mainzer, 11/22/04 + * + *------------------------------------------------------------------------- + */ +static herr_t +H5C__autoadjust__ageout__cycle_epoch_marker(H5C_t *cache_ptr) +{ + int i; + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + + if (cache_ptr->epoch_markers_active <= 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "No active epoch markers on entry?!?!?") + + /* remove the last marker from both the ring buffer and the LRU list */ + i = cache_ptr->epoch_marker_ringbuf[cache_ptr->epoch_marker_ringbuf_first]; + cache_ptr->epoch_marker_ringbuf_first = + (cache_ptr->epoch_marker_ringbuf_first + 1) % (H5C__MAX_EPOCH_MARKERS + 1); + if (cache_ptr->epoch_marker_ringbuf_size <= 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "ring buffer underflow") + + cache_ptr->epoch_marker_ringbuf_size -= 1; + if (cache_ptr->epoch_marker_active[i] != TRUE) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unused marker in LRU?!?") + + H5C__DLL_REMOVE((&((cache_ptr->epoch_markers)[i])), (cache_ptr)->LRU_head_ptr, (cache_ptr)->LRU_tail_ptr, + (cache_ptr)->LRU_list_len, (cache_ptr)->LRU_list_size, (FAIL)) + + /* now, re-insert it at the head of the LRU list, and at the tail of + * the ring buffer. + */ + HDassert(cache_ptr->epoch_markers[i].addr == (haddr_t)i); + HDassert(cache_ptr->epoch_markers[i].next == NULL); + HDassert(cache_ptr->epoch_markers[i].prev == NULL); + + cache_ptr->epoch_marker_ringbuf_last = + (cache_ptr->epoch_marker_ringbuf_last + 1) % (H5C__MAX_EPOCH_MARKERS + 1); + cache_ptr->epoch_marker_ringbuf[cache_ptr->epoch_marker_ringbuf_last] = i; + if (cache_ptr->epoch_marker_ringbuf_size >= H5C__MAX_EPOCH_MARKERS) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "ring buffer overflow") + + cache_ptr->epoch_marker_ringbuf_size += 1; + + H5C__DLL_PREPEND(&(cache_ptr->epoch_markers[i]), cache_ptr->LRU_head_ptr, cache_ptr->LRU_tail_ptr, + cache_ptr->LRU_list_len, cache_ptr->LRU_list_size, FAIL) +done: + + FUNC_LEAVE_NOAPI(ret_value) + +} /* H5C__autoadjust__ageout__cycle_epoch_marker() */ + +/*------------------------------------------------------------------------- + * Function: H5C__autoadjust__ageout__evict_aged_out_entries + * + * Purpose: Evict clean entries in the cache that haven't + * been accessed for at least + * cache_ptr->resize_ctl.epochs_before_eviction epochs, + * and flush dirty entries that haven't been accessed for + * that amount of time. + * + * Depending on configuration, the function will either + * flush or evict all such entries, or all such entries it + * encounters until it has freed the maximum amount of space + * allowed under the maximum decrement. + * + * If we are running in parallel mode, writes may not be + * permitted. If so, the function simply skips any dirty + * entries it may encounter. + * + * The function makes no attempt to maintain the minimum + * clean size, as there is no guarantee that the cache size + * will be changed. + * + * If there is no cache size change, the minimum clean size + * constraint will be met through a combination of clean + * entries and free space in the cache. + * + * If there is a cache size reduction, the minimum clean size + * will be re-calculated, and will be enforced the next time + * we have to make space in the cache. + * + * Return: Non-negative on success/Negative on failure. + * + * Programmer: John Mainzer, 11/22/04 + * + *------------------------------------------------------------------------- + */ +static herr_t +H5C__autoadjust__ageout__evict_aged_out_entries(H5F_t *f, hbool_t write_permitted) +{ + H5C_t *cache_ptr = f->shared->cache; + size_t eviction_size_limit; + size_t bytes_evicted = 0; + hbool_t prev_is_dirty = FALSE; + hbool_t restart_scan; + H5C_cache_entry_t *entry_ptr; + H5C_cache_entry_t *next_ptr; + H5C_cache_entry_t *prev_ptr; + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + HDassert(f); + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + + /* if there is a limit on the amount that the cache size can be decrease + * in any one round of the cache size reduction algorithm, load that + * limit into eviction_size_limit. Otherwise, set eviction_size_limit + * to the equivalent of infinity. The current size of the index will + * do nicely. + */ + if (cache_ptr->resize_ctl.apply_max_decrement) + eviction_size_limit = cache_ptr->resize_ctl.max_decrement; + else + eviction_size_limit = cache_ptr->index_size; /* i.e. infinity */ + + if (write_permitted) { + restart_scan = FALSE; + entry_ptr = cache_ptr->LRU_tail_ptr; + while (entry_ptr != NULL && entry_ptr->type->id != H5AC_EPOCH_MARKER_ID && + bytes_evicted < eviction_size_limit) { + hbool_t skipping_entry = FALSE; + + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(!(entry_ptr->is_protected)); + HDassert(!(entry_ptr->is_read_only)); + HDassert((entry_ptr->ro_ref_count) == 0); + + next_ptr = entry_ptr->next; + prev_ptr = entry_ptr->prev; + + if (prev_ptr != NULL) + prev_is_dirty = prev_ptr->is_dirty; + + if (entry_ptr->is_dirty) { + HDassert(!entry_ptr->prefetched_dirty); + + /* dirty corked entry is skipped */ + if (entry_ptr->tag_info && entry_ptr->tag_info->corked) + skipping_entry = TRUE; + else { + /* reset entries_removed_counter and + * last_entry_removed_ptr prior to the call to + * H5C__flush_single_entry() so that we can spot + * unexpected removals of entries from the cache, + * and set the restart_scan flag if proceeding + * would be likely to cause us to scan an entry + * that is no longer in the cache. + */ + cache_ptr->entries_removed_counter = 0; + cache_ptr->last_entry_removed_ptr = NULL; + + if (H5C__flush_single_entry(f, entry_ptr, H5C__NO_FLAGS_SET) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush entry") + + if (cache_ptr->entries_removed_counter > 1 || + cache_ptr->last_entry_removed_ptr == prev_ptr) + restart_scan = TRUE; + } /* end else */ + } /* end if */ + else if (!entry_ptr->prefetched_dirty) { + bytes_evicted += entry_ptr->size; + + if (H5C__flush_single_entry( + f, entry_ptr, H5C__FLUSH_INVALIDATE_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush entry") + } /* end else-if */ + else { + HDassert(!entry_ptr->is_dirty); + HDassert(entry_ptr->prefetched_dirty); + + skipping_entry = TRUE; + } /* end else */ + + if (prev_ptr != NULL) { + if (skipping_entry) + entry_ptr = prev_ptr; + else if (restart_scan || (prev_ptr->is_dirty != prev_is_dirty) || + (prev_ptr->next != next_ptr) || (prev_ptr->is_protected) || (prev_ptr->is_pinned)) { + /* Something has happened to the LRU -- start over + * from the tail. + */ + restart_scan = FALSE; + entry_ptr = cache_ptr->LRU_tail_ptr; + + H5C__UPDATE_STATS_FOR_LRU_SCAN_RESTART(cache_ptr) + } /* end else-if */ + else + entry_ptr = prev_ptr; + } /* end if */ + else + entry_ptr = NULL; + } /* end while */ + + /* for now at least, don't bother to maintain the minimum clean size, + * as the cache should now be less than its maximum size. Due to + * the vaguries of the cache size reduction algorithm, we may not + * reduce the size of the cache. + * + * If we do, we will calculate a new minimum clean size, which will + * be enforced the next time we try to make space in the cache. + * + * If we don't, no action is necessary, as we have just evicted and/or + * or flushed a bunch of entries and therefore the sum of the clean + * and free space in the cache must be greater than or equal to the + * min clean space requirement (assuming that requirement was met on + * entry). + */ + } /* end if */ + else /* ! write_permitted */ { + /* Since we are not allowed to write, all we can do is evict + * any clean entries that we may encounter before we either + * hit the eviction size limit, or encounter the epoch marker. + * + * If we are operating read only, this isn't an issue, as there + * will not be any dirty entries. + * + * If we are operating in R/W mode, all the dirty entries we + * skip will be flushed the next time we attempt to make space + * when writes are permitted. This may have some local + * performance implications, but it shouldn't cause any net + * slowdown. + */ + HDassert(H5C_MAINTAIN_CLEAN_AND_DIRTY_LRU_LISTS); + entry_ptr = cache_ptr->LRU_tail_ptr; + while (entry_ptr != NULL && ((entry_ptr->type)->id != H5AC_EPOCH_MARKER_ID) && + (bytes_evicted < eviction_size_limit)) { + HDassert(!(entry_ptr->is_protected)); + + prev_ptr = entry_ptr->prev; + + if (!(entry_ptr->is_dirty) && !(entry_ptr->prefetched_dirty)) + if (H5C__flush_single_entry( + f, entry_ptr, H5C__FLUSH_INVALIDATE_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush clean entry") + + /* just skip the entry if it is dirty, as we can't do + * anything with it now since we can't write. + * + * Since all entries are clean, serialize() will not be called, + * and thus we needn't test to see if the LRU has been changed + * out from under us. + */ + entry_ptr = prev_ptr; + } /* end while */ + } /* end else */ + + if (cache_ptr->index_size < cache_ptr->max_cache_size) + cache_ptr->cache_full = FALSE; + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__autoadjust__ageout__evict_aged_out_entries() */ + +/*------------------------------------------------------------------------- + * Function: H5C__autoadjust__ageout__insert_new_marker + * + * Purpose: Find an unused marker cache entry, mark it as used, and + * insert it at the head of the LRU list. Also add the + * marker's index in the epoch_markers array. + * + * Return: SUCCEED on success/FAIL on failure. + * + * Programmer: John Mainzer, 11/19/04 + * + *------------------------------------------------------------------------- + */ +static herr_t +H5C__autoadjust__ageout__insert_new_marker(H5C_t *cache_ptr) +{ + int i; + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + + if (cache_ptr->epoch_markers_active >= cache_ptr->resize_ctl.epochs_before_eviction) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Already have a full complement of markers") + + /* find an unused marker */ + i = 0; + while ((cache_ptr->epoch_marker_active)[i] && i < H5C__MAX_EPOCH_MARKERS) + i++; + if (i >= H5C__MAX_EPOCH_MARKERS) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Can't find unused marker") + + HDassert(((cache_ptr->epoch_markers)[i]).addr == (haddr_t)i); + HDassert(((cache_ptr->epoch_markers)[i]).next == NULL); + HDassert(((cache_ptr->epoch_markers)[i]).prev == NULL); + + (cache_ptr->epoch_marker_active)[i] = TRUE; + + cache_ptr->epoch_marker_ringbuf_last = + (cache_ptr->epoch_marker_ringbuf_last + 1) % (H5C__MAX_EPOCH_MARKERS + 1); + (cache_ptr->epoch_marker_ringbuf)[cache_ptr->epoch_marker_ringbuf_last] = i; + if (cache_ptr->epoch_marker_ringbuf_size >= H5C__MAX_EPOCH_MARKERS) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "ring buffer overflow") + + cache_ptr->epoch_marker_ringbuf_size += 1; + + H5C__DLL_PREPEND(&(cache_ptr->epoch_markers[i]), cache_ptr->LRU_head_ptr, cache_ptr->LRU_tail_ptr, + cache_ptr->LRU_list_len, cache_ptr->LRU_list_size, FAIL) + + cache_ptr->epoch_markers_active += 1; + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__autoadjust__ageout__insert_new_marker() */ + +/*------------------------------------------------------------------------- + * Function: H5C__autoadjust__ageout__remove_all_markers + * + * Purpose: Remove all epoch markers from the LRU list and mark them + * as inactive. + * + * Return: SUCCEED on success/FAIL on failure. + * + * Programmer: John Mainzer, 11/22/04 + * + *------------------------------------------------------------------------- + */ +herr_t +H5C__autoadjust__ageout__remove_all_markers(H5C_t *cache_ptr) +{ + int ring_buf_index; + int i; + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + + while (cache_ptr->epoch_markers_active > 0) { + /* get the index of the last epoch marker in the LRU list + * and remove it from the ring buffer. + */ + + ring_buf_index = cache_ptr->epoch_marker_ringbuf_first; + i = (cache_ptr->epoch_marker_ringbuf)[ring_buf_index]; + + cache_ptr->epoch_marker_ringbuf_first = + (cache_ptr->epoch_marker_ringbuf_first + 1) % (H5C__MAX_EPOCH_MARKERS + 1); + + if (cache_ptr->epoch_marker_ringbuf_size <= 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "ring buffer underflow") + cache_ptr->epoch_marker_ringbuf_size -= 1; + + if (cache_ptr->epoch_marker_active[i] != TRUE) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unused marker in LRU?!?") + + /* remove the epoch marker from the LRU list */ + H5C__DLL_REMOVE(&(cache_ptr->epoch_markers[i]), cache_ptr->LRU_head_ptr, cache_ptr->LRU_tail_ptr, + cache_ptr->LRU_list_len, cache_ptr->LRU_list_size, FAIL) + + /* mark the epoch marker as unused. */ + cache_ptr->epoch_marker_active[i] = FALSE; + + HDassert(cache_ptr->epoch_markers[i].addr == (haddr_t)i); + HDassert(cache_ptr->epoch_markers[i].next == NULL); + HDassert(cache_ptr->epoch_markers[i].prev == NULL); + + /* decrement the number of active epoch markers */ + cache_ptr->epoch_markers_active -= 1; + + HDassert(cache_ptr->epoch_markers_active == cache_ptr->epoch_marker_ringbuf_size); + } + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__autoadjust__ageout__remove_all_markers() */ + +/*------------------------------------------------------------------------- + * Function: H5C__autoadjust__ageout__remove_excess_markers + * + * Purpose: Remove epoch markers from the end of the LRU list and + * mark them as inactive until the number of active markers + * equals the current value of + * cache_ptr->resize_ctl.epochs_before_eviction. + * + * Return: SUCCEED on success/FAIL on failure. + * + * Programmer: John Mainzer, 11/19/04 + * + *------------------------------------------------------------------------- + */ +herr_t +H5C__autoadjust__ageout__remove_excess_markers(H5C_t *cache_ptr) +{ + int ring_buf_index; + int i; + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + + if (cache_ptr->epoch_markers_active <= cache_ptr->resize_ctl.epochs_before_eviction) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "no excess markers on entry") + + while (cache_ptr->epoch_markers_active > cache_ptr->resize_ctl.epochs_before_eviction) { + /* get the index of the last epoch marker in the LRU list + * and remove it from the ring buffer. + */ + ring_buf_index = cache_ptr->epoch_marker_ringbuf_first; + i = (cache_ptr->epoch_marker_ringbuf)[ring_buf_index]; + + cache_ptr->epoch_marker_ringbuf_first = + (cache_ptr->epoch_marker_ringbuf_first + 1) % (H5C__MAX_EPOCH_MARKERS + 1); + + if (cache_ptr->epoch_marker_ringbuf_size <= 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "ring buffer underflow") + cache_ptr->epoch_marker_ringbuf_size -= 1; + + if (cache_ptr->epoch_marker_active[i] != TRUE) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unused marker in LRU?!?") + + /* remove the epoch marker from the LRU list */ + H5C__DLL_REMOVE(&(cache_ptr->epoch_markers[i]), cache_ptr->LRU_head_ptr, cache_ptr->LRU_tail_ptr, + cache_ptr->LRU_list_len, cache_ptr->LRU_list_size, FAIL) + + /* mark the epoch marker as unused. */ + cache_ptr->epoch_marker_active[i] = FALSE; + + HDassert(cache_ptr->epoch_markers[i].addr == (haddr_t)i); + HDassert(cache_ptr->epoch_markers[i].next == NULL); + HDassert(cache_ptr->epoch_markers[i].prev == NULL); + + /* decrement the number of active epoch markers */ + cache_ptr->epoch_markers_active -= 1; + + HDassert(cache_ptr->epoch_markers_active == cache_ptr->epoch_marker_ringbuf_size); + } + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__autoadjust__ageout__remove_excess_markers() */ + +/*------------------------------------------------------------------------- + * Function: H5C__flash_increase_cache_size + * + * Purpose: If there is not at least new_entry_size - old_entry_size + * bytes of free space in the cache and the current + * max_cache_size is less than cache_ptr->resize_ctl.max_size, + * perform a flash increase in the cache size and then reset + * the full cache hit rate statistics, and exit. + * + * Return: Non-negative on success/Negative on failure. + * + * Programmer: John Mainzer, 12/31/07 + * + *------------------------------------------------------------------------- + */ +herr_t +H5C__flash_increase_cache_size(H5C_t *cache_ptr, size_t old_entry_size, size_t new_entry_size) +{ + size_t new_max_cache_size = 0; + size_t old_max_cache_size = 0; + size_t new_min_clean_size = 0; + size_t old_min_clean_size = 0; + size_t space_needed; + enum H5C_resize_status status = flash_increase; /* may change */ + double hit_rate; + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert(cache_ptr->flash_size_increase_possible); + HDassert(new_entry_size > cache_ptr->flash_size_increase_threshold); + HDassert(old_entry_size < new_entry_size); + + if (old_entry_size >= new_entry_size) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "old_entry_size >= new_entry_size") + + space_needed = new_entry_size - old_entry_size; + if (((cache_ptr->index_size + space_needed) > cache_ptr->max_cache_size) && + (cache_ptr->max_cache_size < cache_ptr->resize_ctl.max_size)) { + switch (cache_ptr->resize_ctl.flash_incr_mode) { + case H5C_flash_incr__off: + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, + "flash_size_increase_possible but H5C_flash_incr__off?!") + break; + + case H5C_flash_incr__add_space: + if (cache_ptr->index_size < cache_ptr->max_cache_size) { + HDassert((cache_ptr->max_cache_size - cache_ptr->index_size) < space_needed); + space_needed -= cache_ptr->max_cache_size - cache_ptr->index_size; + } + space_needed = (size_t)(((double)space_needed) * cache_ptr->resize_ctl.flash_multiple); + new_max_cache_size = cache_ptr->max_cache_size + space_needed; + break; + + default: /* should be unreachable */ + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Unknown flash_incr_mode?!?!?") + break; + } + + if (new_max_cache_size > cache_ptr->resize_ctl.max_size) + new_max_cache_size = cache_ptr->resize_ctl.max_size; + HDassert(new_max_cache_size > cache_ptr->max_cache_size); + + new_min_clean_size = (size_t)((double)new_max_cache_size * cache_ptr->resize_ctl.min_clean_fraction); + HDassert(new_min_clean_size <= new_max_cache_size); + + old_max_cache_size = cache_ptr->max_cache_size; + old_min_clean_size = cache_ptr->min_clean_size; + + cache_ptr->max_cache_size = new_max_cache_size; + cache_ptr->min_clean_size = new_min_clean_size; + + /* update flash cache size increase fields as appropriate */ + HDassert(cache_ptr->flash_size_increase_possible); + + switch (cache_ptr->resize_ctl.flash_incr_mode) { + case H5C_flash_incr__off: + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, + "flash_size_increase_possible but H5C_flash_incr__off?!") + break; + + case H5C_flash_incr__add_space: + cache_ptr->flash_size_increase_threshold = + (size_t)((double)cache_ptr->max_cache_size * cache_ptr->resize_ctl.flash_threshold); + break; + + default: /* should be unreachable */ + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Unknown flash_incr_mode?!?!?") + break; + } + + /* note that we don't cycle the epoch markers. We can + * argue either way as to whether we should, but for now + * we don't. + */ + + if (cache_ptr->resize_ctl.rpt_fcn != NULL) { + /* get the hit rate for the reporting function. Should still + * be good as we haven't reset the hit rate statistics. + */ + if (H5C_get_cache_hit_rate(cache_ptr, &hit_rate) != SUCCEED) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Can't get hit rate") + + (cache_ptr->resize_ctl.rpt_fcn)(cache_ptr, H5C__CURR_AUTO_RESIZE_RPT_FCN_VER, hit_rate, status, + old_max_cache_size, new_max_cache_size, old_min_clean_size, + new_min_clean_size); + } + + if (H5C_reset_cache_hit_rate_stats(cache_ptr) < 0) + /* this should be impossible... */ + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5C_reset_cache_hit_rate_stats failed") + } + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__flash_increase_cache_size() */ + +/*------------------------------------------------------------------------- + * Function: H5C__flush_invalidate_cache + * + * Purpose: Flush and destroy the entries contained in the target + * cache. + * + * If the cache contains protected entries, the function will + * fail, as protected entries cannot be either flushed or + * destroyed. However all unprotected entries should be + * flushed and destroyed before the function returns failure. + * + * While pinned entries can usually be flushed, they cannot + * be destroyed. However, they should be unpinned when all + * the entries that reference them have been destroyed (thus + * reduding the pinned entry's reference count to 0, allowing + * it to be unpinned). + * + * If pinned entries are present, the function makes repeated + * passes through the cache, flushing all dirty entries + * (including the pinned dirty entries where permitted) and + * destroying all unpinned entries. This process is repeated + * until either the cache is empty, or the number of pinned + * entries stops decreasing on each pass. + * + * Return: Non-negative on success/Negative on failure or if there was + * a request to flush all items and something was protected. + * + * Programmer: John Mainzer + * 3/24/05 + * + *------------------------------------------------------------------------- + */ +herr_t +H5C__flush_invalidate_cache(H5F_t *f, unsigned flags) +{ + H5C_t *cache_ptr; + H5C_ring_t ring; + herr_t ret_value = SUCCEED; + + FUNC_ENTER_PACKAGE + + HDassert(f); + HDassert(f->shared); + cache_ptr = f->shared->cache; + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert(cache_ptr->slist_ptr); + HDassert(cache_ptr->slist_enabled); + +#ifdef H5C_DO_SANITY_CHECKS + { + int32_t i; + uint32_t index_len = 0; + uint32_t slist_len = 0; + size_t index_size = (size_t)0; + size_t clean_index_size = (size_t)0; + size_t dirty_index_size = (size_t)0; + size_t slist_size = (size_t)0; + + HDassert(cache_ptr->index_ring_len[H5C_RING_UNDEFINED] == 0); + HDassert(cache_ptr->index_ring_size[H5C_RING_UNDEFINED] == (size_t)0); + HDassert(cache_ptr->clean_index_ring_size[H5C_RING_UNDEFINED] == (size_t)0); + HDassert(cache_ptr->dirty_index_ring_size[H5C_RING_UNDEFINED] == (size_t)0); + HDassert(cache_ptr->slist_ring_len[H5C_RING_UNDEFINED] == 0); + HDassert(cache_ptr->slist_ring_size[H5C_RING_UNDEFINED] == (size_t)0); + + for (i = H5C_RING_USER; i < H5C_RING_NTYPES; i++) { + index_len += cache_ptr->index_ring_len[i]; + index_size += cache_ptr->index_ring_size[i]; + clean_index_size += cache_ptr->clean_index_ring_size[i]; + dirty_index_size += cache_ptr->dirty_index_ring_size[i]; + + slist_len += cache_ptr->slist_ring_len[i]; + slist_size += cache_ptr->slist_ring_size[i]; + } /* end for */ + + HDassert(cache_ptr->index_len == index_len); + HDassert(cache_ptr->index_size == index_size); + HDassert(cache_ptr->clean_index_size == clean_index_size); + HDassert(cache_ptr->dirty_index_size == dirty_index_size); + HDassert(cache_ptr->slist_len == slist_len); + HDassert(cache_ptr->slist_size == slist_size); + } +#endif /* H5C_DO_SANITY_CHECKS */ + + /* remove ageout markers if present */ + if (cache_ptr->epoch_markers_active > 0) + if (H5C__autoadjust__ageout__remove_all_markers(cache_ptr) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "error removing all epoch markers") + + /* flush invalidate each ring, starting from the outermost ring and + * working inward. + */ + ring = H5C_RING_USER; + while (ring < H5C_RING_NTYPES) { + if (H5C__flush_invalidate_ring(f, ring, flags) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "flush invalidate ring failed") + ring++; + } /* end while */ + +#ifndef NDEBUG + /* Invariants, after destroying all entries in the hash table */ + if (!(flags & H5C__EVICT_ALLOW_LAST_PINS_FLAG)) { + HDassert(cache_ptr->index_size == 0); + HDassert(cache_ptr->clean_index_size == 0); + HDassert(cache_ptr->pel_len == 0); + HDassert(cache_ptr->pel_size == 0); + } /* end if */ + else { + H5C_cache_entry_t *entry_ptr; /* Cache entry */ + unsigned u; /* Local index variable */ + + /* All rings except ring 4 should be empty now */ + /* (Ring 4 has the superblock) */ + for (u = H5C_RING_USER; u < H5C_RING_SB; u++) { + HDassert(cache_ptr->index_ring_len[u] == 0); + HDassert(cache_ptr->index_ring_size[u] == 0); + HDassert(cache_ptr->clean_index_ring_size[u] == 0); + } /* end for */ + + /* Check that any remaining pinned entries are in the superblock ring */ + entry_ptr = cache_ptr->pel_head_ptr; + while (entry_ptr) { + /* Check ring */ + HDassert(entry_ptr->ring == H5C_RING_SB); + + /* Advance to next entry in pinned entry list */ + entry_ptr = entry_ptr->next; + } /* end while */ + } /* end else */ + + HDassert(cache_ptr->dirty_index_size == 0); + HDassert(cache_ptr->slist_len == 0); + HDassert(cache_ptr->slist_size == 0); + HDassert(cache_ptr->pl_len == 0); + HDassert(cache_ptr->pl_size == 0); + HDassert(cache_ptr->LRU_list_len == 0); + HDassert(cache_ptr->LRU_list_size == 0); +#endif + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__flush_invalidate_cache() */ + +/*------------------------------------------------------------------------- + * Function: H5C__flush_invalidate_ring + * + * Purpose: Flush and destroy the entries contained in the target + * cache and ring. + * + * If the ring contains protected entries, the function will + * fail, as protected entries cannot be either flushed or + * destroyed. However all unprotected entries should be + * flushed and destroyed before the function returns failure. + * + * While pinned entries can usually be flushed, they cannot + * be destroyed. However, they should be unpinned when all + * the entries that reference them have been destroyed (thus + * reduding the pinned entry's reference count to 0, allowing + * it to be unpinned). + * + * If pinned entries are present, the function makes repeated + * passes through the cache, flushing all dirty entries + * (including the pinned dirty entries where permitted) and + * destroying all unpinned entries. This process is repeated + * until either the cache is empty, or the number of pinned + * entries stops decreasing on each pass. + * + * If flush dependencies appear in the target ring, the + * function makes repeated passes through the cache flushing + * entries in flush dependency order. + * + * Return: Non-negative on success/Negative on failure or if there was + * a request to flush all items and something was protected. + * + * Programmer: John Mainzer + * 9/1/15 + * + *------------------------------------------------------------------------- + */ +static herr_t +H5C__flush_invalidate_ring(H5F_t *f, H5C_ring_t ring, unsigned flags) +{ + H5C_t *cache_ptr; + hbool_t restart_slist_scan; + uint32_t protected_entries = 0; + int32_t i; + uint32_t cur_ring_pel_len; + uint32_t old_ring_pel_len; + unsigned cooked_flags; + unsigned evict_flags; + H5SL_node_t *node_ptr = NULL; + H5C_cache_entry_t *entry_ptr = NULL; + H5C_cache_entry_t *next_entry_ptr = NULL; +#ifdef H5C_DO_SANITY_CHECKS + uint32_t initial_slist_len = 0; + size_t initial_slist_size = 0; +#endif /* H5C_DO_SANITY_CHECKS */ + herr_t ret_value = SUCCEED; + + FUNC_ENTER_PACKAGE + + HDassert(f); + HDassert(f->shared); + + cache_ptr = f->shared->cache; + + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert(cache_ptr->slist_enabled); + HDassert(cache_ptr->slist_ptr); + HDassert(ring > H5C_RING_UNDEFINED); + HDassert(ring < H5C_RING_NTYPES); + + HDassert(cache_ptr->epoch_markers_active == 0); + + /* Filter out the flags that are not relevant to the flush/invalidate. + */ + cooked_flags = flags & H5C__FLUSH_CLEAR_ONLY_FLAG; + evict_flags = flags & H5C__EVICT_ALLOW_LAST_PINS_FLAG; + + /* The flush procedure here is a bit strange. + * + * In the outer while loop we make at least one pass through the + * cache, and then repeat until either all the pinned entries in + * the ring unpin themselves, or until the number of pinned entries + * in the ring stops declining. In this later case, we scream and die. + * + * Since the fractal heap can dirty, resize, and/or move entries + * in is flush callback, it is possible that the cache will still + * contain dirty entries at this point. If so, we must make more + * passes through the skip list to allow it to empty. + * + * Further, since clean entries can be dirtied, resized, and/or moved + * as the result of a flush call back (either the entries own, or that + * for some other cache entry), we can no longer promise to flush + * the cache entries in increasing address order. + * + * Instead, we make a pass through + * the skip list, and then a pass through the "clean" entries, and + * then repeating as needed. Thus it is quite possible that an + * entry will be evicted from the cache only to be re-loaded later + * in the flush process. + * + * The bottom line is that entries will probably be flushed in close + * to increasing address order, but there are no guarantees. + */ + + /* compute the number of pinned entries in this ring */ + entry_ptr = cache_ptr->pel_head_ptr; + cur_ring_pel_len = 0; + while (entry_ptr != NULL) { + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(entry_ptr->ring >= ring); + if (entry_ptr->ring == ring) + cur_ring_pel_len++; + + entry_ptr = entry_ptr->next; + } /* end while */ + old_ring_pel_len = cur_ring_pel_len; + + while (cache_ptr->index_ring_len[ring] > 0) { + /* first, try to flush-destroy any dirty entries. Do this by + * making a scan through the slist. Note that new dirty entries + * may be created by the flush call backs. Thus it is possible + * that the slist will not be empty after we finish the scan. + */ + +#ifdef H5C_DO_SANITY_CHECKS + /* Depending on circumstances, H5C__flush_single_entry() will + * remove dirty entries from the slist as it flushes them. + * Thus for sanity checks we must make note of the initial + * slist length and size before we do any flushes. + */ + initial_slist_len = cache_ptr->slist_len; + initial_slist_size = cache_ptr->slist_size; + + /* There is also the possibility that entries will be + * dirtied, resized, moved, and/or removed from the cache + * as the result of calls to the flush callbacks. We use + * the slist_len_increase and slist_size_increase increase + * fields in struct H5C_t to track these changes for purpose + * of sanity checking. + * + * To this end, we must zero these fields before we start + * the pass through the slist. + */ + cache_ptr->slist_len_increase = 0; + cache_ptr->slist_size_increase = 0; +#endif /* H5C_DO_SANITY_CHECKS */ + + /* Set the cache_ptr->slist_changed to false. + * + * This flag is set to TRUE by H5C__flush_single_entry if the slist + * is modified by a pre_serialize, serialize, or notify callback. + * + * H5C__flush_invalidate_ring() uses this flag to detect any + * modifications to the slist that might corrupt the scan of + * the slist -- and restart the scan in this event. + */ + cache_ptr->slist_changed = FALSE; + + /* this done, start the scan of the slist */ + restart_slist_scan = TRUE; + while (restart_slist_scan || (node_ptr != NULL)) { + if (restart_slist_scan) { + restart_slist_scan = FALSE; + + /* Start at beginning of skip list */ + node_ptr = H5SL_first(cache_ptr->slist_ptr); + if (node_ptr == NULL) + /* the slist is empty -- break out of inner loop */ + break; + + /* Get cache entry for this node */ + next_entry_ptr = (H5C_cache_entry_t *)H5SL_item(node_ptr); + if (NULL == next_entry_ptr) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "next_entry_ptr == NULL ?!?!") + + HDassert(next_entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(next_entry_ptr->is_dirty); + HDassert(next_entry_ptr->in_slist); + HDassert(next_entry_ptr->ring >= ring); + } /* end if */ + + entry_ptr = next_entry_ptr; + + /* It is possible that entries will be dirtied, resized, + * flushed, or removed from the cache via the take ownership + * flag as the result of pre_serialize or serialized callbacks. + * + * This in turn can corrupt the scan through the slist. + * + * We test for slist modifications in the pre_serialize + * and serialize callbacks, and restart the scan of the + * slist if we find them. However, best we do some extra + * sanity checking just in case. + */ + HDassert(entry_ptr != NULL); + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(entry_ptr->in_slist); + HDassert(entry_ptr->is_dirty); + HDassert(entry_ptr->ring >= ring); + + /* increment node pointer now, before we delete its target + * from the slist. + */ + node_ptr = H5SL_next(node_ptr); + if (node_ptr != NULL) { + next_entry_ptr = (H5C_cache_entry_t *)H5SL_item(node_ptr); + if (NULL == next_entry_ptr) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "next_entry_ptr == NULL ?!?!") + + HDassert(next_entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(next_entry_ptr->is_dirty); + HDassert(next_entry_ptr->in_slist); + HDassert(next_entry_ptr->ring >= ring); + HDassert(entry_ptr != next_entry_ptr); + } /* end if */ + else + next_entry_ptr = NULL; + + /* Note that we now remove nodes from the slist as we flush + * the associated entries, instead of leaving them there + * until we are done, and then destroying all nodes in + * the slist. + * + * While this optimization used to be easy, with the possibility + * of new entries being added to the slist in the midst of the + * flush, we must keep the slist in canonical form at all + * times. + */ + if (((!entry_ptr->flush_me_last) || + ((entry_ptr->flush_me_last) && (cache_ptr->num_last_entries >= cache_ptr->slist_len))) && + (entry_ptr->flush_dep_nchildren == 0) && (entry_ptr->ring == ring)) { + if (entry_ptr->is_protected) { + /* We have major problems -- but lets flush + * everything we can before we flag an error. + */ + protected_entries++; + } /* end if */ + else if (entry_ptr->is_pinned) { + if (H5C__flush_single_entry(f, entry_ptr, H5C__DURING_FLUSH_FLAG) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "dirty pinned entry flush failed") + + if (cache_ptr->slist_changed) { + /* The slist has been modified by something + * other than the simple removal of the + * of the flushed entry after the flush. + * + * This has the potential to corrupt the + * scan through the slist, so restart it. + */ + restart_slist_scan = TRUE; + cache_ptr->slist_changed = FALSE; + H5C__UPDATE_STATS_FOR_SLIST_SCAN_RESTART(cache_ptr); + } /* end if */ + } /* end else-if */ + else { + if (H5C__flush_single_entry(f, entry_ptr, + (cooked_flags | H5C__DURING_FLUSH_FLAG | + H5C__FLUSH_INVALIDATE_FLAG | + H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG)) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "dirty entry flush destroy failed") + + if (cache_ptr->slist_changed) { + /* The slist has been modified by something + * other than the simple removal of the + * of the flushed entry after the flush. + * + * This has the potential to corrupt the + * scan through the slist, so restart it. + */ + restart_slist_scan = TRUE; + cache_ptr->slist_changed = FALSE; + H5C__UPDATE_STATS_FOR_SLIST_SCAN_RESTART(cache_ptr) + } /* end if */ + } /* end else */ + } /* end if */ + } /* end while loop scanning skip list */ + +#ifdef H5C_DO_SANITY_CHECKS + /* It is possible that entries were added to the slist during + * the scan, either before or after scan pointer. The following + * asserts take this into account. + * + * Don't bother with the sanity checks if node_ptr != NULL, as + * in this case we broke out of the loop because it got changed + * out from under us. + */ + + if (node_ptr == NULL) { + HDassert(cache_ptr->slist_len == + (uint32_t)((int32_t)initial_slist_len + cache_ptr->slist_len_increase)); + HDassert(cache_ptr->slist_size == + (size_t)((ssize_t)initial_slist_size + cache_ptr->slist_size_increase)); + } /* end if */ +#endif /* H5C_DO_SANITY_CHECKS */ + + /* Since we are doing a destroy, we must make a pass through + * the hash table and try to flush - destroy all entries that + * remain. + * + * It used to be that all entries remaining in the cache at + * this point had to be clean, but with the fractal heap mods + * this may not be the case. If so, we will flush entries out + * in increasing address order. + * + * Writes to disk are possible here. + */ + + /* Reset the counters so that we can detect insertions, loads, + * and moves caused by the pre_serialize and serialize calls. + */ + cache_ptr->entries_loaded_counter = 0; + cache_ptr->entries_inserted_counter = 0; + cache_ptr->entries_relocated_counter = 0; + + next_entry_ptr = cache_ptr->il_head; + while (next_entry_ptr != NULL) { + entry_ptr = next_entry_ptr; + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(entry_ptr->ring >= ring); + + next_entry_ptr = entry_ptr->il_next; + HDassert((next_entry_ptr == NULL) || (next_entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC)); + + if (((!entry_ptr->flush_me_last) || + (entry_ptr->flush_me_last && (cache_ptr->num_last_entries >= cache_ptr->slist_len))) && + (entry_ptr->flush_dep_nchildren == 0) && (entry_ptr->ring == ring)) { + + if (entry_ptr->is_protected) { + /* we have major problems -- but lets flush and + * destroy everything we can before we flag an + * error. + */ + protected_entries++; + + if (!entry_ptr->in_slist) + HDassert(!(entry_ptr->is_dirty)); + } /* end if */ + else if (!entry_ptr->is_pinned) { + /* if *entry_ptr is dirty, it is possible + * that one or more other entries may be + * either removed from the cache, loaded + * into the cache, or moved to a new location + * in the file as a side effect of the flush. + * + * It's also possible that removing a clean + * entry will remove the last child of a proxy + * entry, allowing it to be removed also and + * invalidating the next_entry_ptr. + * + * If either of these happen, and one of the target + * or proxy entries happens to be the next entry in + * the hash bucket, we could either find ourselves + * either scanning a non-existent entry, scanning + * through a different bucket, or skipping an entry. + * + * Neither of these are good, so restart the + * the scan at the head of the hash bucket + * after the flush if we detect that the next_entry_ptr + * becomes invalid. + * + * This is not as inefficient at it might seem, + * as hash buckets typically have at most two + * or three entries. + */ + cache_ptr->entry_watched_for_removal = next_entry_ptr; + if (H5C__flush_single_entry(f, entry_ptr, + (cooked_flags | H5C__DURING_FLUSH_FLAG | + H5C__FLUSH_INVALIDATE_FLAG | + H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG)) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Entry flush destroy failed") + + /* Restart the index list scan if necessary. Must + * do this if the next entry is evicted, and also if + * one or more entries are inserted, loaded, or moved + * as these operations can result in part of the scan + * being skipped -- which can cause a spurious failure + * if this results in the size of the pinned entry + * failing to decline during the pass. + */ + if (((NULL != next_entry_ptr) && (NULL == cache_ptr->entry_watched_for_removal)) || + (cache_ptr->entries_loaded_counter > 0) || + (cache_ptr->entries_inserted_counter > 0) || + (cache_ptr->entries_relocated_counter > 0)) { + + next_entry_ptr = cache_ptr->il_head; + + cache_ptr->entries_loaded_counter = 0; + cache_ptr->entries_inserted_counter = 0; + cache_ptr->entries_relocated_counter = 0; + + H5C__UPDATE_STATS_FOR_INDEX_SCAN_RESTART(cache_ptr) + } /* end if */ + else + cache_ptr->entry_watched_for_removal = NULL; + } /* end if */ + } /* end if */ + } /* end for loop scanning hash table */ + + /* We can't do anything if entries are pinned. The + * hope is that the entries will be unpinned as the + * result of destroys of entries that reference them. + * + * We detect this by noting the change in the number + * of pinned entries from pass to pass. If it stops + * shrinking before it hits zero, we scream and die. + */ + old_ring_pel_len = cur_ring_pel_len; + entry_ptr = cache_ptr->pel_head_ptr; + cur_ring_pel_len = 0; + + while (entry_ptr != NULL) { + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(entry_ptr->ring >= ring); + + if (entry_ptr->ring == ring) + cur_ring_pel_len++; + + entry_ptr = entry_ptr->next; + } /* end while */ + + /* Check if the number of pinned entries in the ring is positive, and + * it is not declining. Scream and die if so. + */ + if ((cur_ring_pel_len > 0) && (cur_ring_pel_len >= old_ring_pel_len)) { + /* Don't error if allowed to have pinned entries remaining */ + if (evict_flags) + HGOTO_DONE(TRUE) + + HGOTO_ERROR( + H5E_CACHE, H5E_CANTFLUSH, FAIL, + "Pinned entry count not decreasing, cur_ring_pel_len = %d, old_ring_pel_len = %d, ring = %d", + (int)cur_ring_pel_len, (int)old_ring_pel_len, (int)ring) + } /* end if */ + + HDassert(protected_entries == cache_ptr->pl_len); + + if ((protected_entries > 0) && (protected_entries == cache_ptr->index_len)) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, + "Only protected entries left in cache, protected_entries = %d", + (int)protected_entries) + } /* main while loop */ + + /* Invariants, after destroying all entries in the ring */ + for (i = (int)H5C_RING_UNDEFINED; i <= (int)ring; i++) { + HDassert(cache_ptr->index_ring_len[i] == 0); + HDassert(cache_ptr->index_ring_size[i] == (size_t)0); + HDassert(cache_ptr->clean_index_ring_size[i] == (size_t)0); + HDassert(cache_ptr->dirty_index_ring_size[i] == (size_t)0); + + HDassert(cache_ptr->slist_ring_len[i] == 0); + HDassert(cache_ptr->slist_ring_size[i] == (size_t)0); + } /* end for */ + + HDassert(protected_entries <= cache_ptr->pl_len); + + if (protected_entries > 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Cache has protected entries") + else if (cur_ring_pel_len > 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't unpin all pinned entries in ring") + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__flush_invalidate_ring() */ + +/*------------------------------------------------------------------------- + * Function: H5C__flush_ring + * + * Purpose: Flush the entries contained in the specified cache and + * ring. All entries in rings outside the specified ring + * must have been flushed on entry. + * + * If the cache contains protected entries in the specified + * ring, the function will fail, as protected entries cannot + * be flushed. However all unprotected entries in the target + * ring should be flushed before the function returns failure. + * + * If flush dependencies appear in the target ring, the + * function makes repeated passes through the slist flushing + * entries in flush dependency order. + * + * Return: Non-negative on success/Negative on failure or if there was + * a request to flush all items and something was protected. + * + * Programmer: John Mainzer + * 9/1/15 + * + *------------------------------------------------------------------------- + */ +herr_t +H5C__flush_ring(H5F_t *f, H5C_ring_t ring, unsigned flags) +{ + H5C_t *cache_ptr = f->shared->cache; + hbool_t flushed_entries_last_pass; + hbool_t flush_marked_entries; + hbool_t ignore_protected; + hbool_t tried_to_flush_protected_entry = FALSE; + hbool_t restart_slist_scan; + uint32_t protected_entries = 0; + H5SL_node_t *node_ptr = NULL; + H5C_cache_entry_t *entry_ptr = NULL; + H5C_cache_entry_t *next_entry_ptr = NULL; +#ifdef H5C_DO_SANITY_CHECKS + uint32_t initial_slist_len = 0; + size_t initial_slist_size = 0; +#endif /* H5C_DO_SANITY_CHECKS */ + int i; + herr_t ret_value = SUCCEED; + + FUNC_ENTER_PACKAGE + + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert(cache_ptr->slist_enabled); + HDassert(cache_ptr->slist_ptr); + HDassert((flags & H5C__FLUSH_INVALIDATE_FLAG) == 0); + HDassert(ring > H5C_RING_UNDEFINED); + HDassert(ring < H5C_RING_NTYPES); + +#ifdef H5C_DO_EXTREME_SANITY_CHECKS + if (H5C__validate_protected_entry_list(cache_ptr) < 0 || H5C__validate_pinned_entry_list(cache_ptr) < 0 || + H5C__validate_lru_list(cache_ptr) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "an extreme sanity check failed on entry") +#endif /* H5C_DO_EXTREME_SANITY_CHECKS */ + + ignore_protected = ((flags & H5C__FLUSH_IGNORE_PROTECTED_FLAG) != 0); + flush_marked_entries = ((flags & H5C__FLUSH_MARKED_ENTRIES_FLAG) != 0); + + if (!flush_marked_entries) + for (i = (int)H5C_RING_UNDEFINED; i < (int)ring; i++) + HDassert(cache_ptr->slist_ring_len[i] == 0); + + HDassert(cache_ptr->flush_in_progress); + + /* When we are only flushing marked entries, the slist will usually + * still contain entries when we have flushed everything we should. + * Thus we track whether we have flushed any entries in the last + * pass, and terminate if we haven't. + */ + flushed_entries_last_pass = TRUE; + + /* Set the cache_ptr->slist_changed to false. + * + * This flag is set to TRUE by H5C__flush_single_entry if the + * slist is modified by a pre_serialize, serialize, or notify callback. + * H5C_flush_cache uses this flag to detect any modifications + * to the slist that might corrupt the scan of the slist -- and + * restart the scan in this event. + */ + cache_ptr->slist_changed = FALSE; + + while ((cache_ptr->slist_ring_len[ring] > 0) && (protected_entries == 0) && (flushed_entries_last_pass)) { + flushed_entries_last_pass = FALSE; + +#ifdef H5C_DO_SANITY_CHECKS + /* For sanity checking, try to verify that the skip list has + * the expected size and number of entries at the end of each + * internal while loop (see below). + * + * Doing this get a bit tricky, as depending on flags, we may + * or may not flush all the entries in the slist. + * + * To make things more entertaining, with the advent of the + * fractal heap, the entry serialize callback can cause entries + * to be dirtied, resized, and/or moved. Also, the + * pre_serialize callback can result in an entry being + * removed from the cache via the take ownership flag. + * + * To deal with this, we first make note of the initial + * skip list length and size: + */ + initial_slist_len = cache_ptr->slist_len; + initial_slist_size = cache_ptr->slist_size; + + /* As mentioned above, there is the possibility that + * entries will be dirtied, resized, flushed, or removed + * from the cache via the take ownership flag during + * our pass through the skip list. To capture the number + * of entries added, and the skip list size delta, + * zero the slist_len_increase and slist_size_increase of + * the cache's instance of H5C_t. These fields will be + * updated elsewhere to account for slist insertions and/or + * dirty entry size changes. + */ + cache_ptr->slist_len_increase = 0; + cache_ptr->slist_size_increase = 0; + + /* at the end of the loop, use these values to compute the + * expected slist length and size and compare this with the + * value recorded in the cache's instance of H5C_t. + */ +#endif /* H5C_DO_SANITY_CHECKS */ + + restart_slist_scan = TRUE; + while ((restart_slist_scan) || (node_ptr != NULL)) { + if (restart_slist_scan) { + restart_slist_scan = FALSE; + + /* Start at beginning of skip list */ + node_ptr = H5SL_first(cache_ptr->slist_ptr); + if (node_ptr == NULL) + /* the slist is empty -- break out of inner loop */ + break; + + /* Get cache entry for this node */ + next_entry_ptr = (H5C_cache_entry_t *)H5SL_item(node_ptr); + if (NULL == next_entry_ptr) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "next_entry_ptr == NULL ?!?!") + + HDassert(next_entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(next_entry_ptr->is_dirty); + HDassert(next_entry_ptr->in_slist); + } /* end if */ + + entry_ptr = next_entry_ptr; + + /* With the advent of the fractal heap, the free space + * manager, and the version 3 cache, it is possible + * that the pre-serialize or serialize callback will + * dirty, resize, or take ownership of other entries + * in the cache. + * + * To deal with this, there is code to detect any + * change in the skip list not directly under the control + * of this function. If such modifications are detected, + * we must re-start the scan of the skip list to avoid + * the possibility that the target of the next_entry_ptr + * may have been flushed or deleted from the cache. + * + * To verify that all such possibilities have been dealt + * with, we do a bit of extra sanity checking on + * entry_ptr. + */ + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(entry_ptr->in_slist); + HDassert(entry_ptr->is_dirty); + + if (!flush_marked_entries || entry_ptr->flush_marker) + HDassert(entry_ptr->ring >= ring); + + /* Advance node pointer now, before we delete its target + * from the slist. + */ + node_ptr = H5SL_next(node_ptr); + if (node_ptr != NULL) { + next_entry_ptr = (H5C_cache_entry_t *)H5SL_item(node_ptr); + if (NULL == next_entry_ptr) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "next_entry_ptr == NULL ?!?!") + + HDassert(next_entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(next_entry_ptr->is_dirty); + HDassert(next_entry_ptr->in_slist); + + if (!flush_marked_entries || next_entry_ptr->flush_marker) + HDassert(next_entry_ptr->ring >= ring); + + HDassert(entry_ptr != next_entry_ptr); + } /* end if */ + else + next_entry_ptr = NULL; + + if ((!flush_marked_entries || entry_ptr->flush_marker) && + ((!entry_ptr->flush_me_last) || + ((entry_ptr->flush_me_last) && ((cache_ptr->num_last_entries >= cache_ptr->slist_len) || + (flush_marked_entries && entry_ptr->flush_marker)))) && + ((entry_ptr->flush_dep_nchildren == 0) || (entry_ptr->flush_dep_ndirty_children == 0)) && + (entry_ptr->ring == ring)) { + + HDassert(entry_ptr->flush_dep_nunser_children == 0); + + if (entry_ptr->is_protected) { + /* we probably have major problems -- but lets + * flush everything we can before we decide + * whether to flag an error. + */ + tried_to_flush_protected_entry = TRUE; + protected_entries++; + } /* end if */ + else { + if (H5C__flush_single_entry(f, entry_ptr, (flags | H5C__DURING_FLUSH_FLAG)) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't flush entry") + + if (cache_ptr->slist_changed) { + /* The slist has been modified by something + * other than the simple removal of the + * of the flushed entry after the flush. + * + * This has the potential to corrupt the + * scan through the slist, so restart it. + */ + restart_slist_scan = TRUE; + cache_ptr->slist_changed = FALSE; + H5C__UPDATE_STATS_FOR_SLIST_SCAN_RESTART(cache_ptr) + } /* end if */ + + flushed_entries_last_pass = TRUE; + } /* end else */ + } /* end if */ + } /* while ( ( restart_slist_scan ) || ( node_ptr != NULL ) ) */ + +#ifdef H5C_DO_SANITY_CHECKS + /* Verify that the slist size and length are as expected. */ + HDassert((uint32_t)((int32_t)initial_slist_len + cache_ptr->slist_len_increase) == + cache_ptr->slist_len); + HDassert((size_t)((ssize_t)initial_slist_size + cache_ptr->slist_size_increase) == + cache_ptr->slist_size); +#endif /* H5C_DO_SANITY_CHECKS */ + } /* while */ + + HDassert(protected_entries <= cache_ptr->pl_len); + + if (((cache_ptr->pl_len > 0) && !ignore_protected) || tried_to_flush_protected_entry) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "cache has protected items") + +#ifdef H5C_DO_SANITY_CHECKS + if (!flush_marked_entries) { + HDassert(cache_ptr->slist_ring_len[ring] == 0); + HDassert(cache_ptr->slist_ring_size[ring] == 0); + } /* end if */ +#endif /* H5C_DO_SANITY_CHECKS */ + +done: + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__flush_ring() */ + +/*------------------------------------------------------------------------- + * Function: H5C__make_space_in_cache + * + * Purpose: Attempt to evict cache entries until the index_size + * is at least needed_space below max_cache_size. + * + * In passing, also attempt to bring cLRU_list_size to a + * value greater than min_clean_size. + * + * Depending on circumstances, both of these goals may + * be impossible, as in parallel mode, we must avoid generating + * a write as part of a read (to avoid deadlock in collective + * I/O), and in all cases, it is possible (though hopefully + * highly unlikely) that the protected list may exceed the + * maximum size of the cache. + * + * Thus the function simply does its best, returning success + * unless an error is encountered. + * + * Observe that this function cannot occasion a read. + * + * Return: Non-negative on success/Negative on failure. + * + * Programmer: John Mainzer, 5/14/04 + * + *------------------------------------------------------------------------- + */ +herr_t +H5C__make_space_in_cache(H5F_t *f, size_t space_needed, hbool_t write_permitted) +{ + H5C_t *cache_ptr = f->shared->cache; +#if H5C_COLLECT_CACHE_STATS + int32_t clean_entries_skipped = 0; + int32_t dirty_pf_entries_skipped = 0; + int32_t total_entries_scanned = 0; +#endif /* H5C_COLLECT_CACHE_STATS */ + uint32_t entries_examined = 0; + uint32_t initial_list_len; + size_t empty_space; + hbool_t reentrant_call = FALSE; + hbool_t prev_is_dirty = FALSE; + hbool_t didnt_flush_entry = FALSE; + hbool_t restart_scan; + H5C_cache_entry_t *entry_ptr; + H5C_cache_entry_t *prev_ptr; + H5C_cache_entry_t *next_ptr; +#ifndef NDEBUG + uint32_t num_corked_entries = 0; +#endif + herr_t ret_value = SUCCEED; /* Return value */ + + FUNC_ENTER_PACKAGE + + /* Sanity checks */ + HDassert(f); + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert(cache_ptr->index_size == (cache_ptr->clean_index_size + cache_ptr->dirty_index_size)); + + /* check to see if cache_ptr->msic_in_progress is TRUE. If it, this + * is a re-entrant call via a client callback called in the make + * space in cache process. To avoid an infinite recursion, set + * reentrant_call to TRUE, and goto done. + */ + if (cache_ptr->msic_in_progress) { + reentrant_call = TRUE; + HGOTO_DONE(SUCCEED); + } /* end if */ + + cache_ptr->msic_in_progress = TRUE; + + if (write_permitted) { + restart_scan = FALSE; + initial_list_len = cache_ptr->LRU_list_len; + entry_ptr = cache_ptr->LRU_tail_ptr; + + if (cache_ptr->index_size >= cache_ptr->max_cache_size) + empty_space = 0; + else + empty_space = cache_ptr->max_cache_size - cache_ptr->index_size; + + while ((((cache_ptr->index_size + space_needed) > cache_ptr->max_cache_size) || + ((empty_space + cache_ptr->clean_index_size) < (cache_ptr->min_clean_size))) && + (entries_examined <= (2 * initial_list_len)) && (entry_ptr != NULL)) { + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(!(entry_ptr->is_protected)); + HDassert(!(entry_ptr->is_read_only)); + HDassert((entry_ptr->ro_ref_count) == 0); + + next_ptr = entry_ptr->next; + prev_ptr = entry_ptr->prev; + + if (prev_ptr != NULL) + prev_is_dirty = prev_ptr->is_dirty; + + if (entry_ptr->is_dirty && (entry_ptr->tag_info && entry_ptr->tag_info->corked)) { + /* Skip "dirty" corked entries. */ +#ifndef NDEBUG + ++num_corked_entries; +#endif + didnt_flush_entry = TRUE; + } + else if ((entry_ptr->type->id != H5AC_EPOCH_MARKER_ID) && !entry_ptr->flush_in_progress && + !entry_ptr->prefetched_dirty) { + didnt_flush_entry = FALSE; + if (entry_ptr->is_dirty) { +#if H5C_COLLECT_CACHE_STATS + if ((cache_ptr->index_size + space_needed) > cache_ptr->max_cache_size) + cache_ptr->entries_scanned_to_make_space++; +#endif /* H5C_COLLECT_CACHE_STATS */ + + /* reset entries_removed_counter and + * last_entry_removed_ptr prior to the call to + * H5C__flush_single_entry() so that we can spot + * unexpected removals of entries from the cache, + * and set the restart_scan flag if proceeding + * would be likely to cause us to scan an entry + * that is no longer in the cache. + */ + cache_ptr->entries_removed_counter = 0; + cache_ptr->last_entry_removed_ptr = NULL; + + if (H5C__flush_single_entry(f, entry_ptr, H5C__NO_FLAGS_SET) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush entry") + + if ((cache_ptr->entries_removed_counter > 1) || + (cache_ptr->last_entry_removed_ptr == prev_ptr)) + + restart_scan = TRUE; + } + else if ((cache_ptr->index_size + space_needed) > cache_ptr->max_cache_size +#ifdef H5_HAVE_PARALLEL + && !(entry_ptr->coll_access) +#endif /* H5_HAVE_PARALLEL */ + ) { +#if H5C_COLLECT_CACHE_STATS + cache_ptr->entries_scanned_to_make_space++; +#endif /* H5C_COLLECT_CACHE_STATS */ + + if (H5C__flush_single_entry(f, entry_ptr, + H5C__FLUSH_INVALIDATE_FLAG | + H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush entry") + } + else { + /* We have enough space so don't flush clean entry. */ +#if H5C_COLLECT_CACHE_STATS + clean_entries_skipped++; +#endif /* H5C_COLLECT_CACHE_STATS */ + didnt_flush_entry = TRUE; + } + +#if H5C_COLLECT_CACHE_STATS + total_entries_scanned++; +#endif /* H5C_COLLECT_CACHE_STATS */ + } + else { + + /* Skip epoch markers, entries that are in the process + * of being flushed, and entries marked as prefetched_dirty + * (occurs in the R/O case only). + */ + didnt_flush_entry = TRUE; + +#if H5C_COLLECT_CACHE_STATS + if (entry_ptr->prefetched_dirty) + dirty_pf_entries_skipped++; +#endif /* H5C_COLLECT_CACHE_STATS */ + } + + if (prev_ptr != NULL) { + if (didnt_flush_entry) + /* epoch markers don't get flushed, and we don't touch + * entries that are in the process of being flushed. + * Hence no need for sanity checks, as we haven't + * flushed anything. Thus just set entry_ptr to prev_ptr + * and go on. + */ + entry_ptr = prev_ptr; + else if (restart_scan || prev_ptr->is_dirty != prev_is_dirty || prev_ptr->next != next_ptr || + prev_ptr->is_protected || prev_ptr->is_pinned) { + /* something has happened to the LRU -- start over + * from the tail. + */ + restart_scan = FALSE; + entry_ptr = cache_ptr->LRU_tail_ptr; + H5C__UPDATE_STATS_FOR_LRU_SCAN_RESTART(cache_ptr) + } + else + entry_ptr = prev_ptr; + } + else + entry_ptr = NULL; + + entries_examined++; + + if (cache_ptr->index_size >= cache_ptr->max_cache_size) + empty_space = 0; + else + empty_space = cache_ptr->max_cache_size - cache_ptr->index_size; + + HDassert(cache_ptr->index_size == (cache_ptr->clean_index_size + cache_ptr->dirty_index_size)); + } + +#if H5C_COLLECT_CACHE_STATS + cache_ptr->calls_to_msic++; + + cache_ptr->total_entries_skipped_in_msic += clean_entries_skipped; + cache_ptr->total_dirty_pf_entries_skipped_in_msic += dirty_pf_entries_skipped; + cache_ptr->total_entries_scanned_in_msic += total_entries_scanned; + + if (clean_entries_skipped > cache_ptr->max_entries_skipped_in_msic) + cache_ptr->max_entries_skipped_in_msic = clean_entries_skipped; + + if (dirty_pf_entries_skipped > cache_ptr->max_dirty_pf_entries_skipped_in_msic) + cache_ptr->max_dirty_pf_entries_skipped_in_msic = dirty_pf_entries_skipped; + + if (total_entries_scanned > cache_ptr->max_entries_scanned_in_msic) + cache_ptr->max_entries_scanned_in_msic = total_entries_scanned; +#endif /* H5C_COLLECT_CACHE_STATS */ + + /* NEED: work on a better assert for corked entries */ + HDassert((entries_examined > (2 * initial_list_len)) || + ((cache_ptr->pl_size + cache_ptr->pel_size + cache_ptr->min_clean_size) > + cache_ptr->max_cache_size) || + ((cache_ptr->clean_index_size + empty_space) >= cache_ptr->min_clean_size) || + ((num_corked_entries))); +#if H5C_MAINTAIN_CLEAN_AND_DIRTY_LRU_LISTS + + HDassert((entries_examined > (2 * initial_list_len)) || + (cache_ptr->cLRU_list_size <= cache_ptr->clean_index_size)); + HDassert((entries_examined > (2 * initial_list_len)) || + (cache_ptr->dLRU_list_size <= cache_ptr->dirty_index_size)); + +#endif /* H5C_MAINTAIN_CLEAN_AND_DIRTY_LRU_LISTS */ + } + else { + HDassert(H5C_MAINTAIN_CLEAN_AND_DIRTY_LRU_LISTS); + +#if H5C_MAINTAIN_CLEAN_AND_DIRTY_LRU_LISTS + initial_list_len = cache_ptr->cLRU_list_len; + entry_ptr = cache_ptr->cLRU_tail_ptr; + + while (((cache_ptr->index_size + space_needed) > cache_ptr->max_cache_size) && + (entries_examined <= initial_list_len) && (entry_ptr != NULL)) { + HDassert(!(entry_ptr->is_protected)); + HDassert(!(entry_ptr->is_read_only)); + HDassert((entry_ptr->ro_ref_count) == 0); + HDassert(!(entry_ptr->is_dirty)); + + prev_ptr = entry_ptr->aux_prev; + + if (!entry_ptr->prefetched_dirty +#ifdef H5_HAVE_PARALLEL + && !entry_ptr->coll_access +#endif /* H5_HAVE_PARALLEL */ + ) { + if (H5C__flush_single_entry( + f, entry_ptr, H5C__FLUSH_INVALIDATE_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush entry") + } /* end if */ + + /* we are scanning the clean LRU, so the serialize function + * will not be called on any entry -- thus there is no + * concern about the list being modified out from under + * this function. + */ + + entry_ptr = prev_ptr; + entries_examined++; + } +#endif /* H5C_MAINTAIN_CLEAN_AND_DIRTY_LRU_LISTS */ + } + +done: + /* Sanity checks */ + HDassert(cache_ptr->msic_in_progress); + if (!reentrant_call) + cache_ptr->msic_in_progress = FALSE; + HDassert((!reentrant_call) || (cache_ptr->msic_in_progress)); + + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__make_space_in_cache() */ + +/*------------------------------------------------------------------------- + * Function: H5C__serialize_cache + * + * Purpose: Serialize (i.e. construct an on disk image) for all entries + * in the metadata cache including clean entries. + * + * Note that flush dependencies and "flush me last" flags + * must be observed in the serialization process. + * + * Note also that entries may be loaded, flushed, evicted, + * expunged, relocated, resized, or removed from the cache + * during this process, just as these actions may occur during + * a regular flush. + * + * However, we are given that the cache will contain no protected + * entries on entry to this routine (although entries may be + * briefly protected and then unprotected during the serialize + * process). + * + * The objective of this routine is serialize all entries and + * to force all entries into their actual locations on disk. + * + * The initial need for this routine is to settle all entries + * in the cache prior to construction of the metadata cache + * image so that the size of the cache image can be calculated. + * + * Return: Non-negative on success/Negative on failure or if there was + * a request to flush all items and something was protected. + * + * Programmer: John Mainzer + * 7/22/15 + * + *------------------------------------------------------------------------- + */ +herr_t +H5C__serialize_cache(H5F_t *f) +{ +#ifdef H5C_DO_SANITY_CHECKS + int i; + uint32_t index_len = 0; + size_t index_size = (size_t)0; + size_t clean_index_size = (size_t)0; + size_t dirty_index_size = (size_t)0; + size_t slist_size = (size_t)0; + uint32_t slist_len = 0; +#endif /* H5C_DO_SANITY_CHECKS */ + H5C_ring_t ring; + H5C_t *cache_ptr; + herr_t ret_value = SUCCEED; + + FUNC_ENTER_PACKAGE + + /* Sanity checks */ + HDassert(f); + HDassert(f->shared); + cache_ptr = f->shared->cache; + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert(cache_ptr->slist_ptr); + +#ifdef H5C_DO_SANITY_CHECKS + HDassert(cache_ptr->index_ring_len[H5C_RING_UNDEFINED] == 0); + HDassert(cache_ptr->index_ring_size[H5C_RING_UNDEFINED] == (size_t)0); + HDassert(cache_ptr->clean_index_ring_size[H5C_RING_UNDEFINED] == (size_t)0); + HDassert(cache_ptr->dirty_index_ring_size[H5C_RING_UNDEFINED] == (size_t)0); + HDassert(cache_ptr->slist_ring_len[H5C_RING_UNDEFINED] == 0); + HDassert(cache_ptr->slist_ring_size[H5C_RING_UNDEFINED] == (size_t)0); + + for (i = H5C_RING_USER; i < H5C_RING_NTYPES; i++) { + index_len += cache_ptr->index_ring_len[i]; + index_size += cache_ptr->index_ring_size[i]; + clean_index_size += cache_ptr->clean_index_ring_size[i]; + dirty_index_size += cache_ptr->dirty_index_ring_size[i]; + + slist_len += cache_ptr->slist_ring_len[i]; + slist_size += cache_ptr->slist_ring_size[i]; + } /* end for */ + + HDassert(cache_ptr->index_len == index_len); + HDassert(cache_ptr->index_size == index_size); + HDassert(cache_ptr->clean_index_size == clean_index_size); + HDassert(cache_ptr->dirty_index_size == dirty_index_size); + HDassert(cache_ptr->slist_len == slist_len); + HDassert(cache_ptr->slist_size == slist_size); +#endif /* H5C_DO_SANITY_CHECKS */ + +#ifdef H5C_DO_EXTREME_SANITY_CHECKS + if (H5C__validate_protected_entry_list(cache_ptr) < 0 || H5C__validate_pinned_entry_list(cache_ptr) < 0 || + H5C__validate_lru_list(cache_ptr) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "an extreme sanity check failed on entry") +#endif /* H5C_DO_EXTREME_SANITY_CHECKS */ + +#ifndef NDEBUG + /* if this is a debug build, set the serialization_count field of + * each entry in the cache to zero before we start the serialization. + * This allows us to detect the case in which any entry is serialized + * more than once (a performance issues), and more importantly, the + * case is which any flush dependency parent is serializes more than + * once (a correctness issue). + */ + { + H5C_cache_entry_t *scan_ptr = NULL; + + scan_ptr = cache_ptr->il_head; + while (scan_ptr != NULL) { + HDassert(scan_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + scan_ptr->serialization_count = 0; + scan_ptr = scan_ptr->il_next; + } /* end while */ + } /* end block */ +#endif + + /* set cache_ptr->serialization_in_progress to TRUE, and back + * to FALSE at the end of the function. Must maintain this flag + * to support H5C_get_serialization_in_progress(), which is in + * turn required to support sanity checking in some cache + * clients. + */ + HDassert(!cache_ptr->serialization_in_progress); + cache_ptr->serialization_in_progress = TRUE; + + /* Serialize each ring, starting from the outermost ring and + * working inward. + */ + ring = H5C_RING_USER; + while (ring < H5C_RING_NTYPES) { + HDassert(cache_ptr->close_warning_received); + switch (ring) { + case H5C_RING_USER: + break; + + case H5C_RING_RDFSM: + /* Settle raw data FSM */ + if (!cache_ptr->rdfsm_settled) + if (H5MF_settle_raw_data_fsm(f, &cache_ptr->rdfsm_settled) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "RD FSM settle failed") + break; + + case H5C_RING_MDFSM: + /* Settle metadata FSM */ + if (!cache_ptr->mdfsm_settled) + if (H5MF_settle_meta_data_fsm(f, &cache_ptr->mdfsm_settled) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "MD FSM settle failed") + break; + + case H5C_RING_SBE: + case H5C_RING_SB: + break; + + default: + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Unknown ring?!?!") + break; + } /* end switch */ + + if (H5C__serialize_ring(f, ring) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTSERIALIZE, FAIL, "serialize ring failed") + + ring++; + } /* end while */ + +#ifndef NDEBUG + /* Verify that no entry has been serialized more than once. + * FD parents with multiple serializations should have been caught + * elsewhere, so no specific check for them here. + */ + { + H5C_cache_entry_t *scan_ptr = NULL; + + scan_ptr = cache_ptr->il_head; + while (scan_ptr != NULL) { + HDassert(scan_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(scan_ptr->serialization_count <= 1); + + scan_ptr = scan_ptr->il_next; + } /* end while */ + } /* end block */ +#endif + +done: + cache_ptr->serialization_in_progress = FALSE; + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__serialize_cache() */ + +/*------------------------------------------------------------------------- + * Function: H5C__serialize_ring + * + * Purpose: Serialize the entries contained in the specified cache and + * ring. All entries in rings outside the specified ring + * must have been serialized on entry. + * + * If the cache contains protected entries in the specified + * ring, the function will fail, as protected entries cannot + * be serialized. However all unprotected entries in the + * target ring should be serialized before the function + * returns failure. + * + * If flush dependencies appear in the target ring, the + * function makes repeated passes through the index list + * serializing entries in flush dependency order. + * + * All entries outside the H5C_RING_SBE are marked for + * inclusion in the cache image. Entries in H5C_RING_SBE + * and below are marked for exclusion from the image. + * + * Return: Non-negative on success/Negative on failure or if there was + * a request to flush all items and something was protected. + * + * Programmer: John Mainzer + * 9/11/15 + * + *------------------------------------------------------------------------- + */ +static herr_t +H5C__serialize_ring(H5F_t *f, H5C_ring_t ring) +{ + hbool_t done = FALSE; + H5C_t *cache_ptr; + H5C_cache_entry_t *entry_ptr; + herr_t ret_value = SUCCEED; + + FUNC_ENTER_PACKAGE + + /* Sanity checks */ + HDassert(f); + HDassert(f->shared); + cache_ptr = f->shared->cache; + HDassert(cache_ptr); + HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC); + HDassert(ring > H5C_RING_UNDEFINED); + HDassert(ring < H5C_RING_NTYPES); + + HDassert(cache_ptr->serialization_in_progress); + + /* The objective here is to serialize all entries in the cache ring + * in flush dependency order. + * + * The basic algorithm is to scan the cache index list looking for + * unserialized entries that are either not in a flush dependency + * relationship, or which have no unserialized children. Any such + * entry is serialized and its flush dependency parents (if any) are + * informed -- allowing them to decrement their userialized child counts. + * + * However, this algorithm is complicated by the ability + * of client serialization callbacks to perform operations on + * on the cache which can result in the insertion, deletion, + * relocation, resize, dirty, flush, eviction, or removal (via the + * take ownership flag) of entries. Changes in the flush dependency + * structure are also possible. + * + * On the other hand, the algorithm is simplified by the fact that + * we are serializing, not flushing. Thus, as long as all entries + * are serialized correctly, it doesn't matter if we have to go back + * and serialize an entry a second time. + * + * These possible actions result in the following modifications to + * the basic algorithm: + * + * 1) In the event of an entry expunge, eviction or removal, we must + * restart the scan as it is possible that the next entry in our + * scan is no longer in the cache. Were we to examine this entry, + * we would be accessing deallocated memory. + * + * 2) A resize, dirty, or insertion of an entry may result in the + * the increment of a flush dependency parent's dirty and/or + * unserialized child count. In the context of serializing the + * the cache, this is a non-issue, as even if we have already + * serialized the parent, it will be marked dirty and its image + * marked out of date if appropriate when the child is serialized. + * + * However, this is a major issue for a flush, as were this to happen + * in a flush, it would violate the invariant that the flush dependency + * feature is intended to enforce. As the metadata cache has no + * control over the behavior of cache clients, it has no way of + * preventing this behaviour. However, it should detect it if at all + * possible. + * + * Do this by maintaining a count of the number of times each entry is + * serialized during a cache serialization. If any flush dependency + * parent is serialized more than once, throw an assertion failure. + * + * 3) An entry relocation will typically change the location of the + * entry in the index list. This shouldn't cause problems as we + * will scan the index list until we make a complete pass without + * finding anything to serialize -- making relocations of either + * the current or next entries irrelevant. + * + * Note that since a relocation may result in our skipping part of + * the index list, we must always do at least one more pass through + * the index list after an entry relocation. + * + * 4) Changes in the flush dependency structure are possible on + * entry insertion, load, expunge, evict, or remove. Destruction + * of a flush dependency has no effect, as it can only relax the + * flush dependencies. Creation of a flush dependency can create + * an unserialized child of a flush dependency parent where all + * flush dependency children were previously serialized. Should + * this child dirty the flush dependency parent when it is serialized, + * the parent will be re-serialized. + * + * Per the discussion of 2) above, this is a non issue for cache + * serialization, and a major problem for cache flush. Using the + * same detection mechanism, throw an assertion failure if this + * condition appears. + * + * Observe that either eviction or removal of entries as a result of + * a serialization is not a problem as long as the flush dependency + * tree does not change beyond the removal of a leaf. + */ + while (!done) { + /* Reset the counters so that we can detect insertions, loads, + * moves, and flush dependency height changes caused by the pre_serialize + * and serialize callbacks. + */ + cache_ptr->entries_loaded_counter = 0; + cache_ptr->entries_inserted_counter = 0; + cache_ptr->entries_relocated_counter = 0; + + done = TRUE; /* set to FALSE if any activity in inner loop */ + entry_ptr = cache_ptr->il_head; + while (entry_ptr != NULL) { + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + + /* Verify that either the entry is already serialized, or + * that it is assigned to either the target or an inner + * ring. + */ + HDassert((entry_ptr->ring >= ring) || (entry_ptr->image_up_to_date)); + + /* Skip flush me last entries or inner ring entries */ + if (!entry_ptr->flush_me_last && entry_ptr->ring == ring) { + + /* if we encounter an unserialized entry in the current + * ring that is not marked flush me last, we are not done. + */ + if (!entry_ptr->image_up_to_date) + done = FALSE; + + /* Serialize the entry if its image is not up to date + * and it has no unserialized flush dependency children. + */ + if (!entry_ptr->image_up_to_date && entry_ptr->flush_dep_nunser_children == 0) { + HDassert(entry_ptr->serialization_count == 0); + + /* Serialize the entry */ + if (H5C__serialize_single_entry(f, cache_ptr, entry_ptr) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTSERIALIZE, FAIL, "entry serialization failed") + + HDassert(entry_ptr->flush_dep_nunser_children == 0); + HDassert(entry_ptr->serialization_count == 0); + +#ifndef NDEBUG + /* Increment serialization counter (to detect multiple serializations) */ + entry_ptr->serialization_count++; +#endif + } /* end if */ + } /* end if */ + + /* Check for the cache being perturbed during the entry serialize */ + if ((cache_ptr->entries_loaded_counter > 0) || (cache_ptr->entries_inserted_counter > 0) || + (cache_ptr->entries_relocated_counter > 0)) { + +#if H5C_COLLECT_CACHE_STATS + H5C__UPDATE_STATS_FOR_INDEX_SCAN_RESTART(cache_ptr); +#endif /* H5C_COLLECT_CACHE_STATS */ + + /* Reset the counters */ + cache_ptr->entries_loaded_counter = 0; + cache_ptr->entries_inserted_counter = 0; + cache_ptr->entries_relocated_counter = 0; + + /* Restart scan */ + entry_ptr = cache_ptr->il_head; + } /* end if */ + else + /* Advance to next entry */ + entry_ptr = entry_ptr->il_next; + } /* while ( entry_ptr != NULL ) */ + } /* while ( ! done ) */ + + /* Reset the counters so that we can detect insertions, loads, + * moves, and flush dependency height changes caused by the pre_serialize + * and serialize callbacks. + */ + cache_ptr->entries_loaded_counter = 0; + cache_ptr->entries_inserted_counter = 0; + cache_ptr->entries_relocated_counter = 0; + + /* At this point, all entries not marked "flush me last" and in + * the current ring or outside it should be serialized and have up + * to date images. Scan the index list again to serialize the + * "flush me last" entries (if they are in the current ring) and to + * verify that all other entries have up to date images. + */ + entry_ptr = cache_ptr->il_head; + while (entry_ptr != NULL) { + HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC); + HDassert(entry_ptr->ring > H5C_RING_UNDEFINED); + HDassert(entry_ptr->ring < H5C_RING_NTYPES); + HDassert((entry_ptr->ring >= ring) || (entry_ptr->image_up_to_date)); + + if (entry_ptr->ring == ring) { + if (entry_ptr->flush_me_last) { + if (!entry_ptr->image_up_to_date) { + HDassert(entry_ptr->serialization_count == 0); + HDassert(entry_ptr->flush_dep_nunser_children == 0); + + /* Serialize the entry */ + if (H5C__serialize_single_entry(f, cache_ptr, entry_ptr) < 0) + HGOTO_ERROR(H5E_CACHE, H5E_CANTSERIALIZE, FAIL, "entry serialization failed") + + /* Check for the cache changing */ + if ((cache_ptr->entries_loaded_counter > 0) || + (cache_ptr->entries_inserted_counter > 0) || + (cache_ptr->entries_relocated_counter > 0)) + HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, + "flush_me_last entry serialization triggered restart") + + HDassert(entry_ptr->flush_dep_nunser_children == 0); + HDassert(entry_ptr->serialization_count == 0); +#ifndef NDEBUG + /* Increment serialization counter (to detect multiple serializations) */ + entry_ptr->serialization_count++; +#endif + } /* end if */ + } /* end if */ + else { + HDassert(entry_ptr->image_up_to_date); + HDassert(entry_ptr->serialization_count <= 1); + HDassert(entry_ptr->flush_dep_nunser_children == 0); + } /* end else */ + } /* if ( entry_ptr->ring == ring ) */ + + entry_ptr = entry_ptr->il_next; + } /* while ( entry_ptr != NULL ) */ + +done: + HDassert(cache_ptr->serialization_in_progress); + FUNC_LEAVE_NOAPI(ret_value) +} /* H5C__serialize_ring() */ |