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pma: cleanup

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This commit is contained in:
barter-simsum 2024-08-08 20:05:28 -04:00
parent d246052444
commit 52ed7a8c35
1 changed files with 8 additions and 27 deletions
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35
rust/ares_pma/c-src/btree.c
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@ -614,7 +614,7 @@ _bt_nalloc(BT_state *state)
static int
_node_cow(BT_state *state, BT_page *node, pgno_t *pgno)
{ /* ;;: !!! HERE HERE HERE */
{
BT_page *ret = _bt_nalloc(state); /* ;;: todo: assert node has no dirty entries */
memcpy(ret->datk, node->datk, sizeof node->datk[0] * BT_DAT_MAXKEYS);
*pgno = _fo_get(state, ret);
@ -693,7 +693,7 @@ _bt_find2(BT_state *state,
}
static void
_bt_root_new(BT_meta *meta, BT_page *root) /* ;;: todo: remove meta param */
_bt_root_new(BT_page *root)
{
/* The first usable address in the PMA is just beyond the btree segment */
root->datk[0].va = B2PAGES(BLK_BASE_LEN_TOTAL);
@ -789,7 +789,7 @@ _bt_dirtydata(BT_page *leaf, size_t child_idx)
static int
_bt_cleanchild(BT_page *parent, size_t child_idx)
{ /* ;;: Is this correct? --yes */
{
assert(_bt_ischilddirty(parent, child_idx));
uint8_t *flag = &parent->head.dirty[child_idx >> 3];
*flag ^= 1 << (child_idx & 0x7);
@ -821,7 +821,7 @@ _bt_split_datcopy(BT_page *left, BT_page *right)
static int
_bt_dirtyshift(BT_page *node, size_t idx, size_t n)
/* shift dirty bitset at idx over by n bits */
{ /* ;;: is this correct? */
{
assert(idx + n < 2048);
uint8_t copy[256] = {0};
/* copy bitset left of idx */
@ -911,7 +911,6 @@ _bt_insertdat(vaof_t lo, vaof_t hi, pgno_t fo,
return BT_SUCC;
}
/* ;;: todo: any calls to datshift need to also shift the dirty bitset */
if (llo == lo) {
_bt_datshift(parent, childidx + 1, 1);
_bt_dirtyshift(parent, childidx + 1, 1);
@ -1570,22 +1569,6 @@ _bt_insert2(BT_state *state, vaof_t lo, vaof_t hi, pgno_t fo,
node->datk[childidx].fo = pgno;
_bt_dirtychild(node, childidx);
}
else {
#if 0 /* ;;: ... so where are we failing to mprotect
writable a dirty node? Doesn't really make
sense */
/* ;;: tmp **************************************************************/
BT_page *child = _node_get(state, node->datk[childidx].fo);
if (mprotect(child, sizeof(BT_page), BT_PROT_DIRTY) != 0) {
DPRINTF("mprotect of node: %p failed with %s", child, strerror(errno));
abort();
}
/* - *********************************************************************/
#endif
}
/* ;;: the issue seems to be fundamentally that we've marked a node as dirty
(and therefore not requiring an mprotect(DIRTY)) when it isn't in fact
dirty. The node while marked dirty, remains read-only - hence, SIGSEGV */
/* do we need to split the child node? */
if (N >= BT_DAT_MAXKEYS - 2) {
@ -2419,7 +2402,7 @@ _bt_state_meta_inject_root(BT_state *state)
assert(state->nlist);
BT_meta *meta = state->meta_pages[state->which];
BT_page *root = _bt_nalloc(state);
_bt_root_new(meta, root);
_bt_root_new(root);
meta->root = _fo_get(state, root);
assert(meta->root == INITIAL_ROOTPG);
return BT_SUCC;
@ -2667,7 +2650,7 @@ _bt_sync_hasdirtypage(BT_state *state, BT_page *node) __attribute((unused));
static int
_bt_sync_hasdirtypage(BT_state *state, BT_page *node)
/* ;;: could be more efficiently replaced by a gcc vectorized builtin */
{ /* ;;: check callers to this routine use it correctly */
{
for (size_t i = 0; i < NMEMB(node->head.dirty); i++) {
if (node->head.dirty[i] != 0)
return 1;
@ -2806,7 +2789,7 @@ _bt_sync(BT_state *state, BT_page *node, uint8_t depth, uint8_t maxdepth)
/* do dfs */
for (size_t i = 0; i < N-1; i++) {
if (!_bt_ischilddirty(node, i)) /* ;;: consider removing case until dirty logic is foolproof */
if (!_bt_ischilddirty(node, i))
continue; /* not dirty. nothing to do */
BT_page *child = _node_get(state, node->datk[i].fo);
@ -2818,9 +2801,7 @@ _bt_sync(BT_state *state, BT_page *node, uint8_t depth, uint8_t maxdepth)
e:
/* zero out the dirty bitmap */
/* ZERO(&node->head.dirty[0], sizeof node->head.dirty); */
for (size_t i = 0; i < 256; i++)
node->head.dirty[i] = 0;
ZERO(&node->head.dirty[0], sizeof node->head.dirty);
/* all modifications done in node, mark it read-only */
if (mprotect(node, sizeof(BT_page), BT_PROT_CLEAN) != 0) {