Commit a3ae2e7d authored by Hallvard Furuseth's avatar Hallvard Furuseth
Browse files

Catch most uses of finished/parent txns.

* Add MDB_TXN_FINISHED, MDB_TXN_HAS_CHILD, MDB_TXN_BLOCKED.
* Clear mt_numdbs in writers, for TXN_DBI_EXIST() to catch.
  We already do in readers.
parent 9266843f
......@@ -431,7 +431,7 @@ typedef enum MDB_cursor_op {
#define MDB_INCOMPATIBLE (-30784)
/** Invalid reuse of reader locktable slot */
#define MDB_BAD_RSLOT (-30783)
/** Transaction cannot recover - it must be aborted */
/** Transaction must abort, has a child, or is invalid */
#define MDB_BAD_TXN (-30782)
/** Unsupported size of key/DB name/data, or wrong DUPFIXED size */
#define MDB_BAD_VALSIZE (-30781)
......
......@@ -995,7 +995,8 @@ typedef struct MDB_dbx {
*/
struct MDB_txn {
MDB_txn *mt_parent; /**< parent of a nested txn */
MDB_txn *mt_child; /**< nested txn under this txn */
/** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */
MDB_txn *mt_child;
pgno_t mt_next_pgno; /**< next unallocated page */
/** The ID of this transaction. IDs are integers incrementing from 1.
* Only committed write transactions increment the ID. If a transaction
......@@ -1043,8 +1044,9 @@ struct MDB_txn {
MDB_cursor **mt_cursors;
/** Array of flags for each DB */
unsigned char *mt_dbflags;
/** Number of DB records in use. This number only ever increments;
* we don't decrement it when individual DB handles are closed.
/** Number of DB records in use, or 0 when the txn is finished.
* This number only ever increments until the txn finishes; we
* don't decrement it when individual DB handles are closed.
*/
MDB_dbi mt_numdbs;
......@@ -1057,9 +1059,13 @@ struct MDB_txn {
#define MDB_TXN_RDONLY MDB_RDONLY /**< read-only transaction */
/* internal txn flags */
#define MDB_TXN_WRITEMAP MDB_WRITEMAP /**< copy of #MDB_env flag in writers */
#define MDB_TXN_FINISHED 0x01 /**< txn is finished or never began */
#define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */
#define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
#define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
#define MDB_TXN_HAS_CHILD 0x10 /**< txn has an #MDB_txn.%mt_child */
/** most operations on the txn are currently illegal */
#define MDB_TXN_BLOCKED (MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)
/** @} */
unsigned int mt_flags; /**< @ref mdb_txn */
/** #dirty_list room: Array size - \#dirty pages visible to this txn.
......@@ -1356,7 +1362,7 @@ static char *const mdb_errstr[] = {
"MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
"MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
"MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
"MDB_BAD_TXN: Transaction cannot recover - it must be aborted",
"MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",
"MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
"MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
};
......@@ -2725,9 +2731,7 @@ mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
if (parent) {
/* Nested transactions: Max 1 child, write txns only, no writemap */
flags |= parent->mt_flags;
if (parent->mt_child ||
(flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_ERROR)))
{
if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {
return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
}
/* Child txns save MDB_pgstate and use own copy of cursors */
......@@ -2769,6 +2773,7 @@ mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
txn->mt_u.dirty_list[0].mid = 0;
txn->mt_spill_pgs = NULL;
txn->mt_next_pgno = parent->mt_next_pgno;
parent->mt_flags |= MDB_TXN_HAS_CHILD;
parent->mt_child = txn;
txn->mt_parent = parent;
txn->mt_numdbs = parent->mt_numdbs;
......@@ -2885,9 +2890,10 @@ mdb_txn_end(MDB_txn *txn, unsigned mode)
txn->mt_u.reader = NULL;
} /* else txn owns the slot until it does MDB_END_SLOT */
}
txn->mt_numdbs = 0; /* close nothing if called again */
txn->mt_numdbs = 0; /* prevent further DBI activity */
txn->mt_flags |= MDB_TXN_FINISHED;
txn->mt_dbxs = NULL; /* mark txn as reset */
} else {
} else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {
pgno_t *pghead = env->me_pghead;
if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
......@@ -2896,6 +2902,9 @@ mdb_txn_end(MDB_txn *txn, unsigned mode)
mdb_dlist_free(txn);
}
txn->mt_numdbs = 0;
txn->mt_flags = MDB_TXN_FINISHED;
if (!txn->mt_parent) {
mdb_midl_shrink(&txn->mt_free_pgs);
env->me_free_pgs = txn->mt_free_pgs;
......@@ -2911,6 +2920,7 @@ mdb_txn_end(MDB_txn *txn, unsigned mode)
UNLOCK_MUTEX(env->me_wmutex);
} else {
txn->mt_parent->mt_child = NULL;
txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;
env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
mdb_midl_free(txn->mt_free_pgs);
mdb_midl_free(txn->mt_spill_pgs);
......@@ -3318,8 +3328,8 @@ mdb_txn_commit(MDB_txn *txn)
goto done;
}
if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
DPUTS("error flag is set, can't commit");
if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {
DPUTS("txn has failed/finished, can't commit");
if (txn->mt_parent)
txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
rc = MDB_BAD_TXN;
......@@ -4742,6 +4752,7 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
txn->mt_env = env;
txn->mt_dbxs = env->me_dbxs;
txn->mt_flags = MDB_TXN_FINISHED;
env->me_txn0 = txn;
} else {
rc = ENOMEM;
......@@ -5284,8 +5295,8 @@ mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
/* Make sure the txn is still viable, then find the root from
* the txn's db table and set it as the root of the cursor's stack.
*/
if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
DPUTS("transaction has failed, must abort");
if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {
DPUTS("transaction may not be used now");
return MDB_BAD_TXN;
} else {
/* Make sure we're using an up-to-date root */
......@@ -5472,7 +5483,7 @@ mdb_get(MDB_txn *txn, MDB_dbi dbi,
if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
if (txn->mt_flags & MDB_TXN_BLOCKED)
return MDB_BAD_TXN;
mdb_cursor_init(&mc, txn, dbi, &mx);
......@@ -5993,7 +6004,7 @@ mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
if (mc == NULL)
return EINVAL;
if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
return MDB_BAD_TXN;
switch (op) {
......@@ -6223,7 +6234,7 @@ mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
nospill = flags & MDB_NOSPILL;
flags &= ~MDB_NOSPILL;
if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
if (key->mv_size-1 >= ENV_MAXKEY(env))
......@@ -6716,7 +6727,7 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
MDB_page *mp;
int rc;
if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
if (!(mc->mc_flags & C_INITIALIZED))
......@@ -7285,7 +7296,7 @@ mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
if (txn->mt_flags & MDB_TXN_BLOCKED)
return MDB_BAD_TXN;
/* Allow read access to the freelist */
......@@ -7320,7 +7331,7 @@ mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
if (txn->mt_flags & MDB_TXN_BLOCKED)
return MDB_BAD_TXN;
mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
......@@ -7339,7 +7350,7 @@ mdb_cursor_count(MDB_cursor *mc, size_t *countp)
if (mc->mc_xcursor == NULL)
return MDB_INCOMPATIBLE;
if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
return MDB_BAD_TXN;
if (!(mc->mc_flags & C_INITIALIZED))
......@@ -8089,7 +8100,7 @@ mdb_del(MDB_txn *txn, MDB_dbi dbi,
if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
return EINVAL;
if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
......@@ -9276,7 +9287,7 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *db
if (flags & ~VALID_FLAGS)
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
if (txn->mt_flags & MDB_TXN_BLOCKED)
return MDB_BAD_TXN;
/* main DB? */
......@@ -9374,7 +9385,7 @@ mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
return EINVAL;
if (txn->mt_flags & MDB_TXN_ERROR)
if (txn->mt_flags & MDB_TXN_BLOCKED)
return MDB_BAD_TXN;
if (txn->mt_dbflags[dbi] & DB_STALE) {
......
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