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mdbx: дополнение API функциями lock/unlock/upgrade/downgrade основной блокировки.

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This commit is contained in:
Леонид Юрьев (Leonid Yuriev) 2023-10-10 23:14:40 +03:00
parent dd9fc963d2
commit f0d523c507
6 changed files with 126 additions and 63 deletions
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2
mdbx.h
View File

@ -5570,7 +5570,7 @@ LIBMDBX_API int mdbx_txn_lock(MDBX_env *env, bool dont_wait);
/** \brief Releases write-transaction lock.
* Provided for custom and/or complex locking scenarios.
* \returns A non-zero error value on failure and 0 on success. */
LIBMDBX_API void mdbx_txn_unlock(MDBX_env *env);
LIBMDBX_API int mdbx_txn_unlock(MDBX_env *env);
/** \brief Open an environment instance using specific meta-page
* for checking and recovery.

78
src/core.c
View File

@ -8200,7 +8200,7 @@ retry:;
rc = MDBX_SUCCESS /* means "some data was synced" */;
}
err = mdbx_txn_lock(env, nonblock);
err = osal_txn_lock(env, nonblock);
if (unlikely(err != MDBX_SUCCESS))
return err;
@ -8247,7 +8247,7 @@ retry:;
bailout:
if (locked)
mdbx_txn_unlock(env);
osal_txn_unlock(env);
return rc;
}
@ -8442,7 +8442,7 @@ static void txn_valgrind(MDBX_env *env, MDBX_txn *txn) {
} else if (env->me_flags & MDBX_RDONLY) {
/* read-only mode, no write-txn, no wlock mutex */
last = NUM_METAS;
} else if (mdbx_txn_lock(env, true) == MDBX_SUCCESS) {
} else if (osal_txn_lock(env, true) == MDBX_SUCCESS) {
/* no write-txn */
last = NUM_METAS;
should_unlock = true;
@ -8463,7 +8463,7 @@ static void txn_valgrind(MDBX_env *env, MDBX_txn *txn) {
pgno2bytes(env, edge - last));
}
if (should_unlock)
mdbx_txn_unlock(env);
osal_txn_unlock(env);
}
}
#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */
@ -8840,6 +8840,7 @@ static int txn_renew(MDBX_txn *txn, const unsigned flags) {
txn->mt_flags = MDBX_TXN_RDONLY | MDBX_TXN_FINISHED;
return MDBX_SUCCESS;
}
txn->mt_owner = tid;
/* Seek & fetch the last meta */
uint64_t timestamp = 0;
@ -8915,12 +8916,11 @@ static int txn_renew(MDBX_txn *txn, const unsigned flags) {
rc = MDBX_CORRUPTED;
goto bailout;
}
eASSERT(env, txn->mt_txnid >= env->me_lck->mti_oldest_reader.weak);
txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
txn->mt_numdbs = env->me_numdbs;
ENSURE(env, txn->mt_txnid >=
/* paranoia is appropriate here */ env->me_lck
->mti_oldest_reader.weak);
txn->mt_numdbs = env->me_numdbs;
} else {
eASSERT(env, (flags & ~(MDBX_TXN_RW_BEGIN_FLAGS | MDBX_TXN_SPILLS |
MDBX_WRITEMAP)) == 0);
@ -8946,16 +8946,16 @@ static int txn_renew(MDBX_txn *txn, const unsigned flags) {
/* Not yet touching txn == env->me_txn0, it may be active */
jitter4testing(false);
rc = mdbx_txn_lock(env, !!(flags & MDBX_TXN_TRY));
rc = osal_txn_lock(env, !!(flags & MDBX_TXN_TRY));
if (unlikely(rc))
return rc;
if (unlikely(env->me_flags & MDBX_FATAL_ERROR)) {
mdbx_txn_unlock(env);
osal_txn_unlock(env);
return MDBX_PANIC;
}
#if defined(_WIN32) || defined(_WIN64)
if (unlikely(!env->me_map)) {
mdbx_txn_unlock(env);
osal_txn_unlock(env);
return MDBX_EPERM;
}
#endif /* Windows */
@ -9129,7 +9129,6 @@ static int txn_renew(MDBX_txn *txn, const unsigned flags) {
#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)
txn_valgrind(env, txn);
#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */
txn->mt_owner = tid;
return MDBX_SUCCESS;
}
bailout:
@ -9810,9 +9809,7 @@ static int txn_end(MDBX_txn *txn, const unsigned mode) {
txn->mt_txnid == slot->mr_txnid.weak &&
slot->mr_txnid.weak >= env->me_lck->mti_oldest_reader.weak);
#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)
atomic_add32(&env->me_ignore_EDEADLK, 1);
txn_valgrind(env, nullptr);
atomic_sub32(&env->me_ignore_EDEADLK, 1);
#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */
atomic_store32(&slot->mr_snapshot_pages_used, 0, mo_Relaxed);
safe64_reset(&slot->mr_txnid, false);
@ -9845,7 +9842,6 @@ static int txn_end(MDBX_txn *txn, const unsigned mode) {
#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */
txn->mt_flags = MDBX_TXN_FINISHED;
txn->mt_owner = 0;
env->me_txn = txn->mt_parent;
pnl_free(txn->tw.spilled.list);
txn->tw.spilled.list = nullptr;
@ -9858,7 +9854,7 @@ static int txn_end(MDBX_txn *txn, const unsigned mode) {
if (!(env->me_flags & MDBX_WRITEMAP))
dlist_free(txn);
/* The writer mutex was locked in mdbx_txn_begin. */
mdbx_txn_unlock(env);
osal_txn_unlock(env);
} else {
eASSERT(env, txn->mt_parent != NULL);
MDBX_txn *const parent = txn->mt_parent;
@ -9870,6 +9866,7 @@ static int txn_end(MDBX_txn *txn, const unsigned mode) {
eASSERT(env, memcmp(&txn->tw.troika, &parent->tw.troika,
sizeof(meta_troika_t)) == 0);
txn->mt_owner = 0;
if (txn->tw.lifo_reclaimed) {
eASSERT(env, MDBX_PNL_GETSIZE(txn->tw.lifo_reclaimed) >=
(uintptr_t)parent->tw.lifo_reclaimed);
@ -13258,7 +13255,7 @@ __cold int mdbx_env_set_geometry(MDBX_env *env, intptr_t size_lower,
return MDBX_EACCESS;
if (!inside_txn) {
int err = mdbx_txn_lock(env, false);
int err = osal_txn_lock(env, false);
if (unlikely(err != MDBX_SUCCESS))
return err;
need_unlock = true;
@ -13609,7 +13606,7 @@ __cold int mdbx_env_set_geometry(MDBX_env *env, intptr_t size_lower,
bailout:
if (need_unlock)
mdbx_txn_unlock(env);
osal_txn_unlock(env);
return rc;
}
@ -21675,13 +21672,13 @@ __cold static int env_copy_asis(MDBX_env *env, MDBX_txn *read_txn,
return rc;
/* Temporarily block writers until we snapshot the meta pages */
rc = mdbx_txn_lock(env, false);
rc = osal_txn_lock(env, false);
if (unlikely(rc != MDBX_SUCCESS))
return rc;
rc = txn_renew(read_txn, MDBX_TXN_RDONLY);
if (unlikely(rc != MDBX_SUCCESS)) {
mdbx_txn_unlock(env);
osal_txn_unlock(env);
return rc;
}
@ -21693,7 +21690,7 @@ __cold static int env_copy_asis(MDBX_env *env, MDBX_txn *read_txn,
memcpy(buffer, env->me_map, meta_bytes);
MDBX_meta *const headcopy = /* LY: get pointer to the snapshot copy */
ptr_disp(buffer, ptr_dist(meta_recent(env, &troika).ptr_c, env->me_map));
mdbx_txn_unlock(env);
osal_txn_unlock(env);
if (flags & MDBX_CP_FORCE_DYNAMIC_SIZE)
meta_make_sizeable(headcopy);
@ -21953,7 +21950,7 @@ __cold int mdbx_env_set_flags(MDBX_env *env, MDBX_env_flags_t flags,
env->me_txn0->mt_owner != osal_thread_self();
bool should_unlock = false;
if (lock_needed) {
rc = mdbx_txn_lock(env, false);
rc = osal_txn_lock(env, false);
if (unlikely(rc))
return rc;
should_unlock = true;
@ -21965,7 +21962,7 @@ __cold int mdbx_env_set_flags(MDBX_env *env, MDBX_env_flags_t flags,
env->me_flags &= ~flags;
if (should_unlock)
mdbx_txn_unlock(env);
osal_txn_unlock(env);
return MDBX_SUCCESS;
}
@ -24828,7 +24825,7 @@ __cold int mdbx_env_set_option(MDBX_env *env, const MDBX_option_t option,
return MDBX_EINVAL;
if (env->me_options.dp_reserve_limit != (unsigned)value) {
if (lock_needed) {
err = mdbx_txn_lock(env, false);
err = osal_txn_lock(env, false);
if (unlikely(err != MDBX_SUCCESS))
return err;
should_unlock = true;
@ -24868,7 +24865,7 @@ __cold int mdbx_env_set_option(MDBX_env *env, const MDBX_option_t option,
if (unlikely(env->me_flags & MDBX_RDONLY))
return MDBX_EACCESS;
if (lock_needed) {
err = mdbx_txn_lock(env, false);
err = osal_txn_lock(env, false);
if (unlikely(err != MDBX_SUCCESS))
return err;
should_unlock = true;
@ -24968,7 +24965,7 @@ __cold int mdbx_env_set_option(MDBX_env *env, const MDBX_option_t option,
}
if (should_unlock)
mdbx_txn_unlock(env);
osal_txn_unlock(env);
return err;
}
@ -25490,6 +25487,39 @@ mdbx_key_from_int32(const int32_t i32) {
#endif /* LIBMDBX_NO_EXPORTS_LEGACY_API */
/*------------------------------------------------------------------------------
* Locking API */
int mdbx_txn_lock(MDBX_env *env, bool dont_wait) {
int rc = check_env(env, true);
if (unlikely(rc != MDBX_SUCCESS))
return rc;
if (unlikely(env->me_flags & MDBX_RDONLY))
return MDBX_EACCESS;
if (unlikely(env->me_txn0->mt_owner ||
(env->me_txn0->mt_flags & MDBX_TXN_FINISHED) == 0))
return MDBX_BUSY;
return osal_txn_lock(env, dont_wait);
}
int mdbx_txn_unlock(MDBX_env *env) {
int rc = check_env(env, true);
if (unlikely(rc != MDBX_SUCCESS))
return rc;
if (unlikely(env->me_flags & MDBX_RDONLY))
return MDBX_EACCESS;
if (unlikely(env->me_txn0->mt_owner != osal_thread_self()))
return MDBX_THREAD_MISMATCH;
if (unlikely((env->me_txn0->mt_flags & MDBX_TXN_FINISHED) == 0))
return MDBX_BUSY;
osal_txn_unlock(env);
return MDBX_SUCCESS;
}
/******************************************************************************/
/* *INDENT-OFF* */
/* clang-format off */

1
src/internals.h
View File

@ -1482,7 +1482,6 @@ struct MDBX_env {
int me_valgrind_handle;
#endif
#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)
MDBX_atomic_uint32_t me_ignore_EDEADLK;
pgno_t me_poison_edge;
#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */

61
src/lck-posix.c
View File

@ -120,7 +120,7 @@ mdbx_global_destructor(void) {
* - Блокировка таблицы читателей для регистрации,
* т.е. функции osal_rdt_lock() и osal_rdt_unlock().
* - Блокировка БД для пишущих транзакций,
* т.е. функции mdbx_txn_lock() и mdbx_txn_unlock().
* т.е. функции osal_txn_lock() и osal_txn_unlock().
*
* Остальной функционал реализуется отдельно посредством файловых блокировок:
* - Первоначальный захват БД в режиме exclusive/shared и последующий перевод
@ -527,6 +527,34 @@ MDBX_INTERNAL_FUNC int osal_lck_downgrade(MDBX_env *env) {
return rc;
}
MDBX_INTERNAL_FUNC int osal_lck_upgrade(MDBX_env *env, bool dont_wait) {
assert(env->me_lfd != INVALID_HANDLE_VALUE);
if (unlikely(osal_getpid() != env->me_pid))
return MDBX_PANIC;
const int cmd = dont_wait ? op_setlk : op_setlkw;
int rc = lck_op(env->me_lfd, cmd, F_WRLCK, 0, 1);
if (rc == MDBX_SUCCESS && (env->me_flags & MDBX_EXCLUSIVE) == 0) {
rc = (env->me_pid > 1)
? lck_op(env->me_lazy_fd, cmd, F_WRLCK, 0, env->me_pid - 1)
: MDBX_SUCCESS;
if (rc == MDBX_SUCCESS) {
rc = lck_op(env->me_lazy_fd, cmd, F_WRLCK, env->me_pid + 1,
OFF_T_MAX - env->me_pid - 1);
if (rc != MDBX_SUCCESS && env->me_pid > 1 &&
lck_op(env->me_lazy_fd, op_setlk, F_UNLCK, 0, env->me_pid - 1))
rc = MDBX_PANIC;
}
if (rc != MDBX_SUCCESS && lck_op(env->me_lfd, op_setlk, F_RDLCK, 0, 1))
rc = MDBX_PANIC;
}
if (unlikely(rc != 0)) {
ERROR("%s, err %u", "lck", rc);
assert(MDBX_IS_ERROR(rc));
}
return rc;
}
__cold MDBX_INTERNAL_FUNC int osal_lck_destroy(MDBX_env *env,
MDBX_env *inprocess_neighbor) {
if (unlikely(osal_getpid() != env->me_pid))
@ -822,11 +850,6 @@ __cold static int mdbx_ipclock_failed(MDBX_env *env, osal_ipclock_t *ipc,
#error "FIXME"
#endif /* MDBX_LOCKING */
#if defined(MDBX_USE_VALGRIND) || defined(__SANITIZE_ADDRESS__)
if (rc == EDEADLK && atomic_load32(&env->me_ignore_EDEADLK, mo_Relaxed) > 0)
return rc;
#endif /* MDBX_USE_VALGRIND || __SANITIZE_ADDRESS__ */
ERROR("mutex (un)lock failed, %s", mdbx_strerror(err));
if (rc != EDEADLK)
env->me_flags |= MDBX_FATAL_ERROR;
@ -931,20 +954,28 @@ MDBX_INTERNAL_FUNC void osal_rdt_unlock(MDBX_env *env) {
jitter4testing(true);
}
int mdbx_txn_lock(MDBX_env *env, bool dont_wait) {
int osal_txn_lock(MDBX_env *env, bool dont_wait) {
TRACE("%swait %s", dont_wait ? "dont-" : "", ">>");
eASSERT(env, !env->me_txn0->mt_owner);
jitter4testing(true);
int rc = mdbx_ipclock_lock(env, &env->me_lck->mti_wlock, dont_wait);
TRACE("<< rc %d", rc);
return MDBX_IS_ERROR(rc) ? rc : MDBX_SUCCESS;
const int err = mdbx_ipclock_lock(env, &env->me_lck->mti_wlock, dont_wait);
int rc = err;
if (likely(!MDBX_IS_ERROR(err))) {
env->me_txn0->mt_owner = osal_thread_self();
rc = MDBX_SUCCESS;
}
TRACE("<< rc %d", err);
return rc;
}
void mdbx_txn_unlock(MDBX_env *env) {
void osal_txn_unlock(MDBX_env *env) {
TRACE("%s", ">>");
int rc = mdbx_ipclock_unlock(env, &env->me_lck->mti_wlock);
TRACE("<< rc %d", rc);
if (unlikely(rc != MDBX_SUCCESS))
mdbx_panic("%s() failed: err %d\n", __func__, rc);
eASSERT(env, env->me_txn0->mt_owner == osal_thread_self());
env->me_txn0->mt_owner = 0;
int err = mdbx_ipclock_unlock(env, &env->me_lck->mti_wlock);
TRACE("<< err %d", err);
if (unlikely(err != MDBX_SUCCESS))
mdbx_panic("%s() failed: err %d\n", __func__, err);
jitter4testing(true);
}

33
src/lck-windows.c
View File

@ -178,7 +178,8 @@ static int funlock(mdbx_filehandle_t fd, size_t offset, size_t bytes) {
#define DXB_BODY (env->me_psize * (size_t)NUM_METAS), DXB_MAXLEN
#define DXB_WHOLE 0, DXB_MAXLEN
int mdbx_txn_lock(MDBX_env *env, bool dontwait) {
int osal_txn_lock(MDBX_env *env, bool dontwait) {
eASSERT(env, !env->me_txn0->mt_owner);
if (dontwait) {
if (!TryEnterCriticalSection(&env->me_windowsbug_lock))
return MDBX_BUSY;
@ -194,12 +195,8 @@ int mdbx_txn_lock(MDBX_env *env, bool dontwait) {
}
}
if (env->me_flags & MDBX_EXCLUSIVE) {
/* Zap: Failing to release lock 'env->me_windowsbug_lock'
* in function 'mdbx_txn_lock' */
MDBX_SUPPRESS_GOOFY_MSVC_ANALYZER(26115);
return MDBX_SUCCESS;
}
if (env->me_flags & MDBX_EXCLUSIVE)
goto done;
const HANDLE fd4data =
env->me_overlapped_fd ? env->me_overlapped_fd : env->me_lazy_fd;
@ -218,17 +215,20 @@ int mdbx_txn_lock(MDBX_env *env, bool dontwait) {
}
}
if (rc == MDBX_SUCCESS) {
done:
/* Zap: Failing to release lock 'env->me_windowsbug_lock'
* in function 'mdbx_txn_lock' */
MDBX_SUPPRESS_GOOFY_MSVC_ANALYZER(26115);
return rc;
env->me_txn0->mt_owner = osal_thread_self();
return MDBX_SUCCESS;
}
LeaveCriticalSection(&env->me_windowsbug_lock);
return (!dontwait || rc != ERROR_LOCK_VIOLATION) ? rc : MDBX_BUSY;
}
void mdbx_txn_unlock(MDBX_env *env) {
void osal_txn_unlock(MDBX_env *env) {
eASSERT(env, env->me_txn0->mt_owner == osal_thread_self());
if ((env->me_flags & MDBX_EXCLUSIVE) == 0) {
const HANDLE fd4data =
env->me_overlapped_fd ? env->me_overlapped_fd : env->me_lazy_fd;
@ -236,6 +236,7 @@ void mdbx_txn_unlock(MDBX_env *env) {
if (err != MDBX_SUCCESS)
mdbx_panic("%s failed: err %u", __func__, err);
}
env->me_txn0->mt_owner = 0;
LeaveCriticalSection(&env->me_windowsbug_lock);
}
@ -442,7 +443,7 @@ osal_resume_threads_after_remap(mdbx_handle_array_t *array) {
* The osal_lck_downgrade() moves the locking-FSM from "exclusive write"
* state to the "used" (i.e. shared) state.
*
* The mdbx_lck_upgrade() moves the locking-FSM from "used" (i.e. shared)
* The osal_lck_upgrade() moves the locking-FSM from "used" (i.e. shared)
* state to the "exclusive write" state.
*/
@ -615,7 +616,7 @@ MDBX_INTERNAL_FUNC int osal_lck_downgrade(MDBX_env *env) {
return MDBX_SUCCESS /* 5) now at S-? (used), done */;
}
MDBX_INTERNAL_FUNC int mdbx_lck_upgrade(MDBX_env *env) {
MDBX_INTERNAL_FUNC int osal_lck_upgrade(MDBX_env *env, bool dont_wait) {
/* Transite from used state (S-?) to exclusive-write (E-E) */
assert(env->me_lfd != INVALID_HANDLE_VALUE);
@ -625,7 +626,9 @@ MDBX_INTERNAL_FUNC int mdbx_lck_upgrade(MDBX_env *env) {
/* 1) now on S-? (used), try S-E (locked) */
jitter4testing(false);
int rc = flock(env->me_lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_UPPER);
int rc = flock(env->me_lfd,
dont_wait ? LCK_EXCLUSIVE | LCK_DONTWAIT : LCK_EXCLUSIVE,
LCK_UPPER);
if (rc != MDBX_SUCCESS) {
/* 2) something went wrong, give up */;
VERBOSE("%s, err %u", "S-?(used) >> S-E(locked)", rc);
@ -640,7 +643,9 @@ MDBX_INTERNAL_FUNC int mdbx_lck_upgrade(MDBX_env *env) {
/* 4) now on ?-E (middle), try E-E (exclusive-write) */
jitter4testing(false);
rc = flock(env->me_lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_LOWER);
rc = flock(env->me_lfd,
dont_wait ? LCK_EXCLUSIVE | LCK_DONTWAIT : LCK_EXCLUSIVE,
LCK_LOWER);
if (rc != MDBX_SUCCESS) {
/* 5) something went wrong, give up */;
VERBOSE("%s, err %u", "?-E(middle) >> E-E(exclusive-write)", rc);
@ -686,7 +691,7 @@ MDBX_INTERNAL_FUNC int osal_lck_destroy(MDBX_env *env,
const bool synced = env->me_lck_mmap.lck->mti_unsynced_pages.weak == 0;
osal_munmap(&env->me_lck_mmap);
if (synced && !inprocess_neighbor && env->me_lfd != INVALID_HANDLE_VALUE &&
mdbx_lck_upgrade(env) == MDBX_SUCCESS)
osal_lck_upgrade(env, true) == MDBX_SUCCESS)
/* this will fail if LCK is used/mmapped by other process(es) */
osal_ftruncate(env->me_lfd, 0);
}

14
src/osal.h
View File

@ -718,6 +718,8 @@ MDBX_INTERNAL_FUNC int osal_lck_seize(MDBX_env *env);
/// operational lock.
/// \return Error code or zero on success
MDBX_INTERNAL_FUNC int osal_lck_downgrade(MDBX_env *env);
MDBX_MAYBE_UNUSED MDBX_INTERNAL_FUNC int osal_lck_upgrade(MDBX_env *env,
bool dont_wait);
/// \brief Locks LCK-file or/and table of readers for (de)registering.
/// \return Error code or zero on success
@ -726,16 +728,12 @@ MDBX_INTERNAL_FUNC int osal_rdt_lock(MDBX_env *env);
/// \brief Unlocks LCK-file or/and table of readers after (de)registering.
MDBX_INTERNAL_FUNC void osal_rdt_unlock(MDBX_env *env);
/// \brief Acquires lock for DB change (on writing transaction start)
/// Reading transactions will not be blocked.
/// Declared as LIBMDBX_API because it is used in mdbx_chk.
/// \brief Acquires write-transaction lock.
/// \return Error code or zero on success
LIBMDBX_API int mdbx_txn_lock(MDBX_env *env, bool dont_wait);
MDBX_INTERNAL_FUNC int osal_txn_lock(MDBX_env *env, bool dont_wait);
/// \brief Releases lock once DB changes is made (after writing transaction
/// has finished).
/// Declared as LIBMDBX_API because it is used in mdbx_chk.
LIBMDBX_API void mdbx_txn_unlock(MDBX_env *env);
/// \brief Releases write-transaction lock..
MDBX_INTERNAL_FUNC void osal_txn_unlock(MDBX_env *env);
/// \brief Sets alive-flag of reader presence (indicative lock) for PID of
/// the current process. The function does no more than needed for