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mdbx: support exclusive mode without lck-file.

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Change-Id: I1beef09d62965d0d777f579a8aa6f15c478eebd2
This commit is contained in:
Leo Yuriev 2018-06-30 11:58:57 +03:00
parent 9e81d5b631
commit d90e6187f7
4 changed files with 137 additions and 84 deletions
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3
mdbx.h
View File

@ -100,6 +100,7 @@ typedef DWORD mdbx_tid_t;
#define MDBX_EIO ERROR_WRITE_FAULT
#define MDBX_EPERM ERROR_INVALID_FUNCTION
#define MDBX_EINTR ERROR_CANCELLED
#define MDBX_ENOFILE ERROR_FILE_NOT_FOUND
#else
@ -120,6 +121,8 @@ typedef pthread_t mdbx_tid_t;
#define MDBX_EIO EIO
#define MDBX_EPERM EPERM
#define MDBX_EINTR EINTR
#define MDBX_ENOFILE ENOENT
#endif
#ifdef _MSC_VER

22
src/bits.h
View File

@ -411,7 +411,7 @@ typedef struct MDBX_lockinfo {
volatile uint32_t mti_envmode;
#ifdef MDBX_OSAL_LOCK
/* Mutex protecting write access to this table. */
/* Mutex protecting write-txn. */
union {
MDBX_OSAL_LOCK mti_wmutex;
uint8_t pad_mti_wmutex[MDBX_OSAL_LOCK_SIZE % sizeof(size_t)];
@ -734,14 +734,17 @@ struct MDBX_env {
/* Max MDBX_lockinfo.mti_numreaders of interest to mdbx_env_close() */
unsigned me_close_readers;
mdbx_fastmutex_t me_dbi_lock;
MDBX_dbi me_numdbs; /* number of DBs opened */
MDBX_dbi me_maxdbs; /* size of the DB table */
mdbx_pid_t me_pid; /* process ID of this env */
mdbx_thread_key_t me_txkey; /* thread-key for readers */
char *me_path; /* path to the DB files */
void *me_pbuf; /* scratch area for DUPSORT put() */
MDBX_txn *me_txn; /* current write transaction */
MDBX_txn *me_txn0; /* prealloc'd write transaction */
MDBX_dbi me_numdbs; /* number of DBs opened */
MDBX_dbi me_maxdbs; /* size of the DB table */
mdbx_pid_t me_pid; /* process ID of this env */
mdbx_thread_key_t me_txkey; /* thread-key for readers */
char *me_path; /* path to the DB files */
void *me_pbuf; /* scratch area for DUPSORT put() */
MDBX_txn *me_txn; /* current write transaction */
MDBX_txn *me_txn0; /* prealloc'd write transaction */
#ifdef MDBX_OSAL_LOCK
MDBX_OSAL_LOCK *me_wmutex; /* write-txn mutex */
#endif
MDBX_dbx *me_dbxs; /* array of static DB info */
uint16_t *me_dbflags; /* array of flags from MDBX_db.md_flags */
unsigned *me_dbiseqs; /* array of dbi sequence numbers */
@ -786,6 +789,7 @@ struct MDBX_env {
/* Workaround for LockFileEx and WriteFile multithread bug */
CRITICAL_SECTION me_windowsbug_lock;
#else
mdbx_fastmutex_t me_lckless_wmutex;
mdbx_fastmutex_t me_remap_guard;
#endif
};

23
src/lck-posix.c
View File

@ -86,16 +86,19 @@ static __inline int mdbx_lck_shared(int lfd) {
}
int mdbx_lck_downgrade(MDBX_env *env, bool complete) {
assert(env->me_lfd != INVALID_HANDLE_VALUE);
return complete ? mdbx_lck_shared(env->me_lfd) : MDBX_SUCCESS;
}
int mdbx_lck_upgrade(MDBX_env *env) { return mdbx_lck_exclusive(env->me_lfd); }
int mdbx_rpid_set(MDBX_env *env) {
assert(env->me_lfd != INVALID_HANDLE_VALUE);
return mdbx_lck_op(env->me_lfd, F_SETLK, F_WRLCK, env->me_pid, 1);
}
int mdbx_rpid_clear(MDBX_env *env) {
assert(env->me_lfd != INVALID_HANDLE_VALUE);
return mdbx_lck_op(env->me_lfd, F_SETLKW, F_UNLCK, env->me_pid, 1);
}
@ -106,6 +109,7 @@ int mdbx_rpid_clear(MDBX_env *env) {
* MDBX_RESULT_FALSE, if pid is dead (lock acquired)
* or otherwise the errcode. */
int mdbx_rpid_check(MDBX_env *env, mdbx_pid_t pid) {
assert(env->me_lfd != INVALID_HANDLE_VALUE);
int rc = mdbx_lck_op(env->me_lfd, F_GETLK, F_WRLCK, pid, 1);
if (rc == 0)
return MDBX_RESULT_FALSE;
@ -166,7 +170,8 @@ void mdbx_lck_destroy(MDBX_env *env) {
rc = pthread_mutex_destroy(&env->me_lck->mti_wmutex);
assert(rc == 0);
(void)rc;
/* lock would be released (by kernel) while the me_lfd will be closed */
/* file locks would be released (by kernel)
* while the me_lfd will be closed */
}
}
}
@ -209,15 +214,15 @@ void mdbx_rdt_unlock(MDBX_env *env) {
int mdbx_txn_lock(MDBX_env *env, bool dontwait) {
mdbx_trace(">>");
int rc = dontwait ? mdbx_robust_trylock(env, &env->me_lck->mti_wmutex)
: mdbx_robust_lock(env, &env->me_lck->mti_wmutex);
int rc = dontwait ? mdbx_robust_trylock(env, env->me_wmutex)
: mdbx_robust_lock(env, env->me_wmutex);
mdbx_trace("<< rc %d", rc);
return MDBX_IS_ERROR(rc) ? rc : MDBX_SUCCESS;
}
void mdbx_txn_unlock(MDBX_env *env) {
mdbx_trace(">>");
int rc = mdbx_robust_unlock(env, &env->me_lck->mti_wmutex);
int rc = mdbx_robust_unlock(env, env->me_wmutex);
mdbx_trace("<< rc %d", rc);
if (unlikely(MDBX_IS_ERROR(rc)))
mdbx_panic("%s() failed: errcode %d\n", mdbx_func_, rc);
@ -253,13 +258,15 @@ int mdbx_lck_seize(MDBX_env *env) {
assert(env->me_fd != INVALID_HANDLE_VALUE);
if (env->me_lfd == INVALID_HANDLE_VALUE) {
/* LY: without-lck mode (e.g. on read-only filesystem) */
int rc = mdbx_lck_op(env->me_fd, F_SETLK, F_RDLCK, 0, LCK_WHOLE);
/* LY: without-lck mode (e.g. exclusive or on read-only filesystem) */
int rc = mdbx_lck_op(env->me_fd, F_SETLK,
(env->me_flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, 0,
LCK_WHOLE);
if (rc != 0) {
mdbx_error("%s(%s) failed: errcode %u", mdbx_func_, "without-lck", rc);
return rc;
}
return MDBX_RESULT_FALSE;
return MDBX_RESULT_TRUE;
}
if ((env->me_flags & MDBX_RDONLY) == 0) {
@ -285,7 +292,7 @@ static int __cold mdbx_mutex_failed(MDBX_env *env, pthread_mutex_t *mutex,
if (rc == EOWNERDEAD) {
/* We own the mutex. Clean up after dead previous owner. */
int rlocked = (mutex == &env->me_lck->mti_rmutex);
int rlocked = (env->me_lck && mutex == &env->me_lck->mti_rmutex);
rc = MDBX_SUCCESS;
if (!rlocked) {
if (unlikely(env->me_txn)) {

173
src/mdbx.c
View File

@ -1931,13 +1931,16 @@ static const char *mdbx_durable_str(const MDBX_meta *const meta) {
static txnid_t mdbx_find_oldest(MDBX_txn *txn) {
mdbx_tassert(txn, (txn->mt_flags & MDBX_RDONLY) == 0);
const MDBX_env *env = txn->mt_env;
MDBX_lockinfo *const lck = env->me_lck;
const txnid_t edge = mdbx_reclaiming_detent(env);
mdbx_tassert(txn, edge <= txn->mt_txnid - 1);
MDBX_lockinfo *const lck = env->me_lck;
if (unlikely(env->me_lck == NULL /* exclusive mode */))
return edge;
const txnid_t last_oldest = lck->mti_oldest;
mdbx_tassert(txn, edge >= last_oldest);
if (last_oldest == edge)
if (likely(last_oldest == edge))
return edge;
const uint32_t nothing_changed = MDBX_STRING_TETRAD("None");
@ -2734,9 +2737,6 @@ static int mdbx_env_sync_ex(MDBX_env *env, int force, int nonblock) {
if (unlikely(flags & (MDBX_RDONLY | MDBX_FATAL_ERROR)))
return MDBX_EACCESS;
if (unlikely(!env->me_lck))
return MDBX_PANIC;
const bool outside_txn =
(!env->me_txn0 || env->me_txn0->mt_owner != mdbx_thread_self());
@ -4274,7 +4274,9 @@ int mdbx_txn_commit(MDBX_txn *txn) {
}
if (unlikely(rc != MDBX_SUCCESS))
goto fail;
env->me_lck->mti_readers_refresh_flag = false;
if (likely(env->me_lck))
env->me_lck->mti_readers_refresh_flag = false;
end_mode = MDBX_END_COMMITTED | MDBX_END_UPDATE | MDBX_END_EOTDONE;
done:
@ -4926,6 +4928,12 @@ int __cold mdbx_env_create(MDBX_env **penv) {
mdbx_fastmutex_destroy(&env->me_dbi_lock);
goto bailout;
}
rc = mdbx_fastmutex_init(&env->me_lckless_wmutex);
if (unlikely(rc != MDBX_SUCCESS)) {
mdbx_fastmutex_destroy(&env->me_remap_guard);
mdbx_fastmutex_destroy(&env->me_dbi_lock);
goto bailout;
}
#endif /* Windows */
VALGRIND_CREATE_MEMPOOL(env, 0, 0);
@ -5589,17 +5597,30 @@ static int __cold mdbx_setup_lck(MDBX_env *env, char *lck_pathname,
assert(env->me_fd != INVALID_HANDLE_VALUE);
assert(env->me_lfd == INVALID_HANDLE_VALUE);
int err = mdbx_openfile(lck_pathname, O_RDWR | O_CREAT, mode, &env->me_lfd,
const int open_flags =
(env->me_flags & MDBX_EXCLUSIVE) ? O_RDWR : O_RDWR | O_CREAT;
int err = mdbx_openfile(lck_pathname, open_flags, mode, &env->me_lfd,
(env->me_flags & MDBX_EXCLUSIVE) ? true : false);
if (err != MDBX_SUCCESS) {
if (err != MDBX_EROFS || (env->me_flags & MDBX_RDONLY) == 0)
if (!(err == MDBX_ENOFILE && (env->me_flags & MDBX_EXCLUSIVE)) &&
!(err == MDBX_EROFS && (env->me_flags & MDBX_RDONLY)))
return err;
/* LY: without-lck mode (e.g. on read-only filesystem) */
/* LY: without-lck mode (e.g. exclusive or on read-only filesystem) */
env->me_lfd = INVALID_HANDLE_VALUE;
const int rc = mdbx_lck_seize(env);
if (MDBX_IS_ERROR(rc))
return rc;
env->me_oldest = &env->me_oldest_stub;
env->me_maxreaders = UINT_MAX;
mdbx_debug("lck-setup: %s ", "lockless mode (readonly)");
return MDBX_SUCCESS;
#ifdef MDBX_OSAL_LOCK
env->me_wmutex = &env->me_lckless_wmutex;
#endif
mdbx_debug("lck-setup:%s%s%s", " lck-less",
(env->me_flags & MDBX_RDONLY) ? " readonly" : "",
(rc == MDBX_RESULT_TRUE) ? " exclusive" : " cooperative");
return rc;
}
/* Try to get exclusive lock. If we succeed, then
@ -5608,8 +5629,9 @@ static int __cold mdbx_setup_lck(MDBX_env *env, char *lck_pathname,
if (MDBX_IS_ERROR(rc))
return rc;
mdbx_debug("lck-setup: %s ",
(rc == MDBX_RESULT_TRUE) ? "exclusive" : "shared");
mdbx_debug("lck-setup:%s%s%s", " with-lck",
(env->me_flags & MDBX_RDONLY) ? " readonly" : "",
(rc == MDBX_RESULT_TRUE) ? " exclusive" : " cooperative");
uint64_t size;
err = mdbx_filesize(env->me_lfd, &size);
@ -5699,6 +5721,9 @@ static int __cold mdbx_setup_lck(MDBX_env *env, char *lck_pathname,
mdbx_assert(env, !MDBX_IS_ERROR(rc));
env->me_oldest = &env->me_lck->mti_oldest;
#ifdef MDBX_OSAL_LOCK
env->me_wmutex = &env->me_lck->mti_wmutex;
#endif
return rc;
}
@ -5804,44 +5829,46 @@ int __cold mdbx_env_open(MDBX_env *env, const char *path, unsigned flags,
}
mdbx_debug("opened dbenv %p", (void *)env);
const unsigned mode_flags =
MDBX_WRITEMAP | MDBX_NOSYNC | MDBX_NOMETASYNC | MDBX_MAPASYNC;
if (lck_rc == MDBX_RESULT_TRUE) {
env->me_lck->mti_envmode = env->me_flags & (mode_flags | MDBX_RDONLY);
if ((env->me_flags & MDBX_EXCLUSIVE) == 0) {
/* LY: downgrade lock only if exclusive access not requested.
* in case exclusive==1, just leave value as is. */
rc = mdbx_lck_downgrade(env, true);
mdbx_debug("lck-downgrade-full: rc %i ", rc);
} else {
rc = mdbx_lck_downgrade(env, false);
mdbx_debug("lck-downgrade-partial: rc %i ", rc);
}
if (rc != MDBX_SUCCESS)
goto bailout;
} else {
if ((env->me_flags & MDBX_RDONLY) == 0) {
while (env->me_lck->mti_envmode == MDBX_RDONLY) {
if (mdbx_atomic_compare_and_swap32(&env->me_lck->mti_envmode,
MDBX_RDONLY,
env->me_flags & mode_flags))
break;
/* TODO: yield/relax cpu */
if (env->me_lck) {
const unsigned mode_flags =
MDBX_WRITEMAP | MDBX_NOSYNC | MDBX_NOMETASYNC | MDBX_MAPASYNC;
if (lck_rc == MDBX_RESULT_TRUE) {
env->me_lck->mti_envmode = env->me_flags & (mode_flags | MDBX_RDONLY);
if ((env->me_flags & MDBX_EXCLUSIVE) == 0) {
/* LY: downgrade lock only if exclusive access not requested.
* in case exclusive==1, just leave value as is. */
rc = mdbx_lck_downgrade(env, true);
mdbx_debug("lck-downgrade-full: rc %i ", rc);
} else {
rc = mdbx_lck_downgrade(env, false);
mdbx_debug("lck-downgrade-partial: rc %i ", rc);
}
if ((env->me_lck->mti_envmode ^ env->me_flags) & mode_flags) {
mdbx_error("current mode/flags incompatible with requested");
rc = MDBX_INCOMPATIBLE;
if (rc != MDBX_SUCCESS)
goto bailout;
} else {
if ((env->me_flags & MDBX_RDONLY) == 0) {
while (env->me_lck->mti_envmode == MDBX_RDONLY) {
if (mdbx_atomic_compare_and_swap32(&env->me_lck->mti_envmode,
MDBX_RDONLY,
env->me_flags & mode_flags))
break;
/* TODO: yield/relax cpu */
}
if ((env->me_lck->mti_envmode ^ env->me_flags) & mode_flags) {
mdbx_error("current mode/flags incompatible with requested");
rc = MDBX_INCOMPATIBLE;
goto bailout;
}
}
}
}
if (env->me_lck && (env->me_flags & MDBX_NOTLS) == 0) {
rc = mdbx_rthc_alloc(&env->me_txkey, &env->me_lck->mti_readers[0],
&env->me_lck->mti_readers[env->me_maxreaders]);
if (unlikely(rc != MDBX_SUCCESS))
goto bailout;
env->me_flags |= MDBX_ENV_TXKEY;
if ((env->me_flags & MDBX_NOTLS) == 0) {
rc = mdbx_rthc_alloc(&env->me_txkey, &env->me_lck->mti_readers[0],
&env->me_lck->mti_readers[env->me_maxreaders]);
if (unlikely(rc != MDBX_SUCCESS))
goto bailout;
env->me_flags |= MDBX_ENV_TXKEY;
}
}
if ((flags & MDBX_RDONLY) == 0) {
@ -5952,7 +5979,7 @@ int __cold mdbx_env_close_ex(MDBX_env *env, int dont_sync) {
if (unlikely(env->me_signature != MDBX_ME_SIGNATURE))
return MDBX_EBADSIGN;
if (env->me_lck && (env->me_flags & (MDBX_RDONLY | MDBX_FATAL_ERROR)) == 0) {
if ((env->me_flags & (MDBX_RDONLY | MDBX_FATAL_ERROR)) == 0) {
if (env->me_txn0 && env->me_txn0->mt_owner &&
env->me_txn0->mt_owner != mdbx_thread_self())
return MDBX_BUSY;
@ -5987,6 +6014,8 @@ int __cold mdbx_env_close_ex(MDBX_env *env, int dont_sync) {
/* me_remap_guard don't have destructor (Slim Reader/Writer Lock) */
DeleteCriticalSection(&env->me_windowsbug_lock);
#else
mdbx_ensure(env,
mdbx_fastmutex_destroy(&env->me_lckless_wmutex) == MDBX_SUCCESS);
mdbx_ensure(env,
mdbx_fastmutex_destroy(&env->me_remap_guard) == MDBX_SUCCESS);
#endif /* Windows */
@ -11241,28 +11270,31 @@ int __cold mdbx_reader_list(MDBX_env *env, MDBX_msg_func *func, void *ctx) {
return MDBX_EBADSIGN;
const MDBX_lockinfo *const lck = env->me_lck;
const unsigned snap_nreaders = lck->mti_numreaders;
for (unsigned i = 0; i < snap_nreaders; i++) {
if (lck->mti_readers[i].mr_pid) {
const txnid_t txnid = lck->mti_readers[i].mr_txnid;
if (txnid == ~(txnid_t)0)
snprintf(buf, sizeof(buf), "%10" PRIuPTR " %" PRIxPTR " -\n",
(uintptr_t)lck->mti_readers[i].mr_pid,
(uintptr_t)lck->mti_readers[i].mr_tid);
else
snprintf(buf, sizeof(buf), "%10" PRIuPTR " %" PRIxPTR " %" PRIaTXN "\n",
(uintptr_t)lck->mti_readers[i].mr_pid,
(uintptr_t)lck->mti_readers[i].mr_tid, txnid);
if (likely(lck)) {
const unsigned snap_nreaders = lck->mti_numreaders;
for (unsigned i = 0; i < snap_nreaders; i++) {
if (lck->mti_readers[i].mr_pid) {
const txnid_t txnid = lck->mti_readers[i].mr_txnid;
if (txnid == ~(txnid_t)0)
snprintf(buf, sizeof(buf), "%10" PRIuPTR " %" PRIxPTR " -\n",
(uintptr_t)lck->mti_readers[i].mr_pid,
(uintptr_t)lck->mti_readers[i].mr_tid);
else
snprintf(buf, sizeof(buf),
"%10" PRIuPTR " %" PRIxPTR " %" PRIaTXN "\n",
(uintptr_t)lck->mti_readers[i].mr_pid,
(uintptr_t)lck->mti_readers[i].mr_tid, txnid);
if (first) {
first = 0;
rc = func(" pid thread txnid\n", ctx);
if (first) {
first = 0;
rc = func(" pid thread txnid\n", ctx);
if (rc < 0)
break;
}
rc = func(buf, ctx);
if (rc < 0)
break;
}
rc = func(buf, ctx);
if (rc < 0)
break;
}
}
if (first)
@ -11327,6 +11359,13 @@ int __cold mdbx_reader_check0(MDBX_env *env, int rdt_locked, int *dead) {
}
MDBX_lockinfo *const lck = env->me_lck;
if (unlikely(lck == NULL)) {
/* exclusive mode */
if (dead)
*dead = 0;
return MDBX_SUCCESS;
}
const unsigned snap_nreaders = lck->mti_numreaders;
mdbx_pid_t *pids = alloca((snap_nreaders + 1) * sizeof(mdbx_pid_t));
pids[0] = 0;
@ -11441,7 +11480,7 @@ static txnid_t __cold mdbx_oomkick(MDBX_env *env, const txnid_t laggard) {
mdbx_assert(env, oldest < env->me_txn0->mt_txnid);
mdbx_assert(env, oldest >= laggard);
mdbx_assert(env, oldest >= env->me_oldest[0]);
if (oldest == laggard)
if (oldest == laggard || unlikely(env->me_lck == NULL /* exclusive mode */))
return oldest;
if (MDBX_IS_ERROR(mdbx_reader_check0(env, false, NULL)))