mirror of
https://github.com/isar/libmdbx.git
synced 2025-01-02 01:44:14 +08:00
mdbx: rework windows-clk.
Change-Id: Ie0f8422a39879c9d5e6b4697c7e90fe67076b021
This commit is contained in:
Leo Yuriev
parent
1596bceff2
commit
6b4f92b22e
@ -142,14 +142,23 @@ static BOOL funlock(mdbx_filehandle_t fd, off_t offset, size_t bytes) {
|
||||
/* global `write` lock for write-txt processing,
|
||||
* exclusive locking both meta-pages) */
|
||||
|
||||
#define LCK_MAXLEN (1u + (size_t)(MAXSSIZE_T))
|
||||
#define LCK_META_OFFSET 0
|
||||
#define LCK_META_LEN 0x10000u
|
||||
#define LCK_BODY_OFFSET LCK_META_LEN
|
||||
#define LCK_BODY_LEN (LCK_MAXLEN - LCK_BODY_OFFSET + 1u)
|
||||
#define LCK_META LCK_META_OFFSET, LCK_META_LEN
|
||||
#define LCK_BODY LCK_BODY_OFFSET, LCK_BODY_LEN
|
||||
#define LCK_WHOLE 0, LCK_MAXLEN
|
||||
|
||||
int mdbx_txn_lock(MDB_env *env) {
|
||||
if (flock(env->me_fd, LCK_EXCLUSIVE | LCK_WAITFOR, 0, env->me_psize * 2))
|
||||
if (flock(env->me_fd, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_BODY))
|
||||
return MDB_SUCCESS;
|
||||
return GetLastError();
|
||||
}
|
||||
|
||||
void mdbx_txn_unlock(MDB_env *env) {
|
||||
if (!funlock(env->me_fd, 0, env->me_psize * 2))
|
||||
if (!funlock(env->me_fd, LCK_BODY))
|
||||
mdbx_panic("%s failed: errcode %u", mdbx_func_, GetLastError());
|
||||
}
|
||||
|
||||
@ -186,7 +195,7 @@ void mdbx_rdt_unlock(MDB_env *env) {
|
||||
/* global `initial` lock for lockfile initialization,
|
||||
* exclusive/shared locking first cacheline */
|
||||
|
||||
/* FIXME: locking scheme/algo descritpion.
|
||||
/* FIXME: locking schema/algo descritpion.
|
||||
?-? = free
|
||||
S-? = used
|
||||
E-?
|
||||
@ -204,21 +213,27 @@ int mdbx_lck_init(MDB_env *env) {
|
||||
}
|
||||
|
||||
/* Seize state as exclusive (E-E and returns MDBX_RESULT_TRUE)
|
||||
* or used (S-? and returns MDBX_RESULT_FALSE), otherwise returns an error */
|
||||
int mdbx_lck_seize(MDB_env *env) {
|
||||
/* 1) now on ?-? (free), get ?-E (middle) */
|
||||
if (!flock(env->me_lfd, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_UPPER))
|
||||
return GetLastError() /* 2) something went wrong, give up */;
|
||||
* or used (S-? and returns MDBX_RESULT_FALSE), otherwise returns an error */
|
||||
static int internal_seize_lck(HANDLE lfd) {
|
||||
int rc;
|
||||
assert(lfd != INVALID_HANDLE_VALUE);
|
||||
|
||||
/* 1) now on ?-? (free), get ?-E (middle) */
|
||||
if (!flock(lfd, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_UPPER)) {
|
||||
rc = GetLastError() /* 2) something went wrong, give up */;
|
||||
mdbx_error("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"?-?(free) >> ?-E(middle)", rc);
|
||||
return rc;
|
||||
}
|
||||
/* 3) now on ?-E (middle), try E-E (exclusive) */
|
||||
if (flock(env->me_lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_LOWER))
|
||||
if (flock(lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_LOWER))
|
||||
return MDBX_RESULT_TRUE; /* 4) got E-E (exclusive), done */
|
||||
|
||||
/* 5) still on ?-E (middle) */
|
||||
int rc = GetLastError();
|
||||
rc = GetLastError();
|
||||
if (rc != ERROR_SHARING_VIOLATION && rc != ERROR_LOCK_VIOLATION) {
|
||||
/* 6) something went wrong, give up */
|
||||
if (!funlock(env->me_lfd, LCK_UPPER)) {
|
||||
if (!funlock(lfd, LCK_UPPER)) {
|
||||
rc = GetLastError();
|
||||
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"?-E(middle) >> ?-?(free)", rc);
|
||||
@ -227,13 +242,16 @@ int mdbx_lck_seize(MDB_env *env) {
|
||||
}
|
||||
|
||||
/* 7) still on ?-E (middle), try S-E (locked) */
|
||||
rc = flock(env->me_lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_LOWER)
|
||||
? MDBX_RESULT_FALSE
|
||||
: GetLastError();
|
||||
rc = flock(lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER) ? MDBX_RESULT_FALSE
|
||||
: GetLastError();
|
||||
|
||||
if (rc != MDBX_RESULT_FALSE)
|
||||
mdbx_error("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"?-E(middle) >> S-E(locked)", rc);
|
||||
|
||||
/* 8) now on S-E (locked) or still on ?-E (middle),
|
||||
* transite to S-? (used) or ?-? (free) */
|
||||
if (!funlock(env->me_lfd, LCK_UPPER)) {
|
||||
* transite to S-? (used) or ?-? (free) */
|
||||
if (!funlock(lfd, LCK_UPPER)) {
|
||||
rc = GetLastError();
|
||||
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"X-E(locked/middle) >> X-?(used/free)", rc);
|
||||
@ -243,28 +261,68 @@ int mdbx_lck_seize(MDB_env *env) {
|
||||
return rc;
|
||||
}
|
||||
|
||||
int mdbx_lck_seize(MDB_env *env) {
|
||||
int rc;
|
||||
|
||||
assert(env->me_fd != INVALID_HANDLE_VALUE);
|
||||
if (env->me_lfd == INVALID_HANDLE_VALUE) {
|
||||
/* LY: without-lck mode (e.g. on read-only filesystem) */
|
||||
if (!flock(env->me_fd, LCK_SHARED | LCK_DONTWAIT, LCK_WHOLE)) {
|
||||
rc = GetLastError();
|
||||
mdbx_error("%s(%s) failed: errcode %u", mdbx_func_, "without-lck", rc);
|
||||
return rc;
|
||||
}
|
||||
return MDBX_RESULT_FALSE;
|
||||
}
|
||||
|
||||
rc = internal_seize_lck(env->me_lfd);
|
||||
if (rc == MDBX_RESULT_TRUE && (env->me_flags & MDB_RDONLY) == 0) {
|
||||
/* Check that another process don't operates in without-lck mode.
|
||||
* Doing such check by exclusive locking the body-part of db. Should be
|
||||
* noted:
|
||||
* - we need an exclusive lock for do so;
|
||||
* - we can't lock meta-pages, otherwise other process could get an error
|
||||
* while opening db in valid (non-conflict) mode. */
|
||||
if (!flock(env->me_fd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_BODY)) {
|
||||
rc = GetLastError();
|
||||
mdbx_error("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"lock-against-without-lck", rc);
|
||||
mdbx_lck_destroy(env);
|
||||
} else if (!funlock(env->me_fd, LCK_BODY)) {
|
||||
rc = GetLastError();
|
||||
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"unlock-against-without-lck", rc);
|
||||
}
|
||||
}
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
/* Transite from exclusive state (E-E) to used (S-?) */
|
||||
int mdbx_lck_downgrade(MDB_env *env) {
|
||||
int rc;
|
||||
assert(env->me_fd != INVALID_HANDLE_VALUE);
|
||||
|
||||
/* 1) now at E-E (exclusive), continue transition to ?_E (middle) */
|
||||
if (!funlock(env->me_lfd, LCK_LOWER)) {
|
||||
rc = GetLastError();
|
||||
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"E-E(exclusive) >> ?-E(middle)", rc);
|
||||
}
|
||||
if (env->me_lfd != INVALID_HANDLE_VALUE) {
|
||||
/* 1) must be at E-E (exclusive), transite to ?_E (middle) */
|
||||
if (!funlock(env->me_lfd, LCK_LOWER)) {
|
||||
rc = GetLastError();
|
||||
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"E-E(exclusive) >> ?-E(middle)", rc);
|
||||
}
|
||||
|
||||
/* 2) now at ?-E (middle), transite to S-E (locked) */
|
||||
if (!flock(env->me_lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER)) {
|
||||
rc = GetLastError() /* 3) something went wrong, give up */;
|
||||
return rc;
|
||||
}
|
||||
/* 2) now at ?-E (middle), transite to S-E (locked) */
|
||||
if (!flock(env->me_lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER)) {
|
||||
rc = GetLastError() /* 3) something went wrong, give up */;
|
||||
return rc;
|
||||
}
|
||||
|
||||
/* 4) got S-E (locked), continue transition to S-? (used) */
|
||||
if (!funlock(env->me_lfd, LCK_UPPER)) {
|
||||
rc = GetLastError();
|
||||
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"S-E(locked) >> S-?(used)", rc);
|
||||
/* 4) got S-E (locked), continue transition to S-? (used) */
|
||||
if (!funlock(env->me_lfd, LCK_UPPER)) {
|
||||
rc = GetLastError();
|
||||
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
|
||||
"S-E(locked) >> S-?(used)", rc);
|
||||
}
|
||||
}
|
||||
return MDB_SUCCESS /* 5) now at S-? (used), done */;
|
||||
}
|
||||
@ -272,17 +330,6 @@ int mdbx_lck_downgrade(MDB_env *env) {
|
||||
void mdbx_lck_destroy(MDB_env *env) {
|
||||
int rc;
|
||||
|
||||
if (env->me_fd != INVALID_HANDLE_VALUE) {
|
||||
/* explicitly unlock to avoid latency for other processes (windows kernel
|
||||
* releases such locks via deferred queues) */
|
||||
while (funlock(env->me_fd, 0, env->me_psize * 2))
|
||||
;
|
||||
rc = GetLastError();
|
||||
assert(rc == ERROR_NOT_LOCKED);
|
||||
(void)rc;
|
||||
SetLastError(ERROR_SUCCESS);
|
||||
}
|
||||
|
||||
if (env->me_lfd != INVALID_HANDLE_VALUE) {
|
||||
/* double `unlock` for robustly remove overlapped shared/exclusive locks */
|
||||
while (funlock(env->me_lfd, LCK_LOWER))
|
||||
@ -299,6 +346,31 @@ void mdbx_lck_destroy(MDB_env *env) {
|
||||
(void)rc;
|
||||
SetLastError(ERROR_SUCCESS);
|
||||
}
|
||||
|
||||
if (env->me_fd != INVALID_HANDLE_VALUE) {
|
||||
/* explicitly unlock to avoid latency for other processes (windows kernel
|
||||
* releases such locks via deferred queues) */
|
||||
while (funlock(env->me_fd, LCK_BODY))
|
||||
;
|
||||
rc = GetLastError();
|
||||
assert(rc == ERROR_NOT_LOCKED);
|
||||
(void)rc;
|
||||
SetLastError(ERROR_SUCCESS);
|
||||
|
||||
while (funlock(env->me_fd, LCK_META))
|
||||
;
|
||||
rc = GetLastError();
|
||||
assert(rc == ERROR_NOT_LOCKED);
|
||||
(void)rc;
|
||||
SetLastError(ERROR_SUCCESS);
|
||||
|
||||
while (funlock(env->me_fd, LCK_WHOLE))
|
||||
;
|
||||
rc = GetLastError();
|
||||
assert(rc == ERROR_NOT_LOCKED);
|
||||
(void)rc;
|
||||
SetLastError(ERROR_SUCCESS);
|
||||
}
|
||||
}
|
||||
|
||||
/*----------------------------------------------------------------------------*/
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user