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mdbx-windows: minor cleanup lck_downgrade().

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Change-Id: I7f36baefe3e3d76083171ae0c0f97d21ad1e877a
This commit is contained in:
Leonid Yuriev 2020-05-19 23:22:33 +03:00
parent 3990f1cc07
commit 86a4085bf9
1 changed files with 6 additions and 18 deletions
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24
src/lck-windows.c
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@ -526,43 +526,31 @@ MDBX_INTERNAL_FUNC int mdbx_lck_seize(MDBX_env *env) {
}
MDBX_INTERNAL_FUNC int mdbx_lck_downgrade(MDBX_env *env) {
/* Transite from exclusive state (E-?) to used (S-?) */
/* Transite from exclusive-write state (E-E) to used (S-?) */
assert(env->me_lazy_fd != INVALID_HANDLE_VALUE);
assert(env->me_lfd != INVALID_HANDLE_VALUE);
#if 1
if (env->me_flags & MDBX_EXCLUSIVE)
return MDBX_SUCCESS /* nope since files were must be opened non-shareable */
;
#else
/* 1) must be at E-E (exclusive-write) */
if (env->me_flags & MDBX_EXCLUSIVE) {
/* transite from E-E to E_? (exclusive-read) */
if (!funlock(env->me_lfd, LCK_UPPER))
mdbx_panic("%s(%s) failed: err %u", __func__,
"E-E(exclusive-write) >> E-?(exclusive-read)", GetLastError());
return MDBX_SUCCESS /* 2) now at E-? (exclusive-read), done */;
}
#endif
/* 3) now at E-E (exclusive-write), transite to ?_E (middle) */
/* 1) now at E-E (exclusive-write), transite to ?_E (middle) */
if (!funlock(env->me_lfd, LCK_LOWER))
mdbx_panic("%s(%s) failed: err %u", __func__,
"E-E(exclusive-write) >> ?-E(middle)", GetLastError());
/* 4) now at ?-E (middle), transite to S-E (locked) */
/* 2) now at ?-E (middle), transite to S-E (locked) */
if (!flock(env->me_lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER)) {
int rc = GetLastError() /* 5) something went wrong, give up */;
int rc = GetLastError() /* 3) something went wrong, give up */;
mdbx_error("%s, err %u", "?-E(middle) >> S-E(locked)", rc);
return rc;
}
/* 6) got S-E (locked), continue transition to S-? (used) */
/* 4) got S-E (locked), continue transition to S-? (used) */
if (!funlock(env->me_lfd, LCK_UPPER))
mdbx_panic("%s(%s) failed: err %u", __func__, "S-E(locked) >> S-?(used)",
GetLastError());
return MDBX_SUCCESS /* 7) now at S-? (used), done */;
return MDBX_SUCCESS /* 5) now at S-? (used), done */;
}
/*----------------------------------------------------------------------------*/