ISAR/libmdbx
3
0
Fork 0
mirror of https://github.com/isar/libmdbx.git synced 2025-01-04 17:44:13 +08:00
Code Issues Packages Projects Releases Wiki Activity

mdbx: add mdbx_lck_upgrade() to OSAL.

Browse Source
This commit is contained in:
Leo Yuriev 2017-06-06 20:18:09 +03:00
parent 204904df7c
commit d2d513014d
3 changed files with 61 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/lck-posix.c
View File

@ -93,6 +93,8 @@ static __inline int mdbx_lck_shared(int lfd) {
int mdbx_lck_downgrade(MDBX_env *env) { return mdbx_lck_shared(env->me_lfd); }
int mdbx_lck_upgrade(MDBX_env *env) { return mdbx_lck_exclusive(env->me_lfd); }
int mdbx_rpid_set(MDBX_env *env) {
return mdbx_lck_op(env->me_lfd, F_SETLK, F_WRLCK, env->me_pid, 1);
}

76
src/lck-windows.c
View File

@ -280,31 +280,71 @@ int mdbx_lck_seize(MDBX_env *env) {
return rc;
}
/* Transite from exclusive state (E-E) to used (S-?) */
int mdbx_lck_downgrade(MDBX_env *env) {
int rc;
/* Transite from exclusive state (E-E) to used (S-?) */
assert(env->me_fd != INVALID_HANDLE_VALUE);
assert(env->me_lfd != INVALID_HANDLE_VALUE);
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))
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
"E-E(exclusive) >> ?-E(middle)", GetLastError());
/* 1) must be at E-E (exclusive), transite to ?_E (middle) */
if (!funlock(env->me_lfd, LCK_LOWER))
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
"E-E(exclusive) >> ?-E(middle)", GetLastError());
/* 2) now at ?-E (middle), transite to S-E (locked) */
if (!flock(env->me_lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER)) {
rc = mdbx_get_errno_checked() /* 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))
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
"S-E(locked) >> S-?(used)", GetLastError());
/* 2) now at ?-E (middle), transite to S-E (locked) */
if (!flock(env->me_lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER)) {
int rc = mdbx_get_errno_checked() /* 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))
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
"S-E(locked) >> S-?(used)", GetLastError());
return MDBX_SUCCESS /* 5) now at S-? (used), done */;
}
int mdbx_lck_upgrade(MDBX_env *env) {
/* Transite from locked state (S-E) to exclusive (E-E) */
assert(env->me_fd != INVALID_HANDLE_VALUE);
assert(env->me_lfd != INVALID_HANDLE_VALUE);
/* 1) must be at S-E (locked), transite to ?_E (middle) */
if (!funlock(env->me_lfd, LCK_LOWER))
mdbx_panic("%s(%s) failed: errcode %u", mdbx_func_,
"S-E(locked) >> ?-E(middle)", GetLastError());
/* 3) now on ?-E (middle), try E-E (exclusive) */
mdbx_jitter4testing(false);
if (flock(env->me_lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_LOWER))
return MDBX_RESULT_TRUE; /* 4) got E-E (exclusive), done */
/* 5) still on ?-E (middle) */
int rc = mdbx_get_errno_checked();
mdbx_jitter4testing(false);
if (rc != ERROR_SHARING_VIOLATION && rc != ERROR_LOCK_VIOLATION) {
/* 6) something went wrong, report but continue */
mdbx_error("%s(%s) failed: errcode %u", mdbx_func_,
"?-E(middle) >> E-E(exclusive)", rc);
}
/* 7) still on ?-E (middle), try restore S-E (locked) */
mdbx_jitter4testing(false);
rc = flock(env->me_lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER)
? MDBX_RESULT_FALSE
: mdbx_get_errno_checked();
mdbx_jitter4testing(false);
if (rc != MDBX_RESULT_FALSE) {
mdbx_fatal("%s(%s) failed: errcode %u", mdbx_func_,
"?-E(middle) >> S-E(locked)", rc);
return rc;
}
/* 8) now on S-E (locked) */
return MDBX_RESULT_FALSE;
}
void mdbx_lck_destroy(MDBX_env *env) {
int rc;
@ -327,7 +367,7 @@ void mdbx_lck_destroy(MDBX_env *env) {
if (env->me_fd != INVALID_HANDLE_VALUE) {
/* explicitly unlock to avoid latency for other processes (windows kernel
* releases such locks via deferred queues) */
* releases such locks via deferred queues) */
while (funlock(env->me_fd, LCK_BODY))
;
rc = mdbx_get_errno_checked();

1
src/osal.h
View File

@ -489,6 +489,7 @@ int mdbx_lck_init(MDBX_env *env);
int mdbx_lck_seize(MDBX_env *env);
int mdbx_lck_downgrade(MDBX_env *env);
int mdbx_lck_upgrade(MDBX_env *env);
void mdbx_lck_destroy(MDBX_env *env);
int mdbx_rdt_lock(MDBX_env *env);