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mdbx: introduce internal lck_setlk_with3retries() as workaround EAGAIN on Android.

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Леонид Юрьев (Leonid Yuriev)
2025-09-08 10:46:30 +03:00
parent 71f42a77d5
commit 4adba731f5
1 changed files with 29 additions and 11 deletions
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40
src/lck-posix.c
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@@ -150,6 +150,27 @@ static int lck_op(const mdbx_filehandle_t fd, int cmd, const int lck, const off_
}
}
static int lck_setlk_with3retries(const mdbx_filehandle_t fd, const int lck, const off_t offset, off_t len) {
assert(lck != F_UNLCK);
int retry_left = 3;
#if defined(__ANDROID_API__)
retry_left *= 3;
#endif /* Android */
while (true) {
int rc = lck_op(fd, op_setlk, lck, offset, len);
if (!(rc == EAGAIN || rc == EACCES || rc == EBUSY || rc == EWOULDBLOCK || rc == EDEADLK) || --retry_left < 1)
return rc;
#if defined(__ANDROID_API__)
if (retry_left == 5 || retry_left == 3) {
usleep(1000 * 42 / 2);
continue;
}
#endif /* Android */
if (osal_yield())
return rc;
}
}
int osal_lockfile(mdbx_filehandle_t fd, bool wait) {
#if MDBX_USE_OFDLOCKS
if (unlikely(op_setlk == 0))
@@ -279,7 +300,7 @@ __cold int lck_seize(MDBX_env *env) {
if (env->lck_mmap.fd == INVALID_HANDLE_VALUE) {
/* LY: without-lck mode (e.g. exclusive or on read-only filesystem) */
rc = lck_op(env->lazy_fd, op_setlk, (env->flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, 0, OFF_T_MAX);
rc = lck_setlk_with3retries(env->lazy_fd, (env->flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, 0, OFF_T_MAX);
if (rc != MDBX_SUCCESS) {
ERROR("%s, err %u", "without-lck", rc);
eASSERT(env, MDBX_IS_ERROR(rc));
@@ -287,9 +308,6 @@ __cold int lck_seize(MDBX_env *env) {
}
return MDBX_RESULT_TRUE /* Done: return with exclusive locking. */;
}
#if defined(_POSIX_PRIORITY_SCHEDULING) && _POSIX_PRIORITY_SCHEDULING > 0
sched_yield();
#endif
retry:
if (rc == MDBX_RESULT_TRUE) {
@@ -302,14 +320,14 @@ retry:
}
/* Firstly try to get exclusive locking. */
rc = lck_op(env->lck_mmap.fd, op_setlk, F_WRLCK, 0, 1);
rc = lck_setlk_with3retries(env->lck_mmap.fd, F_WRLCK, 0, 1);
if (rc == MDBX_SUCCESS) {
rc = check_fstat(env);
if (MDBX_IS_ERROR(rc))
return rc;
continue_dxb_exclusive:
rc = lck_op(env->lazy_fd, op_setlk, (env->flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, 0, OFF_T_MAX);
rc = lck_setlk_with3retries(env->lazy_fd, (env->flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, 0, OFF_T_MAX);
if (rc == MDBX_SUCCESS)
return MDBX_RESULT_TRUE /* Done: return with exclusive locking. */;
@@ -357,7 +375,7 @@ retry:
}
/* got shared, retry exclusive */
rc = lck_op(env->lck_mmap.fd, op_setlk, F_WRLCK, 0, 1);
rc = lck_setlk_with3retries(env->lck_mmap.fd, F_WRLCK, 0, 1);
if (rc == MDBX_SUCCESS)
goto continue_dxb_exclusive;
@@ -368,7 +386,7 @@ retry:
}
/* Lock against another process operating in without-lck or exclusive mode. */
rc = lck_op(env->lazy_fd, op_setlk, (env->flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, env->pid, 1);
rc = lck_setlk_with3retries(env->lazy_fd, (env->flags & MDBX_RDONLY) ? F_RDLCK : F_WRLCK, env->pid, 1);
if (rc != MDBX_SUCCESS) {
ERROR("%s, err %u", "lock-against-without-lck", rc);
eASSERT(env, MDBX_IS_ERROR(rc));
@@ -391,7 +409,7 @@ int lck_downgrade(MDBX_env *env) {
rc = lck_op(env->lazy_fd, op_setlk, F_UNLCK, env->pid + 1, OFF_T_MAX - env->pid - 1);
}
if (rc == MDBX_SUCCESS)
rc = lck_op(env->lck_mmap.fd, op_setlk, F_RDLCK, 0, 1);
rc = lck_setlk_with3retries(env->lck_mmap.fd, F_RDLCK, 0, 1);
if (unlikely(rc != 0)) {
ERROR("%s, err %u", "lck", rc);
assert(MDBX_IS_ERROR(rc));
@@ -410,10 +428,10 @@ int lck_upgrade(MDBX_env *env, bool dont_wait) {
rc = (env->pid > 1) ? lck_op(env->lazy_fd, cmd, F_WRLCK, 0, env->pid - 1) : MDBX_SUCCESS;
if (rc == MDBX_SUCCESS) {
rc = lck_op(env->lazy_fd, cmd, F_WRLCK, env->pid + 1, OFF_T_MAX - env->pid - 1);
if (rc != MDBX_SUCCESS && env->pid > 1 && lck_op(env->lazy_fd, op_setlk, F_UNLCK, 0, env->pid - 1))
if (rc != MDBX_SUCCESS && env->pid > 1 && lck_setlk_with3retries(env->lazy_fd, F_UNLCK, 0, env->pid - 1))
rc = MDBX_PANIC;
}
if (rc != MDBX_SUCCESS && lck_op(env->lck_mmap.fd, op_setlk, F_RDLCK, 0, 1))
if (rc != MDBX_SUCCESS && lck_setlk_with3retries(env->lck_mmap.fd, F_RDLCK, 0, 1))
rc = MDBX_PANIC;
}
if (unlikely(rc != 0)) {