/**
* Remove a descriptor from the set of descriptors within the
* polling environment.
* The state change command may fail because concurrent threads may call
* dcb_set_state simultaneously and the conflict is prevented in dcb_set_state.
*
* @param dcb The descriptor to remove
* @return -1 on error or 0 on success
*/
int
poll_remove_dcb(DCB *dcb)
{
struct epoll_event ev;
int rc = -1;
dcb_state_t old_state = DCB_STATE_UNDEFINED;
dcb_state_t new_state = DCB_STATE_NOPOLLING;
CHK_DCB(dcb);
/*< It is possible that dcb has already been removed from the set */
if (dcb->state != DCB_STATE_POLLING)
{
if (dcb->state == DCB_STATE_NOPOLLING ||
dcb->state == DCB_STATE_ZOMBIE)
{
rc = 0;
}
goto return_rc;
}
/*<
* Set state to NOPOLLING and remove dcb from poll set.
*/
if (dcb_set_state(dcb, new_state, &old_state))
{
/**
* Only positive fds can be removed from epoll set.
*/
if (dcb->fd > 0)
{
rc = epoll_ctl(epoll_fd, EPOLL_CTL_DEL, dcb->fd, &ev);
if (rc != 0) {
int eno = errno;
errno = 0;
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : epoll_ctl failed due %d, %s.",
eno,
strerror(eno))));
}
ss_dassert(rc == 0); /*< trap in debug */
}
}
/*<
* This call was redundant, but the end result is correct.
*/
else if (old_state == new_state)
{
rc = 0;
goto return_rc;
}
/*< Set bit for each maxscale thread */
bitmask_copy(&dcb->memdata.bitmask, poll_bitmask());
rc = 0;
return_rc:
return rc;
}
/**
* @brief
* get_cpubits() and get_membits() initialize memory bitmasks used to
* represent the CPUs (resp. memory boards) discovered while parsing
* vnode definitions files.
*
* @param[in] m - pointer to bitmask structure
*
* @return Void
*
*/
void
get_membits(struct bitmask *m)
{
assert(m != NULL);
if (mem_mask != NULL) {
assert(bitmask_nbits(m) == bitmask_nbits(mem_mask));
(void) bitmask_copy(m, mem_mask);
} else {
bitmask_clearall(m);
log_err(PBSE_SYSTEM, __func__, "mem_mask not yet initialized");
}
}
