int _ioreq_enqueue(Drive *d, Fd *fd, Uint8 rd, Iostate state){
Status status;
Key key;
Iorequest *req;
if( (status = _q_remove( free_req_q, (void **) &req ))!= SUCCESS ) {
_kpanic( "_ioreq_enqueue", "No free requests. Status: %s", status );
}
key.v =(void *) d;
req->d=d;
req->fd=fd;
req->read=rd;
req->st=state;
if (state == WAIT_ON_IDLE){
status = _q_insert( idle_q,(void *) req, key);
}else if (state == WAIT_ON_DATA){
status = _q_insert( data_q,(void *) req, key);
}else{
//drop invalid request
status=FAILURE;
}
if( status != SUCCESS ) {
_kpanic( "_ioreq_enqueue", "IO queue insertion status %s", status );
}
return 1;
}
void _dispatch( void ) {
int i;
Status status;
// select a process from the highest-priority
// ready queue that is not empty
for( i = 0; i < N_READYQ; ++i ) {
do {
if( _q_empty(_ready[i]) ) {
break;
}
// found one - make it the currently-running process
status = _q_remove( _ready[i], (void **) &_current );
if( status == SUCCESS ) {
// check to see if it needs to be cleaned up
if( _current->state == KILLED ) {
// yes - deallocate it
_cleanup( _current );
// go back and re-check this queue
continue;
}
_current->state = RUNNING;
_current->quantum = STD_QUANTUM;
return;
} else {
_kpanic( "_dispatch", "readyq deque status %s",
status );
}
} while( 1 );
}
_kpanic( "_dispatch", "no non-empty readyq", EMPTY_QUEUE );
}
status_t _q_remove_by_key( queue_t *queue, void **data, key_t key ) {
qnode_t *qnode;
status_t stat;
// verify that our parameters are usable
if( queue == NULL || data == NULL ) {
return( E_BAD_PARAM );
}
// if the queue is empty, nothing to do
if( _q_empty(queue) ) {
return( E_EMPTY );
}
// if there is no specialized removal routine, do an ordinary remove
if( queue->remove == NULL ) {
return( _q_remove(queue,data) );
}
//
// Traverse the queue, looking for the correct element.
// Use the built-in removal routine to determine when
// we have found the correct entry.
//
qnode = queue->head;
while( qnode != NULL && !queue->remove(qnode->key,key) ) {
qnode = qnode->next;
}
// did we find the one we wanted?
if( qnode == NULL ) {
return( E_NOT_FOUND );
}
// found the correct node - unlink it from the queue
if( qnode->prev != NULL ) {
qnode->prev->next = qnode->next;
} else {
queue->head = qnode->next;
}
if( qnode->next != NULL ) {
qnode->next->prev = qnode->prev;
} else {
queue->tail = qnode->prev;
}
queue->length -= 1;
// return the data from the node
*data = qnode->data;
// release the qnode
//
// INCONSISTENCY: _q_remove() just propogates the status
stat = _qnode_free( qnode );
if( stat != E_SUCCESS ) {
_kpanic( "_q_remove_by_key", "qnode free failed, %s", stat );
}
return( E_SUCCESS );
}
