void _ioreq_handle_idle_request(Drive *d){
Status status;
Key key;
Iorequest *req;
key.v = (void *) d;
status = _q_remove_by_key( idle_q, (void **) &req, key );
if(status == NOT_FOUND || status == EMPTY_QUEUE){
d->state=IDLE;
req = NULL; //wasn't found
return;
} else if (status != SUCCESS){
_kpanic("handle_idle_request", "remove status", status);
}
if (! (_ata_pio_read_status(d) & (BSY | DRQ)) ){
if (req->read){
//send read request and add the data queue
d->state=READING;
req->st = WAIT_ON_DATA;
_q_insert(data_q, (void *) req, key);
_ata_pio_send_read(req->fd->device_data);
} else {
//transfer data and send write reqest
d->state=WRITING;
_ata_pio_send_write(req->fd->device_data);
_ata_pio_write_fd_block(req->fd);
_fd_writeDone(req->fd);
_ioreq_dealloc(req);
}
}else {
//no idle request on disk, despite removing from idle queue.. this shouldn't happen
_q_insert(idle_q, (void *) req, key);
}
}
/**
* Removes the PCB from the buf_block queue. Note, the PCB of the process is
* still returned even if the PCB could not be removed from the buf_block
* queue, but the PCB may be 0 if the corresponding process could not be found.
*
* @param index The index in the requests array of the process to
* remove.
* returns The PCB of the process that was removed, or 0 if the
* index was too large. Note, the PCB returned may be 0
* if the corresponding process could not be found.
*/
Pcb *_ps2_remove_from_queue( Uint8 index ){
if( index >= TOTAL_IO_REQS )
return 0;
void *data;
Key key;
key.u = requests[ index ]->pid;
Status status = _q_remove_by_key( _buf_block, &data, key );
Pcb *pcb = ( Pcb* ) data;
if( status != SUCCESS ){
prt_status( "keyboard, write active: Unable to remove process"
" in buf block queue!\nError: %s\n", status);
}
return pcb;
}
/**
* Performs a blocking buffered read for keyboard input.
*
* Keystrokes are stored in the buffer and will not stop filling the buffer
* until 'size' characters has been read. If there is an error when processing
* the read request, the buffer will be left untouched. Otherwise undefined
* behavior is defined for errors after the read request is processed. Note,
* only user programs which have focus will recieve characters.
*
* @param buf The buffer to fill with character input from the keyboard.
* @param size The number of characters to read.
*/
int buf_read( char* buf, int size, Pcb* cur ){
// Create an IO-Request block
int index = _ps2_get_io_req();
if( index == -1 ){
Key key;
key.u = cur->pid;
void *data;
_q_remove_by_key( _buf_block, &data, key );
_sched( cur );
return 0;
}
// Initialize IO-request
requests[index]->pid = cur->pid;
requests[index]->pdt = (Uint32)cur->pdt;
requests[index]->buf = buf;
requests[index]->size = size;
requests[index]->index = 0;
return 1;
}
void _ioreq_handle_data_request(Drive *d){
Status status;
Key key;
Iorequest *req;
key.v = d;
status = _q_remove_by_key( data_q, (void **) &req, key );
if(status == NOT_FOUND || status == EMPTY_QUEUE){
req = NULL; //wasn't found
//no data request on disk. Unsolicited data
int i,j;
for (i =0; i< 4;i++){
for (j=0;j<4;j++){
if (&_busses[i].drives[j]==d){
c_printf("bus[%d].drive[%d] %s",i,j,d->model);
}
}
}
_kpanic("handle_data_request", "Got unsolicited data.",FAILURE);
return;
}
if (req->st == WAIT_ON_DATA){
if (req->read){
//send read request and add the data queue
req->d->state=IDLE;
_ata_read_finish(req->fd);
_ioreq_dealloc(req);
} else {
//Unsolicited data...
_kpanic("handle_data_request", "Got unsolicited, but waiting to write only.",FAILURE);
}
}else {
//no data request on disk. Unsolicited data
_kpanic("handle_data_request", "Got unsolicited data.",FAILURE);
}
}
void _zombify( pcb_t *pcb ) {
pcb_t *parent;
status_t stat;
pid_t pid;
key_t key;
info_t *info;
// sanity check
if( pcb == NULL ) {
_kpanic( "_zombify", "null pcb", 0 );
}
// Locate the parent of this process
parent = _pcb_find( pcb->ppid );
if( parent == NULL ) {
c_printf( "** zombify(): pid %d ppid %d\n",
pcb->pid, pcb->ppid );
_kpanic( "_zombify", "no process parent", 0 );
}
//
// Found the parent. If it's waiting for this process,
// wake it up, give it this process' status, and clean up.
//
if( parent->state == WAITING ) {
// get the address of the info structure from the
// parent, and pull out the desired PID
info = (info_t *) ARG(parent->context,1);
pid = info->pid;
// if the parent was waiting for any of its children
// or was waiting for us specifically, give it our
// information and terminate this process.
//
// if the parent was waiting for another child,
// turn this process into a zombie.
if( pid == 0 || pid == _current->pid ) {
// pull the parent off the waiting queue
key.u = parent->pid;
stat = _q_remove_by_key(&_waiting,(void **)&parent,key);
if( stat != E_SUCCESS ) {
_kpanic( "_zombify", "wait remove status %s",
stat );
}
// return our PID and our termination status
// to the parent
info->pid = _current->pid;
info->status = ARG(_current->context,1);
// clean up this process
stat = _stack_free( pcb->stack );
if( stat != E_SUCCESS ) {
_kpanic( "_zombify", "stack free status %s",
stat );
}
stat = _pcb_free( pcb );
if( stat != E_SUCCESS ) {
_kpanic( "_zombify", "pcb free status %s",
stat );
}
// schedule the parent; give it a quick dispatch
_schedule( parent, PRIO_MAXIMUM );
return;
}
}
//
// Our parent either wasn't waiting, or was waiting for someone
// else. Put this process on the zombie queue until our parent
// wants us.
//
key.u = _current->pid;
_current->state = ZOMBIE;
stat = _q_insert( &_zombie, (void *)_current, key );
if( stat != E_SUCCESS ) {
_kpanic( "_zombify", "zombie insert status %s", stat );
}
}
