/*
* In this function, you will be modifying the run queue, which can
* also be modified from an interrupt context. In order for thread
* contexts and interrupt contexts to play nicely, you need to mask
* all interrupts before reading or modifying the run queue and
* re-enable interrupts when you are done. This is analagous to
* locking a mutex before modifying a data structure shared between
* threads. Masking interrupts is accomplished by setting the IPL to
* high.
*
* Once you have masked interrupts, you need to remove a thread from
* the run queue and switch into its context from the currently
* executing context.
*
* If there are no threads on the run queue (assuming you do not have
* any bugs), then all kernel threads are waiting for an interrupt
* (for example, when reading from a block device, a kernel thread
* will wait while the block device seeks). You will need to re-enable
* interrupts and wait for one to occur in the hopes that a thread
* gets put on the run queue from the interrupt context.
*
* The proper way to do this is with the intr_wait call. See
* interrupt.h for more details on intr_wait.
*
* Note: When waiting for an interrupt, don't forget to modify the
* IPL. If the IPL of the currently executing thread masks the
* interrupt you are waiting for, the interrupt will never happen, and
* your run queue will remain empty. This is very subtle, but
* _EXTREMELY_ important.
*
* Note: Don't forget to set curproc and curthr. When sched_switch
* returns, a different thread should be executing than the thread
* which was executing when sched_switch was called.
*
* Note: The IPL is process specific.
*/
void
sched_switch(void)
{
/* Do I need to enque prevthr?
* Do I need to continue running prevthr if it is still runnable */
/*for bugs check Run Queue Access Slide */
uint8_t prev_ipl = intr_getipl();
intr_setipl(IPL_HIGH);
kthread_t *prevthr = curthr;
if (prevthr->kt_state == KT_RUN)
ktqueue_enqueue(&kt_runq, prevthr);
while (sched_queue_empty(&kt_runq)) {
panic("I never actually wait on things here");
intr_setipl(IPL_LOW);
intr_wait();
intr_setipl(IPL_HIGH);
}
/*If there is a thread*/
kthread_t *t = ktqueue_dequeue(&kt_runq);
curproc = t->kt_proc;
curthr = t;
/* NOT_YET_IMPLEMENTED("PROCS: sched_switch");*/
context_switch(&prevthr->kt_ctx, &curthr->kt_ctx);
intr_setipl(prev_ipl);
}
/*
* Should be called from the init proc
*/
static void test_proc_create(){
dbg(DBG_TEST, "testing proc_create\n");
proc_t *myproc = proc_create("myproc");
KASSERT(list_empty(&myproc->p_threads));
KASSERT(list_empty(&myproc->p_children));
KASSERT(sched_queue_empty(&myproc->p_wait));
KASSERT(myproc->p_pproc->p_pid == 1 && "created proc's parent isn't the init proc\n");
KASSERT(myproc->p_state == PROC_RUNNING);
/* make sure it's in the proc list */
KASSERT(proc_lookup(myproc->p_pid) == myproc && "created proc not in proc list\n");
/* make sure it's in it's parent's child list */
KASSERT(in_child_list(myproc));
/* clean everything up */
kthread_t *mythread = kthread_create(myproc, simple_function, NULL, NULL);
sched_make_runnable(mythread);
int status;
do_waitpid(myproc->p_pid, 0, &status);
dbg(DBG_TESTPASS, "all proc_create tests passed!\n");
}
void
sched_broadcast_on(ktqueue_t *q)
{
//NOT_YET_IMPLEMENTED("PROCS: sched_broadcast_on");
while (!sched_queue_empty(q)) {
kthread_t *thr = ktqueue_dequeue(q);
sched_make_runnable(thr);
}
}
void
sched_broadcast_on(ktqueue_t *q)
{
kthread_t *t;
while (!sched_queue_empty(q)) {
t = ktqueue_dequeue(q);
sched_make_runnable(t);
}
}
static void *
watch_dog(int arg1, void *arg2)
{
while(!sched_queue_empty(&mynode.my_queue)) {
dbg(DBG_TEST, "Watch_dog wake up all sleeping thread\n");
sched_broadcast_on(&mynode.my_queue);
sched_sleep_on(&mynode.my_queue);
}
return NULL;
}
kthread_t *
sched_wakeup_on(ktqueue_t *q)
{
//NOT_YET_IMPLEMENTED("PROCS: sched_wakeup_on");
if (sched_queue_empty(q)) {
return NULL;
}
kthread_t *thr = ktqueue_dequeue(q);
sched_make_runnable(thr);
return thr;
}
/* The thread executing this MUST be cancelled before it succesfully
* obtains the mutex. Otherwise, bad things will happen
*/
static void * cancellable_lock_kmutex(int arg1, void *arg2){
kmutex_t *m = (kmutex_t *) arg2;
int lock_result = kmutex_lock_cancellable(m);
KASSERT(lock_result == -EINTR);
KASSERT(m->km_holder == NULL);
KASSERT(sched_queue_empty(&m->km_waitq));
return NULL;
}
void
sched_broadcast_on(ktqueue_t *q)
{
/* Dequeue all from wait queue and make runnable */
while (!sched_queue_empty(q)) {
kthread_t *wake_thr = ktqueue_dequeue(q);
wake_thr->kt_wchan = NULL;
sched_make_runnable(wake_thr);
}
/* NOT_YET_IMPLEMENTED("PROCS: sched_broadcast_on"); */
}
static void test_do_waitpid(waitpid_type_t type){
proc_t *test_procs[NUM_PROCS];
kthread_t *test_threads[NUM_PROCS];
int i;
for (i = 0; i < NUM_PROCS; i++){
test_procs[i] = proc_create("test proc");
test_threads[i] = kthread_create(test_procs[i], simple_function, i, NULL);
sched_make_runnable(test_threads[i]);
}
int j;
for (j = 0; j < NUM_PROCS; j++){
if (type == ANY){
int status;
do_waitpid(-1, 0, &status);
} else {
int status;
pid_t proc_pid = test_procs[j]->p_pid;
pid_t waitpid_pid = do_waitpid(proc_pid, 0, &status);
KASSERT(waitpid_pid == proc_pid);
}
}
int k;
for (k = 0; k < NUM_PROCS; k++){
proc_t *p = test_procs[k];
KASSERT(proc_lookup(p->p_pid) == NULL);
/* make sure all children have been reparented */
KASSERT(list_empty(&p->p_children));
/* make sure that it is no longer in it's parent's
* child list
*/
KASSERT(!in_child_list(p));
/* make sure it exited with the correct status */
KASSERT(p->p_status == 0);
KASSERT(p->p_state == PROC_DEAD);
KASSERT(sched_queue_empty(&p->p_wait));
}
}
/*
* If there are any threads waiting to take a lock on the mutex, one
* should be woken up and given the lock.
*
* Note: This should _NOT_ be a blocking operation!
*
* Note: Don't forget to add the new owner of the mutex back to the
* run queue.
*
* Note: Make sure that the thread on the head of the mutex's wait
* queue becomes the new owner of the mutex.
*
* @param mtx the mutex to unlock
*/
void
kmutex_unlock(kmutex_t *mtx)
{
/*NOT_YET_IMPLEMENTED("PROCS: kmutex_unlock");*/
if(sched_queue_empty(&mtx->km_waitq))
{
mtx->km_holder=NULL;
}
else
{
mtx->km_holder=sched_wakeup_on(&mtx->km_waitq);
/*sched_switch();*/
}
}
kthread_t *
sched_wakeup_on(ktqueue_t *q)
{
if(!sched_queue_empty(q)) {
kthread_t *thr = ktqueue_dequeue(q);
KASSERT((thr->kt_state == KT_SLEEP) || (thr->kt_state == KT_SLEEP_CANCELLABLE));
dbg(DBG_PRINT, "(GRADING1A 4.a)\n");
sched_make_runnable(thr);
return thr;
} else {
dbg(DBG_PRINT, "(GRADING1C 1)\n");
return NULL;
}
/*NOT_YET_IMPLEMENTED("PROCS: sched_wakeup_on");
return NULL; */
}
kthread_t *
sched_wakeup_on(ktqueue_t *q)
{
if (sched_queue_empty(q)) return NULL;
/* If you get here, q was not empty, so there's someone to remove */
/* Dequeue one from given queue */
kthread_t *wake_thr = ktqueue_dequeue(q);
/* Reset pointer to queue wake_thr is waiting on */
wake_thr->kt_wchan = NULL;
/* Make runnable */
sched_make_runnable(wake_thr);
/* NOT_YET_IMPLEMENTED("PROCS: sched_wakeup_on"); */
return wake_thr;
}
/*
* In this function, you will be modifying the run queue, which can
* also be modified from an interrupt context. In order for thread
* contexts and interrupt contexts to play nicely, you need to mask
* all interrupts before reading or modifying the run queue and
* re-enable interrupts when you are done. This is analagous to
* locking a mutex before modifying a data structure shared between
* threads. Masking interrupts is accomplished by setting the IPL to
* high.
*
* Once you have masked interrupts, you need to remove a thread from
* the run queue and switch into its context from the currently
* executing context.
*
* If there are no threads on the run queue (assuming you do not have
* any bugs), then all kernel threads are waiting for an interrupt
* (for example, when reading from a block device, a kernel thread
* will wait while the block device seeks). You will need to re-enable
* interrupts and wait for one to occur in the hopes that a thread
* gets put on the run queue from the interrupt context.
*
* The proper way to do this is with the intr_wait call. See
* interrupt.h for more details on intr_wait.
*
* Note: When waiting for an interrupt, don't forget to modify the
* IPL. If the IPL of the currently executing thread masks the
* interrupt you are waiting for, the interrupt will never happen, and
* your run queue will remain empty. This is very subtle, but
* _EXTREMELY_ important.
*
* Note: Don't forget to set curproc and curthr. When sched_switch
* returns, a different thread should be executing than the thread
* which was executing when sched_switch was called.
*
* Note: The IPL is process specific.
*/
void
sched_switch(void)
{
//NOT_YET_IMPLEMENTED("PROCS: sched_switch");
uint8_t orig_ipl = intr_getipl();
intr_setipl(IPL_HIGH);
while (sched_queue_empty(&kt_runq)) {
intr_setipl(IPL_LOW);
intr_wait();
intr_setipl(IPL_HIGH);
}
kthread_t *thr = ktqueue_dequeue(&kt_runq);
context_t *old_context = &(curthr->kt_ctx);
context_t *new_context = &(thr->kt_ctx);
curthr = thr;
curproc = thr->kt_proc;
context_switch(old_context, new_context);
intr_setipl(orig_ipl);
}
/*
* In this function, you will be modifying the run queue, which can
* also be modified from an interrupt context. In order for thread
* contexts and interrupt contexts to play nicely, you need to mask
* all interrupts before reading or modifying the run queue and
* re-enable interrupts when you are done. This is analagous to
* locking a mutex before modifying a data structure shared between
* threads. Masking interrupts is accomplished by setting the IPL to
* high.
*
* Once you have masked interrupts, you need to remove a thread from
* the run queue and switch into its context from the currently
* executing context.
*
* If there are no threads on the run queue (assuming you do not have
* any bugs), then all kernel threads are waiting for an interrupt
* (for example, when reading from a block device, a kernel thread
* will wait while the block device seeks). You will need to re-enable
* interrupts and wait for one to occur in the hopes that a thread
* gets put on the run queue from the interrupt context.
*
* The proper way to do this is with the intr_wait call. See
* interrupt.h for more details on intr_wait.
*
* Note: When waiting for an interrupt, don't forget to modify the
* IPL. If the IPL of the currently executing thread masks the
* interrupt you are waiting for, the interrupt will never happen, and
* your run queue will remain empty. This is very subtle, but
* _EXTREMELY_ important.
*
* Note: Don't forget to set curproc and curthr. When sched_switch
* returns, a different thread should be executing than the thread
* which was executing when sched_switch was called.
*
* Note: The IPL is process specific.
*/
void
sched_switch(void)
{
/* dbg(DBG_PRINT, "(In sched switch)\n");*/
kthread_t *oldthr;
int oldIPL;
oldIPL=intr_getipl();
intr_setipl(IPL_HIGH);
while(sched_queue_empty(&kt_runq)) {
intr_disable();
intr_setipl(0);
intr_wait();
intr_setipl(IPL_HIGH);
}
oldthr=curthr;
curthr=ktqueue_dequeue(&kt_runq);
curproc = curthr->kt_proc;
context_switch(&(oldthr->kt_ctx),&(curthr->kt_ctx));
intr_setipl(oldIPL);
dbg(DBG_PRINT, "(GRADING1C 1)\n");
/*NOT_YET_IMPLEMENTED("PROCS: sched_switch");*/
}
/*
* In this function, you will be modifying the run queue, which can
* also be modified from an interrupt context. In order for thread
* contexts and interrupt contexts to play nicely, you need to mask
* all interrupts before reading or modifying the run queue and
* re-enable interrupts when you are done. This is analagous to
* locking a mutex before modifying a data structure shared between
* threads. Masking interrupts is accomplished by setting the IPL to
* high.
*
* Once you have masked interrupts, you need to remove a thread from
* the run queue and switch into its context from the currently
* executing context.
*
* If there are no threads on the run queue (assuming you do not have
* any bugs), then all kernel threads are waiting for an interrupt
* (for example, when reading from a block device, a kernel thread
* will wait while the block device seeks). You will need to re-enable
* interrupts and wait for one to occur in the hopes that a thread
* gets put on the run queue from the interrupt context.
*
* The proper way to do this is with the intr_wait call. See
* interrupt.h for more details on intr_wait.
*
* Note: When waiting for an interrupt, don't forget to modify the
* IPL. If the IPL of the currently executing thread masks the
* interrupt you are waiting for, the interrupt will never happen, and
* your run queue will remain empty. This is very subtle, but
* _EXTREMELY_ important.
*
* Note: Don't forget to set curproc and curthr. When sched_switch
* returns, a different thread should be executing than the thread
* which was executing when sched_switch was called.
*
* Note: The IPL is process specific.
*/
void
sched_switch(void)
{
kthread_t *next_thr;
/* Somewhere in here: set interrupts to protect run queue
intr_setipl(IPL_LOW) or IPL_HIGH, in include/main/interrupt.h
*/
uint8_t oldIPL = intr_getipl(); /* Check what currently running IPL is */
intr_setipl(IPL_HIGH); /* Block all hardware interrupts */
/* Enqueue requesting thread on run queue if still runnable
(dead threads become unschedulable)
*/
if (curthr->kt_state == KT_RUN) ktqueue_enqueue(&kt_runq, curthr);
/* Pick a runnable thread. Take someone off the run queue. */
/* If no threads on run queue, re-enable interrupts and wait for one to occur */
if (sched_queue_empty(&kt_runq)) {
intr_wait();
/* Once this returns, there should be a process in the run queue */
}
/* Remove a thread from the run queue */
next_thr = ktqueue_dequeue(&kt_runq);
/* Manage curproc, curthr */
kthread_t *old_thr = curthr;
proc_t *old_proc = curproc;
curthr = next_thr;
curproc = next_thr->kt_proc;
/* Switch context from old context to new context */
context_switch(&old_thr->kt_ctx, &curthr->kt_ctx);
/* NOT_YET_IMPLEMENTED("PROCS: sched_switch"); */
}
/*
* The tty subsystem calls this when the tty driver has received a
* character. Now, the line discipline needs to store it in its read
* buffer and move the read tail forward.
*
* Special cases to watch out for: backspaces (both ASCII characters
* 0x08 and 0x7F should be treated as backspaces), newlines ('\r' or
* '\n'), and full buffers.
*
* Return a null terminated string containing the characters which
* need to be echoed to the screen. For a normal, printable character,
* just the character to be echoed.
*/
const char *
n_tty_receive_char(tty_ldisc_t *ldisc, char c)
{
/* DRIVERS{{{ */
static const char echo_newline[] = {CR, LF, '\0'};
static const char echo_bs[] = {BS, SPACE, BS, '\0'};
static const char echo_esc[] = { '^', '\0' };
static const char echo_null[] = { '\0' };
static char echo_char[] = { ' ', '\0' };
n_tty_t *ntty;
KASSERT(NULL != ldisc);
ntty = ldisc_to_ntty(ldisc);
N_TTY_ASSERT_VALID(ntty);
switch (c) {
case BS:
case DEL:
dprintf("Received backspace\n");
if (!n_tty_rawbuf_empty(ntty)) {
n_tty_rawbuf_remove_last(ntty);
return echo_bs;
}
return echo_null;
case ESC:
dprintf("Received escape\n");
if (n_tty_rawbuf_almost_full(ntty)) return echo_null;
n_tty_rawbuf_enqueue(ntty, c);
return echo_esc;
case CR:
c = LF;
case LF:
dprintf("Received newline\n");
if (n_tty_rawbuf_full(ntty)) return echo_null;
n_tty_rawbuf_enqueue(ntty, c);
n_tty_rawbuf_cook(ntty);
if (!sched_queue_empty(&ntty->ntty_rwaitq)) {
kthread_t *thr = sched_wakeup_on(&ntty->ntty_rwaitq);
KASSERT(NULL != thr);
}
return echo_newline;
case EOT:
dprintf("Received EOT\n");
n_tty_rawbuf_cook(ntty);
if (!sched_queue_empty(&ntty->ntty_rwaitq)) {
kthread_t *thr = sched_wakeup_on(&ntty->ntty_rwaitq);
KASSERT(NULL != thr);
}
return echo_null;
default:
dprintf("Receiving printable character\n");
if (n_tty_rawbuf_almost_full(ntty)) return echo_null;
n_tty_rawbuf_enqueue(ntty, c);
echo_char[0] = c;
return echo_char;
}
panic("Should never get here\n");
/* DRIVERS }}} */
return NULL;
}
