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authorChristian Cunningham <cc@localhost>2022-03-18 12:57:53 -0700
committerChristian Cunningham <cc@localhost>2022-03-18 12:57:53 -0700
commit94f2b0b8f48f5715975446c637a078008fb7e941 (patch)
tree2fb1744748e3bd4c93b2dae65a6033763c17e737 /src/sys
parent7ea4a4e970ae4a72ac7b58e98d232662d580ed47 (diff)
Generalized Queue
Diffstat (limited to 'src/sys')
-rw-r--r--src/sys/schedule.c246
1 files changed, 128 insertions, 118 deletions
diff --git a/src/sys/schedule.c b/src/sys/schedule.c
index 389aa1d..748f7ed 100644
--- a/src/sys/schedule.c
+++ b/src/sys/schedule.c
@@ -26,27 +26,31 @@ void init_scheduler(void)
// Initialize Scheduling Queues
for (unsigned long p = 0; p < PRIORITIES; p++) {
// Ready Init
- scheduler.ready[p].start.thread = 0;
+ scheduler.ready[p].start.value = 0;
scheduler.ready[p].start.next = &scheduler.ready[p].end;
scheduler.ready[p].start.entry_type = START_ENTRY;
- scheduler.ready[p].end.thread = 0;
+ scheduler.ready[p].end.value = 0;
scheduler.ready[p].end.next = &scheduler.ready[p].start;
scheduler.ready[p].end.entry_type = END_ENTRY;
// Mutex Wait Init
- scheduler.mwait[p].start.thread = 0;
+ scheduler.mwait[p].start.value = 0;
scheduler.mwait[p].start.next = &scheduler.mwait[p].end;
scheduler.mwait[p].start.entry_type = START_ENTRY;
- scheduler.mwait[p].end.thread = 0;
+ scheduler.mwait[p].end.value = 0;
scheduler.mwait[p].end.next = &scheduler.mwait[p].start;
scheduler.mwait[p].end.entry_type = END_ENTRY;
// Signal Wait Init
- scheduler.swait[p].start.thread = 0;
+ scheduler.swait[p].start.value = 0;
scheduler.swait[p].start.next = &scheduler.swait[p].end;
scheduler.swait[p].start.entry_type = START_ENTRY;
- scheduler.swait[p].end.thread = 0;
+ scheduler.swait[p].end.value = 0;
scheduler.swait[p].end.next = &scheduler.swait[p].start;
scheduler.swait[p].end.entry_type = END_ENTRY;
}
+ scheduler.free_threads.start.value = 0;
+ scheduler.free_threads.start.entry_type = START_ENTRY;
+ scheduler.free_threads.end.value = 0;
+ scheduler.free_threads.end.entry_type = END_ENTRY;
// Initialize nextpid
nextpid = FIRST_AVAIL_PID;
@@ -56,20 +60,22 @@ void init_scheduler(void)
struct Thread* t = &threads[i];
t->offset = i;
t->sp_base = 0x20000000 - STACK_SIZE*i;
- // Clear the stack use
- thread_table[i] = 0;
- struct ThreadEntry* te = &thread_entries[i];
- te->thread = t;
+ struct Entry* te = &thread_entries[i];
+ te->value = t;
// Initialize To No Next Entry Initially
- te->next = 0;
- te->entry_type = THREAD_ENTRY;
+ te->next = &thread_entries[(i+1)%MAX_THREADS];
+ te->entry_type = VALUE_ENTRY;
}
+ // Initialize the free queue
+ scheduler.free_threads.start.next = &thread_entries[0];
+ scheduler.free_threads.end.next = &thread_entries[MAX_THREADS-1];
+ thread_entries[MAX_THREADS-1].next = &scheduler.free_threads.end;
}
-void push_to_queue(struct Thread* t, unsigned char type, unsigned char priority)
+void push_thread_to_queue(struct Thread* t, unsigned char type, unsigned char priority)
{
- struct ThreadEntry* entry = &thread_entries[t->offset];
- struct ThreadQueue* queue;
+ struct Entry* entry = &thread_entries[t->offset];
+ struct Queue* queue;
if (type == THREAD_READY) {
queue = &scheduler.ready[priority];
} else if (type == THREAD_MWAIT) {
@@ -79,15 +85,16 @@ void push_to_queue(struct Thread* t, unsigned char type, unsigned char priority)
} else {
return;
}
- queue->end.next->next = entry;
- queue->end.next = entry;
- entry->next = &queue->end;
+ push_to_queue(entry, queue);
+ //queue->end.next->next = entry;
+ //queue->end.next = entry;
+ //entry->next = &queue->end;
}
-void prepend_to_queue(struct Thread* t, unsigned char type, unsigned char priority)
+void prepend_thread_to_queue(struct Thread* t, unsigned char type, unsigned char priority)
{
- struct ThreadEntry* entry = &thread_entries[t->offset];
- struct ThreadQueue* queue;
+ struct Entry* entry = &thread_entries[t->offset];
+ struct Queue* queue;
if (type == THREAD_READY) {
queue = &scheduler.ready[priority];
} else if (type == THREAD_MWAIT) {
@@ -97,16 +104,17 @@ void prepend_to_queue(struct Thread* t, unsigned char type, unsigned char priori
} else {
return;
}
- entry->next = queue->start.next;
- queue->start.next = entry;
- if (entry->next->entry_type == END_ENTRY)
- queue->end.next = entry;
+ prepend_to_queue(entry, queue);
+ //entry->next = queue->start.next;
+ //queue->start.next = entry;
+ //if (entry->next->entry_type == END_ENTRY)
+ // queue->end.next = entry;
}
-struct ThreadEntry* pop_from_queue(unsigned char type, unsigned char priority)
+struct Entry* pop_thread_from_queue(unsigned char type, unsigned char priority)
{
- struct ThreadEntry* entry = 0;
- struct ThreadQueue* queue;
+ struct Entry* entry = 0;
+ struct Queue* queue;
if (type == THREAD_READY) {
queue = &scheduler.ready[priority];
} else if (type == THREAD_MWAIT) {
@@ -116,40 +124,41 @@ struct ThreadEntry* pop_from_queue(unsigned char type, unsigned char priority)
} else {
return entry;
}
- if (queue->start.next->entry_type == END_ENTRY)
- return entry;
- entry = queue->start.next;
- queue->start.next = entry->next;
- if (entry->next->entry_type == END_ENTRY)
- queue->end.next = &queue->start;
- return entry;
+ return pop_from_queue(queue);
+ //if (queue->start.next->entry_type == END_ENTRY)
+ // return entry;
+ //entry = queue->start.next;
+ //queue->start.next = entry->next;
+ //if (entry->next->entry_type == END_ENTRY)
+ // queue->end.next = &queue->start;
+ //return entry;
}
-struct ThreadEntry* remove_next_from_queue(struct ThreadEntry* te)
-{
- struct ThreadEntry* prev = te;
- struct ThreadEntry* remove = te->next;
- struct ThreadEntry* next = remove->next;
- if (remove->entry_type == END_ENTRY || remove->entry_type == START_ENTRY)
- return 0;
- prev->next = next;
- if (next->entry_type == END_ENTRY)
- next->next = prev;
- return remove;
-}
+//struct Entry* remove_next_from_queue(struct Entry* te)
+//{
+// struct Entry* prev = te;
+// struct Entry* remove = te->next;
+// struct Entry* next = remove->next;
+// if (remove->entry_type == END_ENTRY || remove->entry_type == START_ENTRY)
+// return 0;
+// prev->next = next;
+// if (next->entry_type == END_ENTRY)
+// next->next = prev;
+// return remove;
+//}
-struct ThreadEntry* find_pid(unsigned long pid)
+struct Entry* find_pid(unsigned long pid)
{
for (unsigned char p = 0; p < PRIORITIES; p++) {
- struct ThreadQueue* queue;
- struct ThreadEntry* prev;
- struct ThreadEntry* entry;
+ struct Queue* queue;
+ struct Entry* prev;
+ struct Entry* entry;
queue = &scheduler.ready[p];
prev = &queue->start;
entry = prev->next;
while (entry->entry_type != END_ENTRY) {
- if (entry->thread->pid == pid)
+ if (((struct Thread*)entry->value)->pid == pid)
return prev;
prev = entry;
entry = entry->next;
@@ -159,7 +168,7 @@ struct ThreadEntry* find_pid(unsigned long pid)
prev = &queue->start;
entry = prev->next;
while (entry->entry_type != END_ENTRY) {
- if (entry->thread->pid == pid)
+ if (((struct Thread*)entry->value)->pid == pid)
return prev;
prev = entry;
entry = entry->next;
@@ -169,7 +178,7 @@ struct ThreadEntry* find_pid(unsigned long pid)
prev = &queue->start;
entry = prev->next;
while (entry->entry_type != END_ENTRY) {
- if (entry->thread->pid == pid)
+ if (((struct Thread*)entry->value)->pid == pid)
return prev;
prev = entry;
entry = entry->next;
@@ -178,14 +187,14 @@ struct ThreadEntry* find_pid(unsigned long pid)
return 0;
}
-struct ThreadEntry* find_mutex_wait_next(void* m)
+struct Entry* find_mutex_wait_next(void* m)
{
for (unsigned char p = 0; p < PRIORITIES; p++) {
- struct ThreadQueue* queue = &scheduler.mwait[p];
- struct ThreadEntry* prev = &queue->start;
- struct ThreadEntry* entry = prev->next;
+ struct Queue* queue = &scheduler.mwait[p];
+ struct Entry* prev = &queue->start;
+ struct Entry* entry = prev->next;
while (entry->entry_type != END_ENTRY) {
- if (entry->thread->mptr == m)
+ if (((struct Thread*)entry->value)->mptr == m)
return prev;
prev = entry;
entry = entry->next;
@@ -194,14 +203,14 @@ struct ThreadEntry* find_mutex_wait_next(void* m)
return 0;
}
-struct ThreadEntry* find_signal_wait_next(void* s)
+struct Entry* find_signal_wait_next(void* s)
{
for (unsigned char p = 0; p < PRIORITIES; p++) {
- struct ThreadQueue* queue = &scheduler.swait[p];
- struct ThreadEntry* prev = &queue->start;
- struct ThreadEntry* entry = prev->next;
+ struct Queue* queue = &scheduler.swait[p];
+ struct Entry* prev = &queue->start;
+ struct Entry* entry = prev->next;
while (entry->entry_type != END_ENTRY) {
- if (entry->thread->mptr == s)
+ if (((struct Thread*)entry->value)->mptr == s)
return prev;
prev = entry;
entry = entry->next;
@@ -210,22 +219,24 @@ struct ThreadEntry* find_signal_wait_next(void* s)
return 0;
}
-struct Thread* get_unused_thread(void)
+struct Entry* get_unused_thread(void)
{
- for(unsigned long i = 0; i < MAX_THREADS; i++) {
- if (thread_table[i] == 0)
- return &threads[i];
- }
- return 0;
+ struct Queue* q = &scheduler.free_threads;
+ // If we have no available free threads
+ // return null pointer
+ if (q->start.next->entry_type == END_ENTRY)
+ return 0;
+ // Otherwise, get the next thread
+ return pop_from_queue(q);
}
unsigned char find_duplicate(void* pc)
{
for (unsigned char p = 0; p < PRIORITIES; p++) {
- struct ThreadQueue* queue = &scheduler.ready[p];
- struct ThreadEntry* entry = queue->start.next;
- while (entry->entry_type == THREAD_ENTRY) {
- if (entry->thread->pc == pc) {
+ struct Queue* queue = &scheduler.ready[p];
+ struct Entry* entry = queue->start.next;
+ while (entry->entry_type == VALUE_ENTRY) {
+ if (((struct Thread*)entry->value)->pc == pc) {
return 1;
}
}
@@ -243,12 +254,11 @@ unsigned char add_thread_without_duplicate(void* pc, void* arg, unsigned char pr
unsigned char add_thread(void* pc, void* arg, unsigned char priority)
{
- struct Thread* thread = get_unused_thread();
+ struct Entry* thread_entry = get_unused_thread();
// The only point-of-failure is not having a thread available
- if (thread == 0)
+ if (thread_entry == 0)
return 1;
- /// Mark the Stack Space as In-Use
- thread_table[thread->offset] = 1;
+ struct Thread* thread = thread_entry->value;
/// Thread Setup
thread->pc = pc;
unsigned long* argp = (void*)thread->sp_base;
@@ -274,7 +284,7 @@ unsigned char add_thread(void* pc, void* arg, unsigned char priority)
// Reserved for non-preemptible tasking
thread->preempt = 0;
/// Add Thread to Scheduler
- push_to_queue(thread, THREAD_READY, thread->priority);
+ push_thread_to_queue(thread, THREAD_READY, thread->priority);
// Schedule if this was called in usermode
unsigned long mode = getmode() & 0x1F;
if (mode == 0x10) {
@@ -293,16 +303,16 @@ void uart_scheduler(void)
uart_string("Priority ");
uart_10(p);
uart_char('\n');
- struct ThreadQueue* queue;
- struct ThreadEntry* entry;
+ struct Queue* queue;
+ struct Entry* entry;
queue = &scheduler.ready[p];
uart_string("Ready Queue\n");
entry = queue->start.next;
while (entry->entry_type != END_ENTRY) {
- uart_hex((unsigned long)entry->thread);
+ uart_hex((unsigned long)entry->value);
uart_char(' ');
- kmemshow32((void*)entry->thread, 9);
+ kmemshow32((void*)entry->value, 9);
entry = entry->next;
}
@@ -310,9 +320,9 @@ void uart_scheduler(void)
uart_string("Mutex Wait Queue\n");
entry = queue->start.next;
while (entry->entry_type != END_ENTRY) {
- uart_hex((unsigned long)entry->thread);
+ uart_hex((unsigned long)entry->value);
uart_char(' ');
- kmemshow32((void*)entry->thread, 9);
+ kmemshow32((void*)entry->value, 9);
entry = entry->next;
}
@@ -320,9 +330,9 @@ void uart_scheduler(void)
uart_string("Signal Wait Queue\n");
entry = queue->start.next;
while (entry->entry_type != END_ENTRY) {
- uart_hex((unsigned long)entry->thread);
+ uart_hex((unsigned long)entry->value);
uart_char(' ');
- kmemshow32((void*)entry->thread, 9);
+ kmemshow32((void*)entry->value, 9);
entry = entry->next;
}
}
@@ -333,10 +343,10 @@ struct Thread* next_thread(void)
{
// Recurse through all priorities to try to find a ready thread
for (int p = 0; p < PRIORITIES; p++) {
- struct ThreadQueue* rq = &scheduler.ready[p];
+ struct Queue* rq = &scheduler.ready[p];
if (rq->start.next->entry_type == END_ENTRY)
continue;
- return rq->start.next->thread;
+ return rq->start.next->value;
}
// No thread found, use basic usrloopthread while waiting for new thread
return &usrloopthread;
@@ -345,9 +355,9 @@ struct Thread* next_thread(void)
void c_cleanup(void)
{
struct Thread* rt = scheduler.rthread;
- pop_from_queue(THREAD_READY, rt->priority);
- // Mark Thread Unused
- thread_table[rt->offset] = 0;
+ struct Entry* e = pop_thread_from_queue(THREAD_READY, rt->priority);
+ // Add to free threads
+ prepend_to_queue(e, &scheduler.free_threads);
}
void yield(void)
@@ -359,12 +369,12 @@ void yield(void)
// Put current thread at the end of its ready queue,
// thus any threads of the same priority can be run first
unsigned char priority = rthread->priority;
- struct ThreadEntry* tq;
+ struct Entry* tq;
// Remove from top of queue
- tq = pop_from_queue(THREAD_READY, priority);
+ tq = pop_thread_from_queue(THREAD_READY, priority);
if (tq != 0) {
// Add to bottom of queue
- push_to_queue(tq->thread, THREAD_READY, priority);
+ push_thread_to_queue(tq->value, THREAD_READY, priority);
}
}
@@ -377,30 +387,30 @@ void sched_mutex_yield(void* m)
unsigned char priority = rthread->priority;
// Signify which lock this thread is waiting for
rthread->mptr = m;
- struct ThreadEntry* rt;
+ struct Entry* rt;
// Remove from top of running queue
- rt = pop_from_queue(THREAD_READY, priority);
+ rt = pop_thread_from_queue(THREAD_READY, priority);
if (rt != 0)
// Push to bottom of wait queue
- push_to_queue(rt->thread, THREAD_MWAIT, priority);
+ push_thread_to_queue(rt->value, THREAD_MWAIT, priority);
// Find the thread that has the mutex locked
struct Mutex* mtex = m;
- struct ThreadEntry* mutex_next = find_pid(mtex->pid);
+ struct Entry* mutex_next = find_pid(mtex->pid);
if (mutex_next == 0)
return;
// The next thread is the one with the lock
- struct ThreadEntry* mutex_thread_entry = mutex_next->next;
+ struct Entry* mutex_thread_entry = mutex_next->next;
// Check if it is lower priority
- if (mutex_thread_entry->thread->priority > priority) {
+ if (((struct Thread*)mutex_thread_entry->value)->priority > priority) {
// Remove it from the old priority queue
remove_next_from_queue(mutex_next);
- struct Thread* t = mutex_thread_entry->thread;
+ struct Thread* t = mutex_thread_entry->value;
// Preserve the old priority
if (t->old_priority == 0xFF)
t->old_priority = t->priority;
t->priority = priority;
// Add it to the higher priority queue
- push_to_queue(t, THREAD_READY, priority);
+ push_thread_to_queue(t, THREAD_READY, priority);
}
}
@@ -413,22 +423,22 @@ void sched_semaphore_yield(void* s)
unsigned char priority = rthread->priority;
// Signify which lock this thread is waiting for
rthread->mptr = s;
- struct ThreadEntry* rt;
+ struct Entry* rt;
// Remove from top of running queue
- rt = pop_from_queue(THREAD_READY, priority);
+ rt = pop_thread_from_queue(THREAD_READY, priority);
if (rt != 0)
// Push to bottom of wait queue
- push_to_queue(rt->thread, THREAD_SWAIT, priority);
+ push_thread_to_queue(rt->value, THREAD_SWAIT, priority);
}
void sched_mutex_resurrect(void* m)
{
// Find any mutex to resurrect
- struct ThreadEntry* prev = find_mutex_wait_next(m);
+ struct Entry* prev = find_mutex_wait_next(m);
if (prev == 0)
return;
- struct ThreadEntry* entry = prev->next;
- struct Thread* thread = entry->thread;
+ struct Entry* entry = prev->next;
+ struct Thread* thread = entry->value;
// Resurrect the thread
thread->mptr = 0;
// Remove from wait queue
@@ -436,28 +446,28 @@ void sched_mutex_resurrect(void* m)
if (entry == 0)
return;
// Add to ready queue
- push_to_queue(entry->thread, THREAD_READY, entry->thread->priority);
+ push_thread_to_queue(entry->value, THREAD_READY, ((struct Thread*)entry->value)->priority);
// Demote current thread
struct Thread* rthread = scheduler.rthread;
unsigned long p = rthread->priority;
unsigned long op = rthread->old_priority;
// Restore the original priority level
if (op != 0xFF) {
- struct ThreadEntry* tentry = pop_from_queue(THREAD_READY, p);
- tentry->thread->priority = op;
- tentry->thread->old_priority = 0xFF;
- prepend_to_queue(tentry->thread, THREAD_READY, op);
+ struct Entry* tentry = pop_thread_from_queue(THREAD_READY, p);
+ ((struct Thread*)entry->value)->priority = op;
+ ((struct Thread*)entry->value)->old_priority = 0xFF;
+ prepend_thread_to_queue(tentry->value, THREAD_READY, op);
}
}
void sched_semaphore_resurrect(void* s)
{
// Find any signal/ semaphore to resurrect
- struct ThreadEntry* prev = find_signal_wait_next(s);
+ struct Entry* prev = find_signal_wait_next(s);
if (prev == 0)
return;
- struct ThreadEntry* entry = prev->next;
- struct Thread* thread = entry->thread;
+ struct Entry* entry = prev->next;
+ struct Thread* thread = entry->value;
// Resurrect the thread
thread->mptr = 0;
// Remove from wait queue
@@ -465,5 +475,5 @@ void sched_semaphore_resurrect(void* s)
if (entry == 0)
return;
// Add to ready queue
- push_to_queue(entry->thread, THREAD_READY, entry->thread->priority);
+ push_thread_to_queue(entry->value, THREAD_READY, ((struct Thread*)entry->value)->priority);
}