Fixing scheduling bug

include/scheduler/sched.h

@@ -22,6 +22,7 @@ struct thread {
     proc_state state;
     uint16_t pid;
     struct context *context;
+    char name[8];
 };
 
 void scheduler_init();

src/scheduler/sched.c

@@ -11,6 +11,7 @@
 #include <scheduler/sched.h>
 
 extern void switch_context(struct context **old, struct context *new);
+extern void sched_enter(void *a);
 
 struct ma_cache *thread_cache;
 struct thread *idle;
@@ -27,30 +28,27 @@ void idle_task(){
 
 void test_task(){
     kprintf("Hello world from scheduled task!\n");
-    //for(;;);
+    for(;;);
 }
 
 void best_task(){
     kprintf("Hello world I am best\n");
-    //for(;;);
+    for(;;);
 }
 
 void thread_exit(){
+    asm("cli");
     cpu_state *cpu = get_cpu_struct();
     struct thread *p = cpu->current_process;
 
-    if(p == p->next){
+    if(p == p->next || p->prev == p){
         // If this is the only thread in the queue then set cpu->head to NULL, so scheduler knows to idle
         cpu->head = NULL;
     }else{
         // Remove process from circular linked list
         p->next->prev = p->prev;
         p->prev->next = p->next;
-
-        if(p == cpu->head){
-            //cpu->head = p->next;
-        }
-
+        cpu->head = p->next;
     }
 
     p->state = ZOMBIE;
@@ -72,6 +70,7 @@ struct thread *alloc_thread(void){
 
     uint64_t *sp = (uint64_t*)((uint64_t)t->kstack + 8 * 4096);
     
+
     // Push the exit function (the thread will return to it when it finishes)
     *--sp = (uint64_t)thread_exit;
     
@@ -115,26 +114,23 @@ struct thread *add_thread(uint64_t *entry){
 
 
 [[noreturn]] void sched(){
+    cpu_state *cpu = get_cpu_struct();
     for(;;){
         asm("cli"); // we sti at the end of switch_context
-        cpu_state *cpu = get_cpu_struct();
-        struct thread *prev = cpu->current_process;
         
-        if(prev->state == ZOMBIE){
-            kprintf("we are freeing allocated thread 0x{x}\n", prev);
-            ma_cache_dealloc(prev);
-        }else{
-            prev->state = READY;
-        }
+        struct thread *prev = cpu->current_process;
 
         if(cpu->head == NULL){
             cpu->current_process = idle;
-        }else{
-            if(prev->next){
-                cpu->current_process = prev->next;
         }else{
             cpu->current_process = cpu->head;
+            cpu->head = cpu->head->next;
         }
+
+        if(prev->state == ZOMBIE){
+            ma_cache_dealloc(prev);
+        }else{
+            prev->state = READY;
         }
 
         cpu->current_process->state = RUNNING;
@@ -153,26 +149,32 @@ void scheduler_init(){
     }
 
     idle = alloc_thread();
-    idle->context->rip = (uint64_t)idle;
+    idle->context->rip = (uint64_t)idle_task;
 
     assert(idle != NULL && "Failed to allocate idle task!");
 
     cpu->current_process = idle;
 
     cpu->scheduler_stack = kzalloc(4096);
-    cpu->scheduler_context = (struct context*)((uint64_t)cpu->scheduler_stack + 4096);
+    cpu->scheduler_context = (struct context*)((uint64_t)cpu->scheduler_stack + 4096 - sizeof(struct context));
     cpu->scheduler_context->rbp = (uint64_t)cpu->scheduler_context;
     cpu->scheduler_context->rip = (uint64_t)sched;
 
-    add_thread((uint64_t*)test_task);
+    kprintf("og scheduler context: 0x{x}\n", cpu->scheduler_context);
     
-    add_thread((uint64_t *)best_task);
+    struct thread *t1 = add_thread((uint64_t*)test_task);
+    memcpy(t1->name, "testt", 6);
 
-    // Initialize scheduler -> we will now get timer interrupts to switch us into sched()
-    cpu->scheduler_initialized = true;
+    struct thread *t2 = add_thread((uint64_t *)best_task);
+    memcpy(t2->name, "bestt", 6);
+
+    cpu->scheduler_initialized = true; // Allow us to get interrupts that schedule us
+    
+    for(;;);
 }
 
 
 void yield(){
+    asm("cli");
     switch_context(&get_cpu_struct()->current_process->context, get_cpu_struct()->scheduler_context);
 }