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#include "thread.h"
#include "heap.h"
#include "pic.h"
#include "clock.h"
static thread *current_thread = nil;
void *thread_sched_stack = nil;
static event_queue queue_read = { 0, 0, nil };
event_queue queue_write = { 0, 0, nil };
thread *irq_services[16] = { nil };
void resume(void *stack, void *ret); // yield.asm
void thread_resume(void *ret, thread *t)
{
current_thread = t;
resume(t->stack, ret);
}
#define STACK_SIZE 0x10000
// aligned on 16-byte boundary
static void *alloc_stack(void **alloc)
{
usize stack = (usize) kmalloc(STACK_SIZE+16);
if (alloc != nil)
*alloc = (void *) stack;
stack += 16 - stack % 16;
return (void *) stack;
}
thread *thread_create(str name, void *init)
{
thread *t = kmalloc(sizeof *t);
t->name = name;
t->stack = alloc_stack(&t->stack_bottom) + STACK_SIZE - 16;
*(void **) t->stack = init;
t->stack -= 8*8;
return t;
}
void thread_sched(yield_arg *arg, void *stack)
{
if (current_thread != nil)
current_thread->stack = stack;
if (arg == nil) {
// TODO: add to some sort of runqueue? (nil means not polling for anything)
} else if (arg->exit) {
kfree(current_thread->stack_bottom);
kfree(current_thread);
current_thread = nil;
} else if (arg->timeout >= 0) {
// TODO: meow
}
for (;;) {
clock_sync();
if (queue_read.len == 0) {
disable_irqs();
// swap queues
event_queue tmp = queue_read;
queue_read = queue_write;
queue_write = tmp;
enable_irqs();
}
if (queue_read.len > 0) {
event *e = kmalloc(sizeof *e);
*e = queue_read.data[--queue_read.len];
if (irq_services[e->irq] == nil)
kfree(e); // *shrug*
else
// this never returns. callee must free e
thread_resume(e, irq_services[e->irq]);
}
wait_irq();
}
}
void thread_init()
{
thread_sched_stack = alloc_stack(nil)+STACK_SIZE-8;
queue_read = (event_queue) { 0, 1024, kmalloc(1024 * sizeof(event)) };
queue_write = (event_queue) { 0, 1024, kmalloc(1024 * sizeof(event)) };
}
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