tianole/kernel/sched/thread.c

137 lines
2.8 KiB
C

#include <stddef.h>
#include <stdint.h>
#include <tianole/early_log.h>
#include <tianole/mm.h>
#include <tianole/sched.h>
#define KERNEL_STACK_SIZE (PAGE_SIZE * 4u)
#define STACK_ALIGNMENT 16u
static struct thread *run_queue_head;
static struct thread *run_queue_tail;
static uint64_t next_thread_id = 1;
static int scheduler_ready;
static uintptr_t align_down_uintptr(uintptr_t value, uintptr_t alignment)
{
return value & ~(alignment - 1);
}
static void copy_thread_name(char *dest, size_t dest_size, const char *src)
{
size_t index;
if (dest_size == 0) {
return;
}
if (src == 0) {
src = "thread";
}
for (index = 0; index + 1 < dest_size && src[index] != '\0'; index++) {
dest[index] = src[index];
}
dest[index] = '\0';
}
static void enqueue_thread(struct thread *thread)
{
thread->next = 0;
if (run_queue_tail != 0) {
run_queue_tail->next = thread;
} else {
run_queue_head = thread;
}
run_queue_tail = thread;
}
struct thread *kernel_thread_create(
const char *name, kernel_thread_entry_t entry, void *arg)
{
struct thread *thread;
uintptr_t stack_top;
if (entry == 0) {
return 0;
}
thread = kmalloc(sizeof(*thread));
if (thread == 0) {
return 0;
}
thread->stack_base = kmalloc(KERNEL_STACK_SIZE);
if (thread->stack_base == 0) {
kfree(thread);
return 0;
}
stack_top = (uintptr_t)thread->stack_base + KERNEL_STACK_SIZE;
thread->id = next_thread_id++;
thread->state = THREAD_READY;
thread->entry = entry;
thread->arg = arg;
thread->stack_top = align_down_uintptr(stack_top, STACK_ALIGNMENT);
thread->stack_size = KERNEL_STACK_SIZE;
thread->next = 0;
copy_thread_name(thread->name, sizeof(thread->name), name);
enqueue_thread(thread);
return thread;
}
static void thread_selftest_entry(void *arg)
{
(void)arg;
}
static void scheduler_selftest(void)
{
struct thread *first =
kernel_thread_create("worker-a", thread_selftest_entry, 0);
struct thread *second =
kernel_thread_create("worker-b", thread_selftest_entry, 0);
if (first == 0 || second == 0 || first == second) {
panic("kernel thread selftest allocation failed");
}
if (first->id == second->id || first->state != THREAD_READY ||
second->state != THREAD_READY) {
panic("kernel thread selftest state failed");
}
if ((first->stack_top & (STACK_ALIGNMENT - 1)) != 0 ||
(second->stack_top & (STACK_ALIGNMENT - 1)) != 0) {
panic("kernel thread selftest stack alignment failed");
}
if (run_queue_head != first || first->next != second ||
run_queue_tail != second) {
panic("kernel thread selftest run queue failed");
}
early_log_puts("kernel thread selftest ok\n");
}
void sched_init(void)
{
if (scheduler_ready != 0) {
return;
}
run_queue_head = 0;
run_queue_tail = 0;
scheduler_ready = 1;
early_log_puts("scheduler initialized\n");
scheduler_selftest();
}