feature: fork added and exit_task is almost working

headers/interrupts.h

@@ -25,7 +25,8 @@ static inline void cli(void)
 	__asm__ volatile("cli");
 }
 
-static inline void sti(void)
+// aka sti
+static inline void toris(void)
 {
 	__asm__ volatile("sti");
 }

headers/task.h

@@ -8,7 +8,7 @@
 
 extern struct task *current_task;
 
-enum status { ZOMBIE, THREAD, RUN };
+enum status { ZOMBIE, THREAD, RUN, WAIT, SLEEP, STOPPED };
 enum owner { OWNER_KERNEL, OWNER_USER };
 
 #define STACK_SIZE PAGE_SIZE * 4
@@ -32,4 +32,8 @@ struct task {
 void scheduler(void);
 void switch_to_task(struct task *next_task);
 void exec_fn(void (*fn)(void));
+struct task *create_task(u8 uid);
 i8 create_kernel_task(void);
+void remove_task(struct task *task);
+u16 fork(void);
+u16 wait(void);

src/drivers/clock.c

@@ -25,7 +25,7 @@ static void set_pit_count(unsigned count)
 	outb(0x40, count & 0xFF);          // Low byte
 	outb(0x40, (count & 0xFF00) >> 8); // High byte
 
-	sti();
+	toris();
 }
 
 void clock_init(struct registers *regs)
@@ -41,7 +41,7 @@ static void clock_handler(struct registers *regs)
 	if (scheduler_counter % 100 == 0) {
 		cli();
 		scheduler();
-		sti();
+		toris();
 	}
 	scheduler_counter++;
 	sleep_counter--;

src/kernel.c

@@ -43,8 +43,10 @@ static void owo(void)
 
 static void awa(void)
 {
-	while (true)
-		kprintf("awaille\n");
+	/* if (fork() < 0) */
+	/* 	kprintf("camille il a une grosse bite (18cm)\n"); */
+	kprintf("awaille\n");
+	/* wait(); */
 }
 
 void kernel_main(multiboot_info_t *mbd, u32 magic)
@@ -61,7 +63,6 @@ void kernel_main(multiboot_info_t *mbd, u32 magic)
 	 */
 	/*         "Martin 03:50, 22 March 2009 (UTC)\n"); */
 	create_kernel_task();
-	exec_fn(owo);
 	exec_fn(awa);
 	/* exec_fn(owo); */
 	/* exec_fn(owo); */

src/multitasking/fork.c

@@ -0,0 +1,16 @@
+#include "interrupts.h"
+#include "string.h"
+#include "task.h"
+
+u16 fork(void)
+{
+	cli();
+	struct task *child = create_task(current_task->uid);
+	if (!child)
+		return -1;
+	child->daddy = current_task;
+	current_task->child = child;
+	memcpy(child->esp0, current_task->esp0, STACK_SIZE);
+	toris();
+	return current_task == child ? 0 : child->uid;
+}

src/multitasking/scheduler.c

@@ -1,3 +1,4 @@
+#include "alloc.h"
 #include "debug.h"
 #include "kprintf.h"
 #include "task.h"
@@ -5,14 +6,20 @@
 
 #include <stddef.h>
 
-struct task *current_task = NULL;
+struct task *current_task;
 
 void scheduler(void)
 {
-	if (!current_task || current_task->next == current_task)
+	if (!current_task) // || current_task->next == current_task)
 		return;
 	struct task *it = current_task->next;
-	while (it && it->status != RUN)
+	while (it && it->status != RUN) {
+		if (it->status == STOPPED || it->status == ZOMBIE) {
+			struct task *new_it = it->prev;
+			remove_task(it);
+			it = new_it;
+		}
 		it = it->next;
+	}
 	switch_to_task(it);
 }

src/multitasking/switch_to_task.s

@@ -47,7 +47,7 @@ switch_to_task:
 	pop edx // get func_ptr
 	call edx
 
-	// TODO HANDLE TASK RETURN
+	call exit_task
 
 .END:
 	ret 

src/multitasking/task.c

@@ -1,6 +1,7 @@
 #include "task.h"
 #include "alloc.h"
 #include "debug.h"
+#include "interrupts.h"
 #include "kpanic.h"
 #include "kprintf.h"
 #include "memory.h"
@@ -9,7 +10,7 @@
 
 u32 esp_backup;
 
-static struct task *create_task(u8 owner_id)
+struct task *create_task(u8 uid)
 {
 	static u32 pid = 1;
 	struct task *new_task = vmalloc(sizeof(struct task));
@@ -18,7 +19,7 @@ static struct task *create_task(u8 owner_id)
 	new_task->next = current_task->next;
 	new_task->prev = current_task;
 	current_task->next = new_task;
-	new_task->uid = owner_id;
+	new_task->uid = uid;
 	new_task->esp0 = alloc_pages(STACK_SIZE, NULL);
 	if (!new_task->esp0) {
 		vfree(new_task);
@@ -60,9 +61,31 @@ void exec_fn(void (*fn)(void))
 	new_task->eip = (u32 *)fn;
 }
 
-/*
- * Create task
- * Allocate new pd => kmalloc(4096)
- * Add pd address to the struct task
- *
- */
+void remove_task(struct task *task)
+{
+	struct task *left = task->prev;
+	struct task *right = task->next;
+	if (task->child)
+		remove_task(task->child);
+	if (task->heap)
+		vfree(task->heap);
+	if (task->esp0)
+		vfree(task->esp0);
+	task->heap = NULL;
+	task->esp0 = NULL;
+	if (task->status != ZOMBIE) {
+		left->next = right;
+		right->prev = left;
+		vfree(task);
+	}
+}
+
+void exit_task(void)
+{
+	cli();
+	if (current_task->daddy && current_task->daddy->status != WAIT)
+		current_task->status = ZOMBIE;
+	else
+		current_task->status = STOPPED;
+	toris();
+}

src/multitasking/wait.c

@@ -0,0 +1,9 @@
+#include "interrupts.h"
+#include "task.h"
+
+u16 wait(void)
+{
+	cli();
+	toris();
+	return 0;
+}