delay syscall ok

inc/kern/process.h

@@ -46,6 +46,7 @@ typedef struct s_proc {
 	phyaddr_t		cr3;
 	int			priority;
 	int			ticks;
+	int 		target_tick;
 }PROCESS_0;
 
 #define KERN_STACKSIZE	(8 * KB)
@@ -59,7 +60,7 @@ typedef union u_proc {
 // kern/main.c
 extern PROCESS *p_proc_ready;
 /* pcb表 */
-#define PCB_SIZE	2
+#define PCB_SIZE	3
 // kern/main.c
 extern PROCESS	proc_table[];
 
@@ -72,4 +73,7 @@ void	switch_kern_context(
 // 处理函数
 void	schedule(void);
 u32	kern_get_pid(PROCESS *p_proc);
+void kern_delay_tick(PROCESS*, u32);
+
+extern bool has_runnable;
 #endif /* MINIOS_KERN_PROCESS_H */

inc/kern/syscall.h

@@ -21,5 +21,5 @@ ssize_t	do_get_pid(void);
 // kern/fs.c
 ssize_t	do_read(int fd, void *buf, size_t count);
 ssize_t	do_write(int fd, const void *buf, size_t count);
-
+ssize_t do_delay_ticks(u32 ticks);
 #endif /* MINIOS_KERN_SYSCALL_H */

inc/syscall.h

@@ -6,5 +6,6 @@
 #define _NR_get_pid		1
 #define _NR_read		2
 #define _NR_write		3
+#define _NR_delay_ticks 4
 
 #endif /* MINIOS_SYSCALL_H */

inc/user/syscall.h

@@ -15,5 +15,5 @@ ssize_t get_ticks();
 ssize_t get_pid();
 ssize_t read(int fd, void *buf, size_t count);
 ssize_t write(int fd, const void *buf, size_t count);
-
+ssize_t delay_ticks(u32 ticks);
 #endif

kern/main.c

@@ -79,8 +79,11 @@ void kernel_main(void)
 		// lcr3(p_proc->pcb.cr3);
 		
 		static char filename[PCB_SIZE][12] = {
-			"TESTPID BIN",
+			// "TESTPID BIN",
-			"TESTKEY BIN",	
+			// "TESTKEY BIN",	
+			"DELAY   BIN",
+			"DELAY   BIN",
+			"DELAY   BIN",
 		};
 		// 从磁盘中将文件读出，需要注意的是要满足短目录项的文件名长度11，
 		// 前八个为文件名，后三个为后缀名，跟BootLoader做法一致
@@ -147,10 +150,11 @@ void kernel_main(void)
 
 		// 初始化其余量
 		p_proc->pcb.pid = i;
-		static int priority_table[PCB_SIZE] = {1, 2};
+		static int priority_table[PCB_SIZE] = {1, 1, 1};
 		// priority 预计给每个进程分配的时间片
 		// ticks 进程剩余的进程片
 		p_proc->pcb.priority = p_proc->pcb.ticks = priority_table[i];
+		p_proc->pcb.target_tick = 0;
 	}
 
 	p_proc_ready = proc_table;

kern/process.c

@@ -8,6 +8,7 @@
 #include <kern/process.h>
 #include <kern/protect.h>
 #include <kern/syscall.h>
+#include <kern/time.h>
 
 /*
  * 这个函数是写给汇编函数用，
@@ -36,6 +37,7 @@ to_kern_stack(u32 ret_esp)
 /*
  * 调度函数
  */
+bool has_runnable = true;
 void
 schedule(void)
 {
@@ -44,13 +46,29 @@ schedule(void)
 	// 如果中断没关，一定！一定！一定！要关中断保证当前执行流操作的原子性
 	if (IF_BIT != 0)
 		disable_int();
-	
+// kprintf("sched\n");
 	PROCESS *p_cur_proc = p_proc_ready;
-	PROCESS *p_next_proc = p_proc_ready + 1;
+	PROCESS *p_next_proc = p_proc_ready;
+	has_runnable = false;
+_again:
+	do {
+		p_next_proc = p_next_proc + 1;
 		if (p_next_proc >= proc_table + PCB_SIZE) {
 			p_next_proc = proc_table;
 		}
-
+		if (p_next_proc->pcb.target_tick == 0 || p_next_proc->pcb.target_tick <= kern_get_ticks()) {
+			p_next_proc->pcb.target_tick = 0;
+			has_runnable = true;
+			break;
+		}
+	} while(p_next_proc != p_proc_ready);
+	if (!has_runnable) {
+		enable_int(); // remember to enable int, or it'll die here
+		asm volatile("hlt"); // hlt will wake up when int comes
+		IF_BIT = read_eflags() & FL_IF;
+		if (IF_BIT != 0) disable_int(); // retry with int disabled
+		goto _again;
+	}
 	p_proc_ready = p_next_proc;
 	// 切换进程页表和tss
 	lcr3(p_proc_ready->pcb.cr3);
@@ -102,3 +120,14 @@ do_get_pid(void)
 {
 	return (ssize_t)kern_get_pid(p_proc_ready);
 }
+
+void kern_delay_ticks(PROCESS *p_proc, u32 target_tick) {
+	p_proc->pcb.target_tick = target_tick;
+}
+
+ssize_t
+do_delay_ticks(u32 ticks) {
+	kern_delay_ticks(p_proc_ready, kern_get_ticks() + ticks);
+	schedule();
+	return 0;
+}

kern/syscall.c

@@ -9,12 +9,14 @@ static ssize_t sys_get_ticks(void);
 static ssize_t sys_get_pid(void);
 static ssize_t sys_read(void);
 static ssize_t sys_write(void);
+static ssize_t sys_delay_ticks(void);
 
 ssize_t (*syscall_table[])(void) = {
 [_NR_get_ticks]	sys_get_ticks,
 [_NR_get_pid]	sys_get_pid,
 [_NR_read]	sys_read,
 [_NR_write]	sys_write,
+[_NR_delay_ticks] sys_delay_ticks,
 };
 
 /*
@@ -84,3 +86,8 @@ sys_write(void)
 {
 	return do_write(get_arg(0), (const void *)get_arg(1), get_arg(2));
 }
+
+static ssize_t
+sys_delay_ticks(void) {
+	return do_delay_ticks(get_arg(0));
+}

kern/trap.c

@@ -150,6 +150,11 @@ void
 clock_interrupt_handler(int irq)
 {
 	timecounter_inc();
+	if (!has_runnable) return; 
+	// maybe do nothing would be better, try to avoid recursive call to schedule
+	// because we must be in a schedule when runnable is false
+	// we just need a clock int to wake up it
+
 	// 当一个函数的时间片全用完时
 	if (--p_proc_ready->pcb.ticks == 0) {
 		p_proc_ready->pcb.ticks = p_proc_ready->pcb.priority;

lib/user/syscall.c

@@ -114,3 +114,9 @@ write(int fd, const void *buf, size_t count)
 {
 	return syscall3(_NR_write, fd, (size_t)buf, count);
 }
+
+ssize_t
+delay_ticks(u32 ticks)
+{
+	return syscall1(_NR_delay_ticks, ticks);
+}

user/delay.c

@@ -12,7 +12,7 @@ int main()
 		printf("\x1b[%dmI'm %d!\x1b[0m", 90 + pid + 1, pid);
 		fflush();
 		int before_ticks = get_ticks();
-		//delay_ticks(target_ticks);
+		delay_ticks(target_ticks);
 		int after_ticks = get_ticks();
 		
 		int real_ticks = after_ticks - before_ticks;