改善FIFO缓冲区

07_day/bootpack.c

@@ -9,7 +9,7 @@ void HariMain(void)
 {
 	struct BOOTINFO *binfo = (struct BOOTINFO *) ADR_BOOTINFO;
 	char s[40], mcursor[256];
-	int mx, my, i;
+	int mx, my, i, j;
 
 	init_gdtidt();
 	init_pic();
@@ -29,11 +29,15 @@ void HariMain(void)
 
 	for (;;) {
 		io_cli();
-		if (keybuf.flag == 0) {
+		if (keybuf.len == 0) {
 			io_stihlt();
 		} else {
-			i = keybuf.data;
-			keybuf.flag = 0;
+			i = keybuf.data[keybuf.next_r];
+			keybuf.len--;
+			keybuf.next_r++;
+			if (keybuf.next_r == 32) {
+				keybuf.next_r = 0;
+			}
 			io_sti();
 			sprintf(s, "%02X", i);
 			boxfill8(binfo->vram, binfo->scrnx, COL8_008484, 0, 16, 15, 31);

07_day/bootpack.h

@@ -75,7 +75,8 @@ void set_gatedesc(struct GATE_DESCRIPTOR *gd, int offset, int selector, int ar);
 
 /* int.c */
 struct KEYBUF {
-	unsigned char data, flag;
+	unsigned char data[32];
+	int next_r, next_w, len;
 };
 void init_pic(void);
 void inthandler21(int *esp);

07_day/int.c

@@ -35,9 +35,13 @@ void inthandler21(int *esp)
 	unsigned char data, s[4];
 	io_out8(PIC0_OCW2, 0x61);	/* 通知PIC IRQ-01 已经受理完毕 */
 	data = io_in8(PORT_KEYDAT);
-	if (keybuf.flag == 0) {
-		keybuf.data = data;
-		keybuf.flag = 1;
+	if (keybuf.len < 32) {
+		keybuf.data[keybuf.next_w] = data;
+		keybuf.len++;
+		keybuf.next_w++;
+		if (keybuf.next_w == 32) {
+			keybuf.next_w = 0;
+		}
 	}
 	return;
 }