✨ 061 数据结构循环队列

docs/06 数据结构/061 数据结构循环队列.md

@@ -0,0 +1,21 @@
+# 数据结构循环队列
+
+```c++
+typedef struct fifo_t
+{
+    char *buf;
+    u32 length;
+    u32 head;
+    u32 tail;
+} fifo_t;
+
+void fifo_init(fifo_t *fifo, char *buf, u32 length);
+bool fifo_full(fifo_t *fifo);
+bool fifo_empty(fifo_t *fifo);
+char fifo_get(fifo_t *fifo);
+void fifo_put(fifo_t *fifo, char byte);
+```
+
+queue / fifo First in First out
+
+生产者 - 消费者

src/include/onix/fifo.h

@@ -0,0 +1,20 @@
+#ifndef ONIX_FIFO_H
+#define ONIX_FIFO_H
+
+#include <onix/types.h>
+
+typedef struct fifo_t
+{
+    char *buf;
+    u32 length;
+    u32 head;
+    u32 tail;
+} fifo_t;
+
+void fifo_init(fifo_t *fifo, char *buf, u32 length);
+bool fifo_full(fifo_t *fifo);
+bool fifo_empty(fifo_t *fifo);
+char fifo_get(fifo_t *fifo);
+void fifo_put(fifo_t *fifo, char byte);
+
+#endif

src/kernel/keyboard.c

@@ -2,6 +2,9 @@
 #include <onix/io.h>
 #include <onix/assert.h>
 #include <onix/debug.h>
+#include <onix/fifo.h>
+#include <onix/mutex.h>
+#include <onix/task.h>
 
 #define LOGK(fmt, args...) DEBUGK(fmt, ##args)
 
@@ -220,6 +223,13 @@ static char keymap[][4] = {
     /* 0x5F */ {INV, INV, false, false}, // PrintScreen
 };
 
+static lock_t lock;    // 锁
+static task_t *waiter; // 等待输入的任务
+
+#define BUFFER_SIZE 64        // 输入缓冲区大小
+static char buf[BUFFER_SIZE]; // 输入缓冲区
+static fifo_t fifo;           // 循环队列
+
 static bool capslock_state; // 大写锁定
 static bool scrlock_state;  // 滚动锁定
 static bool numlock_state;  // 数字锁定
@@ -372,7 +382,30 @@ void keyboard_handler(int vector)
     if (ch == INV)
         return;
 
-    LOGK("keydown %c \n", ch);
+    // LOGK("keydown %c \n", ch);
+    fifo_put(&fifo, ch);
+    if (waiter != NULL)
+    {
+        task_unblock(waiter);
+        waiter = NULL;
+    }
+}
+
+u32 keyboard_read(char *buf, u32 count)
+{
+    lock_acquire(&lock);
+    int nr = 0;
+    while (nr < count)
+    {
+        while (fifo_empty(&fifo))
+        {
+            waiter = running_task();
+            task_block(waiter, NULL, TASK_WAITING);
+        }
+        buf[nr++] = fifo_get(&fifo);
+    }
+    lock_release(&lock);
+    return count;
 }
 
 void keyboard_init()
@@ -382,6 +415,10 @@ void keyboard_init()
     capslock_state = false;
     extcode_state = false;
 
+    fifo_init(&fifo, buf, BUFFER_SIZE);
+    lock_init(&lock);
+    waiter = NULL;
+
     set_leds();
 
     set_interrupt_handler(IRQ_KEYBOARD, keyboard_handler);

src/kernel/thread.c

@@ -19,15 +19,25 @@ void idle_thread()
     }
 }
 
+extern u32 keyboard_read(char *buf, u32 count);
+
 void init_thread()
 {
     set_interrupt_state(true);
     u32 counter = 0;
 
+    char ch;
     while (true)
     {
+        bool intr = interrupt_disable();
+        keyboard_read(&ch, 1);
+        // LOGK("%c\n", ch);
+        printk("%c", ch);
+
+        set_interrupt_state(intr);
+
         // LOGK("init task %d....\n", counter++);
-        sleep(500);
+        // sleep(500);
     }
 }
 

src/lib/fifo.c

@@ -0,0 +1,44 @@
+#include <onix/fifo.h>
+#include <onix/assert.h>
+
+static _inline u32 fifo_next(fifo_t *fifo, u32 pos)
+{
+    return (pos + 1) % fifo->length;
+}
+
+void fifo_init(fifo_t *fifo, char *buf, u32 length)
+{
+    fifo->buf = buf;
+    fifo->length = length;
+    fifo->head = 0;
+    fifo->tail = 0;
+}
+
+bool fifo_full(fifo_t *fifo)
+{
+    bool full = (fifo_next(fifo, fifo->head) == fifo->tail);
+    return full;
+}
+
+bool fifo_empty(fifo_t *fifo)
+{
+    return (fifo->head == fifo->tail);
+}
+
+char fifo_get(fifo_t *fifo)
+{
+    assert(!fifo_empty(fifo));
+    char byte = fifo->buf[fifo->tail];
+    fifo->tail = fifo_next(fifo, fifo->tail);
+    return byte;
+}
+
+void fifo_put(fifo_t *fifo, char byte)
+{
+    while (fifo_full(fifo))
+    {
+        fifo_get(fifo);
+    }
+    fifo->buf[fifo->head] = byte;
+    fifo->head = fifo_next(fifo, fifo->head);
+}

src/makefile

@@ -57,6 +57,7 @@ $(BUILD)/kernel.bin: \
 	$(BUILD)/kernel/keyboard.o \
 	$(BUILD)/lib/bitmap.o \
 	$(BUILD)/lib/list.o \
+	$(BUILD)/lib/fifo.o \
 	$(BUILD)/lib/string.o \
 	$(BUILD)/lib/vsprintf.o \
 	$(BUILD)/lib/stdlib.o \