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@@ -0,0 +1,101 @@
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+/**
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+ * @file semaphore.h
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+ * @author fslngjin (lonjin@RinGoTek.cn)
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+ * @brief 信号量
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+ * @version 0.1
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+ * @date 2022-04-12
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+ *
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+ * @copyright Copyright (c) 2022
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+ *
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+ */
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+
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+#pragma once
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+#include <process/atomic.h>
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+
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+#include <process/process.h>
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+#include <sched/sched.h>
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+
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+/**
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+ * @brief 信号量的等待队列
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+ *
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+ */
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+typedef struct
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+{
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+ struct List wait_list;
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+ struct process_control_block *pcb;
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+} wait_queue_node_t;
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+
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+/**
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+ * @brief 初始化信号量的等待队列
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+ *
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+ * @param wait_queue 等待队列
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+ * @param pcb pcb
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+ */
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+void wait_queue_init(wait_queue_node_t *wait_queue, struct process_control_block *pcb)
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+{
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+ list_init(&wait_queue->wait_list);
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+ wait_queue->pcb = pcb;
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+}
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+
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+/**
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+ * @brief 信号量的结构体
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+ *
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+ */
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+typedef struct
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+{
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+ atomic_t counter;
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+ wait_queue_node_t wait_queue;
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+} semaphore_t;
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+
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+/**
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+ * @brief 初始化信号量
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+ *
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+ * @param sema 信号量对象
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+ * @param count 信号量的初始值
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+ */
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+void semaphore_init(semaphore_t *sema, ul count)
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+{
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+ atomic_set(&sema->counter, count);
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+ wait_queue_init(&sema->wait_queue, NULL);
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+}
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+
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+/**
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+ * @brief 信号量down
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+ *
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+ * @param sema
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+ */
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+void semaphore_down(semaphore_t *sema)
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+{
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+ if (atomic_read(&sema->counter) > 0) // 信号量大于0,资源充足
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+ atomic_dec(&sema->counter);
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+ else // 资源不足,进程休眠
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+ {
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+ // 将当前进程加入信号量的等待队列
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+ wait_queue_node_t wait;
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+ wait_queue_init(&wait, current_pcb);
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+
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+ current_pcb->state = PROC_UNINTERRUPTIBLE;
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+
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+ list_append(&sema->wait_queue.wait_list, &wait.wait_list);
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+
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+ // 执行调度
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+ sched_cfs();
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+ }
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+}
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+
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+void semaphore_up(semaphore_t *sema)
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+{
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+ if (list_empty(&sema->wait_queue.wait_list)) // 没有进程在等待资源
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+ {
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+ atomic_inc(&sema->counter);
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+ }
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+ else // 有进程在等待资源,唤醒进程
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+ {
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+
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+ wait_queue_node_t *wq = container_of(list_next(&sema->wait_queue.wait_list), wait_queue_node_t, wait_list);
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+ list_del(&wq->wait_list);
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+
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+ wq->pcb->state = PROC_RUNNING;
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+ sched_cfs_enqueue(wq->pcb);
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+ }
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+}
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