Support kernel semaphore.

2024-05-29 11:06:03 +08:00
parent bd7966c5a3
commit 5a2c07e1a9
17 changed files with 394 additions and 16 deletions
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2020 AIIT XUOS Lab
+ * XiUOS is licensed under Mulan PSL v2.
+ * You can use this software according to the terms and conditions of the Mulan PSL v2.
+ * You may obtain a copy of Mulan PSL v2 at:
+ *        http://license.coscl.org.cn/MulanPSL2
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PSL v2 for more details.
+ */
+/**
+ * @file semaphore.c
+ * @brief semaphore implementation
+ * @version 3.0
+ * @author AIIT XUOS Lab
+ * @date 2024.05.28
+ */
+
+#include "assert.h"
+#include "ksemaphore.h"
+#include "task.h"
+
+void semaphore_pool_init(struct XiziSemaphorePool* sem_pool)
+{
+    assert(sem_pool != NULL);
+    sem_pool->next_sem_id = 1;
+    slab_init(&sem_pool->allocator, sizeof(struct ksemaphore));
+    doubleListNodeInit(&sem_pool->sem_list_guard);
+}
+
+static inline struct ksemaphore* ksemaphore_get_by_id(struct XiziSemaphorePool* sem_pool, int sem_id)
+{
+    struct ksemaphore* sem = NULL;
+    DOUBLE_LIST_FOR_EACH_ENTRY(sem, &sem_pool->sem_list_guard, sem_list_node)
+    {
+        if (sem->id == sem_id) {
+            break;
+        }
+    }
+    return sem;
+}
+
+int ksemaphore_alloc(struct XiziSemaphorePool* sem_pool, int val)
+{
+    struct ksemaphore* sem = (struct ksemaphore*)slab_alloc(&sem_pool->allocator);
+    if (sem == NULL) {
+        ERROR("No memeory to alloc new semaphore.\n");
+        return -1;
+    }
+
+    /* No error down here */
+    /* init ksemaphore since here */
+    /// @warning sem->id could overflow
+    sem->id = sem_pool->next_sem_id++;
+    if (UNLIKELY(sem->id == 0)) {
+        slab_free(&sem_pool->allocator, sem);
+        return -1;
+    }
+    sem->val = val;
+    doubleListNodeInit(&sem->sem_list_node);
+    doubleListNodeInit(&sem->wait_list_guard);
+
+    /* list sem to sem_pool */
+    doubleListAddOnHead(&sem->sem_list_node, &sem_pool->sem_list_guard);
+
+    return sem->id;
+}
+
+bool ksemaphore_wait(struct XiziSemaphorePool* sem_pool, struct Thread* thd, uint32_t sem_id)
+{
+    assert(thd != NULL);
+    assert(thd->state == RUNNING);
+    /* find sem */
+    struct ksemaphore* sem = ksemaphore_get_by_id(sem_pool, sem_id);
+    // invalid sem id
+    if (sem == NULL) {
+        return false;
+    }
+
+    // no need to wait
+    if (sem->val > 0) {
+        sem->val--;
+        return true;
+    }
+
+    // waiting at the sem
+    sem->val--;
+    xizi_task_manager.task_yield_noschedule(thd, false);
+    xizi_task_manager.task_block(&sem->wait_list_guard, thd);
+    return true;
+}
+
+bool ksemaphore_signal(struct XiziSemaphorePool* sem_pool, uint32_t sem_id)
+{
+    /* find sem */
+    struct ksemaphore* sem = ksemaphore_get_by_id(sem_pool, sem_id);
+    // invalid sem id
+    if (sem == NULL) {
+        return false;
+    }
+
+    if (sem->val < 0) {
+        if (!IS_DOUBLE_LIST_EMPTY(&sem->wait_list_guard)) {
+            assert(sem->wait_list_guard.next != NULL);
+            xizi_task_manager.task_unblock(CONTAINER_OF(sem->wait_list_guard.next, struct Thread, node));
+        }
+    }
+
+    sem->val++;
+    return true;
+}
+
+bool ksemaphore_free(struct XiziSemaphorePool* sem_pool, uint32_t sem_id)
+{
+    /* find sem */
+    struct ksemaphore* sem = ksemaphore_get_by_id(sem_pool, sem_id);
+    // invalid sem id
+    if (sem == NULL) {
+        return false;
+    }
+
+    struct Thread* thd = NULL;
+    DOUBLE_LIST_FOR_EACH_ENTRY(thd, &sem->wait_list_guard, node)
+    {
+        assert(thd != NULL);
+        xizi_task_manager.task_unblock(thd);
+    }
+
+    doubleListDel(&sem->sem_list_node);
+    slab_free(&sem_pool->allocator, sem);
+
+    return true;
+}