Patch add idr (#52)

* 增加了idr模块

* 增加了IDR模块,并尝试覆盖上一个错误版本.

* 增加了IDR模块

* 完善了注释内容

* 修改了test-idr.c文件

* 进一步完善函数注释

Signed-off-by: guanjinquan <1666320330@qq.com>
Co-authored-by: fslongjin <longjin@RinGoTek.cn>

kernel/common/idr.h

@@ -0,0 +1,139 @@
+
+
+#include <common/errno.h>
+#include <common/spinlock.h>
+
+/**
+ * idr: 基于radix-tree的ID-pointer的数据结构
+ * 主要功能:
+ * 1. 获取一个ID, 并且将该ID与一个指针绑定  - 需要外部加锁
+ * 2. 删除一个已分配的ID                  - 需要外部加锁
+ * 3. 根据ID查找对应的指针                (读操作,看情况加锁)
+ * 4. 根据ID使用新的ptr替换旧的ptr        - 需要外部加锁
+ *
+ * 附加功能:
+ * 1. 给定starting_id, 查询下一个已分配的next_id  (即:next_id>starting_id)
+ * 2. 销毁整个idr
+ *
+ *
+ * .... 待实现
+ */
+
+// 默认64位机器
+#define IDR_BITS 6
+#define IDR_FULL 0xfffffffffffffffful
+
+// size = 64
+#define IDR_SIZE (1 << IDR_BITS)
+#define IDR_MASK ((1 << IDR_BITS) - 1)
+
+// 能管理的ID范围[0:1<<31]
+#define MAX_ID_SHIFT (sizeof(int) * 8 - 1)
+#define MAX_ID_BIT (1U << MAX_ID_SHIFT)
+#define MAX_ID_MASK (MAX_ID_BIT - 1)
+
+// IDR可能最大的层次 以及 IDR预分配空间的最大限制
+#define MAX_LEVEL (MAX_ID_SHIFT + IDR_BITS - 1) / IDR_BITS
+#define IDR_FREE_MAX (MAX_LEVEL << 1)
+
+// 给定layer, 计算完全64叉树的大小
+#define TREE_SIZE(layer) ((layer >= 0) ? (1ull << ((layer + 1) * IDR_BITS)) : 1)
+
+// 计算最后(最低位)一个1的位置 (注意使用64位的版本)
+#define __lowbit_id(x) ((x) ? (__builtin_ctzll(x)) : -1)
+
+// 计算最前(最高位)一个1的位置 (注意使用64位的版本)
+#define __mostbit_id(x) ((x) ? (__builtin_clzll(x)) : -1)
+
+// radix-tree 节点定义
+struct idr_layer
+{
+    struct idr_layer *ary[IDR_SIZE]; // IDR_SIZE叉树
+    unsigned long bitmap;            // 每一位表示这个子树是否被使用
+    unsigned long full;              // 64个儿子子树, 每一位代表一个子树是否满了
+    int layer;                       // 层数(从底向上)
+};
+
+// idr: 将id与pointer绑定的数据结构
+struct idr
+{
+    struct idr_layer *top;
+    struct idr_layer *free_list;
+    int id_free_cnt;
+    spinlock_t lock;
+};
+
+#define DECLARE_IDR(name)    \
+    struct idr name = {0};   \
+    name.top = (NULL);       \
+    name.free_list = (NULL); \
+    name.id_free_cnt = (0);  \
+    spin_init(&name.lock);
+
+#define DECLARE_IDR_LAYER(name)  \
+    struct idr_layer name = {0}; \
+    memset(name, 0, sizeof(struct idr_layer));
+
+/**
+ * 对外函数声明
+ **/
+int idr_pre_get(struct idr *idp, gfp_t gfp_mask);
+int idr_get_new(struct idr *idp, void *ptr, int *id);
+void idr_remove(struct idr *idp, int id);
+void idr_remove_all(struct idr *idp);
+void idr_destroy(struct idr *idp);
+void *idr_find(struct idr *idp, int id);
+void *idr_find_next(struct idr *idp, int start_id);
+void *idr_find_next_getid(struct idr *idp, int start_id, int *nextid);
+int idr_replace_get_old(struct idr *idp, void *ptr, int id, void **oldptr);
+int idr_replace(struct idr *idp, void *ptr, int id);
+void idr_init(struct idr *idp);
+
+/**
+ * ida: 基于IDR实现的ID分配器
+ * 主要功能:
+ * 1. 获取一个未分配的ID
+ * 2. 询问一个ID是否被分配
+ * 3. 删除一个已分配ID
+ *
+ * 附加功能:
+ * 1. 暂定
+ */
+
+// 一个块的大小 - 即 sizeof(struct ida_bitmap)
+#define IDA_CHUNK_SIZE 128
+// ida_bitmap的长度
+#define IDA_BITMAP_LONGS (IDA_CHUNK_SIZE / sizeof(long) - 1)
+// 对应linux的IDA_BITMAP_BITS = 960 = 15 * 64
+#define IDA_FULL (IDA_BITMAP_LONGS * sizeof(long) * 8)
+#define IDA_BITMAP_BITS IDA_FULL
+#define IDA_BMP_SIZE (8 * sizeof(long))
+
+// 自定义bitmap
+struct ida_bitmap
+{
+    unsigned long count;                    // bitmap中已经分配的id数量
+    unsigned long bitmap[IDA_BITMAP_LONGS]; // bitmap本身, 每一个bit代表一个ID
+};
+
+// id-allocater 管理+分配ID的数据结构
+struct ida
+{
+    struct idr idr;
+    struct ida_bitmap *free_list; // 预分配的数据块
+};
+
+#define DECLARE_IDA(name)  \
+    struct ida name = {0}; \
+    idr_init(&name.idr);   \
+    name.free_list = (NULL);
+
+/**
+ * 对外函数声明
+ */
+void ida_init(struct ida *ida_p);
+int ida_pre_get(struct ida *ida_p, gfp_t gfp_mask);
+int ida_get_new(struct ida *ida_p, int *p_id);
+bool ida_count(struct ida *ida_p, int id);
+void ida_remove(struct ida *ida_p, int id);
+void ida_destroy(struct ida *ida_p);

kernel/ktest/Makefile

@@ -2,7 +2,7 @@
 CFLAGS += -I .
 
 
-all: ktest.o bitree.o kfifo.o mutex.o
+all: ktest.o bitree.o kfifo.o mutex.o idr.o
 
 ktest.o: ktest.c
 	gcc $(CFLAGS) -c ktest.c -o ktest.o
@@ -14,4 +14,7 @@ kfifo.o: test-kfifo.c
 	gcc $(CFLAGS) -c test-kfifo.c -o test-kfifo.o
 
 mutex.o: test-mutex.c
-	gcc $(CFLAGS) -c test-mutex.c -o test-mutex.o
+	gcc $(CFLAGS) -c test-mutex.c -o test-mutex.o
+
+idr.o: test-idr.c
+	gcc $(CFLAGS) -c test-idr.c -o test-idr.o

kernel/ktest/ktest.h

@@ -4,6 +4,7 @@
 int ktest_test_bitree(void* arg);
 int ktest_test_kfifo(void* arg);
 int ktest_test_mutex(void* arg);
+int ktest_test_idr(void* arg);
 
 /**
  * @brief 开启一个新的内核线程以进行测试

kernel/ktest/test-idr.c

@@ -0,0 +1,529 @@
+
+
+#include "ktest.h"
+#include "ktest_utils.h"
+#include <common/idr.h>
+
+/**
+ * @brief 测试idr的构建,预获取空间是否成功
+ *
+ * 以下函数将被测试:
+ * 1. idr_pre_get
+ * 2. DECLARE_IDR
+ * 3. idr_init
+ * 4. idr_destroy
+ *
+ * 同时还会(间接)测试一些内部函数:
+ * 1. move_to_free_list
+ *
+ * @param arg0
+ * @param arg1
+ */
+static long ktest_idr_case0(uint64_t arg0, uint64_t arg1)
+{
+    unsigned long bitmap = -1;
+    assert((int)(bitmap == IDR_FULL));
+
+    DECLARE_IDR(k_idr);
+    assert(k_idr.top == NULL);      // 刚被创建,必须是NULL
+    assert(k_idr.id_free_cnt == 0); // 必须是0
+    assert(k_idr.free_list == NULL);
+
+    k_idr.id_free_cnt = arg1;
+    idr_init(&k_idr);
+    assert(k_idr.id_free_cnt == 0);
+
+    assert(idr_pre_get(&k_idr, 0) == 1);
+    assert(k_idr.id_free_cnt == IDR_FREE_MAX);
+
+    for (int i = 1; i < 64; i++)
+    {
+        int id = __lowbit_id(i), chk_id = -1;
+        for (int j = 0; j < 64; j++)
+            if ((i >> j) & 1)
+            {
+                chk_id = j;
+                break;
+            }
+        assert(id == chk_id);
+    }
+
+    // 销毁
+    idr_destroy(&k_idr);
+    assert(k_idr.id_free_cnt == 0);
+    assert(k_idr.free_list == NULL);
+    assert(k_idr.top == NULL);
+
+    return 0;
+}
+
+/**
+ * @brief 测试id的获取，id的删除，id的全体删除, idr的find函数
+ *
+ * @param arg0
+ * @param arg1
+ */
+static long ktest_idr_case1(uint64_t arg0, uint64_t arg1)
+{
+    DECLARE_IDR(k_idr);
+    int a[128];
+
+    // 获取128个id
+    for (int i = 0; i < 128; i++)
+    {
+        assert(idr_get_new(&k_idr, &a[i], &a[i]) == 0);
+        assert(a[i] == i);
+    }
+
+    // 查询128个ptr
+    for (int i = 0; i < 128; i++)
+    {
+        int *ptr = idr_find(&k_idr, a[i]);
+        assert(ptr == &a[i]);
+        assert(ptr != NULL);
+        assert(*ptr == a[i]);
+    }
+
+    // 倒序：删除64个id
+    for (int i = 127; i >= 64; i--)
+    {
+        idr_remove(&k_idr, a[i]);
+        assert(idr_find(&k_idr, a[i]) == NULL);
+    }
+
+    // 正序：删除64个id
+    for (int i = 0; i <= 63; i++)
+    {
+        idr_remove(&k_idr, a[i]);
+        assert(idr_find(&k_idr, a[i]) == NULL);
+    }
+
+    // 重新申请128个id, 值域范围应该仍然是[0,127]
+    for (int i = 0; i < 128; i++)
+    {
+        assert(idr_get_new(&k_idr, &a[i], &a[i]) == 0);
+        assert(a[i] == i);
+    }
+
+    // 正序：删除32个id
+    for (int i = 0; i <= 31; i++)
+    {
+        idr_remove(&k_idr, a[i]);
+        assert(idr_find(&k_idr, a[i]) == NULL);
+    }
+
+    // 倒序：删除32个id
+    for (int i = 127; i >= 96; i--)
+    {
+        idr_remove(&k_idr, a[i]);
+        assert(idr_find(&k_idr, a[i]) == NULL);
+    }
+
+    // 整体删除
+    idr_remove_all(&k_idr);
+    assert(k_idr.top == NULL);
+
+    // 获取128个id
+    for (int i = 0; i < 128; i++)
+    {
+        assert(idr_get_new(&k_idr, &a[i], &a[i]) == 0);
+        assert(a[i] == i);
+    }
+
+    // 查询128个ptr
+    for (int i = 0; i < 128; i++)
+    {
+        int *ptr = idr_find(&k_idr, a[i]);
+        assert(ptr == &a[i]);
+        assert(*ptr == a[i]);
+    }
+
+    // 正序：删除64个id
+    for (int i = 0; i <= 63; i++)
+    {
+        idr_remove(&k_idr, a[i]);
+        assert(idr_find(&k_idr, a[i]) == NULL);
+    }
+
+    // 倒序：删除64个id
+    for (int i = 127; i >= 64; i--)
+    {
+        idr_remove(&k_idr, a[i]);
+        assert(idr_find(&k_idr, a[i]) == NULL);
+    }
+
+    // 销毁
+    idr_destroy(&k_idr);
+    assert(k_idr.id_free_cnt == 0);
+    assert(k_idr.free_list == NULL);
+
+    return 0;
+}
+
+/**
+ * @brief case1 的大数据测试
+ *
+ * @param arg0
+ * @param arg1
+ */
+static long ktest_idr_case2(uint64_t arg0, uint64_t arg1)
+{
+    DECLARE_IDR(k_idr);
+
+    // 获取 1000‘000 个ID
+    const int N = 1e7;
+    const int M = 3e6;
+
+    int tmp;
+    for (int i = 0; i < N; i++)
+    {
+        assert(idr_get_new(&k_idr, &tmp, &tmp) == 0);
+        assert(tmp == i);
+
+        int *ptr = idr_find(&k_idr, i);
+        assert(ptr != NULL);
+        assert(*ptr == i);
+    }
+
+    // 正向: M 个ID
+    for (int i = 0; i < M; i++)
+    {
+        int *ptr = idr_find(&k_idr, i);
+        assert(ptr != NULL);
+        assert(*ptr == N - 1);
+        idr_remove(&k_idr, i);
+        assert(idr_find(&k_idr, i) == NULL);
+    }
+
+    // 倒序: N-M 个ID
+    for (int i = (N)-1; i >= M; i--)
+    {
+        int *ptr = idr_find(&k_idr, i);
+        assert(*ptr == N - 1);
+        idr_remove(&k_idr, i);
+        assert(idr_find(&k_idr, i) == NULL);
+    }
+
+    // 重新插入数据
+    for (int i = 0; i < N; i++)
+    {
+        assert(idr_get_new(&k_idr, &tmp, &tmp) == 0);
+        assert(tmp == i);
+        assert(k_idr.top != NULL);
+
+        int *ptr = idr_find(&k_idr, i);
+        assert(ptr != NULL);
+        assert(*ptr == i);
+    }
+
+    assert(k_idr.top != NULL);
+
+    for (int i = 0; i < M; i++)
+    {
+        assert(idr_replace(&k_idr, NULL, i) == 0);
+    }
+
+    // 销毁
+    idr_destroy(&k_idr);
+    assert(k_idr.id_free_cnt == 0);
+    assert(k_idr.free_list == NULL);
+
+    return 0;
+}
+
+/**
+ * @brief case1 的大数据测试
+ *
+ * @param arg0
+ * @param arg1
+ */
+static long ktest_idr_case3(uint64_t arg0, uint64_t arg1)
+{
+    DECLARE_IDR(k_idr);
+
+    const int N = 1949;
+    int tmp;
+
+    // 获取ID
+    for (int i = 0; i < N; i++)
+    {
+        assert(idr_get_new(&k_idr, &tmp, &tmp) == 0);
+        assert(tmp == i);
+
+        int *ptr = idr_find(&k_idr, i);
+        assert(ptr != NULL);
+        assert(*ptr == i);
+    }
+
+    // 查询 nextid
+    for (int i = 1; i <= N; i++)
+    {
+        int nextid;
+        int *ptr = idr_find_next_getid(&k_idr, i - 1, &nextid);
+        if (likely(i < N))
+        {
+            assert(ptr != NULL);
+            assert(*ptr == N - 1);
+            assert(nextid == i);
+        }
+        else
+        {
+            assert(ptr == NULL);
+            assert(nextid == -1);
+        }
+    }
+
+    int sz = N;
+    // 删掉某一段
+    for (int i = N / 3, j = 2 * (N / 3), k = 0; i <= j; k++, i++)
+    {
+        int *ptr = idr_find(&k_idr, i);
+        assert(ptr != NULL);
+        assert(*ptr == N - 1);
+        idr_remove(&k_idr, i);
+
+        assert(idr_find(&k_idr, i) == NULL);
+        sz--;
+        assert(k_idr.top != NULL);
+    }
+
+    // 查询 nextid
+    for (int i = 1; i <= N; i++)
+    {
+        int nextid;
+        int *ptr = idr_find_next_getid(&k_idr, i - 1, &nextid);
+        if (likely(i < N))
+        {
+            int target = i < N / 3 ? i : max(i, 2 * (N / 3) + 1);
+            assert(ptr != NULL);
+            assert(*ptr == N - 1);
+            assert(nextid == target);
+        }
+        else
+        {
+            assert(ptr == NULL);
+            assert(nextid == -1);
+        }
+    }
+
+    // 销毁
+    idr_destroy(&k_idr);
+    assert(k_idr.id_free_cnt == 0);
+    assert(k_idr.free_list == NULL);
+
+    return 0;
+}
+
+/**
+ * @brief 更加全面覆盖所有函数 - 小数据测试
+ *
+ * @param arg0
+ * @param arg1
+ */
+static long ktest_idr_case4(uint64_t arg0, uint64_t arg1)
+{
+    DECLARE_IDR(k_idr);
+    idr_init(&k_idr);
+
+    const int N =91173;
+    int tmp;
+
+    for (int i = 1; i <= 20; i++)
+    {
+        int M = N / i, T = M / 3, O = 2 * T;
+        for (int j = 0; j < M; j++)
+        {
+            assert(idr_get_new(&k_idr, &tmp, &tmp) == 0);
+            assert(tmp == j);
+        }
+
+        for (int j = O; j >= T; j--)
+        {
+            int *ptr = idr_find(&k_idr, j);
+            assert(ptr != NULL);
+            assert(*ptr == M - 1);
+            idr_remove(&k_idr, j);
+        }
+
+        for (int j = O + 1; j < M; j++)
+        {
+            int *ptr = idr_find(&k_idr, j);
+            assert(ptr != NULL);
+            assert(*ptr == M - 1);
+            idr_remove(&k_idr, j);
+        }
+
+        for (int j = T - 1; j >= 0; j--)
+        {
+            int *ptr = idr_find(&k_idr, j);
+            assert(ptr != NULL);
+            assert(*ptr == M - 1);
+            idr_remove(&k_idr, j);
+        }
+
+        assert(k_idr.top == NULL);
+    }
+
+    // 销毁
+    idr_destroy(&k_idr);
+    assert(k_idr.id_free_cnt == 0);
+    assert(k_idr.free_list == NULL);
+
+    return 0;
+}
+
+/**
+ * @brief 测试id的获取，id的删除，id的全体删除, idr的find函数
+ *
+ * @param arg0
+ * @param arg1
+ */
+static long ktest_idr_case5(uint64_t arg0, uint64_t arg1)
+{
+    DECLARE_IDR(k_idr);
+    const int N = 128;
+    int a[N];
+
+    // 获取128个id
+    for (int i = 0; i < N; i++)
+    {
+        assert(idr_get_new(&k_idr, &a[i], &a[i]) == 0);
+        assert(a[i] == i);
+    }
+
+    // 把id指向的指针向后移动一个单位
+    for (int i = 0; i < N; i++)
+    {
+        int *ptr;
+        int flags = idr_replace_get_old(&k_idr, &a[(i + 1) % N], i, (void*)&ptr);
+        assert(flags == 0); // 0 是成功
+        assert(ptr != NULL);
+        assert(*ptr == i);
+
+        // 测试是否替换成功
+        ptr = idr_find(&k_idr, i);
+        assert(ptr != NULL);
+        assert(*ptr == (i + 1) % N);
+    }
+
+    // 销毁
+    idr_destroy(&k_idr);
+    assert(k_idr.id_free_cnt == 0);
+    assert(k_idr.free_list == NULL);
+
+    // destroy之后，再获取128个id
+    for (int i = 0; i < N; i++)
+    {
+        assert(idr_get_new(&k_idr, &a[i], &a[i]) == 0);
+        assert(a[i] == i);
+    }
+
+    // 销毁
+    idr_destroy(&k_idr);
+    assert(k_idr.id_free_cnt == 0);
+    assert(k_idr.free_list == NULL);
+
+    return 0;
+}
+
+/**
+ * @brief 测试ida的插入/删除
+ *
+ * @param arg0
+ * @param arg1
+ * @return long
+ */
+static long ktest_idr_case6(uint64_t arg0, uint64_t arg1)
+{
+    assert(IDA_BITMAP_LONGS != 0);
+    assert(IDA_BMP_SIZE != 0);
+    assert(IDA_FULL != 0);
+    assert(IDA_BITMAP_BITS != 0);
+
+    DECLARE_IDA(k_ida);
+    ida_init(&k_ida);
+
+    const int N = IDA_FULL * IDR_SIZE + 1;
+
+    for (int i = 0; i < N; i++)
+    {
+        int p_id;
+        assert(ida_get_new(&k_ida, &p_id) == 0);
+        assert(p_id == i);
+    }
+
+    for (int i = 0; i < N; i++)
+    {
+        assert(ida_count(&k_ida, i) == 1);
+    }
+
+    for (int i = N - 1; i >= 0; i--)
+    {
+        ida_remove(&k_ida, i);
+        assert(ida_count(&k_ida, i) == 0);
+    }
+
+    assert(k_ida.idr.top == NULL);
+
+    for (int i = 0; i < N; i++)
+    {
+        int p_id;
+        assert(ida_get_new(&k_ida, &p_id) == 0);
+        assert(p_id == i);
+    }
+
+    assert(k_ida.idr.top != NULL);
+    ida_destroy(&k_ida);
+    assert(k_ida.idr.top == NULL);
+    assert(k_ida.free_list == NULL);
+
+    // 测试destroy之后能否重新获取ID
+    for (int i = 0; i < N; i++)
+    {
+        int p_id;
+        assert(ida_get_new(&k_ida, &p_id) == 0);
+        assert(p_id == i);
+    }
+
+    for (int i = 0; i < N / 3; i++)
+    {
+        ida_remove(&k_ida, i);
+        assert(ida_count(&k_ida, i) == 0);
+    }
+
+    for (int i = 2 * N / 3; i < N; i++)
+    {
+        ida_remove(&k_ida, i);
+        assert(ida_count(&k_ida, i) == 0);
+    }
+
+    assert(k_ida.idr.top != NULL);
+    ida_destroy(&k_ida);
+    assert(k_ida.idr.top == NULL);
+    assert(k_ida.free_list == NULL);
+
+    return 0;
+}
+
+static ktest_case_table kt_idr_func_table[] = {
+    ktest_idr_case0,
+    ktest_idr_case1,
+    // ktest_idr_case2, // 为了加快启动速度, 暂时注释掉这个测试
+    ktest_idr_case3,
+    ktest_idr_case4,
+    ktest_idr_case5,
+    ktest_idr_case6,
+};
+
+int ktest_test_idr(void* arg)
+{
+    kTEST("Testing idr...");
+    unsigned int sz = sizeof(kt_idr_func_table) / sizeof(ktest_case_table);
+    for (int i = 0; i < sz; ++i)
+    {
+        kTEST("Testing case %d", i);
+        kt_idr_func_table[i](i, i + 1);
+    }
+    kTEST("idr Test done.");
+    return 0;
+}

kernel/lib/idr.c

@@ -0,0 +1,883 @@
+#include <common/idr.h>
+#include <mm/slab.h>
+
+/**
+ * @brief 更换两个idr_layer指针
+ *
+ * @param a
+ * @param b
+ */
+static void __swap(struct idr_layer **a, struct idr_layer **b)
+{
+    struct idr_layer *t = *a;
+    *a = *b, *b = t;
+}
+
+/**
+ * @brief 初始化idr - 你需要保证函数调用之前 free_list指针 为空
+ *
+ * @param idp
+ */
+void idr_init(struct idr *idp)
+{
+    memset(idp, 0, sizeof(struct idr));
+    spin_init(&idp->lock);
+}
+
+/**
+ * @brief 向idr的free_list中添加一个节点(空节点)
+ *
+ * @param idp
+ * @param p
+ */
+static void __move_to_free_list(struct idr *idp, struct idr_layer *p)
+{
+    unsigned long flags;
+    spin_lock_irqsave(&idp->lock, flags);
+
+    // 插入free_list
+    p->ary[0] = idp->free_list;
+    idp->free_list = p;
+    ++(idp->id_free_cnt);
+
+    spin_unlock_irqrestore(&idp->lock, flags);
+}
+
+/**
+ * @brief Get the free_idr_layer from free list object
+ *
+ * @param idp
+ * @return void*
+ */
+static void *__get_from_free_list(struct idr *idp)
+{
+    if (idp->id_free_cnt == 0)
+    {
+        if (idr_pre_get(idp, 0) != 0)
+        {
+            kBUG("idr-module find a BUG: get free node fail.(Possible ENOMEM error)");
+            return NULL;
+        }
+    }
+
+    unsigned long flags;
+    spin_lock_irqsave(&idp->lock, flags);
+
+    // free_list还有节点
+    struct idr_layer *item = idp->free_list;
+    idp->free_list = idp->free_list->ary[0];
+    item->ary[0] = NULL; // 记得清空原来的数据
+    --(idp->id_free_cnt);
+
+    spin_unlock_irqrestore(&idp->lock, flags);
+
+    return item;
+}
+
+/**
+ * @brief 为idr预分配空间
+ *
+ * @param idp
+ * @param gfp_mask
+ * @return int (如果分配成功,将返回0; 否则返回负数 -ENOMEM, 有可能是内存空间不够)
+ */
+int idr_pre_get(struct idr *idp, gfp_t gfp_mask)
+{
+    int timer = 0;
+    while (idp->id_free_cnt < IDR_FREE_MAX)
+    {
+        struct idr_layer *new_one;
+        new_one = kzalloc(sizeof(struct idr_layer), gfp_mask); // 默认清空?
+        if (NULL == new_one)
+            return -ENOMEM;
+        __move_to_free_list(idp, new_one);
+        timer++;
+    }
+    return 0;
+}
+
+/**
+ * @brief 释放一个layer的空间
+ *
+ * @param p
+ */
+static void __idr_layer_free(struct idr_layer *p)
+{
+    kfree(p);
+}
+
+/**
+ * @brief 向上生长一层idr_layer
+ *
+ * @param idp
+ * @return int (0生长成功, 否则返回错误码)
+ */
+static int __idr_grow(struct idr *idp)
+{
+    struct idr_layer *new_node = __get_from_free_list(idp);
+    if (NULL == new_node)
+        return -ENOMEM;
+
+    __swap(&new_node, &idp->top);
+
+    idp->top->ary[0] = new_node;
+    idp->top->layer = new_node ? (new_node->layer + 1) : 0; // 注意特判空指针
+    idp->top->bitmap = 0;
+    idp->top->full = 0; // clear
+
+    if (new_node != NULL) // 设置第0位 = 1, 同时维护树的大小
+    {
+        idp->top->bitmap = 1;
+    }
+    if (new_node != NULL && new_node->full == IDR_FULL)
+    {
+        idp->top->full = 1; // 别忘了初始化 full
+    }
+
+    return 0;
+}
+
+/**
+ * @brief 获取一个没有被占领的ID
+ *
+ * @param idp
+ * @param stk  栈空间
+ * @return int (负数表示获取ID失败, [0 <= id && id <= INT_MAX] 则获取ID成功)
+ */
+static int __idr_get_empty_slot(struct idr *idp, struct idr_layer **stk)
+{
+    // 注意特判 idp->top == NULL
+    while (NULL == idp->top || idp->top->full == IDR_FULL)
+        if (__idr_grow(idp) != 0)
+            return -ENOMEM;
+
+    int id = 0;
+    int layer = idp->top->layer;
+
+    stk[layer + 1] = NULL; // 标志为数组末尾
+
+    struct idr_layer *cur_layer = idp->top;
+    while (layer >= 0)
+    {
+        stk[layer] = cur_layer;
+        int pos = __lowbit_id(~cur_layer->full);
+
+        if (unlikely(pos < 0))
+        {
+            kBUG("Value 'cur_layer->full' had been full;"
+                 "but __idr_get_empty_slot still try to insert a value.");
+        }
+
+        id = (id << IDR_BITS) | pos;
+        cur_layer = cur_layer->ary[pos];
+
+        if (layer > 0 && NULL == cur_layer) // 只有非叶子节点才需要开辟儿子节点
+        {
+            // 初始化儿子节点
+            cur_layer = __get_from_free_list(idp);
+            if (NULL == cur_layer)
+                return -ENOMEM;
+            cur_layer->layer = layer - 1; // 儿子节点的layer
+            cur_layer->full = 0;
+            cur_layer->bitmap = 0;
+
+            stk[layer]->ary[pos] = cur_layer; // 最后别忘了记录儿子节点
+        }
+
+        --layer;
+    }
+
+    return id;
+}
+
+/**
+ * @brief 更新full对象 (辅助函数，内部没有边界特判)
+ *
+ * @param idp
+ * @param id
+ * @param stk  需要保证stk数组末尾是NULL
+ * @param mark 0代表叶子空, 1代表叶子非空但未满, 2代表满
+ */
+static __always_inline void __idr_mark_full(struct idr *idp, int id, struct idr_layer **stk, int mark)
+{
+    if (unlikely(NULL == stk[0] || NULL == idp->top))
+    {
+        kBUG("idr-module find a BUG: idp->top can't be NULL.");
+        return;
+    }
+
+    // 处理叶子节点的full/bitmap标记
+    int layer_id = id & IDR_MASK;
+    if (mark == 2)
+        stk[0]->full |= (1ull << layer_id);
+    if (mark >= 1)
+        stk[0]->bitmap |= (1ull << layer_id);
+
+    for (int i = 1; stk[i]; ++i)
+    {
+        id >>= IDR_BITS;
+        layer_id = id & IDR_MASK;
+
+        stk[i]->bitmap |= (1ull << layer_id);
+        if (stk[i - 1]->full == IDR_FULL)
+            stk[i]->full |= (1ull << layer_id);
+    }
+}
+
+/**
+ * @brief 提取一条已存在的路径
+ *
+ * @param idp
+ * @param id
+ * @param stk
+ * @return int (0表示没有这条路径, 1表示找到这条路径)
+ */
+static __always_inline int __idr_get_path(struct idr *idp, int id, struct idr_layer **stk)
+{
+    if (unlikely(idp->top == NULL || id < 0))
+    {
+        kBUG("idr-module find a BUG: idp->top can't be NULL and id must be non-negative.");
+        return 0;
+    }
+
+    struct idr_layer *cur_layer = idp->top;
+    int layer = cur_layer->layer;
+    stk[layer + 1] = NULL; // 标志数组结尾
+
+    // 提取路径
+    while (layer >= 0)
+    {
+        stk[layer] = cur_layer;
+        int layer_id = (id >> (layer * IDR_BITS)) & IDR_MASK;
+
+        if (unlikely(((cur_layer->bitmap >> layer_id) & 1) == 0))
+        {
+            kBUG("idr-module find a BUG: no-such son.");
+            return 0; // 没有这一个儿子
+        }
+
+        cur_layer = cur_layer->ary[layer_id];
+        --layer;
+    }
+
+    return 1;
+}
+
+/**
+ * @brief 更新full对象 (辅助函数，内部没有边界特判)
+ *
+ * @param idp
+ * @param id
+ * @param stk 需要保证stk数组末尾是NULL
+ * @param mark 0代表叶子空, 1代表叶子非空但未满, 2代表满
+ */
+static __always_inline void __idr_erase_full(struct idr *idp, int id, struct idr_layer **stk, int mark)
+{
+    if (unlikely(NULL == stk[0] || NULL == idp->top))
+    {
+        kBUG("idr-module find a BUG: idp->top can't be NULL.");
+        return;
+    }
+
+    // 处理叶子节点的full/bitmap标记
+    int layer_id = id & IDR_MASK;
+    if (mark == 0) // 叶子的某个插槽为空
+    {
+        stk[0]->ary[layer_id] = NULL;
+        stk[0]->bitmap ^= (1ull << layer_id);
+    }
+    if (mark != 2 && ((stk[0]->full >> layer_id) & 1))
+        stk[0]->full ^= (1ull << layer_id);
+
+    // 删除节点
+    for (int layer = 1; stk[layer]; ++layer)
+    {
+        id >>= IDR_BITS;
+        layer_id = id & IDR_MASK;
+
+        if (NULL == stk[layer - 1]->bitmap) // 儿子是空节点
+        {
+            stk[layer]->ary[layer_id] = NULL;
+            stk[layer]->bitmap ^= (1ull << layer_id);
+
+            if ((stk[layer]->full >> layer_id) & 1)
+                stk[layer]->full ^= (1ull << layer_id);
+
+            __idr_layer_free(stk[layer - 1]);
+            stk[layer - 1] = NULL; // 释放空间记得设置为 NULL
+        }
+        else if (stk[layer - 1]->full != IDR_FULL)
+        {
+            if ((stk[layer]->full >> layer_id) & 1)
+                stk[layer]->full ^= (1ull << layer_id);
+        }
+    }
+
+    // 特判根节点是否只剩0号儿子节点 (注意还要layer > 0)
+    // (注意,有可能出现idp->top=NULL)
+    // bitmap: 1000...000/00.....000
+    while (idp->top != NULL &&
+           ((idp->top->bitmap <= 1 && idp->top->layer > 0) || // 一条链的情况
+            (idp->top->layer == 0 && idp->top->bitmap == 0))) // 最后一个点的情况
+    {
+        struct idr_layer *t = idp->top->layer ? idp->top->ary[0] : NULL;
+        __idr_layer_free(idp->top);
+        idp->top = t;
+    }
+}
+
+/**
+ * @brief 内部的分配ID函数 (辅助函数)
+ *
+ * @param idp
+ * @param ptr
+ * @param starting_id 暂时没用
+ * @return (0 <= id <= INT_MAX 表示申请的ID；否则是负数错误码, 可能是内存空间不够或者程序逻辑有误)；
+ */
+static int __idr_get_new_above_int(struct idr *idp, void *ptr, int starting_id)
+{
+    struct idr_layer *stk[MAX_LEVEL + 1]; // 你可以选择memset(0)
+    int id = __idr_get_empty_slot(idp, stk);
+
+    if (id >= 0)
+    {
+        stk[0]->ary[IDR_MASK & id] = ptr;
+        __idr_mark_full(idp, id, stk, 2);
+    }
+
+    return id;
+}
+
+/**
+ * @brief 从[0,INT_MAX]区间内返回一个最小的空闲ID
+ *
+ * @param idp
+ * @param ptr     - id 所对应的指针
+ * @param int* id - 传入int指针，获取到的NEW_ID存在id里
+ * @return int (0表示获取id成功, 负数代表错误 - 可能是内存空间不够)
+ */
+int idr_get_new(struct idr *idp, void *ptr, int *id)
+{
+    int rv = __idr_get_new_above_int(idp, ptr, 0);
+    if (rv < 0)
+        return rv; // error
+    *id = rv;
+    return 0;
+}
+
+/**
+ * @brief 删除一个id，但是不释放对应的ptr指向的空间
+ *
+ * @param idp
+ * @param id
+ */
+void idr_remove(struct idr *idp, int id)
+{
+    if (unlikely(idp->top == NULL || id < 0))
+        return;
+
+    struct idr_layer *stk[MAX_LEVEL + 1];
+    if (0 == __idr_get_path(idp, id, stk))
+        return; // 找不到路径
+
+    __idr_erase_full(idp, id, stk, 0);
+}
+
+/**
+ * @brief 移除IDR中所有的节点,如果free=true,则同时释放所有数据指针的空间(kfree)
+ *
+ * @param idp
+ * @param free
+ */
+static void __idr_remove_all_with_free(struct idr *idp, bool free)
+{
+    if (unlikely(NULL == idp->top))
+    {
+        kBUG("idr-module find a BUG: idp->top can't be NULL.");
+        return;
+    }
+
+    int sz = sizeof(struct idr_layer);
+    struct idr_layer *stk[MAX_LEVEL + 1];
+    struct idr_layer *cur_layer = idp->top;
+    int layer = cur_layer->layer;
+    stk[layer + 1] = NULL; // 标记数组结尾
+
+    while (cur_layer != NULL)
+    {
+        if (layer > 0 && cur_layer->bitmap) // 非叶子节点
+        {
+            stk[layer] = cur_layer; // 入栈
+            int id = __lowbit_id(cur_layer->bitmap);
+
+            cur_layer->bitmap ^= (1ull << id);
+            cur_layer = cur_layer->ary[id];
+            stk[layer]->ary[id] = NULL;
+            --layer;
+        }
+        else
+        {
+            if (free)
+            {
+                for (int i = 0; i < IDR_SIZE; i++) // 释放数据指针的空间
+                {
+                    kfree(cur_layer->ary[i]);
+                    cur_layer->ary[i] = NULL;
+                }
+            }
+
+            __idr_layer_free(cur_layer); //  释放空间记得设置为NULL
+            ++layer;
+
+            cur_layer = stk[layer]; // 出栈
+        }
+    }
+    idp->top = NULL;
+}
+
+/**
+ * @brief 删除idr的所有节点，同时释放数据指针的空间，回收free_list的所有空间 - (数据指针指ID所绑定的pointer)
+ * @param idp
+ */
+static void __idr_destroy_with_free(struct idr *idp)
+{
+    if (likely(idp->top))
+        __idr_remove_all_with_free(idp, 1);
+    idp->top = NULL;
+    while (idp->id_free_cnt)
+        __idr_layer_free(__get_from_free_list(idp));
+    idp->free_list = NULL;
+}
+
+/**
+ * @brief 删除所有的ID
+ *
+ * @param idp
+ */
+void idr_remove_all(struct idr *idp)
+{
+    if (unlikely(NULL == idp->top))
+        return;
+
+    __idr_remove_all_with_free(idp, 0);
+}
+
+/**
+ * @brief 释放一个idr占用的所有空间
+ *
+ * @param idp
+ */
+void idr_destroy(struct idr *idp)
+{
+    idr_remove_all(idp);
+    idp->top = NULL;
+    while (idp->id_free_cnt)
+        __idr_layer_free(__get_from_free_list(idp));
+    idp->free_list = NULL;
+}
+
+/**
+ * @brief 返回id对应的数据指针
+ *
+ * @param idp
+ * @param id
+ * @return void* (如果id不存在返回NULL；否则返回对应的指针ptr; 注意: 有可能用户的数据本来就是NULL)
+ */
+void *idr_find(struct idr *idp, int id)
+{
+    if (unlikely(idp->top == NULL || id < 0))
+        return NULL;
+
+    struct idr_layer *cur_layer = idp->top;
+    int layer = cur_layer->layer; // 特判NULL
+
+    // 如果查询的ID的bit数量比layer*IDR_BITS还大, 直接返回NULL
+    if ((id >> ((layer + 1) * IDR_BITS)) > 0)
+        return NULL;
+
+    while (layer >= 0 && cur_layer)
+    {
+        int layer_id = (id >> (IDR_BITS * layer)) & IDR_MASK;
+        cur_layer = cur_layer->ary[layer_id];
+        --layer;
+    }
+    return cur_layer;
+}
+
+/**
+ * @brief  返回id大于 start_id 的数据指针(即非空闲id对应的指针), 如果没有则返回NULL; 可以传入nextid指针，获取下一个id; 时间复杂度O(log_64(n)), 空间复杂度O(log_64(n)) 约为 6;
+ *
+ * @param idp
+ * @param start_id
+ * @param nextid
+ * @return void*
+ */
+void *idr_find_next_getid(struct idr *idp, int start_id, int *nextid)
+{
+    if (unlikely(idp->top == NULL))
+    {
+        *nextid = -1;
+        return NULL;
+    }
+
+    ++start_id;
+    start_id = max(0, start_id); // 特判负数
+    *nextid = 0;
+
+    struct idr_layer *stk[MAX_LEVEL + 1];
+    bool state[MAX_LEVEL + 1]; // 标记是否大于等于]
+    int pos_i[MAX_LEVEL + 1];
+
+    memset(pos_i, 0, sizeof(pos_i)); // 必须清空
+
+    struct idr_layer *cur_layer = idp->top;
+    bool cur_state = false;
+    bool init_flag = true;
+    int layer = cur_layer->layer;
+    stk[layer + 1] = NULL; // 标记数组结尾
+
+    // 如果查询的ID的bit数量比layer*IDR_BITS还大, 直接返回NULL
+    if ((start_id >> ((layer + 1) * IDR_BITS)) > 0)
+    {
+        *nextid = -1;
+        return NULL;
+    }
+
+    while (cur_layer) // layer < top->layer + 1
+    {
+        if (init_flag) // 第一次入栈
+        {
+            stk[layer] = cur_layer;
+            state[layer] = cur_state;
+            pos_i[layer] = cur_state ? 0 : ((start_id >> (layer * IDR_BITS)) & IDR_MASK);
+        }
+        else
+        {
+            pos_i[layer]++;
+            state[layer] = cur_state = true;
+        }
+
+        unsigned long t_bitmap = (cur_layer->bitmap >> pos_i[layer]);
+        if (t_bitmap) // 进一步递归到儿子下面去
+        {
+            int layer_id = __lowbit_id(t_bitmap) + pos_i[layer];
+
+            // 特别情况
+            if (NULL == cur_state && layer_id > pos_i[layer] > 0)
+                cur_state = true;
+
+            pos_i[layer] = layer_id;
+
+            *nextid = (((uint64_t)*nextid) << IDR_BITS) | layer_id; // 更新答案
+            if (layer == 0)
+            {
+                //  找到下一个id: nextid
+                return cur_layer->ary[layer_id];
+            }
+
+            cur_layer = cur_layer->ary[layer_id];
+            init_flag = true; // 儿子节点第一次入栈, 需要init
+            --layer;
+        }
+        else // 子树搜索完毕,向上回溯
+        {
+            (*nextid) >>= IDR_BITS; // 维护答案
+
+            ++layer;
+            cur_layer = stk[layer];
+            init_flag = false; // 不是第一次入栈, 不需要init
+        }
+    }
+
+    *nextid = -1;
+    return NULL; // 找不到
+}
+
+/**
+ * @brief 返回id大于 start_id 的数据指针(即非空闲id对应的指针), 如果没有则返回NULL
+ *
+ * @param idp
+ * @param start_id
+ * @return void*
+ */
+void *idr_find_next(struct idr *idp, int start_id)
+{
+    int nextid;
+    void *ptr = idr_find_next_getid(idp, start_id, &nextid);
+
+    return ptr; // 当 nextid == -1 时， 出现错误
+}
+
+/**
+ * @brief 根据id替换指针，你需要保证这个id存在于idr中，否则将会出现错误
+ *
+ * @param idp
+ * @param ptr (要替换旧指针的新指针 - new_ptr)
+ * @param id
+ * @param old_ptr (返回旧指针, 注意NULL不一定是出现错误，有可能是数据本来就是NULL)
+ * @return int (0代表成功，否则就是负数 - 代表错误)
+ */
+int idr_replace_get_old(struct idr *idp, void *ptr, int id, void **old_ptr)
+{
+    *old_ptr = NULL;
+
+    if (unlikely(idp->top == NULL || id < 0))
+        return -EDOM; // 参数错误
+
+    struct idr_layer *cur_layer = idp->top;
+    int layer = cur_layer->layer;
+
+    // 如果查询的ID的bit数量比layer*IDR_BITS还大, 直接返回NULL
+    if ((id >> ((layer + 1) * IDR_BITS)) > 0)
+        return -EDOM;
+
+    while (layer > 0)
+    {
+        int layer_id = (id >> (layer * IDR_BITS)) & IDR_MASK;
+
+        if (unlikely(NULL == cur_layer->ary[layer_id]))
+            return -ENOMEM;
+
+        cur_layer = cur_layer->ary[layer_id];
+        layer--;
+    }
+
+    id &= IDR_MASK;
+    *old_ptr = cur_layer->ary[id];
+    cur_layer->ary[id] = ptr;
+
+    return 0;
+}
+
+/**
+ * @brief 根据id替换指针，你需要保证这个id存在于idr中，否则将会出现错误
+ *
+ * @param idp
+ * @param ptr (要替换 '旧数据指针' 的 '新数据指针' - new_ptr)
+ * @param id
+ * @return int (0代表成功，否则就是错误码 - 代表错误)
+ */
+int idr_replace(struct idr *idp, void *ptr, int id)
+{
+    if (id < 0)
+        return -EDOM;
+
+    void *old_ptr;
+    int flags = idr_replace_get_old(idp, ptr, id, &old_ptr);
+
+    return flags;
+}
+
+/**
+ * @brief 初始化IDA, 你需要保证调用函数之前, ida的free_list为空, 否则会导致内存泄漏
+ * @param ida_p
+ */
+void ida_init(struct ida *ida_p)
+{
+    memset(ida_p, 0, sizeof(struct ida));
+    idr_init(&ida_p->idr);
+}
+
+/**
+ * @brief 释放bitmap空间
+ *
+ */
+static void __ida_bitmap_free(struct ida_bitmap *bitmap)
+{
+    kfree(bitmap);
+}
+
+/**
+ * @brief 为ida预分配空间
+ *
+ * @param ida_p
+ * @param gfp_mask
+ * @return int (如果分配成功,将返回0; 否则返回负数错误码, 有可能是内存空间不够)
+ */
+int ida_pre_get(struct ida *ida_p, gfp_t gfp_mask)
+{
+    if (idr_pre_get(&ida_p->idr, gfp_mask) != 0)
+        return -ENOMEM;
+
+    unsigned long flags;
+    spin_lock_irqsave(&ida_p->idr.lock, flags);
+
+    if (NULL == ida_p->free_list)
+    {
+        struct ida_bitmap *bitmap;
+        bitmap = kzalloc(sizeof(struct ida_bitmap), gfp_mask);
+        if (NULL == bitmap)
+        {
+            spin_unlock_irqrestore(&ida_p->idr.lock, flags);
+            return -ENOMEM;
+        }
+        ida_p->free_list = bitmap;
+    }
+
+    spin_unlock_irqrestore(&ida_p->idr.lock, flags);
+    return 0;
+}
+
+/**
+ * @brief Get the ida bitmap object
+ *
+ * @param ida_p
+ * @return void*
+ */
+static void *__get_ida_bitmap(struct ida *ida_p, gfp_t gfp_mask)
+{
+    if (NULL == ida_p->free_list)
+        if (ida_pre_get(ida_p, gfp_mask) < 0)
+            return NULL;
+
+    struct ida_bitmap *tmp = ida_p->free_list;
+    ida_p->free_list = NULL;
+    return tmp;
+}
+
+/**
+ * @brief 从bitmap中获取id， 并且标记这个ID已经被使用
+ * @return int
+ */
+static int __get_id_from_bitmap(struct ida_bitmap *bmp)
+{
+    int ret = 0;
+    for (int ary_id = 0; ary_id < IDA_BITMAP_LONGS; ary_id++)
+    {
+        if (bmp->bitmap[ary_id] != IDR_FULL)
+        {
+            int bmp_id = __lowbit_id(~bmp->bitmap[ary_id]);
+            bmp->bitmap[ary_id] |= (1ull << bmp_id);
+            bmp->count++; // 注意， 这里已经标记这一位已经使用， 同时更新了ida_count
+
+            if (unlikely((unsigned long long)ary_id * IDA_BMP_SIZE + bmp_id > INT32_MAX))
+            {
+                kBUG("ida设置id范围为[0, INT32_MAX], 但ida获取的id数值超过INT32_MAX.");
+                return -EDOM;
+            }
+
+            return ary_id * IDA_BMP_SIZE + bmp_id;
+        }
+    }
+
+    return -EDOM; // 不合法
+}
+
+/**
+ * @brief 获取一个ID
+ *
+ * @param ida_p
+ * @param p_id
+ * @return int (0表示获取ID成功， 否则是负数 - 错误码)
+ */
+int ida_get_new(struct ida *ida_p, int *p_id)
+{
+    *p_id = -1;
+
+    struct idr_layer *stk[MAX_LEVEL + 1]; // 你可以选择memset(0)
+    memset(stk, 0, sizeof(stk));
+    int idr_id = __idr_get_empty_slot(&ida_p->idr, stk);
+
+    // 如果stk[0]=NULL,可能是idr内部出错/内存空间不够
+    if (unlikely(NULL == stk[0]))
+        return -ENOMEM;
+
+    if (unlikely(idr_id < 0))
+        return idr_id;
+
+    int layer_id = idr_id & IDR_MASK;
+
+    if (NULL == stk[0]->ary[layer_id])
+        stk[0]->ary[layer_id] = __get_ida_bitmap(ida_p, 0);
+
+    if (unlikely(NULL == stk[0]->ary[layer_id]))
+        return -ENOMEM;
+
+    struct ida_bitmap *bmp = (struct ida_bitmap *)stk[0]->ary[layer_id];
+    int low_id = __get_id_from_bitmap(bmp);
+
+    if (unlikely(low_id < 0))
+        return low_id;
+
+    *p_id = idr_id * IDA_BITMAP_BITS + low_id;
+    __idr_mark_full(&ida_p->idr, idr_id, stk, (bmp->count == IDA_FULL ? 2 : 1));
+
+    return 0;
+}
+
+/**
+ * @brief 查询ID是否已经被分配
+ *
+ * @param ida_p
+ * @param id
+ * @return true
+ * @return false
+ */
+bool ida_count(struct ida *ida_p, int id)
+{
+    if (unlikely(NULL == ida_p || NULL == ida_p->idr.top || id < 0))
+        return false;
+
+    int idr_id = id / IDA_BITMAP_BITS;
+    int ary_id = (id % IDA_BITMAP_BITS) / IDA_BMP_SIZE;
+    int bmp_id = (id % IDA_BITMAP_BITS) % IDA_BMP_SIZE;
+
+    struct ida_bitmap *bmp = idr_find(&ida_p->idr, idr_id);
+    if (NULL == bmp)
+        return false;
+
+    return ((bmp->bitmap[ary_id] >> bmp_id) & 1);
+}
+
+/**
+ * @brief 删除一个ID
+ *
+ * @param ida_p
+ * @param id
+ */
+void ida_remove(struct ida *ida_p, int id)
+{
+    if (unlikely(NULL == ida_p || NULL == ida_p->idr.top || id < 0))
+        return;
+
+    int idr_id = id / IDA_BITMAP_BITS;
+    int ary_id = (id % IDA_BITMAP_BITS) / IDA_BMP_SIZE;
+    int bmp_id = (id % IDA_BITMAP_BITS) % IDA_BMP_SIZE;
+
+    struct idr_layer *stk[MAX_LEVEL + 1];
+    memset(stk, 0, sizeof(stk));
+    if (0 == __idr_get_path(&ida_p->idr, idr_id, stk))
+        return;
+
+    struct ida_bitmap *b_p = (struct ida_bitmap *)stk[0]->ary[idr_id & IDR_MASK];
+
+    // 不存在这个ID 或者 b_p == NULL
+    if (unlikely(NULL == b_p || 0 == ((b_p->bitmap[ary_id] >> bmp_id) & 1)))
+        return;
+
+    b_p->count--; // 更新了ida_count
+    b_p->bitmap[ary_id] ^= (1ull << bmp_id);
+
+    __idr_erase_full(&ida_p->idr, idr_id, stk, (b_p->count > 0 ? 1 : 0));
+    if (0 == b_p->count)
+    {
+        __ida_bitmap_free(b_p);
+        if (stk[0])                                // stk[0] 有可能在 __idr_erase_full 里面已经kfree了
+            stk[0]->ary[idr_id & IDR_MASK] = NULL; // 记得设置为空
+    }
+}
+
+/**
+ * @brief 释放所有空间(包括: idr + ida_bitmap + free_list)
+ * @param ida_p
+ */
+void ida_destroy(struct ida *ida_p)
+{
+    if (unlikely(ida_p == NULL))
+        return;
+
+    __idr_destroy_with_free(&ida_p->idr);
+    ida_p->idr.top = NULL;
+    __ida_bitmap_free(ida_p->free_list);
+    ida_p->free_list = NULL;
+}

kernel/process/process.c

@@ -496,6 +496,7 @@ ul initial_kernel_thread(ul arg)
         ktest_start(ktest_test_bitree, 0),
         ktest_start(ktest_test_kfifo, 0),
         ktest_start(ktest_test_mutex, 0),
+        ktest_start(ktest_test_idr, 0),
         // usb_pid,
     };
     kinfo("Waiting test thread exit...");