学习到了 常用函数 system

C16-并发/parallel/signal/mytbf/mytbf.c

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+/***********************************************************************
+ * @file     mytbf.c
+ * @brief
+ *           令牌桶库实现
+ *
+ * @author   lzy (lllzzzyyy@buaa.edu.cn)
+ * @url      https://lzyyyyyy.fun
+ *
+ * @date     2024-05-26
+ *
+ ***********************************************************************/
+
+#include "mytbf.h"
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+struct mytbf_st
+{
+    int cps;
+    int burst;
+    int token;
+    int pos;
+};
+
+static struct mytbf_st *job[MYTBF_MAX];
+static int              inited = 0;
+static __sighandler_t   alrm_handler_save;   //!!! 保存原来的alarm行为
+
+
+static int get_free_pos()
+{
+    int i;
+
+    for (i = 0; i < MYTBF_MAX; i++)
+    {
+        if (NULL == job[i])
+            return i;
+    }
+
+    return -1;
+}
+
+static void alrm_handler(int s)
+{
+    int i;
+
+    alarm(1);
+
+    for (i = 0; i < MYTBF_MAX; i++)
+    {
+        if (NULL != job[i])
+        {
+            job[i]->token += job[i]->cps;
+            if (job[i]->token > job[i]->burst)
+                job[i]->token = job[i]->burst;
+        }
+    }
+}
+
+static void module_unload()
+{
+    int i;
+
+    signal(SIGALRM, alrm_handler_save);
+    alarm(0);
+    for (i = 0; i < MYTBF_MAX; i++)
+        free(job[i]);
+}
+
+static void module_load()
+{
+    alrm_handler_save = signal(SIGALRM, alrm_handler);
+    alarm(1);
+
+    atexit(module_unload);   //!!! atexit()
+}
+
+mytbf_t *mytbf_init(int cps, int burst)
+{
+    struct mytbf_st *me;
+    int              pos;
+
+    if (!inited)
+    {
+        module_load();
+        inited = 1;
+    }
+
+    pos = get_free_pos();
+    if (pos < 0)
+        return NULL;
+
+    me = malloc(sizeof(*me));
+    if (NULL == me)
+        return NULL;
+
+    me->cps   = cps;
+    me->burst = burst;
+    me->token = 0;
+    me->pos   = pos;
+
+    job[pos] = me;
+
+    return me;
+}
+
+static int min(int a, int b)
+{
+    return a < b ? a : b;
+}
+
+int mytbf_fetchtoken(mytbf_t *ptr, int size)
+{
+    if (size <= 0)
+        return -EINVAL;
+
+    struct mytbf_st *me = ptr;
+    int              n;
+
+    while (me->token <= 0)
+        pause();
+
+    n = min(size, me->token);
+
+    me->token -= n;
+
+    return n;
+}
+
+int mytbf_returntoken(mytbf_t *ptr, int size)
+{
+    if (size <= 0)
+        return -EINVAL;
+
+    struct mytbf_st *me = ptr;
+
+    me->token += size;
+    if (me->token > me->burst)
+        me->token = me->burst;
+
+    return size;
+}
+
+int mytbf_destroy(mytbf_t *ptr)
+{
+    struct mytbf_st *me = ptr;
+
+    job[me->pos] = NULL;
+
+    free(ptr);
+    return 0;
+}