github.com/outcaste-io/ristretto@v0.2.3/contrib/memtestc/list.c (about)

     1  /*
     2   * Copyright 2020 Dgraph Labs, Inc. and Contributors
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  // A simple C program for traversal of a linked list
    18  #include <stdio.h>
    19  #include <stdlib.h>
    20  #include <unistd.h>
    21  
    22  struct Node {
    23  	int data;
    24    char* buf;
    25  	struct Node* next;
    26  };
    27  
    28  // This function prints contents of linked list starting from
    29  // the given node
    30  void printList(struct Node* n)
    31  {
    32  	while (n != NULL) {
    33  		printf(" %d ", n->data);
    34  		n = n->next;
    35  	}
    36  }
    37  
    38  long long int lo = 1L << 30;
    39  long long int hi = 16L << 30;
    40  
    41  struct Node* newNode(int sz) {
    42    struct Node* n = (struct Node*)calloc(1, sizeof(struct Node));
    43    n->buf = calloc(sz, 1);
    44    for (int i = 0; i < sz; i++) {
    45      n->buf[i] = 0xff;
    46    }
    47    n->data = sz;
    48    n->next = NULL;
    49    return n;
    50  }
    51  
    52  void allocate(struct Node* n, int sz) {
    53    struct Node* nn = newNode(sz);
    54    struct Node* tmp = n->next;
    55    n->next = nn;
    56    nn->next = tmp;
    57  }
    58  
    59  int dealloc(struct Node* n) {
    60    if (n->next == NULL) {
    61      printf("n->next is NULL\n");
    62      exit(1);
    63    }
    64    struct Node* tmp = n->next;
    65    n->next = tmp->next;
    66    int sz = tmp->data;
    67    free(tmp->buf);
    68    free(tmp);
    69    return sz;
    70  }
    71  
    72  int main()
    73  {
    74    struct Node* root = newNode(100);
    75  
    76    long long int total = 0;
    77    int increase = 1;
    78    while(1) {
    79      if (increase == 1) {
    80        int sz = (1 + rand() % 256) << 20;
    81        allocate(root, sz);
    82        if (root->next == NULL) {
    83          printf("root->next is NULL\n");
    84          exit(1);
    85        }
    86        total += sz;
    87        if (total > hi) {
    88          increase = 0;
    89        }
    90      } else {
    91        int sz = dealloc(root);
    92        total -= sz;
    93        if (total < lo) {
    94          increase = 1;
    95          sleep(5);
    96        } else {
    97          usleep(10);
    98        }
    99      }
   100  
   101      long double gb = total;
   102      gb /= (1 << 30);
   103      printf("Total size: %.2LF\n", gb);
   104    };
   105  
   106  	return 0;
   107  }
   108