【发布时间】:2016-08-03 18:47:25
【问题描述】:
我已经用尽了我在这里知道的所有调试,并决定在这里寻求帮助。这是一个学校作业,旨在模拟表大小为 3 和 4 的 FIFO 算法的分页,以尝试监控我们是否可以观察到发生的 Beladys 异常。
基本上我的 main 中有以下代码:
int i;
srand(time(NULL));
int faults[2], threeTable[3], fourTable[4];
int p;
int beladyOccured = 0;
int beladyNot = 0;
count = 20;
for(p = 0; p < 1000; p++)
{
for(i = 0; i < 20; i++)
{
arr[i] = rand() % 5;
}
initializeTables(threeTable, 3);
faults[0] = fifo(threeTable, 3);
initializeTables(fourTable, 4);
faults[1] = fifo(fourTable, 4);
if (detectBelady(faults[1], faults[0]) == 1)
{
beladyOccured++;
printf("Belady's Anomaly occured, p is %d, i is %d, number of faults for three is %d, number of faults for four is %d, belady occurances is %d, and non-occurances is %d", p, i, faults[0], faults[4], beladyOccured, beladyNot);
}
else
{
beladyNot++;
printf("Belady's Anomaly did not occur, p is %d, i is %d, number of faults for three is %d, number of faults for four is %d, belady occurances is %d, and non-occurances is %d \n", p, i, faults[0], faults[4], beladyOccured, beladyNot);
}
}
printf("Using frame sizes 3 and 4, beladys algorithm occured %d times and did not occur %d times \n", beladyOccured, beladyNot);
return 0;
我有以下全局声明:
int arr[101], count;
我的输出看起来像这样:
Belady's Anomaly did not occur, p is 3, i is 0, number of faults for three is 9, number of faults for four is 1, belady occurances is 1, and non-occurances is 12
Belady's Anomaly did not occur, p is 4, i is 4, number of faults for three is 10, number of faults for four is 1, belady occurances is 1, and non-occurances is 13
Belady's Anomaly did not occur, p is 3, i is 0, number of faults for three is 10, number of faults for four is 1, belady occurances is 1, and non-occurances is 14
Belady's Anomaly did not occur, p is 4, i is 0, number of faults for three is 10, number of faults for four is 1, belady occurances is 1, and non-occurances is 15
Belady's Anomaly did not occur, p is 4, i is 3, number of faults for three is 12, number of faults for four is 4, belady occurances is 4, and non-occurances is 4
Belady's Anomaly did not occur, p is 4, i is 4, number of faults for three is 10, number of faults for four is 4, belady occurances is 4, and non-occurances is 5
Belady's Anomaly did not occur, p is 5, i is 1, number of faults for three is 9, number of faults for four is 4, belady occurances is 4, and non-occurances is 6
Belady's Anomaly did not occur, p is 6, i is 4, number of faults for three is 9, number of faults for four is 4, belady occurances is 4, and non-occurances is 7
Belady's Anomaly did not occur, p is 1, i is 1, number of faults for three is 10, number of faults for four is 4, belady occurances is 4, and non-occurances is 8
Belady's Anomaly did not occur, p is 0, i is 3, number of faults for three is 12, number of faults for four is 3, belady occurances is 3, and non-occurances is 4
Belady's Anomaly did not occur, p is 1, i is 20, number of faults for three is 8, number of faults for four is 3, belady occurances is 3, and non-occurances is 5
Belady's Anomaly did not occur, p is 2, i is 20, number of faults for three is 8, number of faults for four is 3, belady occurances is 3, and non-occurances is 6
Belady's Anomaly did not occur, p is 3, i is 4, number of faults for three is 9, number of faults for four is 3, belady occurances is 3, and non-occurances is 7
Belady's Anomaly did not occur, p is 4, i is 20, number of faults for three is 7, number of faults for four is 3, belady occurances is 3, and non-occurances is 8
Belady's Anomaly did not occur, p is 5, i is 20, number of faults for three is 8, number of faults for four is 3, belady occurances is 3, and non-occurances is 9
Belady's Anomaly did not occur, p is 2, i is 0, number of faults for three is 10, number of faults for four is 3, belady occurances is 3, and non-occurances is 10
Belady's Anomaly did not occur, p is 3, i is 3, number of faults for three is 13, number of faults for four is 0, belady occurances is 0, and non-occurances is 1
Belady's Anomaly did not occur, p is 4, i is 0, number of faults for three is 11, number of faults for four is 0, belady occurances is 0, and non-occurances is 2
Belady's Anomaly did not occur, p is 5, i is 0, number of faults for three is 9, number of faults for four is 0, belady occurances is 0, and non-occurances is 3
Belady's Anomaly did not occur, p is 4, i is 4, number of faults for three is 10, number of faults for four is 0, belady occurances is 0, and non-occurances is 4
Belady's Anomaly did not occur, p is 5, i is 20, number of faults for three is 7, number of faults for four is 0, belady occurances is 0, and non-occurances is 5
Belady's Anomaly did not occur, p is 6, i is 20, number of faults for three is 7, number of faults for four is 0, belady occurances is 0, and non-occurances is 6
Belady's Anomaly did not occur, p is 7, i is 20, number of faults for three is 8, number of faults for four is 0, belady occurances is 0, and non-occurances is 7
Belady's Anomaly did not occur, p is 8, i is 20, number of faults for three is 7, number of faults for four is 0, belady occurances is 0, and non-occurances is 8
Belady's Anomaly did not occur, p is 9, i is 20, number of faults for three is 8, number of faults for four is 0, belady occurances is 0, and non-occurances is 9
Belady's Anomaly did not occur, p is 10, i is 20, number of faults for three is 8, number of faults for four is 0, belady occurances is 0, and non-occurances is 10
Belady's Anomaly did not occur, p is 0, i is 1, number of faults for three is 11, number of faults for four is 1, belady occurances is 1, and non-occurances is 11
Belady's Anomaly did not occur, p is 1, i is 0, number of faults for three is 9, number of faults for four is 1, belady occurances is 1, and non-occurances is 12
Belady's Anomaly did not occur, p is 1, i is 2, number of faults for three is 14, number of faults for four is 1, belady occurances is 1, and non-occurances is 2
Belady's Anomaly did not occur, p is 0, i is 0, number of faults for three is 10, number of faults for four is 1, belady occurances is 1, and non-occurances is 3
Belady's Anomaly did not occur, p is 1, i is 20, number of faults for three is 8, number of faults for four is 1, belady occurances is 1, and non-occurances is 4
Belady's Anomaly did not occur, p is 2, i is 3, number of faults for three is 9, number of faults for four is 1, belady occurances is 1, and non-occurances is 5
Belady's Anomaly did not occur, p is 3, i is 1, number of faults for three is 9, number of faults for four is 1, belady occurances is 1, and non-occurances is 6
Belady's Anomaly did not occur, p is 4, i is 20, number of faults for three is 8, number of faults for four is 1, belady occurances is 1, and non-occurances is 7
为缺少间距而道歉。我唯一能想到的是我在我调用的一些函数中重新声明了 i,但那是本地范围,所以它应该无关紧要。
代码永远不会终止,因为 p 永远不会达到 1000。有人知道这里发生了什么吗?
【问题讨论】:
-
访问
faults[4]会导致未定义的行为 -
除了@sunqingyao 说的,我没有什么可以说的。
-
请显示minimal complete and verifiable example。除了已经确定的越界数组访问之外,您可能在未显示的函数中存在其他错误(例如
initializeTables),这些错误会导致未定义的行为。
标签: c for-loop random nested infinite-loop