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我想实现一个内存管理模拟（好友），采用二叉树C的系统是如何工作的想法是这里概述：麻烦与二叉树结构实现
http://en.wikipedia.org/wiki/Buddy_memory_allocation
第一次输入一个值时，代码工作正常，并给出所需的输出。第二次输入值时会出现问题。我使用递归函数来遍历树，并且我得到一个错误，从而结构存在，但是结构的成员不存在。
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1 (LWP 1)]
0x00010b2c in allocate (node=0x401ba18a, reqSize=1000) at temp.c:95
95 if(node->flag == 1){
(gdb) print node
$1 = (struct block *) 0x401ba18a
(gdb) print node->flag
Cannot access memory at address 0x401ba192
相关的代码贴在下面，任何帮助将真正理解！
static int allocate(struct block* node, int reqSize) {
//BASE CASES!
printf("We've called allocate\n");
//check if the request is too small
if(reqSize < minSize){
printf("The request is too small!\n");
return -1;
}
//check if the request is too large
if(reqSize > memory){
printf("The request is too large!\n");
return -1;
}
//check if the current block is already allocated
if(node->flag == 1){
printf("This block has been allocated!\n");
return -1;
}
//var to hold returned value
int returnVal = 0;
//If the size of the request is less than or equal to half the node
if(reqSize<(node->size)/2){
printf("The size of the request is less than or equal too half the node\n");
//check if there is a left node, if not, make one and call allocate
if(node->left == NULL){
printf("There's no left node so we are making one and calling allocate with it\n");
struct block buddy1 = { .init =1.};
buddy1 = findSpace();
buddy1.init = 1;
buddy1.size = ((node->size)/2);
printf("with the size %d\n",(node->size)/2);
buddy1.flag = 0;
buddy1.parent = node;
buddy1.left = NULL;
buddy1.right = NULL;
struct block buddy2 = { .init =1.};
buddy2 = findSpace();
buddy2.init = 1;
buddy2.size = ((node->size)/2);
printf("with the size %d\n",(node->size)/2);
buddy2.flag = 0;
buddy2.parent = node;
buddy1.left = NULL;
buddy1.right = NULL;
node->left = &buddy1;
node->right = &buddy2;
returnVal = allocate(node->left,reqSize);
return returnVal;
}
//otherwise call allocate on the left node
printf("There is a left node so we are calling allocate on it\n");
returnVal = allocate(node->left,reqSize);
if(returnVal == -1){
printf("couldn't allocate a left node for some reason, so we are checking if a right node exists\n");
if(node->right ==NULL){
printf("it doesn't. We're making one and calling allocate on it!\n");
struct block buddy = { .init =1.};
buddy = findSpace();
buddy.init = 1;
buddy.size = ((node->size)/2);
printf("with the size %d\n",(node->size)/2);
buddy.flag = 0;
buddy.parent = node;
//node->left = NULL;
node->right = &buddy;
returnVal = allocate(&buddy,reqSize);
}
printf("it did, so we are calling allocate on it\n");
returnVal = allocate(node->right,reqSize);
//return returnVal;
}
return returnVal;
}
if(node->flag == 1){
return -1;
}
printf("This is the node we need!\n");
node->flag = 1;
printPostOrder(&blockArr[position]);
return 1;
}