Memory management 删除Vala中的GLib.Tree元素时指针无效
此代码导致以下错误Memory management 删除Vala中的GLib.Tree元素时指针无效,memory-management,glib,vala,Memory Management,Glib,Vala,此代码导致以下错误 free():指针无效 使用GLib; 使用油嘴滑舌。随机; //全局变量 主树; 公共静态int main(字符串[]args){ //启动随机种子 Random.set_seed((uint32)get_单调_time()); //主目录树初始化 mainTree=new Tree.full(mainTreeCompareDataFunction,free,free); //循环的随机大小 对于(int i=0;i{ mainTree.remove(mainTreeKe
free():指针无效
使用GLib;
使用油嘴滑舌。随机;
//全局变量
主树;
公共静态int main(字符串[]args){
//启动随机种子
Random.set_seed((uint32)get_单调_time());
//主目录树初始化
mainTree=new Tree.full(mainTreeCompareDataFunction,free,free);
//循环的随机大小
对于(int i=0;i{
mainTree.remove(mainTreeKey);//此行导致free():无效指针错误
返回false;
});
返回0;
}
公共字符串randomString(){
string charset=“abcdefghijklmnopqrstuvxyzabefghijklmnopqrstuvxyz”;
字符串stringToReturn=“”;
//创建一个随机的8字符字符串
对于(int i=0;i<8;i++){
stringToReturn+=charset[int_range(0,charset.length)]。到_字符串();
}
返回字符串返回;
}
公共int树嵌套比较数据函数(int a、int b){
如果(ab)返回1;
返回0;
}
public int mainTreeCompareDataFunction(字符串a、字符串b){
返回strcmp(a,b);
}
我怀疑这是因为树中有一个嵌套的GLib.Tree
,并且free()
不能用于这些对象。如果我对mainTree
的值使用null
而不是destroy函数,则不会发生崩溃,但是如果我要重用mainTree
变量,就会产生内存泄漏
有没有办法清空树并释放内存?找到了解决方案,即手动管理内存。首先,使嵌套树成为指针。其次,将null
传递给用于指定释放嵌套树的函数的参数。第三,将null
传递给用于指定释放嵌套树的int
键的函数的参数。最后,在清空主树时,使用delete
关键字减少对嵌套树的引用
由于手动调用delete
(此处特别调用g_tree\u unref
)在Vala生成的C代码中,对嵌套树的引用将在此代码中降至0,因此嵌套树的所有键和值将被销毁,树分配的所有内存将被释放。这样就不会再发生无效指针错误,也不会出现内存泄漏
using GLib;
using GLib.Random;
// Global variable
Tree<string, Tree<int, string>* > mainTree;
public static int main (string[] args) {
// Initiate random seed
Random.set_seed ((uint32) get_monotonic_time());
// mainTree initialization
mainTree = new Tree<string, Tree<int, string> >.full (mainTreeCompareDataFunction, free, null);
// Random sized for loop
for (int i = 0; i < int_range (1000, 10001); i++) {
// If a condition is met (i is even)
if (i % 2 == 0) {
// Create a Tree to nest onto mainTree
Tree<int, string>* treeToNest = new Tree<int, string>.full (treeToNestCompareDataFunction, null, free);
// Insert random content into treeToNest
treeToNest->insert (int_range (0, 101), randomString ());
// Insert the tree onto mainTree
mainTree.insert (randomString (), treeToNest);
}
}
// Empty the tree
mainTree.@foreach ((mainTreeKey, mainTreeValue) => {
delete mainTree.lookup (mainTreeKey);
mainTree.remove (mainTreeKey);
return false;
});
return 0;
}
public string randomString () {
string charset = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
string stringToReturn = "";
// Create a random 8 character string
for (int i = 0; i < 8; i++) {
stringToReturn += charset[int_range (0, charset.length)].to_string ();
}
return stringToReturn;
}
public int treeToNestCompareDataFunction (int a, int b) {
if (a < b) return -1;
if (a > b) return 1;
return 0;
}
public int mainTreeCompareDataFunction (string a, string b) {
return strcmp (a, b);
}
使用GLib;
使用油嘴滑舌。随机;
//全局变量
主树;
公共静态int main(字符串[]args){
//启动随机种子
Random.set_seed((uint32)get_单调_time());
//主目录树初始化
mainTree=new Tree.full(mainTreeCompareDataFunction,free,null);
//循环的随机大小
对于(int i=0;i插入(int_范围(0,101),随机字符串());
//将树插入mainTree
mainTree.insert(randomString(),treeToNest);
}
}
//把树倒空
mainTree@foreach((mainTreeKey,mainTreeValue)=>{
删除mainTree.lookup(mainTreeKey);
mainTree.remove(mainTreeKey);
返回false;
});
返回0;
}
公共字符串randomString(){
string charset=“abcdefghijklmnopqrstuvxyzabefghijklmnopqrstuvxyz”;
字符串stringToReturn=“”;
//创建一个随机的8字符字符串
对于(int i=0;i<8;i++){
stringToReturn+=charset[int_range(0,charset.length)]。到_字符串();
}
返回字符串返回;
}
公共int树嵌套比较数据函数(int a、int b){
如果(ab)返回1;
返回0;
}
public int mainTreeCompareDataFunction(字符串a、字符串b){
返回strcmp(a,b);
}
资料来源:
您可以编写lambda,该lambda将使用所有权转移删除子树
mainTree = new Tree<string, Tree<int, string> >.full (mainTreeCompareDataFunction, free,
(data) => {
var tree = (Tree<string, Tree<int, string>>) data;
// Ownership is transfered to this local var which calls unref when it goes out of scope
var tree2 = (owned) tree;
});
mainTree=new Tree.full(mainTreeCompareDataFunction,free,
(数据)=>{
变量树=(树)数据;
//所有权被转移到这个本地var,当它超出范围时调用unref
var tree2=(拥有的)树;
});
以下是完整的代码:
using GLib;
using GLib.Random;
// Global variable
Tree<string, Tree<int, string> > mainTree;
public static int main (string[] args) {
// Initiate random seed
Random.set_seed ((uint32) get_monotonic_time());
// mainTree initialization
mainTree = new Tree<string, Tree<int, string> >.full (mainTreeCompareDataFunction, free,
(data) => {
var tree = (Tree<string, Tree<int, string>>) data;
// Ownership is transfered to this local var which calls unref when it goes out of scope
var tree2 = (owned) tree;
});
// Random sized for loop
for (int i = 0; i < int_range (1000, 10001); i++) {
// If a condition is met (i is even)
if (i % 2 == 0) {
// Create a Tree to nest onto mainTree
Tree<int, string> treeToNest = new Tree<int, string>.full (treeToNestCompareDataFunction, null, free);
// Insert random content into treeToNest
treeToNest.insert (int_range (0, 101), randomString ());
// Insert the tree onto mainTree
mainTree.insert (randomString (), treeToNest);
}
}
// Empty the tree
mainTree.@foreach ((mainTreeKey, mainTreeValue) => {
mainTree.remove (mainTreeKey);
return false;
});
return 0;
}
public string randomString () {
string charset = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
string stringToReturn = "";
// Create a random 8 character string
for (int i = 0; i < 8; i++) {
stringToReturn += charset[int_range (0, charset.length)].to_string ();
}
return stringToReturn;
}
public int treeToNestCompareDataFunction (int a, int b) {
if (a < b) return -1;
if (a > b) return 1;
return 0;
}
public int mainTreeCompareDataFunction (string a, string b) {
return strcmp (a, b);
}
使用GLib;
使用油嘴滑舌。随机;
//全局变量
主树;
公共静态int main(字符串[]args){
//启动随机种子
Random.set_seed((uint32)get_单调_time());
//主目录树初始化
mainTree=new Tree.full(mainTreeCompareDataFunction,free,
(数据)=>{
变量树=(树)数据;
//所有权被转移到这个本地var,当它超出范围时调用unref
var tree2=(拥有的)树;
});
//循环的随机大小
对于(int i=0;iusing GLib;
using GLib.Random;
// Global variable
Tree<string, Tree<int, string> > mainTree;
public static int main (string[] args) {
// Initiate random seed
Random.set_seed ((uint32) get_monotonic_time());
// mainTree initialization
mainTree = new Tree<string, Tree<int, string> >.full (mainTreeCompareDataFunction, free,
(data) => {
var tree = (Tree<string, Tree<int, string>>) data;
// Ownership is transfered to this local var which calls unref when it goes out of scope
var tree2 = (owned) tree;
});
// Random sized for loop
for (int i = 0; i < int_range (1000, 10001); i++) {
// If a condition is met (i is even)
if (i % 2 == 0) {
// Create a Tree to nest onto mainTree
Tree<int, string> treeToNest = new Tree<int, string>.full (treeToNestCompareDataFunction, null, free);
// Insert random content into treeToNest
treeToNest.insert (int_range (0, 101), randomString ());
// Insert the tree onto mainTree
mainTree.insert (randomString (), treeToNest);
}
}
// Empty the tree
mainTree.@foreach ((mainTreeKey, mainTreeValue) => {
mainTree.remove (mainTreeKey);
return false;
});
return 0;
}
public string randomString () {
string charset = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
string stringToReturn = "";
// Create a random 8 character string
for (int i = 0; i < 8; i++) {
stringToReturn += charset[int_range (0, charset.length)].to_string ();
}
return stringToReturn;
}
public int treeToNestCompareDataFunction (int a, int b) {
if (a < b) return -1;
if (a > b) return 1;
return 0;
}
public int mainTreeCompareDataFunction (string a, string b) {
return strcmp (a, b);
}