内存泄漏问题

Question

内存泄漏问题

3

请问为什么我的代码会出现内存泄漏？

我已在代码中的分析器中添加了注释。如果有人能帮忙解决问题并解释一下为什么会出现这两个注释，我将不胜感激。

- (void)viewDidDisappear:(BOOL)animated {

// Empty array to be sure it is empty
[playerArray removeAllObjects];

//============CLEAN OUT DOUBLE NAMES FROM ARRAY==============//
NSArray *sortedDummyArray = [[NSArray alloc] initWithArray:selectedPlayersArray];
    ////>>>>The line above is line 84<<<<<<<////

// Sort the array
sortedDummyArray = [sortedDummyArray sortedArrayUsingSelector:@selector(compare:)];

NSMutableArray *finalArray = [[NSMutableArray alloc]initWithArray:sortedDummyArray];
    ////>>>>>> Possible memory leak on line 84 <<<<<<<<//// 



int xx = [sortedDummyArray count];
int yy;
int counter = 0;
int rr = 0;

for (int oo = 0; oo < xx; oo++) {
    yy = [finalArray count];

    for (int zz = 0; zz < yy; zz++) {

        // If hit, clean out the double name
        if ([[sortedDummyArray objectAtIndex:oo] isEqualToString:[finalArray objectAtIndex:rr]]) {

            counter++;

            // Check if there is more than one of this name
            if (counter > 1) {
                [finalArray removeObjectAtIndex:rr];
                rr--;
                counter--;
            }
        }
        rr++;
    }
    counter = 0;
    rr = 0;
}

[sortedDummyArray retain];

// Save who is in the game

AccessQuestionsDB *shufflePlayersFunction = [AccessQuestionsDB new];
finalArray = [shufflePlayersFunction shufflePlayers: finalArray];
[shufflePlayersFunction release];

TempPlayersInTheGame *savePlayersInTheGame = [TempPlayersInTheGame new];
[savePlayersInTheGame saveSelectedPlayers:finalArray];
[savePlayersInTheGame release];

[finalArray release]; //>>>> see comment below
    ////>>>>>Incorrect decrement of the reference count of an object that is not owned at this point by the caller <<<<<<///// 

    [sortedDummyArray release];
[super viewDidDisappear:animated];

}

- PeterK

3个回答

1

你的问题在于这一行：

finalArray = [shufflePlayersFunction shufflePlayers: finalArray];

早些时候，您正在内存中创建一个新数组，并告诉finalArray指向它。但是这里的这行代码告诉finalArray指向不同的东西。因此，现在，您创建的原始数组仍然存在于内存中，而且您正在释放不同的数组。

您还使用sortedDummyArray进行完全相同类型的操作。如果您分配了一个对象，请不要将指针设置为指向其他内容。

- GendoIkari

1

需要保留dummySortedArray的调用吗？我认为在初始化集合时，您可能已经对其进行了保留计数。

NSArray *sortedDummyArray = [[NSArray alloc] initWithArray:selectedPlayersArray];

- JFoulkes

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可以查看英文原文，
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- theChrisKent · Accepted Answer

你的第一个泄漏是由于调用以下代码：

[sortedDummyArray retain];

您已经调用了一个执行此操作的alloc，但是您只在最后释放它一次（因此请删除上面的行）。然后，您重新分配它，这是不正确的。

您的第二个泄漏是由于您使用alloc设置了finalArray，然后用函数的结果替换了它。您可以通过替换此行来解决这个问题：

NSMutableArray *finalArray = [[NSMutableArray alloc]initWithArray:sortedDummyArray];

使用这个：

NSMutableArray *finalArray = [NSMutableArray arrayWithArray:sortedDummyArray];

然后删除这一行：

[finalArray release];

所以你的函数看起来应该像这样：

- (void)viewDidDisappear:(BOOL)animated {

    // Empty array to be sure it is empty
    [playerArray removeAllObjects];

    //============CLEAN OUT DOUBLE NAMES FROM ARRAY==============//   
    // Sort the array
    NSArray *sortedDummyArray = [selectedPlayersArray sortedArrayUsingSelector:@selector(compare:)];

    NSMutableArray *finalArray = [NSMutableArray arrayWithArray:sortedDummyArray];    

    int xx = [sortedDummyArray count];
    int yy;
    int counter = 0;
    int rr = 0;

    for (int oo = 0; oo < xx; oo++) {
        yy = [finalArray count];

        for (int zz = 0; zz < yy; zz++) {

            // If hit, clean out the double name
            if ([[sortedDummyArray objectAtIndex:oo] isEqualToString:[finalArray objectAtIndex:rr]]) {

               counter++;

               // Check if there is more than one of this name
               if (counter > 1) {
                   [finalArray removeObjectAtIndex:rr];
                   rr--;
                   counter--;
               }
            }
            rr++;
        }
        counter = 0;
        rr = 0;
    }

    // Save who is in the game

    AccessQuestionsDB *shufflePlayersFunction = [AccessQuestionsDB new];
    finalArray = [shufflePlayersFunction shufflePlayers: finalArray];
    [shufflePlayersFunction release];

    TempPlayersInTheGame *savePlayersInTheGame = [TempPlayersInTheGame new];
    [savePlayersInTheGame saveSelectedPlayers:finalArray];
    [savePlayersInTheGame release];

    [super viewDidDisappear:animated];
}

但是所有这些都是过度的，只是为了删除重复条目，将您的数组转换为NSSet（始终唯一），然后将其转换回NSArray应该为您处理此操作，因此您的函数应该是：

- (void)viewDidDisappear:(BOOL)animated {

    // Empty array to be sure it is empty
    [playerArray removeAllObjects];

    //============CLEAN OUT DOUBLE NAMES FROM ARRAY==============//   
    NSSet *uniquePlayers = [NSSet setWithArray:selectedPlayersArray];

    // Save who is in the game

    AccessQuestionsDB *shufflePlayersFunction = [AccessQuestionsDB new];
    NSArray *finalArray = [shufflePlayersFunction shufflePlayers: [uniquePlayers allObjects]];
    [shufflePlayersFunction release];

    TempPlayersInTheGame *savePlayersInTheGame = [TempPlayersInTheGame new];
    [savePlayersInTheGame saveSelectedPlayers:finalArray];
    [savePlayersInTheGame release];

    [super viewDidDisappear:animated];
}