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碰到了一个内存释放的问题，在进行某个复杂的操作时内存释放后否则会造成崩溃。经过多方面调查发现此时根据就不能释放内存（历史原因），否则会造成不可预知的问题。所以我打算把要删除的指针暂时保存起来，并不立马delete，等到10秒钟还没有操作的时候（稍微空闲）再把保存的指针都销毁掉。
后来顺利的解决了问题，而且改动较小。
代码如下：
class DelayDestory : public QObject {
Q_OBJECT
public:
static DelayDestory* instance();
void deleteItem(TreeItem *item);
void deleteItem(const QList<TreeItem*> &items);
private slots:
void onTimer();
private:
DelayDestory();
private:
static const int INTERVAL_SECOND = 5;
static const int TIMEOUT_SECOND = 10;
QList<TreeItem*> items_;
class QTimer *timer_;
QMutex mutex_;
qint64 lastTime_;
};
DelayDestory* DelayDestory::instance()
{
static DelayDestory s_inst;
return &s_inst;
}
void DelayDestory::deleteItem(TreeItem *item)
{
if (!item) {
return;
}
lastTime_ = QDateTime::currentMSecsSinceEpoch();
QMutexLocker lock(&mutex_);
if (!items_.contains(item)) {
items_.push_back(item);
}
}
void DelayDestory::deleteItem(const QList<TreeItem*> &items)
{
if (items.isEmpty()) {
return;
}
lastTime_ = QDateTime::currentMSecsSinceEpoch();
QMutexLocker lock(&mutex_);
for (int i = 0; i < items.size(); i++) {
if (items[i] && !items_.contains(items[i])) {
items_.push_back(items[i]);
}
}
}
DelayDestory::DelayDestory()
: mutex_(QMutex::Recursive), lastTime_(0)
{
timer_ = new QTimer(this);
connect(timer_, SIGNAL(timeout()), this, SLOT(onTimer()));
timer_->start(INTERVAL_SECOND * 1000);
}
void DelayDestory::onTimer()
{
qint64 currentTime = QDateTime::currentMSecsSinceEpoch();
if (currentTime - lastTime_ >= TIMEOUT_SECOND * 1000 && !items_.isEmpty()) {
QList<TreeItem*> tempList;
{
QMutexLocker lock(&mutex_);
tempList = items_;
items_.clear();
}
qDebug() << "delete tree items, size:" << tempList.size();
for (int i = 0; i < tempList.size(); i++) {
delete tempList[i];
}
}
}