我的应用程序涉及备份用户设置的某些sqlite数据库。此备份基于某些条件。所以为了做到这一点,我使用一个工作对象(在QThread上运行)检查条件是否匹配。如果条件匹配,我会进行备份。我的问题是,我检查了任务管理器,我的应用程序总是使用至少25%(因为线程正在运行)。如果我禁用自动备份,它将恢复正常。我做错了什么或这是正常的吗?任何人都可以指出我如何保持低CPU使用率?下面是我的自动备份线程的代码。
void Automatic_Backup_Logic::Thread_Run()
{
QSettings settings(ORGANISATION, APPLICATION_NAME);
while(!m_Stop){
// First check the backup type
int backup_type = settings.value(BACKUP_TYPE).toInt();
QTime BackupTime = qvariant_cast<QTime>(settings.value(BACKUP_TIME));
// Check for backup time; if it's in range only then do backup
if(!Check_Backup_Time(BackupTime)){
continue;
}
switch (backup_type)
{
case BACKUP_TYPE_MANUAL:
// do nothing here
continue;
case BACKUP_TYPE_DAILY:
Backup_Daily();
break;
case BACKUP_TYPE_WEEKLY:
Backup_Weekly();
break;
case BACKUP_TYPE_MONTHLY:
Backup_Monthly();
break;
case BACKUP_TYPE_YEARLY:
Backup_Yearly();
break;
default:
break;
}
// Wait for the current backup minute to pass by to avoid multiple copies
QTime t1 = qvariant_cast<QTime> (settings.value(BACKUP_TIME));
while(t1.minute()==QTime::currentTime().minute()){
if(m_Stop)
return;
QCoreApplication::processEvents();
}
}
}
PS:我正在通过标准Qt过程运行此线程,该过程创建一个工作线程并使用moveToThread()函数
解决这个问题的一个简洁方法是利用Qt的信号/插槽机制。
只需设置一个QTimer
剩余时间备份并将其timeout()
信号与备份插槽连接,如:
class Automatic_Backup_Logic {
public:
Automatic_Backup_Logic() {
connect(&mBackupTimer, &QTimer::timeout, this, &Automatic_Backup_Logic::performBackup);
}
void scheduleBackup(QTime backupTime) {
int millisRemaining = getTimeRemaining(backupTime);
mBackupTimer.singleShot(millisRemaining);
}
private slots:
void performBackup() {
}
private:
QTimer mBackupTimer;
}
正如评论中所建议的,我把延迟放在我的线程中,现在一切都按预期工作了。谢谢你们
编辑代码
// Check for backup time; if it's in range only then do backup
while(!Check_Backup_Time(BackupTime) && !m_Stop){
QThread::sleep(1);
BackupTime = qvariant_cast<QTime>(settings.value(BACKUP_TIME));
}