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POShould I use CRITICAL_SECTION or not?
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I have a program which has a Ui with which users choose the way to display and do small configurations. It also has a background procedure, which continuously reads data from the network and update the data to display. Now I put them in one process: background procedure: <pre><code> STATE MainWindow::Rcv() { DeviceMAP::iterator dev; for(dev= dev_map.begin(); dev!= dev_map.end(); dev++) { dev->second.rcvData();//receive data from the network, the time can be ignored. BitLog* log = new BitLog(); dev->second.parseData(log); LogItem* logItem = new LogItem(); logItem->time = QString::fromLocal8Bit(log->rcvTime.c_str()); logItem->name = QString::fromLocal8Bit(log->basicInfo.getName().c_str()); logItem->PIN = QString::fromLocal8Bit(log->basicInfo.getPIN().c_str()).toShort(); delete log; add_logItem(logItem); } return SUCCESS; } </code></pre> add_logItem: <pre><code>void MainWindow::add_logItem(LogItem* logItem) { writeToFile(logItem); Device* r = getDevbyPIN(QString::number(logItem->PIN)); if(r == NULL)return; devInfo_inside_widget::States state = logItem->state; bool bool_list[portsNum_X]; for(int i =0; i < portsNum_X; i++) { bool_list[i] = 0; } for(int i = 0; i < portsNum; i++) { bool_list[i] = (logItem->BITS[i/8] >> (7 - i%8)) & 0x1; } r->refresh(state, logItem->time, bool_list);//update data inside...state, time , BITS... IconLabel* icl = getIConLabelByDev(r);//update data icl->refresh(state); logDisplayQueue.enqueue(logItem);//write queue here int size = logDisplayQueue.size(); if(size > 100) { logDisplayQueue.dequeue();//write queue here } } </code></pre> The section above has not dealt with any ui operations yet, but when user push a radio button in the ui, the program has to filter the data in the queue and display it in the table widget: ui operations: <pre><code>void MainWindow::filter_log_display(bool bol) { row_selectable = false; ui->tableWidget->setRowCount(0);//delete table items all row_selectable = true; int size_1 = logDisplayQueue.size() - 1; ui->tableWidget->verticalScrollBar()->setSliderPosition(0); if(size_1+1 < 100) { ui->tableWidget->setRowCount(size_1 + 1); } else { ui->tableWidget->setRowCount(100);//display 100 rows at most } if(bol)//filter from logDisplayQueue and display unworking-state-log rows { int index = 0; for(int queue_i = size_1; queue_i >= 0; queue_i--) { LogItem* logItem = (LogItem*)logDisplayQueue.at(queue_i); // read queue here if(logItem->state == STATE_WORK || logItem->state == STATE_UN)continue; QString BITS_str = bits2Hexs(logItem->BITS); ui->tableWidget->setItem(index, 0, new QTableWidgetItem(logItem->time));//time ui->tableWidget->setItem(index, 1, new QTableWidgetItem(logItem->name));//name ui->tableWidget->setItem(index, 2, new QTableWidgetItem(BITS_str));//BITS if(queue_i == oldRowItemNo)ui->tableWidget->selectRow(index); index++; } ui->tableWidget->setRowCount(index); } else//display all rows { for(int queue_i = size_1, index = 0; queue_i >= 0; queue_i--, index++) { LogItem* logItem = (LogItem*)logDisplayQueue.at(queue_i); //read queue here QString BITS_str = bits2Hexs(logItem->BITS);// finish = clock(); ui->tableWidget->setItem(index, 0, new QTableWidgetItem(logItem->time));//time ui->tableWidget->setItem(index, 1, new QTableWidgetItem(logItem->name));//name ui->tableWidget->setItem(index, 2, new QTableWidgetItem(BITS_str));//BITS if(queue_i == oldRowItemNo)ui->tableWidget->selectRow(index); } } } </code></pre> So the queue is quite samll and the background procedure is quite frequent(nearly 500 times per sec). That is, the queue will be written 500 times in 1 sec, but displayed time from time by the user. I want to split the functions into two threads and run them together, one rev and update data, one display. If i do not use any lock or mutex, the user may get the wrong data, but if i force the write-data procedure enter critical section and leave critical section everytime, it will be a heavy overload. :) Should I use CRITICAL_SECTION or something else, any suggestions related?(my words could be verbose for you :) , i only hope for some hints :) 
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<multithreading><qt><user-interface><locking>
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Should I use CRITICAL_SECTION or not?
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