CODEWITHSUNDEEP
iosobjective-cmultithreadinggrand-central-dispatch
GhostCode
GhostCode

Reputation: 454

is it recommended to start a background thread inside another background thread in iOS

I have the following code:

    -(void) alternateQuestion
    {
 NSDictionary *dictQuestion=nil;
    PMIiSMSQuestionModel *objQuestion=nil;  
    int iQuestionCount=[arrQuestion count];
    for (m_iIndex=0; m_iIndex<iQuestionCount; m_iIndex++){
        dictQuestion=[arrQuestion objectAtIndex:m_iIndex];   
        objQuestion=[[PMIiSMSQuestionModel alloc]init];
        [objQuestion setM_strCode: [dictQuestion valueForKey:QUESTION_CODE]];
        [objQuestion setM_strText: [dictQuestion valueForKey:QUESTION_TEXT]];
        [objQuestion setM_iAnswerType:[((NSString*)[dictQuestion valueForKey:ANSWER_TYPE]) intValue]];
        [objQuestion setM_iNumRangeStart: [((NSString*)[dictQuestion valueForKey:NUMBER_RANGE_START]) intValue]];
        [objQuestion setM_iNumRangeEnd: [((NSString*)[dictQuestion valueForKey:NUMBER_RANGE_END]) intValue]];
        [objQuestion setM_strDtRangeStart: [dictQuestion valueForKey:DATE_RANGE_START]];
        [objQuestion setM_strDtRangeEnd: [dictQuestion valueForKey:DATE_RANGE_END]];
        [objQuestion setM_strEmptyValue: [dictQuestion valueForKey:EMPTY_VALUE]];
        [objQuestion setM_bSkipEmptyValue: [((NSString*)[dictQuestion valueForKey:SKIP_EMPTY_VALUE]) boolValue]];
        [objQuestion setM_bIsMandatory:[((NSString*)[dictQuestion valueForKey:IS_MANDATORY]) boolValue]];
        [objQuestion setM_iIsReadOnly: [((NSString*)[dictQuestion valueForKey:IS_READONLY]) intValue]];
        [objQuestion setM_iHideIfReadOnly:[((NSString*)[dictQuestion valueForKey:HIDE_IF_READONLY]) intValue]];
        [objQuestion setM_strDefaultQuestion: [dictQuestion valueForKey:DEFAULT_QUESTION]];
        m_strSubCode = [dictQuestion valueForKey:@"SUBJECT_CODE"]; 
      NSString *strTemp=[[NSString alloc]initWithFormat:    CALLCARD_GET_QUESTION_QUERY,[self.m_objActiveCallcard m_iFunctionType],     
[self.m_objActiveCallcard m_strCode]];
    self.m_strQuery=strTemp;
    strTemp=nil;

        dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            [self verifyQuestions];

    //----------
    });

}

As we can see the method alternateQuestion has started a background thread.We are also performing many tasks in alternateQuestion method which currently runs on the main thread. Is it advisable to move alternateQuestion method in a new background thread using GCD so that the background threads will be nested.

Thanks in advance.

Upvotes: 1

Views: 333

Answers (2)

Ashish P.
Ashish P.

Reputation: 858

Check this apple documentation.

In listing 3-4, nested dispatch_async is used.

Upvotes: 1

nandu kathmandi
nandu kathmandi

Reputation: 33

If you are Using GCD, No problem to launching new task. because there is no effect to main thread.

Upvotes: 0

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