CODEWITHSUNDEEP
iphoneexc-bad-access
iDragon
iDragon

Reputation: 1

"EXC_BAD_ACCESS" when i call static function

Consider this function in class ABC having one instance variable as sName and i have static object of this class as obj

+ (ABC*) getInstance : (NSString *) name
{
     if(obj == nil)
    {
      obj = [[ABC alloc] initWithName: name];
    } 
    // checking the name is same or reinitializing it again
    else if ([name isEqualToString:[obj sName]] == NO)  
    { 
      obj = [[ABC alloc] initWithName: name];
   } 
  return obj ;
}

This snippet of code works perfectly fine on simulator, but when i run it on device. This function is getting called couple of times and third time i get "EXC_BAD_ACCESS".

What may the problem? Any suggestions to improve the code.

Upvotes: 0

Views: 1306

Answers (3)

Arvid
Arvid

Reputation: 11245

Here are a few things I would look into:

  1. the second block in the if-statement appears to leak obj. If called enough times, perhaps you actually run out of memory, and [ABC alloc] will in fact start to return NULL, which would crash, probably with EXC_BAD_ACCESS sending a message to a NULL pointer.

  2. This looks suspiciously similar to a singleton initializer. It is not thread safe, so if you're calling it from multiple threads, you might want to fix that (this is not a trivial problem btw.).

Upvotes: 0

Varun Chatterji
Varun Chatterji

Reputation: 5099

There seems to be a memory leak!!!!

Also, if sName is an instance varaible, why don't you synthesize it as a property and then call it differently:

@synthesize sName;

+ (ABC*) getInstance : (NSString *) name
{
      if(obj == nil)
      {
         obj = [[ABC alloc] initWithName: name];
      } 
      // checking the name is same or reinitializing it again
      else if (![name isEqualToString:obj.sName])  
      { 
         //obj is not nil so if we are creating a new obj we should release the old one
         [obj release]
         obj = [[ABC alloc] initWithName: name];
      } 
      return obj ;
}

Upvotes: 1

Mahesh
Mahesh

Reputation: 34625

Static methods cannot access non static variables.

"class ABC having one instance variable as sName", and so sName cannot be accessed in this method.

else if ([name isEqualToString:[obj sName]] == NO)
                                    ^^^^ Error

Upvotes: 2

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