Re: checking if the memory was allocted previously

=?ISO-8859-1?Q?Marcel_M=FCller?= <>
Wed, 09 Jun 2010 11:46:54 +0200

mjoachimiak wrote:

mystrucure *dynamic_element = NULL

void some_function()
if (dynamic_element == NULL)
                 dynamic_element = malloc(sizeofm(mystructure));
if (dynamic_element != NULL) do_smth(dynamic_element);

If you use C++ you should prefer new/delete over malloc where possible.
This eliminates the need for the second NULL check since new will not
return NULL.

call some_function() many times;
if (dynamic_element != NULL)
what about my previous memory allocation ?
Can it cause race condition also?

Yes, if and only if "call some_function() many times" calls
some_function in parallel.

You should put the initialization of dynamic_element in main before the
other processing. This would completely eliminate the need for the NULL
checks in some_funtion.

However, the content of mystructure has to be accessed synchronized or
atomic or read only anyway if you intend to operate in parallel without
race conditions.


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