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C (programming language): Difference between revisions
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Memory allocated by <code>alloca</code> is allocated on the stack and will automatically be freed. Do not call <code>free</code> on this memory. Do not allocate more than a few bytes using <code>alloca</code> or you will risk a stack overflow leading to undefined behavior.<br> | Memory allocated by <code>alloca</code> is allocated on the stack and will automatically be freed. Do not call <code>free</code> on this memory. Do not allocate more than a few bytes using <code>alloca</code> or you will risk a stack overflow leading to undefined behavior.<br> | ||
For automatic garbage collection, use [[C++]] which has smart pointers. | For automatic garbage collection, use [[C++]] which has smart pointers. | ||
{{ hidden | <code>_malloca</code> | | |||
On Windows you also have: | |||
* <code>_malloca</code> | |||
* <code>_calloca</code> | |||
These are not portable so I wouldn't use them. They are a safer version of <code>alloca</code> which allocates to the heap if there isn't enough stack space. However, you need to free them using <code>_freea</code> which eliminates the main benefit of <code>alloca</code>.<br> | |||
As far as I can tell, the only benefit is to prevent heap fragmentation. | |||
}} | |||