On 11/19/07, John Stanton <[EMAIL PROTECTED]> wrote: > Malloc is a concept implemented in various ways, some more successful > than others but all of them hidden from the programmer. Free tries to > give back memory but as you can appreciate unless you use some garbage > collection scheme with backwards pointers fragmentation and > checkerboarding is very difficult to avoid.
Malloc and free as a concept do not imply fragmentation; it depends on the implementation and how you use it. > Various OS's have ways of allocating memory under control of the virtual > memory manager so that it is not in the heap and can be completely > returned. This is no different than the malloc and free interface: you can easily fragment virtual address space. One form of allocator that is sometimes used in large task-oriented programs is an arena-style one. Essentially, a given task creates an arena and performs malloc/free as necessary within the arena. When the task completes, the entire arena is destroyed, much like cleaning up a stack. Thus no memory-related issue such as fragmentation is propagated between separate tasks. It can be quite reliable when used properly. ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
