The AOLserver uses dynamically allocated memory extensively. To ease the burden of checking for memory-allocation failures, the AOLserver provides wrapper functions for the malloc family of memory allocation functions.
The AOLserver functions differ from their system counterparts: instead of returning NULL on memory-allocation failure, they instead attempt to recover automatically from a low-memory situation. The AOLserver attempts to recover by first freeing any memory from internal caches that can safely be flushed. If flushing caches fails to free enough memory, the AOLserver will wait 1 second and then, if necessary, another 10 seconds, in the hope that the memory shortage is temporary, perhaps caused by another program that will shortly stop executing. If the AOLserver cannot recover from a low-memory situation, it logs the failure and shuts down the server.
Using the AOLserver memory allocation functions is a matter replacing the corresponding malloc family system function with a function of the same name preceded by ns_. You can currently mix calls to the ns_ functions and their system counterparts. However, this is not recommended because the interface may change in future releases of AOLserver.