On Mon, 2007-08-27 at 09:25 -0700, [EMAIL PROTECTED] wrote: > i tried valgrind in combination with the GLIBCXX_FORCE_NEW option. > valgrind > says i have freed all the the heap blocks, but still the memory > occupied by the program > doesn't reduce after doing the free. > (i have increased the loop count from 10,000 to 100,000) > here is the output:
Then you don't have any memory leaks. I'll assume that you are looking at 'sysguard' output, or anything similar which displays the size of the heap of a certain process. To understand why this is happening, you have to first understand how malloc/free works. When you call malloc to allocate a block of memory, malloc looks for a free block (i.e. a block that was allocated and freed before), if it didn't find one then it will increase the heap using the 'brk' system call and returns a pointer to the new block. Later when you free a block of memory, free will save the address and size of that block to be used in further allocations. The trick here is whether 'free' will return the memory to the operating system or not. As far as I know GNU systems don't do this, and even if a system do that, it's not always possible due to memory fragmentation. The result is that the heap will increase and never decrease after you allocate a big chunk of memory as the one you're allocating in your program. Notice that if you tried to allocate the same amount of memory again after you freed it, there's a big chance that you heap will remain the same and won't increase. Again this will depend on the implementation of malloc/free. Hope that helped, -- John V. Shahid <[EMAIL PROTECTED]> _______________________________________________ help-gplusplus mailing list help-gplusplus@gnu.org http://lists.gnu.org/mailman/listinfo/help-gplusplus
