I am trying to use valgrind to detect a memory leak. It works well when heap leaks (i.e. allocating memory from malloc or new). however, does the mmap protector support in linux?
Thanks Chang
Not immediately, it’s very difficult to debug, take a look at valgrind.h
VALGRIND_MALLOCLIKE_BLOCK should be put immediately after the point where a heap block -- that will be used by the client program -- is allocated. It best to put it at the outermost level of the allocator if possible; for example, if you have a function my_alloc() which calls internal_alloc(), and the client request is put inside internal_alloc(), stack traces relating to the heap block will contain entries for both my_alloc() and internal_alloc(), which is probably not what you want. For Memcheck users: if you use VALGRIND_MALLOCLIKE_BLOCK to carve out custom blocks from within a heap block, B, that has been allocated with malloc/calloc/new/etc, then block B will be *ignored* during leak-checking -- the custom blocks will take precedence. VALGRIND_FREELIKE_BLOCK is the partner to VALGRIND_MALLOCLIKE_BLOCK. For Memcheck, it does two things: - It records that the block has been deallocated. This assumes that the block was annotated as having been allocated via VALGRIND_MALLOCLIKE_BLOCK. Otherwise, an error will be issued. - It marks the block as being unaddressable. VALGRIND_FREELIKE_BLOCK should be put immediately after the point where a heap block is deallocated.