RE: memory leak in apr_buck_alloc...

[Jean-Jacques Clar]

I think I have been seeing the same thing for a long time when refreshing entries in mod_mem_cache. If you find something in the alloc path I will be more than happy to try it in my lab.   "Jean-Jacques Clar" <[EMAIL PROTECTED]> on 05/21/2002 06:23:58 PM To:    W G Stoddard/Raleigh/IBM@IBMUS cc: Subject:    memory leak Bill, I still have a memory leak when refreshing expired entries  in the cache. On heavy load - short expire interval it gets pretty ugly (1  Mb every 4 sec). It looks like some allocators are never being  freed. Here are the calls leading to a leak: cache_in_filter()     there is a pre-existing cache handle and  new entity, replacing it   cache_remove_entity()   cache_create_entity()   cache_write_entity_body() ->  write_body() when it calls apr_bucket_read() (then  file_bucket_read()->apr_bucket_alloc()->apr_allocator_alloc() and finally  malloc()) in the following loop from write_body(): In apr_allocator_alloc, it looks like once  in a while there are no free nodes ( allocator->max_index = 0), so calls to malloc are made. However, the previously allocated memory in the allocator does  not look to be freed. This is how the leak is happening.     /* Iterate across the brigade and populate the cache  storage */     APR_BRIGADE_FOREACH(e, b)         const char  *s;         apr_size_t len;         if (APR_BUCKET_IS_EOS(e))             /* Open  for business  */              obj->complete =  1;              break;         rv = apr_bucket_read(e, &s,  &len, eblock);         if (rv !=  APR_SUCCESS)             return  rv;         if (len)             /* Check  for buffer overflow  */            if  ((obj->count + len) > mobj->m_len)                 return  APR_ENOMEM;            else                 memcpy(cur, s,  len);                 cur+=len;                 obj->count+=len;         /* This should not happen, but  if it does, we are in BIG  trouble          * cause we just  stomped all over the heap.           */         AP_DEBUG_ASSERT(obj->count  > mobj->m_len);     } Do you have any suggestions on what I should try to find a  solution to that leak? Let me known if you need more details. Thank you very much, Jean-Jacques Clar >>> [EMAIL PROTECTED] 09/09/02 03:11PM >>> > From: Cliff Woolley [mailto:[EMAIL PROTECTED]] > Sent: 09 September 2002 22:42 > On Mon, 9 Sep 2002, Brad Nicholes wrote: > > >      Has anybody else noticed a memory leak when requesting pages less > > than 8k?  If I repeatedly request pages less than 8k I have noticed that > > apr_bucket_alloc() calls allocator_alloc() which seems to continuously > > malloc() memory rather than finding it in the free list.  The reason why > > is because allocator->max_index seems to always be 0 and contain no free > > nodes.  If I request pages greater than 8k, allocator->max_index appears > > to be 2.  I can't seem to figure out why the bucket allocator passed in > > by apr_bucket_alloc always contains a max_index of 0 on small page > > requests.  Any ideas? > > Ughuuhhhhhh ... good question!  I'll let Sander take a stab at that one > before I try to dig in and see what's going on... but I will do so if no > answers are forthcoming in the near-term. I'll give it a look tomorrow.  I've got a pretty decent hunch on what is going on... Sander