git.net

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: svn commit: r1841225 - /httpd/httpd/trunk/modules/dav/main/props.c


Pools are very tricky in mod_dav. Hence additional eyeballs are very much welcome here.
As I only did testing with mod_dav_fs I would be keen to know if things still work with Subversion.
So if someone from the Subversion guys is listening here: Having this tested with Subversion would be very welcome :-).

Regards

Rüdiger

On 09/18/2018 02:58 PM, rpluem@xxxxxxxxxx wrote:
> Author: rpluem
> Date: Tue Sep 18 12:58:57 2018
> New Revision: 1841225
> 
> URL: http://svn.apache.org/viewvc?rev=1841225&view=rev
> Log:
> * Doing a PROPFIND on a large collection e.g. 50.000 elements can easily
>   consume 1 GB of memory as the subrequests and propdb pools are not
>   destroyed and cleared after each element was handled.
>   Do this now. There is one case in dav_get_props where elem->priv
>   lives longer then the propdb pool. In this case allocate from r->pool.
>   Furthermore also recycle propdb's which allows to clear the propdb's
>   pools instead of destroying them and creating them again.
> 
> Modified:
>     httpd/httpd/trunk/modules/dav/main/props.c
> 
> Modified: httpd/httpd/trunk/modules/dav/main/props.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/dav/main/props.c?rev=1841225&r1=1841224&r2=1841225&view=diff
> ==============================================================================
> --- httpd/httpd/trunk/modules/dav/main/props.c (original)
> +++ httpd/httpd/trunk/modules/dav/main/props.c Tue Sep 18 12:58:57 2018
> @@ -524,7 +524,21 @@ DAV_DECLARE(dav_error *)dav_open_propdb(
>                                          apr_array_header_t * ns_xlate,
>                                          dav_propdb **p_propdb)
>  {
> -    dav_propdb *propdb = apr_pcalloc(r->pool, sizeof(*propdb));
> +    dav_propdb *propdb = NULL;
> +    /*
> +     * Check if we have tucked away a previous propdb and reuse it.
> +     * Otherwise create a new one and tuck it away
> +     */
> +    apr_pool_userdata_get((void **)&propdb, "propdb", r->pool);
> +    if (!propdb) {
> +        propdb = apr_pcalloc(r->pool, sizeof(*propdb));
> +        apr_pool_userdata_setn(propdb, "propdb", NULL, r->pool);
> +        apr_pool_create(&propdb->p, r->pool);
> +    }
> +    else {
> +        /* Play safe and clear the pool of the reused probdb */
> +        apr_pool_clear(propdb->p);
> +    }
>  
>      *p_propdb = NULL;
>  
> @@ -537,7 +551,6 @@ DAV_DECLARE(dav_error *)dav_open_propdb(
>  #endif
>  
>      propdb->r = r;
> -    apr_pool_create(&propdb->p, r->pool);
>      propdb->resource = resource;
>      propdb->ns_xlate = ns_xlate;
>  
> @@ -562,10 +575,12 @@ DAV_DECLARE(void) dav_close_propdb(dav_p
>          (*propdb->db_hooks->close)(propdb->db);
>      }
>  
> -    /* Currently, mod_dav's pool usage doesn't allow clearing this pool. */
> -#if 0
> -    apr_pool_destroy(propdb->p);
> -#endif
> +    if (propdb->subreq) {
> +        ap_destroy_sub_req(propdb->subreq);
> +        propdb->subreq = NULL;
> +    }
> +
> +    apr_pool_clear(propdb->p);
>  }
>  
>  DAV_DECLARE(dav_get_props_result) dav_get_allprops(dav_propdb *propdb,
> @@ -815,7 +830,8 @@ DAV_DECLARE(dav_get_props_result) dav_ge
>          */
>  
>          if (elem->priv == NULL) {
> -            elem->priv = apr_pcalloc(propdb->p, sizeof(*priv));
> +            /* elem->priv outlives propdb->p. Hence use the request pool */
> +            elem->priv = apr_pcalloc(propdb->r->pool, sizeof(*priv));
>          }
>          priv = elem->priv;
>  
> 
> 
>