Re: svn commit: r1927658 - apr/apr/trunk/memory/unix

[Sent from the wrong e-mail address the first time]

Found this while trying to use pool debugging to track down an issue in 
Serf. Apparently testing pool debugging hasn't been much of a priority, heh.

Related to this, with lifetime and owner checking enabled, some of our 
tests break; I haven't tracked these down yet, but the symptoms are that 
the test program aborts when it tries to destroy a pool, due to 
ownership checks; apparently the pool is destroyed by a different thread 
than the one that created it. This happens in testlockperf, 
testmutexscope and testall.

Given that this is a likely scenario when multiple threads create pools, 
and then the main thread calls apr_terminate(), I wonder if these 
ownership checks are necessary. Or, conversely, if they should be 
disabled during [global] pool destruction. They're actually triggered by 
apr_pool_clear(), which /should/ pass a strict ownership check under 
normal circumstances.

-- Brane

--
On 2025/08/07 06:19:52 [email protected] wrote:

> Author: brane
> Date: Thu Aug  7 06:19:52 2025
> New Revision: 1927658
> 
> Log:
> Fix pool debugging. With lifetime or owner checks enabled, pools couldn't
> even be created, except for the global pool which is a special case.
> 
> * memory/unix/apr_pools.c
>   (struct apr_pool_t): Add an 'unmanaged' member for pool-debug mode.
>    The lifetime checks must be skipped for unmanaged pools, since they
>    inevitably fail: apr_pool_is_child_of() expects all pools to have a
>    parent, which obviously is not the case for unmanaged pools.
> 
>   (apr_pool_create_ex_debug): Create the pool's mutex after the parent
>    has been assigned, because that involves an allocation which triggers
>    a lifetime check which ... well, see above.
> 
>   (apr_pool_create_unmanaged): Set the pool->unmanaged flag and create the
>    pool's mutex after the owner and allocator have been assigned. A pool
>    without the owner set fails the ownershhip check, and without an
>    allocator it's sort of hard to allocate space for the mutex.
> 
> Modified:
>    apr/apr/trunk/memory/unix/apr_pools.c
> 
> Modified: apr/apr/trunk/memory/unix/apr_pools.c
> ==============================================================================
> --- apr/apr/trunk/memory/unix/apr_pools.c	Thu Aug  7 05:08:51 2025	(r1927657)
> +++ apr/apr/trunk/memory/unix/apr_pools.c	Thu Aug  7 06:19:52 2025	(r1927658)
> @@ -600,6 +600,7 @@ struct apr_pool_t {
>      apr_os_thread_t       owner;
>      apr_thread_mutex_t   *mutex;
>  #endif /* APR_HAS_THREADS */
> +    int                   unmanaged;
>  #endif /* APR_POOL_DEBUG */
>  #ifdef NETWARE
>      apr_os_proc_t         owner_proc;
> @@ -1619,7 +1620,8 @@ static void apr_pool_check_lifetime(apr_
>       * people have searched for the top level parent and
>       * started to use that...
>       */
> -    if (pool == global_pool || global_pool == NULL)
> +    if (pool == global_pool || global_pool == NULL
> +        || (pool->parent == NULL && pool->unmanaged))
>          return;
>  
>      /* Lifetime
> @@ -2063,6 +2065,22 @@ APR_DECLARE(apr_status_t) apr_pool_creat
>      pool->owner_proc = (apr_os_proc_t)getnlmhandle();
>  #endif /* defined(NETWARE) */
>  
> +    if ((pool->parent = parent) != NULL) {
> +        pool_lock(parent)
> +
> +        if ((pool->sibling = parent->child) != NULL)
> +            pool->sibling->ref = &pool->sibling;
> +
> +        parent->child = pool;
> +        pool->ref = &parent->child;
> +
> +        pool_unlock(parent);
> +    }
> +    else {
> +        pool->sibling = NULL;
> +        pool->ref = NULL;
> +    }
> +
>  #if APR_HAS_THREADS
>      if (parent == NULL || parent->allocator != allocator) {
>          apr_status_t rv;
> @@ -2086,22 +2104,6 @@ APR_DECLARE(apr_status_t) apr_pool_creat
>      }
>  #endif /* APR_HAS_THREADS */
>  
> -    if ((pool->parent = parent) != NULL) {
> -        pool_lock(parent);
> -
> -        if ((pool->sibling = parent->child) != NULL)
> -            pool->sibling->ref = &pool->sibling;
> -
> -        parent->child = pool;
> -        pool->ref = &parent->child;
> -
> -        pool_unlock(parent);
> -    }
> -    else {
> -        pool->sibling = NULL;
> -        pool->ref = NULL;
> -    }
> -
>  #if (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE)
>      apr_pool_log_event(pool, "CREATE", file_line, 1);
>  #endif /* (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE) */
> @@ -2130,11 +2132,30 @@ APR_DECLARE(apr_status_t) apr_pool_creat
>  
>      memset(pool, 0, SIZEOF_POOL_T);
>  
> +    pool->unmanaged = 1;
>      pool->abort_fn = abort_fn;
>      pool->tag = file_line;
>      pool->file_line = file_line;
>  
>  #if APR_HAS_THREADS
> +    pool->owner = apr_os_thread_current();
> +#endif /* APR_HAS_THREADS */
> +#ifdef NETWARE
> +    pool->owner_proc = (apr_os_proc_t)getnlmhandle();
> +#endif /* defined(NETWARE) */
> +
> +    if ((pool_allocator = allocator) == NULL) {
> +        apr_status_t rv;
> +        if ((rv = apr_allocator_create(&pool_allocator)) != APR_SUCCESS) {
> +            if (abort_fn)
> +                abort_fn(rv);
> +            return rv;
> +        }
> +        pool_allocator->owner = pool;
> +    }
> +    pool->allocator = pool_allocator;
> +
> +#if APR_HAS_THREADS
>      {
>          apr_status_t rv;
>  
> @@ -2154,24 +2175,6 @@ APR_DECLARE(apr_status_t) apr_pool_creat
>      }
>  #endif /* APR_HAS_THREADS */
>  
> -#if APR_HAS_THREADS
> -    pool->owner = apr_os_thread_current();
> -#endif /* APR_HAS_THREADS */
> -#ifdef NETWARE
> -    pool->owner_proc = (apr_os_proc_t)getnlmhandle();
> -#endif /* defined(NETWARE) */
> -
> -    if ((pool_allocator = allocator) == NULL) {
> -        apr_status_t rv;
> -        if ((rv = apr_allocator_create(&pool_allocator)) != APR_SUCCESS) {
> -            if (abort_fn)
> -                abort_fn(rv);
> -            return rv;
> -        }
> -        pool_allocator->owner = pool;
> -    }
> -    pool->allocator = pool_allocator;
> -
>  #if (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE)
>      apr_pool_log_event(pool, "CREATEU", file_line, 1);
>  #endif /* (APR_POOL_DEBUG & APR_POOL_DEBUG_VERBOSE) */
> 
>