Why not check the return status of the lock and unlock calls??

On Feb 28, 2011, at 12:26 PM, Simone Caruso wrote:

> Hi all,
> 
> I wrote a simple cache inside my module with apr_shm and apr_rmm, but I have 
> problems with apr mutex...
> 
> I have this peace of code:
> 
> static apr_global_mutex_t *mtx = NULL;
> static void module_translate_name(request_rec *r)
> {
>       if(apr_global_mutex_trylock(mtx) == APR_EBUSY)
>               ap_log_rerror(APLOG_MARK, APLOG_WARNING|APLOG_NOERRNO, 0, r, 
> "Memory Locked!! ");
>       apr_global_mutex_lock(mtx);
>       element = get_from_cache();
>       if(element == NULL){
>               element = insert_into_cache();
>               strcpy(element.name,"name\0");
>       }
>       apr_global_mutex_unlock(mtx);
> }
> 
> static void module_post_config(apr_pool_t *p, apr_pool_t *plog, apr_pool_t 
> *ptemp, server_rec *s)
> {
>       result = apr_global_mutex_create(&mtx, "cache_entries_lck", 
> APR_LOCK_DEFAULT, p);
> }
> 
> 
> static void mod_vhost_ldap_child_init(apr_pool_t * p, server_rec * s)
> {
>       apr_status_t ret;
>       ret = apr_global_mutex_child_init(&mtx, "cache_entries_lck", p);
> }
> 
> 
> 
> During my tests with 'ab -c 15 -n 3000' i NEVER get the "Memory Locked" error 
> in logs, plus i get duplicated entries in cache but I don't know why!
> 
> Does someone have an idea? (please consider i use apr_global_mutex_trylock() 
> only for test)
> Regards.
> 
> -- 
> Simone Caruso
> 

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