[sr-dev] git:master: pv: use msg context id when caching the value for $TV

[Klaus Darilion]

Hi Daniel!

I reviewed the patch and it still does not work reliable. The new 
approach uses msg-id and pid to find out if $TV(s) still works on the 
same message or if a new message is processed and time stamp needs to be 
fetched.

Consider the following scenario:

worker process with pid 100 receives msg with msg-id 7:
--> msg context id = 100,7
--> $TV(s) is calculated on first usage

forwarding times out, timer with pid 99 processes message with msg-id 7 
in failure route:
--> msg context id = 99,7
--> $TV(s) is calculated on first usage

second forwarding times out, timer with pid 99 processes message with 
msg-id 7 in failure route:
--> msg context id = 99,7
--> $TV(s) is not calculated context ids are the same


Thus, $TV(s) is different in request route and failure route, but 
identically in both failure routes, if the failure route does not 
process another message. Thus, current implementation behaves different, 
depending on if other requests are forwarded/failed too.

So, we need a different implementation. Before implementing, we should 
define the expected behavior. There are 2 possible (useful) implementations.
a) $TV(s) in failure route has always the same value as in request route
b) $TV(s) in failure route has always the value when the requests 
entered the respective failure route

I would vote for implementation 2.

regards
Klaus









On 23.03.2012 12:54, Daniel-Constantin Mierla wrote:
> Module: sip-router
> Branch: master
> Commit: e4972ebd926b1fea6af795f58785a2b766439e5d
> URL:    http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=e4972ebd926b1fea6af795f58785a2b766439e5d
>
> Author: Daniel-Constantin Mierla<miconda at gmail.com>
> Committer: Daniel-Constantin Mierla<miconda at gmail.com>
> Date:   Fri Mar 23 12:53:31 2012 +0100
>
> pv: use msg context id when caching the value for $TV
>
> - reported by Klaus Darilion
>
> ---
>
>   modules_k/pv/pv_time.c |   30 ++++++++++++++----------------
>   1 files changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/modules_k/pv/pv_time.c b/modules_k/pv/pv_time.c
> index ad7dd2c..9cbc375 100644
> --- a/modules_k/pv/pv_time.c
> +++ b/modules_k/pv/pv_time.c
> @@ -35,17 +35,15 @@
>
>   #include "pv_time.h"
>
> -static unsigned int _pv_msg_id = 0;
> -static int _pv_msg_pid = 0;
> +static msg_ctx_id_t _pv_time_msgid = { 0 };
>   static time_t _pv_msg_tm = 0;
>
> -static int pv_update_time(struct sip_msg *msg, time_t *t)
> +static int pv_update_time(sip_msg_t *msg, time_t *t)
>   {
> -	if(_pv_msg_id != msg->id || _pv_msg_pid != msg->pid || _pv_msg_tm==0)
> +	if(msg_ctx_id_match(msg,&_pv_time_msgid)!=1 || _pv_msg_tm==0)
>   	{
>   		_pv_msg_tm = time(NULL);
> -		_pv_msg_id = msg->id;
> -		_pv_msg_pid = msg->pid;
> +		msg_ctx_id_set(msg,&_pv_time_msgid);
>   		
>   		if(t!=NULL)
>   			*t=_pv_msg_tm;
> @@ -124,7 +122,7 @@ int pv_parse_strftime_name(pv_spec_p sp, str *in)
>   }
>
>   static struct tm _cfgutils_ts;
> -static unsigned int _cfgutils_msg_id = 0;
> +static msg_ctx_id_t _cfgutils_msgid = { 0 };
>
>   /**
>    * return broken-down time attributes
> @@ -137,10 +135,10 @@ int pv_get_time(struct sip_msg *msg, pv_param_t *param,
>   	if(msg==NULL || param==NULL)
>   		return -1;
>
> -	if(_cfgutils_msg_id != msg->id)
> +	if(msg_ctx_id_match(msg,&_cfgutils_msgid)!=1)
>   	{
>   		pv_update_time(msg,&t);
> -		_cfgutils_msg_id = msg->id;
> +		msg_ctx_id_set(msg,&_cfgutils_msgid);
>   		if(localtime_r(&t,&_cfgutils_ts) == NULL)
>   		{
>   			LM_ERR("unable to break time to attributes\n");
> @@ -189,10 +187,10 @@ int pv_get_strftime(struct sip_msg *msg, pv_param_t *param,
>   	if(msg==NULL || param==NULL)
>   		return -1;
>
> -	if(_cfgutils_msg_id != msg->id)
> +	if(msg_ctx_id_match(msg,&_cfgutils_msgid)!=1)
>   	{
>   		pv_update_time(msg,&t);
> -		_cfgutils_msg_id = msg->id;
> +		msg_ctx_id_set(msg,&_cfgutils_msgid);
>   		if(localtime_r(&t,&_cfgutils_ts) == NULL)
>   		{
>   			LM_ERR("unable to break time to attributes\n");
> @@ -267,7 +265,7 @@ int pv_get_timeb(struct sip_msg *msg, pv_param_t *param,
>   }
>
>   static struct timeval _timeval_ts;
> -static unsigned int _timeval_msg_id = 0;
> +static msg_ctx_id_t _timeval_msgid = { 0 };
>   static char _timeval_ts_buf[32];
>
>   int pv_get_timeval(struct sip_msg *msg, pv_param_t *param,
> @@ -282,14 +280,14 @@ int pv_get_timeval(struct sip_msg *msg, pv_param_t *param,
>   	switch(param->pvn.u.isname.name.n)
>   	{
>   		case 1:
> -			if(_timeval_msg_id != msg->id)
> +			if(msg_ctx_id_match(msg,&_timeval_msgid)!=1)
>   			{
>   				if(gettimeofday(&_timeval_ts, NULL)!=0)
>   				{
>   					LM_ERR("unable to get time val attributes\n");
>   					return -1;
>   				}
> -				_timeval_msg_id = msg->id;
> +				msg_ctx_id_set(msg,&_timeval_msgid);
>   			}
>   			return pv_get_uintval(msg, param, res, (unsigned int)_timeval_ts.tv_usec);
>   		case 2:
> @@ -319,14 +317,14 @@ int pv_get_timeval(struct sip_msg *msg, pv_param_t *param,
>   			s.s = _timeval_ts_buf;
>   			return pv_get_strval(msg, param, res,&s);
>   		default:
> -			if(_timeval_msg_id != msg->id)
> +			if(msg_ctx_id_match(msg,&_timeval_msgid)!=1)
>   			{
>   				if(gettimeofday(&_timeval_ts, NULL)!=0)
>   				{
>   					LM_ERR("unable to get time val attributes\n");
>   					return -1;
>   				}
> -				_timeval_msg_id = msg->id;
> +				msg_ctx_id_set(msg,&_timeval_msgid);
>   			}
>   			return pv_get_uintval(msg, param, res, (unsigned int)_timeval_ts.tv_sec);
>   	}
>
>
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