Merge pull request #34 from dsandras/bi-presence-fixes

Bi presence fixes

This is a critical fix ensuring the serial processing of the PUBLISHs for the same presentity. Failing to do so may lead to inconsistent state of the presentity, especially with BLF.
This fix is work on progress for 3 week, tested by Damien.

modules/presence/hash.c

@@ -355,7 +355,7 @@ int update_shtable(shtable_t htable,unsigned int hash_code,
 	else
 	{
 		subs->local_cseq= s->local_cseq++;
-		s->version= subs->version+ 1;
+		subs->version= s->version++;
 	}
 
 	if(strncmp(s->contact.s, subs->contact.s, subs->contact.len))
@@ -506,7 +506,7 @@ void update_pres_etag(pres_entry_t* p, str* etag)
 	p->etag_count++;
 }
 
-int insert_phtable(str* pres_uri, int event, str* etag, char* sphere)
+pres_entry_t* insert_phtable(str* pres_uri, int event, str* etag, char* sphere, int init_turn)
 {
 	unsigned int hash_code;
 	pres_entry_t* p= NULL;
@@ -543,14 +543,16 @@ int insert_phtable(str* pres_uri, int event, str* etag, char* sphere)
 	p->next= pres_htable[hash_code].entries->next;
 	pres_htable[hash_code].entries->next= p;
 
+	p->last_turn = init_turn;
+
 	lock_release(&pres_htable[hash_code].lock);
 
-	return 0;
+	return p;
 
 error:
 	if(p)
 		shm_free(p);
-	return -1;
+	return NULL;
 }
 
 int delete_phtable_query(str *pres_uri, int event, str* etag)
@@ -572,6 +574,25 @@ int delete_phtable_query(str *pres_uri, int event, str* etag)
 	return 0;
 }
 
+
+void next_turn_phtable(pres_entry_t* p_p, unsigned int hash_code)
+{
+	pres_entry_t* p;
+
+	lock_get(&pres_htable[hash_code].lock);
+	for ( p=pres_htable[hash_code].entries->next ; p ; p=p->next ) {
+		if(p==p_p) {
+			p->current_turn++;
+			LM_DBG("xXx - new current turn is %d\n",p->current_turn);
+			break;
+		}
+	}
+
+	lock_release(&pres_htable[hash_code].lock);
+	return;
+}
+
+
 int delete_phtable(pres_entry_t* p, unsigned int hash_code)
 {
 	pres_entry_t* prev_p= NULL;

modules/presence/hash.h

@@ -127,6 +127,9 @@ typedef struct pres_entry
 	char* sphere;
 	char etag[ETAG_LEN];
 	int etag_len;
+	/* ordering */
+	unsigned int current_turn;
+	unsigned int last_turn;
 	struct pres_entry* next;
 }pres_entry_t;
 
@@ -144,10 +147,12 @@ pres_entry_t* search_phtable_etag(str* pres_uri, int event,
 
 void update_pres_etag(pres_entry_t* p, str* etag);
 
-int insert_phtable(str* pres_uri, int event, str* etag, char* sphere);
+pres_entry_t* insert_phtable(str* pres_uri, int event, str* etag, char* sphere, int init_turn);
 
 int update_phtable(struct presentity* presentity, str pres_uri, str body);
 
+void next_turn_phtable(pres_entry_t* p_p, unsigned int hash_code);
+
 int delete_phtable(pres_entry_t* p, unsigned int hash_code);
 int delete_phtable_query(str *pres_uri, int event, str* etag);
 

modules/presence/presentity.c

@@ -411,6 +411,7 @@ int update_presentity(struct sip_msg* msg, presentity_t* presentity, int* sent_r
 	str pres_uri= {NULL, 0};
 	pres_entry_t* p= NULL;
 	unsigned int hash_code;
+	unsigned int turn;
 	str body = presentity->body;
 	str *extra_hdrs = presentity->extra_hdrs;
 	db_res_t *result= NULL;
@@ -462,6 +463,7 @@ int update_presentity(struct sip_msg* msg, presentity_t* presentity, int* sent_r
 	n_query_cols++;
 
 	result_cols[0] = &str_etag_col;
+	hash_code= core_hash(&pres_uri, NULL, phtable_size);
 
 	if(presentity->etag_new)
 	{
@@ -473,8 +475,9 @@ int update_presentity(struct sip_msg* msg, presentity_t* presentity, int* sent_r
 		*sent_reply= 1;
 
 		/* insert new record in hash_table */
-		if(insert_phtable(&pres_uri, presentity->event->evp->parsed,
-					&presentity->etag, presentity->sphere)< 0)
+		p = insert_phtable(&pres_uri, presentity->event->evp->parsed,
+					&presentity->etag, presentity->sphere, 1);
+		if (p==NULL)
 		{
 			LM_ERR("inserting record in hash table\n");
 			goto error;
@@ -542,14 +545,27 @@ int update_presentity(struct sip_msg* msg, presentity_t* presentity, int* sent_r
 	}
 	else
 	{
-		hash_code= core_hash(&pres_uri, NULL, phtable_size);
 		lock_get(&pres_htable[hash_code].lock);
-
 		p = search_phtable_etag(&pres_uri, presentity->event->evp->parsed,
 				&presentity->etag, hash_code);
+		if (p) {
+
+			turn = p->last_turn++;
+			LM_DBG("xXx - %.*s my turn is %d, current turn is %d\n",pres_uri.len, pres_uri.s, turn, p->current_turn);
+
+			/* wait to get our turn as order of handling pubishs
+			   (need to wait the ongoing published to terminate
+			   before starting */
+			while (p && turn!=p->current_turn) {
+				lock_release(&pres_htable[hash_code].lock);
+				sleep_us(100);
+				lock_get(&pres_htable[hash_code].lock);
+				p = search_phtable_etag(&pres_uri, presentity->event->evp->parsed,
+					&presentity->etag, hash_code);
+			}
+
+		} else {
 
-		if(!p)
-		{
 			lock_release(&pres_htable[hash_code].lock);
 			/* search also in db */
 			if (pa_dbf.use_table(pa_db, &presentity_table) < 0)
@@ -580,7 +596,6 @@ int update_presentity(struct sip_msg* msg, presentity_t* presentity, int* sent_r
 					goto done;
 			}
 
-
 			pa_dbf.free_result(pa_db, result);
 			LM_INFO("*** found in db but not in htable [%.*s]\n",
 					presentity->etag.len, presentity->etag.s);
@@ -644,8 +659,9 @@ int update_presentity(struct sip_msg* msg, presentity_t* presentity, int* sent_r
 			else
 			{
 				lock_release(&pres_htable[hash_code].lock);
-				if(insert_phtable(&pres_uri, presentity->event->evp->parsed,
-							&presentity->etag, presentity->sphere)< 0)
+				p = insert_phtable(&pres_uri, presentity->event->evp->parsed,
+							&presentity->etag, presentity->sphere, 1);
+				if ( p==NULL )
 				{
 					LM_ERR("inserting record in hash table\n");
 					goto error;
@@ -806,6 +822,10 @@ int update_presentity(struct sip_msg* msg, presentity_t* presentity, int* sent_r
 	}
 
 done:
+	/* allow next publish to be handled */
+	if (p)
+		next_turn_phtable( p, hash_code);
+
 	if (notify_body.s)
 		xmlFree(notify_body.s);
 
@@ -820,6 +840,10 @@ int update_presentity(struct sip_msg* msg, presentity_t* presentity, int* sent_r
 	return 0;
 
 error:
+	/* allow next publish to be handled */
+	if (p)
+		next_turn_phtable( p, hash_code);
+
 	if(result)
 		pa_dbf.free_result(pa_db, result);
 	if(etag.s)
@@ -962,7 +986,7 @@ int pres_htable_restore(void)
 				sphere= extract_sphere(body);
 			}
 
-			if(insert_phtable(&uri, event, &etag, sphere)< 0)
+			if(insert_phtable(&uri, event, &etag, sphere, 0)== NULL)
 			{
 				LM_ERR("inserting record in presentity hash table");
 				pkg_free(uri.s);