Merge "Actually clear all DNS stats on resolver changes" (8a1916dc) · Commits · e / os / android_packages_modules_DnsResolver

res_cache.cpp

+12 −19

Original line number	Original line	Diff line number	Diff line
	@@ -1315,7 +1315,7 @@ static struct resolv_cache_info res_cache_list GUARDED_BY(cache_mutex);
	static void insert_cache_info_locked(resolv_cache_info* cache_info);		static void insert_cache_info_locked(resolv_cache_info* cache_info);
	// creates a resolv_cache_info		// creates a resolv_cache_info
	static resolv_cache_info* create_cache_info();		static resolv_cache_info* create_cache_info();
	// empty the nameservers set for the named cache		// Clears nameservers set for \|cache_info\| and clears the stats
	static void free_nameservers_locked(resolv_cache_info* cache_info);		static void free_nameservers_locked(resolv_cache_info* cache_info);
	// Order-insensitive comparison for the two set of servers.		// Order-insensitive comparison for the two set of servers.
	static bool resolv_is_nameservers_equal(const std::vector<std::string>& oldServers,		static bool resolv_is_nameservers_equal(const std::vector<std::string>& oldServers,
	@@ -1554,15 +1554,6 @@ int resolv_set_nameservers(unsigned netid, const std::vector<std::string>& serve
	<< ", addr = " << cache_info->nameservers[i];		<< ", addr = " << cache_info->nameservers[i];
	}		}
	cache_info->nscount = numservers;		cache_info->nscount = numservers;

	// Clear the NS statistics because the mapping to nameservers might have changed.
	res_cache_clear_stats_locked(cache_info);

	// increment the revision id to ensure that sample state is not written back if the
	// servers change; in theory it would suffice to do so only if the servers or
	// max_samples actually change, in practice the overhead of checking is higher than the
	// cost, and overflows are unlikely
	++cache_info->revision_id;
	} else {		} else {
	if (cache_info->params.max_samples != old_max_samples) {		if (cache_info->params.max_samples != old_max_samples) {
	// If the maximum number of samples changes, the overhead of keeping the most recent		// If the maximum number of samples changes, the overhead of keeping the most recent
	@@ -1571,7 +1562,6 @@ int resolv_set_nameservers(unsigned netid, const std::vector<std::string>& serve
	// not invalidate the samples, as they only affect aggregation and the conditions		// not invalidate the samples, as they only affect aggregation and the conditions
	// under which servers are considered usable.		// under which servers are considered usable.
	res_cache_clear_stats_locked(cache_info);		res_cache_clear_stats_locked(cache_info);
	++cache_info->revision_id;
	}		}
	for (int j = 0; j < numservers; j++) {		for (int j = 0; j < numservers; j++) {
	freeaddrinfo(nsaddrinfo[j]);		freeaddrinfo(nsaddrinfo[j]);
	@@ -1602,15 +1592,13 @@ static void free_nameservers_locked(resolv_cache_info* cache_info) {
	int i;		int i;
	for (i = 0; i < cache_info->nscount; i++) {		for (i = 0; i < cache_info->nscount; i++) {
	cache_info->nameservers.clear();		cache_info->nameservers.clear();
	if (cache_info->nsaddrinfo[i] != NULL) {		if (cache_info->nsaddrinfo[i] != nullptr) {
	freeaddrinfo(cache_info->nsaddrinfo[i]);		freeaddrinfo(cache_info->nsaddrinfo[i]);
	cache_info->nsaddrinfo[i] = NULL;		cache_info->nsaddrinfo[i] = nullptr;
	}		}
	cache_info->nsstats[i].sample_count = cache_info->nsstats[i].sample_next = 0;
	}		}
	cache_info->nscount = 0;		cache_info->nscount = 0;
	res_cache_clear_stats_locked(cache_info);		res_cache_clear_stats_locked(cache_info);
	++cache_info->revision_id;
	}		}

	void _resolv_populate_res_for_net(res_state statp) {		void _resolv_populate_res_for_net(res_state statp) {
	@@ -1668,11 +1656,16 @@ static void _res_cache_add_stats_sample_locked(res_stats* stats, const res_sampl
	}		}

	static void res_cache_clear_stats_locked(resolv_cache_info* cache_info) {		static void res_cache_clear_stats_locked(resolv_cache_info* cache_info) {
	if (cache_info) {
	for (int i = 0; i < MAXNS; ++i) {		for (int i = 0; i < MAXNS; ++i) {
	cache_info->nsstats->sample_count = cache_info->nsstats->sample_next = 0;		cache_info->nsstats[i].sample_count = 0;
	}		cache_info->nsstats[i].sample_next = 0;
	}		}

			// Increment the revision id to ensure that sample state is not written back if the
			// servers change; in theory it would suffice to do so only if the servers or
			// max_samples actually change, in practice the overhead of checking is higher than the
			// cost, and overflows are unlikely.
			++cache_info->revision_id;
	}		}

	int android_net_res_stats_get_info_for_net(unsigned netid, int* nscount,		int android_net_res_stats_get_info_for_net(unsigned netid, int* nscount,